positioning for radial artery cannulation

Correspondence

Elderly anaesthesia as partof a multidisciplinary team

We read with interest the comments inthe recent letter �Anaesthesia in theelderly� (Crowe. Anaesthesia 2002; 57:

501). The suggestion that the develop-ment of a subspecialty for elderlyanaesthesia, as is done with paediatric

anaesthesia, is an interesting one withmerit and has been suggested in aprevious NCEPOD report [1]. How-ever, we agree that the development of

this area of expertise as a separatesubspeciality within anaesthesia may beunrealistic for several reasons.

First, as eluded to in both DrCrowe’s letter, and the Association ofAnaesthetists guideline document [2],

the projected increase in the elderlypopulation and the expanse in demandfor anaesthetic services for them islikely to outstrip the human resources

available for provision of such a service.Second, the definition of an �elderly�patient is also likely to cause problems

at this extreme of the age spectrum.Whilst the provision of anaesthesiaservices for neonatal patients is clearer

to define, as this age group havegenerally accepted physiological andanatomical differences to those of the

older infant, child or adult, the oppositeextreme of the age spectrum have awide variation between biological vs.chronological age. Rather than catego-

rise a patient purely according to theirage, the anaesthetist should regard eachpatient as an individual, and assess their

physiological status on that basis.

Third, as also pointed out in DrCrowe’s letter, �pigeon-holing� elderlyanaesthesia into a separate subspecialitymay ultimately lead to the deskilling of

general anaesthetists in this field. How-ever, it is generally recognised thatmultiple pathology and �polypharmacy�,as well as deterioration in cognitivefunction in the postoperative period, doindeed become more prevalent with

increasing age. Anaesthesia is only onestep in the care pathway of a patientfrom diagnosis, treatment and surgical

intervention, through to postoperativecare and subsequent rehabilitation. Boththe NCEPOD report and the NationalService Framework for Older People

highlight the peri-operative needs ofolder people, citing the requirement that�A team of senior surgeons, anaesthetists

and physicians needs to be closelyinvolved in the care of older peoplewho have poor physical status and high

operative risk� [3]. The Scottish Auditof Surgical Mortality 2000 also identi-fied that mortality of elderly patients

undergoing surgery for fractured neckof femur was particularly high, andthere were suggestions that postopera-tive care could be improved [4]. The

Association Guidelines also reiterate theimportance of cross-speciality adviceinvolving anaesthetists, surgeons and

physicians contributing to the pre-operative assessment.

We suggest therefore that an alterna-

tive to developing a specialist anaesth-etic role for elderly patients wouldinstead be investment in the develop-ment of specialist multidisciplinary

teams for the elderly patient undergoingsurgery. Such teams should receiveinput from elderly care physicians,anaesthetists, surgeons, physiotherapists,

occupational therapists, pain specialists,pharmacists and social services, to pro-vide a confluent care pathway of the

elderly patient undergoing surgery fromadmission to discharge and subsequentrehabilitation and community care. We

agree that anaesthetic departmentsshould have a recognised lead clinicianwith an interest in care of the elderly,

and provided with the appropriate ses-sions to support this service input.Similarly, the �orthogeriatric� team rolewithin hospitals to provide improved

medical and surgical care to high-riskelderly patients undergoing orthopaedicprocedures should be expanded, again

with appropriate sessions for lead clini-cians specializing in this field.

To summarise, in accordance with the

ideals of the �New NHS� becoming atruly patient-centred service, we believethat we should be examining a broader,

multidisciplinary, team-based approachto pathways of care of the elderly patientundergoing surgery, rather than focusingpurely on anaesthesia and therefore sub-

specializing what is to contribute to asignificant amount of the future work-load of general anaesthetists.

H. Wise

Salisbury District Hospital,

Salisbury, UK

M. Thomas

Poole Hospital,

Poole BHIS 2JB, UK

All correspondence should be addressed to Professor M. Harmer, Editor of Anaesthesia, Department of Anaesthetics, University of

Wales College of Medicine, Heath Park, Cardiff CF14 4XN UK.

Letters (two copies) must be typewritten on one side of the paper only and double spaced with wide margins. In addition, please

include your letter as a Word for Windows or .rtf document on disk or alternatively submit as an e-mail attachment addressed to

[email protected]. Copy should be prepared in the usual style and format of the Correspondence section. Authors must follow the

advice about references and other matters contained in the Notice to Contributors to Anaesthesia printed at the back of each issue. The

degree and diploma of each author must be given in a covering letter personally signed by all the authors.

Correspondence presented in any other style or format may be the subject of considerable delay and may be returned to the author for

revision. If the letter comments on a published article in Anaesthesia, please send three copies; otherwise two copies of your letter will suffice.

Anaesthesia, 2002, 57, pages 926–943.....................................................................................................................................................................................................................

926 � 2002 Blackwell Publishing Ltd

References1 Extremes of age: The 1999 Report of

the National Confidential Enquiry into

Perioperative Deaths.

2 The Association of Anaesthetists of

Great Britain and Ireland. Anaesthesia

and peri-operative care of the elderly.

December 2001.

3 National Service Framework for Older

People: http://www.doh.gov/nsf/ ol-

derpeople.htm

4 Scottish Audit of Surgical Mortality

Annual Report 2000: http://

www.show.scot.nhs.uk/sasm/ 2000re-

port/downloads.htm

Acute Pain Services – howeffective are we?

The report �Pain after Surgery� in 1990

[1] recommended the formation ofacute pain teams to manage postopera-tive analgesia, and by 2000, some 88%of hospital trusts had created such teams

[2]. There is no national (or interna-tional) consensus on the optimal struc-ture or responsibilities that an acute pain

service should adopt, and unsurprisinglythe exact format, resourcing andresponsibilities of these teams varies.

We have analysed the performance of14 hospitals’ acute pain services, varyingin size from small district general hos-

pitals through to large teaching hospi-tals. Each adopted a standard datacollection system and definitions, andcollected their data at identical time

intervals.In the first instance, we looked only

at the performance of epidurals sited for

postoperative analgesia. On day 1 post-operatively, an average of 18.5% ofpatients with epidural analgesia had

experienced �significant pain� (definedas pain scores of 2 or 3 out of 3 for twoconsecutive data collection periods).This figure masked a range throughout

the hospitals of between 6.9% and37.6%. There was no striking associa-tion with infusion drugs, mode of

delivery or type of surgery.The situation was even more extreme

when �epidural failure� was considered.

An epidural failure was defined as anyincident that resulted in a need tochange analgesia modality, and so in-

cluded organisational difficulties as well

as clinical problems. The mean failurerate during the entire period of use was19.3%, but the range this time was from6.4% to 57.8%.

The reasons for the apparent varia-tion in performance are unclear, but arelikely to be multifactorial. They clearly

warrant closer attention, and we will beattempting to establish whether thesedifferences are related to resources,

working practices or simply a reflectionof local surgical workload variation.

Acute pain provision services are now

over 10 years old and 60% of hospitalsperform continuous internal audit [3].Isn’t it time to produce national stan-dards against which performance can be

judged? In our opinion, this can befacilitated by the adoption of moreeffective, national audit rather than

focusing on internal audits that do notallow multicentre comparisons. Nation-al audit could then provide data for the

formation of appropriate standardsagainst which we could audit locally.

M. K. Sanders

Southampton General Hospital,

Southampton SO16 6YD, UK

M. Z. M. Michel

Royal Bournemouth Hospital,

Bournemouth BH7 7DW, UK

References1 The Royal College of Surgeons of

England and the College of Anaesthe-

tists. Report of the Working Party on Pain

after Surgery. London RCS, 1990.

2 Clinical Standards Advisory Group.

Services for patients with pain. London

HMSO, 2000.

3 Sutherland P, Michel MZM. Acute

pain service audit: A national survey to

agree an optimal data set. Acute Pain

2000; 3: 10–14.

Patient or PAC?

In reminding us that the role of thepulmonary artery catheter (PAC) inpatient management requires resolution,

the authors (Nethirasigamani & Fielden.Anaesthesia 2002; 57: 405–6) imply thatPAC usage is tightly coupled to critical

care provision. Whilst this may be truein the USA, it is much less so in theUK, past and certainly present.

In 1991 Professor Marino wrote inhis textbook of the PAC: �It is morethan an important development in crit-ical care: it is critical care.� (His empha-

sis.) He then wisely mentions that �thiscatheter is like a politician … you arenever sure that you trust what it is

telling you.� [1].Times (and fashions) change. Critical

care, certainly in the UK, has not and

does not give the PAC pre-eminence.Critical care is much more than PACplacement and so Nethirasigamani and

Fielden’s assertation that renewed scru-tiny of PAC efficacy and safety weakensthe argument for critical care provisiondoes not, we feel, apply here.

The publication of ComprehensiveCritical Care by the Department ofHealth [2] give new directions for

critical care in the UK, with patient-(not PAC-) centred provision of care ata level appropriate to need. Nethirasig-

amani and Fielden agree with this bywriting that �without the need for PACplacement, pre-optimisation is probably

possible outside the ICU ⁄HDU envi-ronment with correct education, train-ing and resources�. This is in effect LevelOne Critical Care and we emphasise

that correct resourcing of this is crucial.We also write to mention that the

UK Critical Care Community, through

the Intensive Care Society, has recentlyembarked on the PAC-Man trial, anevaluation of the clinical and cost

effectiveness of this device involvingabout 6000 patients. This landmarkstudy garnered praise in a leading edi-torial in the British Medical Journal: �It is

the perfect example of commitment togreater scrutiny and optimisation ofpractice that we all must engage in

across all fields of medicine.� [3].

D. R. Ball

W. Abdel-Rhaman

Dumfries and Galloway Royal

Infirmary,

Dumfries DG1 4AP, UK

References1 Marino PL. The ICU Book. 1st Edition.

Philadelphia: Lea and Febiger, 1991.

2 Department of Health. Comprehensive

Critical Care. A Review of Adult Critical

Care Services. London: Department of

Health, 2000.

Anaesthesia, 2002, 57, pages 926–943 Correspondence......................................................................................................................................................................................................................

� 2002 Blackwell Publishing Ltd 927

3 Angus D, Black N. Wider lessons of the

pulmonary artery catheter trial. British

Medical Journal 2001; 322: 446.

Meningococcalchemoprophylaxis foranaesthetists

I intubated an adult patient with sus-pected meningitis in the accident and

emergency department of my hospitalrecently. I was subsequently informed byone of the intensive care consultants thatI should receive antibiotic prophylaxis in

accordance with new national guidelinesfor the prophylaxis of healthcare workersagainst meningococcal disease [1]. A

prescription for a single oral dose ofciprofloxacin 500 mg was provided.Subsequent discussions with other local

anaesthetists revealed that many wereunaware of this new recommendation. Isuspect this is the case with most anaes-

thetists across the country.It has previously been reported that

anaesthetists, nurses, ODAs, and para-medics who are directly exposed to

nasopharyngeal secretions from patientswith meningococcal disease may be atincreased risk of contracting the disease

[2, 3]. This risk is probably very low. Inthe literature, few anecdotal reportsexist of healthcare workers developing

meningococcal disease after such expo-sure [3, 4]. The case often cited is thatof a French paediatrician who devel-oped meningococcal septicaemia a

week after she intubated a child withmeningococcal meningitis [4].

Recommendations on antimeningo-

coccal prophylaxis for healthcare work-ers undertaking airway managementprocedures vary between countries. In

North America and Australia, antibioticsare recommended for healthcare workersafter exposure to oral or nasopharyngeal

secretions of a patient [5, 6]. Previousguidelines in the UK recommendedantibiotic prophylaxis exclusively forhealthcare workers undertaking mouth-

to-mouth resuscitation [7]. As a result ofthese variations in national recommen-dations and controversy over the need

for meningococcal chemoprophylaxis inhealthcare workers, various authorscalled for a review of the UK guidelines

[2, 8].

In June 2001, a change to the UKrecommendation was proposed by aworking group of the Public HealthLaboratory Service Meningococcus

Forum. This was based on new data onthe risk of secondary meningococcaldisease in healthcare workers, a review

of published cases and an assessment ofthe available evidence [1]. Highlights ofthe new recommendations are as follows:

1 Chemoprophylaxis is recommend-ed for those healthcare workers whosemouth or nose is directly exposed to

infectious respiratory droplets ⁄ secre-tions within a distance of 3 ft from aprobable or confirmed case of meningo-coccal disease. This type of exposure

is most likely to occur in staff whoundertake airway management (e.g.intubation, airway toilet, and closely

examining oropharynx of patients) dur-ing resuscitation without wearing amask or other mechanical protection.

2 Oral antibiotics such as rifampicin600 mg twice daily for 2 days or cip-rofloxacin 500 mg as a single dose are

recommended for prophylaxis.3 Healthcare workers are encouraged

to wear surgical facemasks and use closedsuction devices when carrying out pro-

cedures which may result in exposure toinfectious respiratory droplets.

Undoubtedly, these guidelines will

generate further discussions. I agreewith Gilmore et al. that the benefit ofwidespread chemoprophylaxis must be

balanced against recognised but poten-tially serious sequelae such as allergy,elimination of protective flora, druginteractions and the development of

antibiotic resistance [8].However, there is a need for anaes-

thetic departments, intensive care units,

and accident and emergency depart-ments to make their staff aware of thesenew national guidelines so that exposed

personnel can make informed decisionsabout the need for antibiotic prophy-laxis.

N. I. Gbinigie

Arrowe Park Hospital,

Wirral L49 5PE, UK

References1 Stuart JM, Gilmore AB, Ross A, et al.

Preventing secondary meningococcal

disease in health care workers: recom-

mendations of a working group of the

PHLS Meningococcus Forum. Com-

municable Disease and Public Health 2001;

4: 102–5.

2 Pollard AJ, Begg N. Meningococcal

disease and health care workers. British

Medical Journal 1999; 319: 1147.

3 Gilmore A, Stuart J, Andrews N. Risk

of secondary meningococcal disease in

health care workers. Lancet 2000; 356:

1654–5.

4 Gehanno J-F, Kohen-Couderc L,

Lemeland J-F, Leroy J. Nosocomial

meningococcaemia in a physician.

Infection Control and Hospital Epidem-

iology 1999; 20: 564–5.

5 Advisory Committee on Epidemiology.

Guidelines for control of meningococ-

cal disease. Canada Communicable

Disease Report 1994; 20: 17–27.

6 Patel MS, Collingnon PJ, Watson CE,

Condon RJ, Doherty RR, Merianos A,

Stewart GJ. New guidelines for man-

agement and prevention of meningo-

coccal disease in Australia. Medical

Journal of Australia 1997; 166: 598–601.

7 Anon. Control of meningococcal dis-

ease: guidance for consultants in com-

municable disease control. PHLS

Meningococcal Infections Working

Group and Public Health Medicine

Environmental Group. Communicable

Disease Report 1995; 5: R189–95.

8 Gilmore A, Stuart J, Cartwright K,

Patterson W. Recommendations

will cause unease among healthcare

staff. British Medical Journal 2000; 320:

247–8.

Sevoflurane usage

The introduction of the newer vola-tile agents, sevoflurane and desflurane,

has led to debate about the useful-ness and cost effectiveness of theseagents with relatively low blood gas

solubility.We undertook an observational study

to asses the frequency of use of sevo-flurane for maintenance of anaesthesia

in elective cases in our hospital. Ourhospital is a large district general spreadover three sites, Royal Hospital Has-

lar (RHH), Queen Alexandra Hospital(QAH) and St. Mary’s Hospital (SMH).We undertake all forms of surgery in

adults and children other than cardiac

Correspondence Anaesthesia, 2002, 57, pages 926–943......................................................................................................................................................................................................................


and neurosurgery. Children form 10%of our workload. Isoflurane, desfluraneand sevoflurane are all readily availableand all theatres have circle systems.

Propofol infusion for maintenance ofanaesthesia is not regularly used. Theexpenditure on sevoflurane in our unit

has increased from £60 000 3 yearsago (the year of its introduction) to aprojected £300 000 this year.

In an attempt to identify the indica-tions and methods of using differentagents, we carried out an observational

study of their use in our unit. For fiveconsecutive days, each of 27 theatreswas observed once a day at a randomtime. We used a simple data sheet to

collect information about the grade ofanaesthetist, consultant (C), non-con-sultant career grade (NCCG) or trainee.

Choice of induction and maintenanceagents and the fresh gas flow usedduring maintenance of anaesthesia was

noted, as was the age of patient and typeof procedure. We obtained 98 com-pleted data sheets. The results are sum-

marised in Table 1.Whilst we appreciate that the data

collection was quite crude, it is repre-sentative of the choice of volatile agents

used in our hospital. Approximately onequarter of our elective patients under-going general anaesthesia receive sevo-

flurane maintenance. The majority ofthese patients did not receive an inha-lational induction. Using sevoflurane

for maintenance in these cases wouldappear to be a positive choice ratherthan continuing to use it after a gasinduction. Only half of anaesthetists

used flows of less than 2 l.min)1 whenusing sevoflurane.

There is evidence to suggest that

sevoflurane has no better a recovery

profile than isoflurane in terms of timeto discharge from recovery [1–4] andcauses more respiratory and cardiovas-cular problems [1] and postoperative

nausea [1, 2]. The agitation seen insome patients (particularly preschoolchildren) associated with sevoflurane

recovery is well documented [5, 6].Isoflurane has recently been recom-mended as the agent of choice in

coronary artery disease [7].This survey was, in part, prompted

by issues of cost but does raise some

important points. Many anaesthetistsbelieve sevoflurane to have advantagesover other volatiles that are not wellsupported by evidence. We would

welcome comments about practice inother hospitals.

M. Rice

S. Butler

M. Wood

Portsmouth Hospitals,

Portsmouth, UK

References1 Elcock DH, Sweeney BP. Sevoflurane

vs. isoflurane: a clinical comparison in

day surgery. Anaesthesia 2002; 57: 52–6.

2 Le Berre PY, Wodey E, Joly A, Carre

P, Ecoffey C. Comparison of recovery

after intermediate duration of anaes-

thesia with sevoflurane and isoflurane.

Paediatric Anaesthesia 2001; 11: 443–8.

3 Karlsen KL, Persson E, Wennberg E,

Stenqvist O. Anaesthesia, recovery and

postoperative nausea and vomiting after

breast surgery. A comparison between

desflurane, sevoflurane and isoflurane

anaesthesia. Acta Anaesthesiologica

Scandinavica 2000; 44: 489–93.

4 Welborn LG, Hannallah RS, Norden

JM, Ruttimen UE, Callan AM. Com-

parison of emergence and recovery

statistics of sevoflurane, desflurane, and

halothane in paediatric ambulatory

patients. Anesthesia and Analgesia 1996;

83: 917–20.

5 Uezono S, Goto T, Terui K, et al.

Emergence agitation after sevoflurane

vs. propofol in paediatric patients.

Anesthesia and Analgesia 2000; 91:

563–6.

6 Cravero JP, Surgenor S, Whalen K.

Emergence agitation in paediatric

patients after sevoflurane anaesthesia

and no surgery. A comparison with

halothane. Paediatric Anaesthesia 2000;

10: 419–24.

7 Agnew NM, Pennefather SH, Russell

GN. Isoflurane and coronary artery

disease. Anaesthesia 2002; 57: 338–45.

An apparently normal lookingvalve as a cause of rebreathing

We would like to share with others arather subtle fault in a circle systemwhich took us a while to fully appre-ciate. We currently use Blease Frontline

(model 690) anaesthetic machines witha Blease circle absorber system in ouroperating rooms to maintain anaesthesia

intra-operatively. During use, it wasnoted that the inspired carbon dioxideon the gas monitor, a mainstream

infrared absorption monitor, was per-sistently elevated and that the capno-graph trace did not return fully tobaseline. This was initially though to

be a faulty gas monitor but a4–5 mmHg elevation of inspired carbondioxide was confirmed with a second

mainstream analyser.A search for the cause of the rebrea-

thing revealed a faulty unidirectional

Table 1 Table to show characteristics of total sample and anaesthetics using sevoflurane maintenance.

Grade of anaesthetist Form of induction Low flow Age (years)

Consultant NCCG Trainee I.V. Sevo (< 2 l) < 2 2–5 5–11 > 11

Total samplen ¼ 98 61 18 19 94 4 76 1 3 7 87(percentage) (69) (18) (19) (96) (4) (78) (1) (3) (7) (88)

Sevofluranemaintenancen ¼ 24(percentage)

17(71)

5(21)

2(8)

21(87)

3(13)

13(54)

0(0)

2(8)

2(8)

20(84)



valve on the expiratory port of thecircle absorber system, which was not

obvious when scrutinised with the valveassembled within its dome. The valveappeared to function normally in use

but was found on close examination tobe slightly distorted (see Fig. 1). Onreflection, this damage was probably

caused by the mechanical PEEP valvethat was utilised for the previous case.The inspired fraction of carbon diox-ide normalised to zero following the

replacement of the deformed valve. Theflap of these valves is made of alumin-ium rather than brittle plastic, which

would have been broken rather thandeformed by the PEEP valve, produc-ing a more obvious fault with massive

rebreathing rather than the subtle prob-lem encountered.

A. M. S. Dawood

T. Digger

Russells Hall Hospital,

Dudley DY1 2HQ, UK

Critical incident involving theDraeger Cato ventilator

I would like to report a critical incident

occurring during intermittent positivepressure ventilation (IPPV) of a pronepatient using the Draeger Cato ventila-

tor (Draeger Gmbh, Lubeck, Germany ⁄Draeger UK Ltd, The Willows, HemelHempstead, Hertfordshire).

The incident occurred to the thirdpatient on a list, the previous patientshaving been anaesthetised uneventfully.General anaesthesia was established by

intravenous induction and maintainedwith sevoflurane in air and oxygen.The patient was intubated with a

reinforced tracheal tube using mivacu-rium as the muscle relaxant. Thepatient was transferred to theatre wherehe was connected to the ventilator

prior to being turned from supine toprone. The vaporiser was switched onand the fresh gas flow was set to

8 l.min–l to flush the system. Despite adialled concentration of 2.5% only alow end-tidal sevoflurane concentra-

tion (0.2%) was measured. Simulta-neously, the ventilator signalled a �Sub-System 1 leak�. It was noted that the

patient was being ventilated because anormal capnography waveform andend-tidal carbon dioxide was recorded.(With hindsight, I believe this may

have been due to the flow-decouplingreservoir bag that contained gas priorto connection of the patient.) Transfer

to manual ventilation confirmed adisconnection from the fresh gas supplyas the reservoir bag failed to fill, despite

increasing the fresh gas flow. A Bainsystem was called for and anaesthesiawas maintained uneventfully with

Figure 2

Figure 1



intravenous propofol. The problemwas finally solved after inspection ofthe circle system (by sitting on thefloor!) when a disconnection of the

distal fresh gas pipe to the ventilatorblock was found. This connection is ofa Schrader probe type with spring-

loaded outer ring which when liftedreleases the probe (Figs 2 and 3).

I am concerned at the ease of releasing

this connection, which I believe wasachieved by accident, possibly duringtransfer and positioning of the patient. I

suggest that it may be safer to have ascrew-tightening outer ring to avoidaccidental release of the probe by lightcontact with the Schrader unit. This

modification would provide extra secur-ity and yet enable intentional discon-nection with one hand.

This critical incident also highlightsthe benefits of a period of manualventilation prior to commencement of

IPPV, which in this case, would haveimmediately drawn attention to a dis-connection of the fresh gas flow supply.

J. Wilden

Hope Hospital,

Manchester, UK

E-mail: [email protected]

Oxygen failure alarms onmodern anaesthetic machines

We would like to draw readers’ atten-tion to a potential problem when using

some of the newer anaesthetic machinesavailable on the market.

Anaesthesia was induced uneventfullyon a 55-year-old male diabetic due to

undergo a vitrectomy. Having suspend-ed all monitoring during transfer fromthe anaesthetic room to theatre, a pulse

oximeter was reattached and ventilationrecommenced using a Datex Aestiva 5anaesthetic machine, prior to sliding the

patient up onto the operating table,whereupon all remaining monitoringwas reconnected. Needless to say, at this

time many alarms tend to go off, both onthe patient monitor and the Aestiva’sbuilt in ventilator. While reattaching themonitoring and silencing the alarms, it

was noticed that the patient’s oxygensaturation was only 92% and on attempt-ing to increase the oxygen concentra-

tion, the rotameters were showing noflow and it became clear that the oxygensupply had in fact failed. The fault was

found to lie at the wall outlet, and thesupply was re-established rapidly usingthe cylinder supply. (It was later foundthat the Schrader valve was faulty.) No

patient harm occurred.The Aestiva does not have the tradi-

tional oxygen failure whistle. The ma-

chine announces lack of oxygenpressure with a screen message, and analarm not very dissimilar to its other

messages and alarms. These featuresworked properly on this occasion inthe technical sense; however, we would

suggest that they failed in the humansense, since the oxygen failure alarmswere insufficiently distinguishable fromthe others on the machine.

There is no other alarm in anaesthe-sia quite like the oxygen failure whistle.It can be heard from the next room,

and the action that then needs to betaken is immediately obvious to anaes-thetists and theatre staff alike. It is an

alarm that is currently part of us.Figure 3



Departments using anaesthetic ma-chines without oxygen failure whistlesshould be aware that their absenceincreases the difficulties in trouble-

shooting machine failures.

J. Andrzejowski

R. Freeman

Royal Hallamshire Hospital,

Sheffield S10 2JF, UK

When and by whom was thecurved tip of a gum-elasticbougie first introduced?

A gum-elastic bougie is now an essen-tial airway management tool used inunexpected difficult intubations in the

operating theatre [1] or emergencydepartment [2] in the UK. From ahistorical point of view, however,although Macintosh described the first

use of a gum-elastic catheter as early as1949 [3], it was not widely used in histime [4]. Following Macintosh’s sugges-

tion of the use of a gum-elastic catheterin the management of difficult intuba-tion arising from anatomical problems,

the British firm of Eschmann (EschmannHealthcare, SIMS Portex Ltd. Hythe,Kent CT21 6JL, UK) began manufac-turing a device designed specifically for

this purpose [5, 6]. In the early stage, theintroducer does not seem to have beenequipped with a tip anteriorly curved at

an angle of 35 degrees [7]. This angu-lation helps successful insertion into thetrachea during a difficult intubation.

Even though we have examined manypast papers, we could not find anydescription of the angulation of the tip

of the gum-elastic bougie. We areanxious to know when and by whomthe curved tip of a gum-elastic bougiewas first introduced, so that we can give

credit where it is due.

H. Toyoyama

Y. Hirose

Y. Toyoda

Osaka Kosei-Nenkin Hospital,

Osaka 553–0003, Japan


References1 Dogra S, Falconer R, Latto IP. Suc-

cessful difficult intubation-tracheal tube

placement over a gum-elastic bougie.

Anaesthesia 1990; 45: 774–6.

2 Morton T, Brady S, Clancy M. Diffi-

cult airway equipment in English

emergency department. Anaesthesia

2000; 55: 485–8.

3 Macintosh RR. An aid to oral intu-

bation. British Medical Journal 1949;

1: 28.

4 Dogra S, Falconer R, Latto IP. Suc-

cessful difficult intubation. Anaesthesia

1991; 46: 72–3.

5 Cormack RS, Lehane J. Difficult tra-

cheal intubation in obstetrics. Anaes-

thesia 1984; 39: 1105–11.

6 Viswanathan S, Campbell C, Wood

DG, Riopelle JM, Naraghi M. The

Eschmann tracheal tube introducer.

Anaesthesiology Review 1992; 19: 29–34.

7 Gray TC, Nunn JF, Utting JE. General

Anaesthesia, 4th edn. London: Butter-

worths, 1985: 1274.

Delayed presentation oftracheo-oesophageal fistulafollowing percutaneousdilatational tracheostomy

Posterior tracheal wall damage is aserious complication of percutaneous

tracheostomy. Recent correspondencehas highlighted the importance of fibreoptic vision during the procedure [1].

The following case illustrates the needfor endoscopic inspection of the airwayprior to the formation of a tracheostomy.

A 29-year-old man with severe dia-

betic ketoacidosis complicated by car-diac arrest and hypoxic brain injury, wasadmitted to the ICU for respiratory

support. On day 33 of his admission, anexperienced consultant anaesthetist per-formed a percutaneous tracheostomy

procedure. A Ciaglia percutaneous dila-tational tracheostomy set (Cook CriticalCare Limited, Letchworth, Herts, UK)

was used. A fibre-optic bronchoscopewas not available at the time of theprocedure. The first attempt was trau-matic and ventilation of the lungs via

the tracheostomy tube was not possible.The procedure was repeated successful-ly through the initial stoma.

Two weeks after the tracheostomywas formed, there was a sudden deteri-oration in the patient’s condition. An

abrupt decrease in the exhaled tidal

volume was associated with a rapidaccumulation of gas in the nasogastricdrainage bag. Fibre-optic bronchoscopywas performed through the tracheosto-

my tube. A tracheo-oesophageal fistula(TOF) was identified immediately distalto the tip of the tube (Fig. 4). A thoracic

surgeon advised conservative manage-ment. Unfortunately, the patient died ofrespiratory failure 39 days later.

Unlike previously reported instancesof TOF, this case presented 14 days afterpercutaneous tracheostomy. It is unclear

whether the TOF resulted from thetraumatic tracheostomy procedure orfrom the prolonged period of trachealintubation. There is good evidence to

show that there are fewer peri-operativecomplications when percutaneous dila-tational tracheostomies are performed

under fibre-optic vision compared tothose performed without it [2, 3]. Inaddition, fibre-optic bronchoscopy

allows assessment of the airway prior topercutaneous tracheostomy in order todocument any pre-existing posterior

tracheal wall damage.In common with other authors, we

strongly recommend that such proce-dures are only performed under direct

vision using a fibre-optic bronchoscope.

S. M. Drage

C. Pac Soo

T. Dexter

Wycombe Hospital,

High Wycombe HP11 2TT, UK

Figure 4 View of the tracheal lumen, viaa fibre-optic bronchoscope, showing thetracheo-oesophageal fistula (TOF) locatedon the postero-lateral aspect of the tra-cheal wall.



References1 Westphal K. Posterior tracheal wall

perforation with the Blue RhinoTM

tracheostomy set. Anaesthesia 2002; 57:

89–90.

2 Susanto I. Comparing percutaneous

tracheostomy with open surgical

tracheostomy. British Medical Journal

2002; 324: 3–4.

3 Dulgerov P, Gysin C, Pernerger TV,

Chevrolet JC. Percutaneous or surgical

tracheostomy: A meta-analysis. Critical

Care Medicine 1999: 27: 617–25.

Percutaneous dilatationaltracheostomy and tracheal ringrupture

We would like to report a seriouscomplication of the insertion of a

percutaneous dilatational tracheostomy(PDT) using the PercuTwist system(Rusch, Kernen, Germany).

A 40-year-old male was transferred

for treatment of ARDS following anaspiration pneumonitis. At day 6, inview of his ongoing ventilatory require-

ments, it was decided to perform aPDT. Initial assessment revealed nocontra-indications, a thin neck with

easily palpable anatomy and access tohis trachea at the level of his second andthird tracheal rings. A Rusch Percu-

Twist tracheostomy set was used for acontrolled PDT. Anaesthesia was pro-vided via a laryngeal mask airway withendoscopic control and an experienced

intensivist performed the tracheostomy.In accordance with the manufacturersguidelines, the PercuTwist dilator was

used to expand the access to the tracheallumen by turning it under slight initialpressure into the soft tissues of the neck

until the proximal end of the Percu-Twist was visible on endoscopy. Thethread of the PercuTwist cuts throughthe pretracheal tissues and tracheal wall

under twisting movements. However,during this phase the second trachealring was seen to split and protrude into

the tracheal lumen rostral to the inser-tion site. A Crystal Clear tracheostomycannula (provided in the set) was

introduced and advice sought from anENT consultant. The patient was man-aged conservatively and decannulated

successfully 7 days later.

A search of the Medline databaserevealed two reports of a previoustracheal ring herniation followingPDT. The first case was picked up

incidentally after failure to decannulateand the anterior herniated segment waselevated and partially resected under

endoscopic guidance [1]. The secondwas picked up during bronchoscopyafter PDT [2]. A further series of

complications using the Blue Rhino�technique (Cook Critical Care) repor-ted tracheal ring fractures in 8.9% [3].

A study of 42 tracheal specimens ofintensive care patients at postmortemrevealed extended cartilaginous defectsare rare, which may explain the low

rate of tracheal stenosis following PDT[4]. However, 20 specimens showed ahorizontal intercartilaginous rupture of

the anterior tracheal wall, 12 tracheasadditionally had fractures of trachealrings and in 10 specimens, defects of

tracheal cartilage. This evidence sug-gests bronchoscopy is not sensitive inthe detection of tracheal ring fractures.

Damage to the tracheal skeleton,although important, could not beavoided despite the use of a broncho-scope. We perform over 200 PDTs per

year and have not previously encoun-tered this problem. We feel the Percu-Twist technique may be more likely to

produce tracheal ring ruptures becauseof its twisting motion rather than asplitting dilatational technique. Fibre-

optic bronchoscopy may help diagnosea number of these complications but isno substitute for operator experienceand an effective, simple dilatational

technique.

R. G. Roberts

P. Morgan

G. P. Findlay

University Hospital of Wales,

Cardiff CF14 4XW, UK

References1 Osborne JE, Osman EZ, Cuddihy P,

Ranta M. Tracheal ring herniation

following percutaneous dilatational

tracheostomy and its resection under

endoscopic control. Journal of Laryngol-

ogy amd Otolology 1999; 113: 1116–18.

2 Frosh A, Thomas ML, Weinbren J,

Djazaeri B, Richards A. Tracheal ring

rupture and herniation during percuta-

neous dilatational tracheostomy identi-

fied by fibreoptic bronchoscopy. Review

of Laryngol Otol Rhinol (Bord) 1997; 118:

179–80.

3 Edwards SM, Williams JC. Tracheal

cartilage fracture with the Blue Rhino

Ciaglia percutaneous tracheostomy

system. European Journal of Anaesthesiol-

ogy 2001; 18: 487.

4 Walz MK, Schmidt U. Tracheal lesion

caused by percutaneous dilatational

tracheostomy – a clinico-pathological

study. Intensive Care Medicine 1999; 25:

102–5.

A replyThe manufacturers have asked us tocomment on this letter. The authorsdescribe the rupture and protrusion of

the second tracheal ring during thedilatation process while using the Percu-Twist� set (Rusch, Kernen, Germany).

We have personally performed nowmore than 100 percutaneous tracheos-tomies using the same technique andhave observed tracheal ring rupture in an

incidence of about 2%. We confirmtherefore the observation of Roberts andcolleagues that, while using the Percu-

Twist� technique, damage to the trac-heal skeleton with tracheal ring rupturecan occur. However, we have some

problems in how the authors interprettheir observation.

First, we do not understand why they

classified their observation as serious.Serious, at least to our understanding,means (life) threatening, requiring anacute or at least subacute intervention.

The patient described was successfullydecannulated without any problems onday 13. We agree that a tracheal ring

rupture is something that is worthwhilereporting; however, we totally disagreewith classifying the event described as

serious. In our series, and in accordancewith the case report by Roberts et al.,the tracheal ring ruptures never caused

any serious problems requiring any kindof intervention. So far, we know little ofthe potential long-term consequences oftracheal ring ruptures caused by what-

ever kind of percutaneous tracheostomytechnique. However, our own expe-rience, as well as data given in the

literature, suggest that relevant acuteclinical complications related to trachealring fractures are obviously rare [1–3].



Second, we do not understand what theauthors mean with their sentence: �Theidentification, although important, ofdamage to the tracheal skeleton could

not be avoided despite the use of abronchoscope�. As they stated, theauthors identified the tracheal ring rup-

ture with the bronchoscope and as longas there is no loss of fibre-optic controlduring the procedure, we cannot imag-

ine any significant laceration to thetracheal wall that could not be observedwhile using a bronchoscope. In addi-

tion, the postmortem study by Walz andcoworkers did not intend to evaluatethe specificity or sensitivity of bronchos-copy in identifying lacerations to the

tracheal skeleton and therefore cannotbe used to state that bronchoscopy ingeneral is not sensitive in the detection

of tracheal ring fractures. On the otherhand, we have no idea in which way abronchoscope could help to avoid the

occurrence of a tracheal ring rupturewhatever percutaneous tracheostomytechnique might be used.

In addition to the series cited in thecommunication of Roberts et al. Bew-sher and colleagues [1] reported anincidence of 1 of 36 (2.7%) and Byhahn

and colleagues [2] in 9 of 25 (36%)tracheal ring ruptures while using theBlue RhinoTM technique. Interestingly,

both without describing any relatedcomplications. Roberts and colleaguesfeel that the PercuTwist� technique

may be more likely to produce trachealring ruptures compared with the split-ting, dilatational techniques; we wouldspeculate that the contrary is true. A split-

ting dilatational technique, especiallywhen performed as a single step proce-dure, has a higher likelihood to pro-

trude parts of the tracheal rings into thetracheal lumen than a more displacingtechnique like a screw-based procedure.

However, we would like to deal withevidence rather than with speculationand we are therefore looking forward to

forthcoming studies that will certainlyshow the incidence of tracheal ringruptures while using the PercuTwist�technique. These data can then serious-

ly be compared to the number oftracheal ring rupture observed withother techniques as already given in

the literature [1–3].

M. Quintel

Universitatsklinikum Mannheim,

68167 Mannheim, Germany


heidelberg.de

G. Frova

Ospedale Civile di Brescia,

Brescia, Italy

References1 Bewsher MS, Adams AM, Clarke

CWM, McConachie I, Kelly DR.

Evaluation of a new percutaneous dil-

atational tracheostomy set. Anaesthesia

2000; 56: 859–64.

2 Byhahn C, Wilke HJ, Halbig S, Lischke

V, Westphal K. Percutaneous trach-

eostomy: Ciaglia Blue Rhino vs. the

basic Ciaglia technique of percutaneous

dilational tracheostomy. Anesthesia and

Analgesia 2000; 91: 882–6.

3 Edwards SM, Williams JC. Tracheal

cartilage fracture with the Blue Rhino

Ciaglia percutaneous tracheostomy

system. European Journal of Anaesthesia

2001; 18: 487.

Percutaneous tracheostomyand microlaryngeal tubes

We were very interested to read thearticle regarding the use of microlaryn-geal tubes (MLT) to aid safer passage ofpercutaneous tracheostomies (Fisher

et al. Anaesthesia 2002; 57: 253–5). Inparticular, we were impressed in theirdiligence in recording 250 procedures.

Persistent air leak around the deflatedcuff of the tracheal tube during theperformance of a percutaneous trach-

eostomy is indeed a problem. Theirmethod does, however, raise a fewquestions.

First, there was a failure to report

what mode of ventilation was employedduring the procedure. Did the research-ers find they had to compromise on

tidal volume to accommodate the nec-essary high pressures of ventilatingthrough a 5-mm MLT? Did they have

to restrict their patient selection in orderto achieve this? Second, we think,despite their best efforts, protection of

the patients’ lungs from soiling ondeflation of the cuff of the MLT was

not achieved. The throat pack, it seemsto us, might only conceal regurgitationif it occurred. In that case, it may not bethat superior to ventilating with an

ordinary tracheal tube with the cuffdeflated. Finally, whilst we accept thatthe micro laryngeal tube can be used to

maintain �full tracheal intubation andventilation until the correct positioningof the tracheostomy tube can be veri-

fied�, their technique does not allow forsimultaneous use of a bronchoscope toconfirm intratracheal placement of the

guidewire. Whilst this is not always thenorm in every intensive care unit [1],we believe it is the best means of con-firming correct placement of the needle

and guidewire, preventing malposition-ing of the tracheostomy tube [2] andreducing subsequent complications [3].

Can the authors really be advocating theuse of an MLT as providing a safertechnique?

A. M. Tate

A. Asumang

Diana Princess of Wales Hospital,

Grimsby DN33 2BA, UK

References1 Cooper RM. Use and safety of percu-

taneous tracheostomy in intensive care.

Anaesthesia 1998; 53: 1209–27.

2 Walz MK, Schmidt U. Tracheal lesion

caused by percutaneous dilational

tracheostomy – a clinico-pathologic

study. Intensive Care Medicine 1999; 25:

102–5.

3 Berrouschot J, Oeken J, Steiniger L,

Sneider D. Peri-operative complica-

tions of percutaneous dilational trach-

eostomy. Laryngoscope 1997; 107:

1538–44.

A replyThank you for the opportunity ofreplying to Drs Tate and Asumang’sletter. Dealing with the points raised

sequentially:Mode of ventilation; prior to inser-

tion of the microlaryngeal tube, all

patients were fully paralysed and trans-ferred to traditional constant volumeIPPV mode of ventilation utilizing

100% oxygen. The inspiratory flow rateand peak inspired pressure was adjustedto allow for the increased airway resis-



tance concomitant with using a smallbore tube. Following deflation of themicrolaryngeal cuff, the throat pack wasadjusted until the measured exhaled

tidal volume was within 50 ml of theinspired tidal volume. Plateau pressureswere not dramatically altered by this

mode of ventilation, as the increase ininspiratory pressure was largely relatedto the pressure drop down the tube.

Patient selection; only those patientswith anatomical problems (such asfractured C4 ⁄ 5 cervical vertebrae, thy-

roid goitre) were referred for a surgicaltracheostomy. Although tracheostomywas not performed on patients requir-ing large values of PEEP, inspired

oxygen concentration and who werecardiovascularly unstable, we wouldassume that this type of patient is

unsuitable for tracheostomy by what-ever method. Under these circumstanc-es, tracheostomy was postponed until

the prevailing pathophysiology wasmore favourable.

Tracheal soiling; every effort was

made to ensure that the patient’s stom-ach was empty prior to performing theprocedure. It is recognised that ITUpatients can be subject to tracheal

soiling past an inflated cuff under nor-mal conditions. Thus the risk of soilingis present whether or not the tracheal

tube cuff is inflated above or below thecords to achieve a seal, or left deflatedwith a throat pack. In our series, this did

not appear to be a problem; however, itwould be useful to test both systems forthis complication.

Use of the bronchoscope; it was

pointed out in the original paper that adisadvantage of this method was that itdid not allow the utilisation of a bron-

choscope. We agree that the use of abronchoscope for confirming the place-ment of the guide wire and tracheostomy

tube is desirable. Since the publication ofthe paper we have been amending ourtechnique so as to permit the use of a

bronchoscope while maintaining theairway with a microlaryngeal tube.

Safety; our series demonstrated thatthe incidence of complications utilizing

this method of airway management waslow and comparable to other series of asimilar size. Thus the technique would

appear to be safe. The paper did not test

the use of the microlaryngeal tube againstother techniques of airway management.Following the success of this system, itwould now be justified to do so.

D. Read

The Princess Royal Hospital,

Haywards Heath RH16 4EX, UK

L. Fisher

Derriford Hospital,

Plymouth, UK

Percutaneous tracheostomywith the PercuTwistTM

technique not so easy

Several techniques for percutaneoustracheostomy are available, althoughonly three have been widely used.These are percutaneous tracheostomy:

with multiple dilators, with the guide-wire dilating forceps, and with one(Blue Rhino) dilator. Recently, a new

technique, the PercuTwistTM, was in-troduced by G. Frova and coworkers[1]. We wish to report our experiences

with this technique.All patients requiring tracheostomy in

April and May 2002 were offered a

percutaneous tracheostomy with thePercuTwistTM kit (Rusch, PO Box 77,1420 AB Uithoorn, The Netherlands).After local infiltration with lidocaine 1%

and epinephrine 1 : 100 000, a 2-cmtransverse incision was made through theskin and subcutaneous tissues. Subse-

quently, the trachea was punctured withan introducer needle, aiming for theinterspace between first and second or

second and third tracheal ring, and aguidewire was threaded. The positionand depth of the tracheal puncture, aswell as the position of the guidewire,

were routinely checked with a broncho-scope in all patients. After lubricating thehydrophilically coated PercuTwistTM

screw in water for half a minute, it wasintroduced over the guidewire andscrewed into the trachea under constant

bronchoscopic control. The screw waswithdrawn and the appropriately sizedtracheostomy tube was introduced into

the trachea. For women and men, weused the cuffed tracheostomy tube size 8and 9, respectively, that comes with theset. Finally, the tube was connected to

the ventilator and its position was con-firmed by capnography.

The dilating procedure was scored asproposed by Frova [1]. A three-staged

scale was used: I (controlled rotatingdilation without any difficulties), II(some difficulties but possible) and III

(impossible, shift to another percutane-ous technique).

A total of six patients underwent

elective percutaneous tracheostomy.The mean age was 46 years (range27–61 years) with five men and one

woman. The mean procedure timefrom incision until introduction of thetube was 8 min (range 5–13 min). Theprocedure was successful in all patients.

In one patient, venous bleedingoccurred requiring surgical explorationseveral hours after the procedure. Of

the six tracheostomies, five dilationprocedures were classified as II: in thosepatients, the dilation of the trachea

required much force. In order to avoidtwisting of the skin by the screw, itneeded to be stretched by an assistant.

Despite this, twisting of the skin as wellas of tracheal mucosa occurred in almostall patients. Appropriate lubrication didnot resolve this problem. In one case,

the green coating of the guidewire waslocally ripped off by the repeated twist-ing movement of the screw. There

were no complications during cannula-tion.

In our unit, we initially used the

guidewire dilating forceps technique.Since the Blue RhinoTM kit becameavailable, it has become our preferredchoice. The first publication of the

PercuTwistTM presented it as a newtechnique, being both very simple andsafe. In our experience, the advanced

screwing manoeuvre is a risk forlaceration or even perforation of theposterior tracheal wall. A recent case

report has drawn attention to this [2].We feel that the difficult dilationprocedure is an important drawback

of the technique.

B. G. Fikkers

J. M. M. Verwiel

R. J. G. H. Tillmans

University Medical Centre Nijmegen,

PO Box 9100, 6500 HB Nijmegen,

The Netherlands




References1 Frova G, Quintel M. A new simple

method for percutaneous tracheostomy:

controlled rotating dilation. A prelimi-

nary report. Intensive Care Medicine

2002; 28: 299–303.

2 Thant M, Samuel T. Posterior tracheal

wall tear with PercuTwist. Anaesthesia

2002; 57: 507–8.

Margin of safety for theuncuffed tracheal tube

We read with great interest an article

regarding the margin of safety for thepaediatric tracheal tube (TT) (Ho et al.Anaesthesia 2002; 57: 173–5). The

authors suggest that, when comparedwith an uncuffed TT, a cuffed TT has areduced margin of safety of approxi-

mately 50% or more. For the cuffedTT, the proximal limit was where theproximal edge of the cuff impinges onthe vocal cord. For the uncuffed TT,

the vocal cord was used as the upperlimit of safe placement, so the wholetracheal length was regarded as a margin

of safety. They also state that for anuncuffed TT, the most cephalad posi-tion without excessive leak and the risk

of extubation is where the top end ofthe bevel aligns with the vocal cord.Their results seemed to be overemphas-

ised. We would like to raise some pointsconcerning the article.

The reason that uncuffed TTs havebeen advocated in young children is

that the narrowest portion of theirairway is the cricoid ring rather thanthe glottis. This anatomical feature

obviates the need for a cuffed tube.For children, the upper limit should bedefined as when the top end of the

bevel is level with the cricoid ring, notwith the vocal cord because theuncuffed TT, with an outer diametersimilar to the lumen of the cricoid ring,

plays a key role in preventing excessiveleak. Additionally, to calculate the mar-gin of safety for an uncuffed TT, the

minimal length of the TT for preven-tion of inadvertent extubation should besubtracted from the tracheal length.

Therefore, not the whole tracheallength, but the distance from the cricoidring to the lower margin of the trachea

should be regarded as a margin of safety

for the uncuffed TT. Calculation of thereduced margin of safety should beadjusted by subtracting the distancebetween the vocal cord and the cricoid

ring from the tracheal length.Incidentally, if we use a cuffed TT

instead of an uncuffed TT, as well as

having to reduce the size by 0.5–1.0 mm[1, 2], potential problems due toincreased cuff pressure and the reduced

margin of safety are the main disadvan-tages. Recently, the advantage of theouter diameter of an uncuffed TT was

emphasised for paediatric patients [3, 4].When an uncuffed TT that permits theexact leak sought for clinical purposes isnot available, we can overcome the

problem by choosing a TT of a differentkind with a different outer diameter [4].All the disadvantages of uncuffed TTs

(except the need for repeated attempts oflaryngoscopy to change the TT) can beavoided. Thus, we do not think it

necessary to stress the rationale behindthe use of cuffed TT in children.

J-H. Bahk

S-H. Han

Seoul National University

Hospital,Seoul 110–744, Korea


References1 Motoyama EK. Endotracheal Intuba-

tion. In: Motoyama EK, Davis PJ, eds.

Smith’s Anaesthesia for Infants and Chil-

dren, 5th edn. St. Louis: CV Mosby,

1990: 269–90.

2 Khine HH, Corddry DH, Kettrick RG,

et al. Comparison of cuffed and

uncuffed tracheal tubes in young

children during general anaesthesia.

Anesthesiology 1997; 86: 627–31.

3 Malhotra SK, Dutta A. Pediatric tracheal

tubes: the advantage of outer diameter.

Anesthesia and Analgesia 2001; 93: 801–2.

4 Bahk JH, Ahn WS. How to manage the

unavailability of an appropriately sized

uncuffed tracheal tube? Paediatric

Anaesthesia 2002, in press.

A replyWe thank Drs Bahk and Han for theirinterest in our article, and for the

opportunity to respond.It is clear that the margin of safety

varies depending on how one definessafety and danger. We use inadvertent

tracheal extubation as the upper limit oftube position whereas Drs Bahk and Hanuse loss of optimum seal around the trac-heal tube. Both conditions, if uncorrect-

ed, are seriously undesirable: the formercan result in death quickly and the lattercan compromise ventilation.

As pointed out in our paper, cuffedtracheal tubes have the disadvantages ofsmaller diameters and the risk of cuff

over-inflation. They are nonethelessused because uncuffed tracheal tubeshave disadvantages. Choosing the cor-

rect uncuffed tracheal tube for childrentypically involves the application of awell-known formula:

Internal diameter of tube¼ age

4þ 4mm

However, since children vary in sizes, a

tube that is too small or too big is ofteninadvertently chosen. Based on thisformula, Khine et al. [1] found that 54

of 237 children with uncuffed tubesrequired a tube change because of poorfit, compared to 3 of 251 of childrenwith cuffed tubes (p < 0.001) selected

using a modified formula. Mostafa et al.[2] found that 16% of children wereintubated with cuffed tubes that turned

out to be too small, and 11% of caseswere with cuffed tubes that turned outto be too big. Too big a tube results in

tracheal trauma and ischaemia. Toosmall a tube would result in the problemthat Drs Bahk and Han have pointedout: loss of optimum fit between the

cricoid ring and the tube. The problemof poor fit may be accentuated inabdominal laparoscopic procedures,

which are increasingly performed inyoung children. Changing tubes is notwithout important risks and problems.

We therefore, respectively, disagreewith Drs Bahk and Han on the impor-tance of the rationale behind the use of

cuffed tracheal tubes in children.

A. M-H. Ho

C. S. T. Aun

M. K. Karmakar

The Chinese University of Hong

Kong,

Hong Kong

References1 Khine HH, Corddry DH, Kettrick RG,

et al. Comparison of cuffed and



uncuffed tracheal tubes in young

children during general anaesthesia.


2 Mostafa SM. Variation in subglottic size

in children. Procedures of the Royal Society

of Medicine 1976; 69: 793–5.

A case of airway obstruction

In recent times, much concern has been

generated with regards to blockagesoccurring within anaesthetic breathingsystems and several incidents have beenreported in the press. We report a case

of airway obstruction that is unusual andeasily preventable.

A 14-year-old girl was admitted for

elective extraction of a deciduous tooth.She had an unremarkable medical his-tory. No premedication was prescribed.

Anaesthesia was induced using fentanyl,propofol and maintained with 1–2%sevoflurane (inspired concentration) and

nitrous oxide in oxygen. Manual ven-tilation with a bag and mask using aBain’s circuit was easy to perform.Muscle relaxation was achieved with

mivarcurium. The patient was intubat-ed with a 6-mm nasal tracheal tube anda Portex right angle connector. The

view at laryngoscopy was grade 1 andintubation was atraumatic. Followingconnection to the breathing circuit, the

patient could not be ventilated manu-ally. The tracheal tube was withdrawn1–2 cm but this made no difference. Acheck laryngoscopy showed that the

tube was through the vocal cords andno kink or bend in the tube was seen.The tracheal tube was taken out,

inspected and used again for re-intuba-tion. Again ventilation through it wasnot possible. The tracheal tube was

again removed and the patient easilyventilated with a bag and mask. Another6 mm nasal tube was prepared and

intubation was attempted for a thirdtime. Manual ventilation via the secondnasal tracheal tube was still unsuccessful.Under direct laryngoscopy, the nasal

tube was replaced with a 7-mm southfacing RAE tube and manual ventila-tion was achieved. Oxygen saturation

remained at 98–99% throughout. Sur-gery and recovery were uneventful.

At all times, manual ventilation with

a bag and mask was possible. Following

the initial intubations with the nasaltracheal tubes, ventilation could not beachieved because of high resistance.Everything pointed to some kind of

obstruction in the nasal tracheal tubes.On examination of the tracheal tubes,no obstruction was found and lumen

patency was confirmed. However, therewas found to be a high resistance toflow through the Portex right angle

connector. The Portex connectors areof transparent plastic and initially noobvious obstruction could be seen

(Fig. 5). On closer inspection, a clearjelly type substance was found to bepresent in the lumen of the connector(Fig. 6). Aqueous K-Y jelly had been

used to facilitate insertion of the con-nector into the tracheal tube. Althoughobstruction was incomplete, the resis-

tance through the connector had beenincreased sufficiently to prevent manualventilation.

The anaesthetic equipment had beenchecked prior to the start of the oper-ating list according to the Association of

Anaesthetists guidelines [1]. The nasaltube and Portex right angle connectorwere assembled prior to intubation butwould not have been part of the routine

equipment check before the start of theoperating list. It is unclear if the practice

of using aqueous K-Y jelly to enablefitting of the connector to tracheal tubeis commonplace. However, this casehighlights the potential risk of this

practice.We have observed that aqueous K-Y

jelly within a connector becomes more

viscid after approximately 20 min ofexposure to the atmosphere and cannotbe dislodged easily. In its aqueous form,

pressured airflow could not displace itfrom the connector. Thus the aqueousK-Y jelly added resistance to flow even

before it became more viscid. Right-angled connectors can cause more resis-tance to a given flow than curvedconnectors due to increased turbulence.

It is not clear whether this fact contrib-uted to the picture of partial obstructionwith only a minor block caused by

aqueous K-Y jelly.There have been other episodes of

unusual airway obstruction reported

[2, 3]. These cases involved cathetermount obstructions. This piece ofequipment is also not part of the routine

breathing system testing. We recom-mend that any item to be attached to abreathing circuit should be tested incircuit prior to use on a patient. Also,

the practice of using aqueous K-Y jellyFigure 5 Portex right-angle connector.Upper containing aqueous K-Y jelly.

Figure 6 End on view of Portex right-angle connector. Upper containing aque-ous K-Y jelly.



to facilitate insertion of connectors totracheal tube should be discontinued,especially when using small size tubes.

M. Kan

A. Hassani

Broomfield Hospital,

Chelmsford CM1 7ET, UK

References1 Association of Anaesthetists of Great

Britain and Ireland. Checklist for

Anaesthetic Apparatus. London: AAGBI;

1997.

2 Thomas R, Finch S. A blocked catheter

mount. Anaesthesia 2001; 56: 88.

3 Kurian J, Renwick N. An unusual case

of airway obstruction. British Journal of

Anaesthesia 2001; 87: 804–5.

Pneumocoele following psoascompartment block

Psoas Compartment Block (PCB) is a

useful technique for alleviating thedisabling pain of osteo-arthritis of thehip. Good relief of moderate to severehip pain can be achieved for several

months with PCB [1]. Hence, PCB isone of the regional blocks offered topatients with hip pain attending the pain

clinic whilst they are awaiting hipsurgery. PCB produces a block of alllumbar and some sacral nerves thus

producing anaesthesia of the anteriorlateral thigh. The nerves of the lumbarplexus can be anaesthetised by depos-

iting local anaesthetic in the psoascompartment, which is immediatelyposterior to the psoas muscle and ante-rior to the quadratus lumborum muscle

[2]. In 1976, Chayen described a tech-nique using loss of resistance to air tolocate the psoas compartment. After

locating the psoas compartment andensuring negative aspiration to bloodand cerebrospinal fluid, 20 ml of air is

injected to dilate the psoas sheath topromote uniform spread of the localanaesthetic agent [3]. Nerve stimulator,fluoroscopy and ultrasound have been

used to locate the lumbar plexus.Despite the many advantages of PCB,complications do occur. Spinal, epidural

and intravascular injections have beenreported [4]. I wish to report a case ofan iatrogenic pneumocoele in a patient

with chronic hip pain, followingattempted identification of the psoascompartment by the loss of resistancetechnique.

A 40-year-old man was referred tothe pain clinic for treatment of his long-standing hip and lumbar pain. He had a

2-year history of intermittent hip painfollowing a road traffic accident in1977. His current medication consisted

of oral diclofenac and codeine phos-phate. His past medical history includedhay-fever and depression; cardiovascular

and respiratory system were unremark-able. Physical examination revealedan obese man weighing 130 kg withextensive fat over the lumbar spine. As

oral pain killers could not control thepain, a PCB was offered under localanalgesia and Entonox. The patient was

placed in the right lateral position.Monitoring included pulse oximetryand non-invasive blood pressure. As

fluoroscopy was not available, the left-sided PCB was performed by the con-ventional posterior approach with loss

of resistance to air, as described byCheyan. A 20-gauge, 150 mm spinalneedle was used and the psoas compart-ment was successfully located at the

second attempt at a depth of 16 cm.After negative aspiration to blood andcerebrospinal fluid, 20 ml of air was

injected to dilate the psoas sheath. Thiswas followed by slow injection of 30 mlof bupivacaine 0.375% in increments of

5 ml. The entire procedure lasted forabout 20 min, during which the patientbreathed Entonox for analgesia. Imme-diately after the procedure, the patient

was transferred to the recovery area.Soon after, the patient complained ofmoderate to severe pain in his left groin

and a lump in the abdomen and groin.On examination, there was a palpablecrepitus in the groin and oxygen was

administered at 4 l.min)1 via a Hudsonmask. The patient was closely observedfor the next hour during which time he

was haemodynamically stable. Thepatient was reassured and his symptomsgradually improved over the next hour.The patient was admitted overnight and

discharged the next afternoon withoutany sequelae.

Very muscular patients tend to have

bulging psoas muscles, which could

bulge beyond the anterior surface ofthe body of the lumbar vertebrae [4]. Inthis patient 20 ml of air was deliberatelyinjected to dilate the psoas sheath to

promote the uniform spread of localanaesthetic agent. In addition, thepatient inhaled Entonox for analgesia

during the entire procedure, whichlasted for about 20 min Air bubbles areknown to persist for more than 24 h after

injection [5]. Nitrous oxide can causeexpansion of these bubbles. Inhalednitrous oxide has been shown to increase

the size of the air pockets in closed spaces[6] due to its rapid transfer from theblood into the air pockets. As has beenwell described with pneumo-encepha-

lography [7], nitrous oxide diffuses intothe air-filled cavity to equilibrate thepartial pressure with the blood. As the

solubility of nitrous oxide is 34 timesgreater than nitrogen, the anaestheticenters the space many times faster than

nitrogen diffuses out. In our patient thiscould have caused the expansion of theair bubble in the psoas sheath generating

sufficient pressure to produce clinicalsymptoms of a lump and pain. The paindescribed by the patient was probably theresult of gaseous distension of the psoas

sheath. Furthermore, on assuming asupine position from the lateral in therecovery area, the air could have tracked

along the anterior surface of the psoasmuscle into the groin.

Nitrous oxide has been implicated in

the development of tension pneumoco-ele during craniotomy in the sittingposition [8]. Furthermore, the use ofnitrous oxide is a relative contra-indi-

cation during anaesthesia for middle earsurgery and intestinal obstruction [9].Neck pain caused by subcutaneous

emphysema after lumbar epidural anal-gesia has been described [10].

Anaesthetists using the loss of resis-

tance to air technique along with gen-eral anaesthesia should be cautiousregarding the use of high concentrations

of nitrous oxide. Presumably this com-plication is avoidable if saline ratherthan air is used. Fluoroscopy or a nervestimulator can be used to position the

needle precisely. This case illustratesanother potential complication of PCBand the use of large volumes of air

should be avoided.



M. B. Reddy

Northampton General Hospital,

Northampton NN15BD, UK

References1 Wedley J, Gauci CA. Regional blocks.

Hand Book of Clinical Techniques in the

Management of Chronic Pain 1994; 88–9.

2 Wedley J, Gauci CA. Autonomic

blocks. Hand Book of clinical Techniques

in the Management of Chronic Pain 1994;

49–50.

3 Chayen D, Nathan H, Chayen M.

The Psoas Compartment Block 1976; 45:

95–9.

4 Brown DL. Regional Anesthesia 1996;

21: 310–11.

5 Petty R, Stevens R, Erickson S, Lucio

J, Kao T-C. Inhalation of nitrous

oxide expands epidural air bubbles.

Regional Anesthesia 1996; 21: 144–8.

6 Steven RA, Schuber A, Minal-Stevens

M, Weinstein Z, Van Clief M.

Deliberate epidural air injection in

dogs: a radiographic study. Regional

Anesthesia 1989; 14: 180–2.

7 MacGuillevray RG. Pneumocephalus

and posterior fossa surgery. Anaesthesia

1984; 37: 722–7.

8 Saidman LJ, Eger E. Change in cere-

bra-spinal fluid pressure during pneu-

moencephography under nitrous oxide

anaesthesia. Anesthesiology 1965; 26:

67–72.

9 Eger E, Sardman LJ. Hazards of

anaesthesia in bowel obstruction and

pnuemothorax. Anesthesiology 1965;

26: 61–6.

10 Edwards GM, Sprigge J. Unexplained

pain during epidural analgesia. Anaes-

thesia 1984; 39: 194.

Respiratory arrest in aparturient following intrathecaladministration of fentanyl andbupivacaine as part of acombined spinal-epiduralanalgesia for labour

The safety of the combined spinalepidural (CSE) technique for labour

analgesia is well established. However,several authors have recently reporteduncommon complications includingaphasia [1], dysphagia [2], altered level

of consciousness [3], high sensory block

[4], respiratory depression [5], and respi-ratory arrest [6] following induction ofCSE for labour pain. I herein report acase of a healthy parturient who devel-

oped sudden respiratory arrest andrequired tracheal intubation followingintrathecal injection of fentanyl 10 lg

in combination with bupivacaine2.5 mg as part of a CSE technique forpain relief in labour.

A 26-year-old, 162 cm, 65 kg, grav-ida 4, para 2, healthy female at 39 weeksgestation was in labour and requested

analgesia. She had no drug allergies andhad had no previous anaesthetics prioranaesthesia. Her admission blood pres-sure was 104 ⁄ 62 mmHg, heart rate

66 beats.min)1 and respiratory rate17 breaths.min)1. Fetal heart rate(FHR) was 140 beats.min)1 and reac-

tive. The course of her pregnancy hadbeen uneventful.

No contra-indications to regional

anaesthesia were identified and thepatient consented to epidural analgesia.The epidural catheter insertion tech-

nique consisted of using the sittingposition and a median approach at theL3-4 vertebral interspace. An 18-gaugeTuohy-Schliff epidural needle was

introduced with the loss of resistanceto saline technique and the epiduralspace was identified on the first attempt.

A 20-gauge multi-orifice epidural cath-eter was inserted 5 cm into the epiduralspace. Aspiration from the epidural

catheter was negative for blood andcerebro-spinal fluid (CSF). An epiduraltest dose consisting of 1.5% lidocaine3 ml (45 mg) with epinephrine

1 : 200 000 (15 lg) was administeredand was found to be negative forintravascular and subarachnoid catheter

placement. Epidural analgesia consistedof an initial bolus, loading dose of0.125% bupivacaine 10 ml with fenta-

nyl 50 lg, followed by a maintenancecontinuous infusion of 0.1% bupiva-caine with fentanyl 2 lg.ml)1 at the rate

of 10 ml.h)1. However, over the next2 h, two rescue boluses of 0.25% bup-ivacaine (45 mg total) with fentanyl(100 lg total) were required for break-

through pain, providing no relief oflabour pain. The epidural catheterwas removed and the decision was

made to proceed with the adminis-

tration of CSE via a needle-through-needle technique at the L2-3 vertebralinterspace.

The technical aspects of epidural

space identification were identical tothose previously described. After anuneventful epidural needle placement

(18-gauge Touhy-Schliff epidural nee-dle on the first attempt), a 27-gaugePencan needle was inserted inside the

epidural needle. Following the appear-ance of CSF at the hub of the spinalneedle, fentanyl 10 lg combined with

bupivacaine 2.5 mg (1 ml of 0.25%solution) was injected into the intrathe-cal space. A 20-gauge multi-orificeepidural catheter was inserted 5 cm into

the epidural space. Aspiration from theepidural catheter was negative for bloodand CSF. The patient reported pain

relief 2 min after the intrathecal injec-tion.

Approximately 4 min after the intra-

thecal injection when the anaesthetistwas securing the epidural catheter withtape, the patient became increasingly

somnolent with subsequent loss of con-sciousness and the development ofapnoea. Pulse oximetry revealed pro-gressive desaturation to 85% while blood

pressure decreased to 75 ⁄ 40, and FHRdecreased to 60 beats.min)1. Airwaycontrol with tracheal intubation was

accomplished at the bedside withinapproximately 60 s. Following 2–3 minofpositivepressureventilationwith100%

oxygen, oxygen saturation returned to100%, blood pressure increased to104 ⁄ 60, and fetal bradycardia resolvedwith prompt return to baseline (140

beats.min)1). The return of spontaneousrespiration was reported in 5–6 minfollowing tracheal intubation, and

approximately 12–13 min after intra-thecal injection of fentanyl and bupiva-caine. Four minutes later she regained

consciousness, was alert and able tofollow commands. The pinprick sensorylevel of analgesia was at T8. No signs of

motor blockade were documented. Thechest was clear to auscultation and vitalsigns remained stable. Chest X-ray andarterial blood gas analysis were normal.

The patient did not require any furthertreatment and was extubated approxi-mately 30 min after the episode of respi-

ratory arrest.



An epidural test dose, as describedabove, was administered 60 min laterand was found to be negative forintravascular and subarachnoid catheter

placement. Labour epidural analgesiaconsisted of a maintenance continuousinfusion of 0.1% bupivacaine with fen-

tanyl 2 lg.ml)1 at the rate of 10 ml.h)1,and provided good pain relief for therest of her labour.

However, 3 h after the induction ofCSE and respiratory arrest, Caesareansection was required for failure to

progress. A T4 sensory level of anaes-thesia, as documented by pinprick, wasestablished with incremental doses of2% lidocaine to a total of 18 ml

(360 mg) and fentanyl 100 lg adminis-tered through an epidural catheter. Anuneventful Caesarean delivery of a

female fetus weighing 3500 g, whohad Apgar scores of 9 and 10, after 1and 5 min, respectively, was accom-

plished.When interviewed after the delivery,

the patient had incomplete recall of the

events leading to respiratory arrest,particularly recalling only sudden onsetof �sleepiness�. Her postoperative coursewas uneventful and she was discharged

home on the fourth postoperative day.The time of onset of respiratory arrest

in the patient described in this report is

consistent with a reaction to intrathecalfentanyl administration. Extensive ceph-alad spread of fentanyl might have been

facilitated by the volume of the epiduralrescue boluses of bupivacaine with fen-tanyl (each 10 ml, for a total volume of20 ml), given in addition to a continu-

ous maintenance infusion (10 ml.h)1),which had been administered over 2 hprior to induction of CSE. Greenhalgh

reported a similar case of an obstetricpatient who had a respiratory arrestshortly after receiving intrathecal sufen-

tanil and bupivacaine as part of a CSEtechnique for pain relief in labour [6].The author of this report is not aware of

any other reports documenting emer-gent, intrapartum anaesthetic manage-ment of a parturient developing suddenonset of respiratory arrest following

induction of CSE with fentanyl andbupivacaine.

In conclusion, this case adds one

more piece of evidence that respiratory

depression is now a recognised featureof intrathecal administration of lipid-soluble opioids for labour analgesia.Increased level of vigilance, appropriate

monitoring of these patients and avail-ability of resuscitation equipment aretherefore necessary.

K. M. Kuczkowski

UCSD Medical Center,

San Diego, CA 92103–8770, USA


References1 Fragneto RY, Fisher A. Mental status

change and aphasia after labour anal-

gesia with intrathecal sufentanil ⁄ bupi-

vacaine. Anesthesia and Analgesia 2000;

90: 1175–6.

2 Currier DS, Levin KR, Campbell.

Dysphagia with intrathecal fentanyl.


3 Scavone BM. Altered level of con-

sciousness after combined spinal-epi-

dural labour analgesia with intrathecal

fentanyl and bupivacaine. Anesthesiology

2002; 96: 1021–2.

4 Hamilton CL, Cohen SE. High sensory

block after intrathecal sufentanil for

labour analgesia. Anesthesiology 1995;

83: 1118–21.

5 Ferouz F, Norris MC, Leighton BL.

Risk of respiratory arrest after intra-

thecal sufentanil. Anesthesia and Analge-

sia 1997; 85: 1088–90.

6 Greenhalgh CA. Respiratory arrest in a

parturient following intrathecal injec-

tion of sufentanil and bupivacaine.

Anaesthesia 1996; 51: 173–5.

Epidural fixation

We read with interest the article on theeffect of the Lockit epidural catheterclamp on epidural catheter migration(Clark et al. Anaesthesia 2001: 56: 865–

70) and more recently the correspon-dence (Cowan et al. Anaesthesia 2002;57: 514–15). We were surprised by the

high rate of migration (43%) andresulting analgesic failure (15%) in thestandard epidural dressing group and

therefore we carried out an audit ofepidural catheter migration and adequa-cy of analgesia in postoperative surgical

patients.

Placement of epidurals was standar-dised using a median approach in thesitting position. The catheters wereinserted leaving 5–6 cm in the epidural

space and then secured with a loop andcovered with a transparent sterile dress-ing (Tegaderm – 3M) to leave a viewing

window. The distal catheter was tapedup the patients back with Mefix tape(Molnycke Healthcare) and the filter

secured to the anterior chest wall. Thedepth of the epidural space and the cmmark at the skin were documented. Fifty

consecutive patients were followed-upfor the first 4 postoperative days andassessed with regard to epidural catheterposition and adequacy of analgesia. Early

mobilisation was encouraged.Of the epidurals, 42 were thoracic

and eight lumbar. We used Clark et al.’s

definition of significant inward andoutward migration (‡ 1 cm and‡ 2 cm, respectively). There was signif-

icant catheter migration in six patients(12%), of which only one migratedoutwards (2%), considerably fewer than

Clark’s control group. Migration con-tributing to analgesic failure occurred inonly two patients (4%). Overall analge-sic failure rate was 12%.

We concluded that these results didnot merit a change in our fixationtechnique but have intensified our

training of ward management of epid-urals.

K. Campbell

D. McAuley

C. Judge

Ulster Hospital,

Belfast, UK

Head-up tilt and subarachnoidblock for Caesarean section

I read with interest the recent article(Loke et al. Anaesthesia 2002; 57: 169–72) and associated correspondence

(Wildsmith. Anaesthesia 2002; 57: 617,Sia et al. Anaesthesia 2002; 57: 617). Iroutinely use head-up tilt, to prevent

shoulder pain during Caesarean sectionunder subarachnoid block. I do not putthe patient in this position prior to

starting subarachnoid block, but justbefore the uterine incision. In the head-down position, amniotic fluid can



trickle towards the diaphragm and maybe responsible for the shoulder pain. Iknow a variety of drugs are used to treatthis shoulder pain, But I take the

approach that �prevention is betterthan cure�. As I position the patientin the head-up tilt after the onset of

analgesia, I have never experienced aproblem with pain due to too low alevel of sensory block.

B. V. S. Murthy

Royal Liverpool University Hospital,

Liverpool, UK

Midazolam for PONV. What’snew?

I was interested to read two recentletters about the use of midazolam forpostoperative nausea and vomiting(Watts & Brierley. Anaesthesia 2001;

56: 1129, Prasad et al. Anaesthesia 2002;57: 415). I was not surprised by theefficacy of midazolam in PONV as I

have been using low dose midazolam(subhypnotic) for prolonged postopera-tive emesis that is resistant to the usual

treatments (antidopaminergics includingdroperidol, hyoscine patch, 5HT3 an-tagonists, dexamethasone and acupunc-ture) for 14 years.

In 1992, I published three casereports [1] suggesting the usefulness oflow dose midazolam infusion (0.5–

1 mg bolus followed by 1 mg.h)1) inprolonged PONV that was resistant tostandard interventions. In 1999 I pub-

lished a study [2] supporting the use andsafety of low dose midazolam infusionin resistant postoperative emesis. Since

the original case reports, I have alsoused midazolam by the sublingual andnasal routes (0.5 mg half hourly prn)and intramuscularly (1–2 mg 2 hourly

prn) when an intravenous infusion wasinconvenient. It can also be used incombination with morphine in PCA

(morphine 1.0 mg, midazolam 0.2 mg).All of these routes of administrationare relatively successful. However,

1 mg.h)1 intravenously seems to bemost efficacious and I save this tech-nique for the problem patient that does

not respond to other medication.I think it is important to stress that

low dose midazolam works at subhyp-

notic doses and patients will normallytell you that they feel better very soonafter starting the infusion. Low dosemidazolam is safe to use on the surgical

ward even in combination with opioids[2–4]. However, I do recommendoxygen supplementation and pulse

oximetry monitoring.The mechanism by which midazolam

produces its anti-emetic effect is poorly

understood. It has been suggested thatmidazolam decreases anxiety and dop-aminergic input to the chemoreceptor

trigger zone [1]. The inhibitory effecton dopaminergic pathways may beadenosine mediated [1] or GABA neu-rone mediated [2, 5, 6]. Midazolam may

also reduce 5HT release [7].Postoperative emesis is a difficult

multifactorial problem. It is best treated

with combinations of drugs working viadifferent receptors [8, 9]. Low dosemidazolam is one of the drugs that can

form part of the combination requiredfor difficult patients.

T. Di Florio

South Perth,

Western Australia

References1 Di Florio T. The use of midazolam for

persistent postoperative nausea and

vomiting. Anaesthesia and Intensive Care

1992; 20: 383–6.

2 Di Florio T, Goucke CR. The effect of

midazolam on persistent postoperative

nausea and vomiting. Anaesthesia and

Intensive Care 1999; 27: 38–40.

3 Gilliland HEM, Prasad BK, Mirakhur

RK, Fee JPH. An investigation of the

potential morphine sparing effect of

midazolam. Anaesthesia 1996; 51:

808–11.

4 Egan M, Ready LB, Nessly M, Greer

BE. Self administration of midazolam

for postoperative anxiety: a double

blinded study. Pain 1992: 49: 3–8.

5 Reid MS, Herrera-Marschitz M,

Hokfelt T, Terenius L, Ungerstedt U.

Differential modulation of striatal dop-

amine release by intranigral injection of

gamma-aminobutyric acid (GABA),

dynorphan A and substance P. European

Journal of Pharmacology 1988; 147:

411–20.

6 Takada K, Murai T, Kanayama T,

Koshikawa N. Effects of midazolam and

flunitrazepam on the release of dop-

amine from rat striatum measured by

in vivo microdialysis. British Journal of

Anaesthesia 1993; 70: 181–5.

7 Racke K, Schwore H, Kilbinger H.

The pharmacology of 5HT release from

enterochromaffin cells. In: Reynolds

WM, Andrews PLR, Davis CJ, eds.

Serotonin and the Scientific Basis of

Antiemetic Therapy. Oxford Clinical

Communications 1995; 84–9.

8 Matson A, Palazzo M. Postoperative

nausea and vomiting. In: Adams AP,

Cashman IN, eds. Recent Advances in

Anaesthesia and Analgesia 1995; 19:

107–26.

9 Di Florio T. An update on postopera-

tive nausea and vomiting. In: Keneally

J, Jones M, eds. Australasian Anaesthesia.

Melbourne: Australian and New Zea-

land College of Anaesthetists 1996;

155–9.

Spinal opioids, midazolam andantiemesis

We read with interest the account of

the use of intravenous midazolam totreat persistent vomiting in a patientwho had received intrathecal diamor-

phine (Prasad et al. Anaesthesia 2002; 57:

415). Nausea and vomiting are recog-nised side-effects of neuraxial opioid

administration [1] and our initialthought was to suggest that the authorsmight have used intravenous naloxoneto try to treat their patient’s symptoms.

However, we were surprised to discov-er on searching the literature that intra-venous naloxone appears not to reverse

the emetic effect of opioids given viathe intrathecal route [2]. Avoidance ofneuraxial opiates in patients susceptible

to postoperative nausea and vomiting(PONV) might therefore be prudent, asthe authors suggest.

Regarding Prasad’s use of midazolamas an anti-emetic, we note that bothmidazolam and other benzodiazepineshave been reported to stop vomiting

induced by chemotherapy [3]. As far as aproposed mechanism of action is con-cerned, we postulate that the effect may

be a central sedative one, which occurseven at concentrations which do notexplicitly affect the level of conscious-

ness. This is based on the evidence



(quoted by Prasad et al.) that subhyp-notic doses of propofol prevent PONV[4], and the entirely subjective observa-tion by one of us (EM) that 25 mg of

thiopental has successfully been used tostop emesis in two of his patients whowere vomiting on arrival in theatre for

emergency appendicectomy.

S. G. Pickard

E. A. J. Morris

Southmead Hospital,

Bristol BSIO 5NB, UK

References1 Chaney MA. Side-effects of intrathecal

and epidural opioids. Canadian Journal of

Anaesthesia 1995; 42: 891–903.

2 Dailey PA, Brookshire GL, et al. The

effects of naloxone associated with the

intrathecal use of morphine in labour.

Anesthesia and Analgesia 1985; 64:

658–66.

3 Olynyk JK, Cullen SR, Leahy MF.

Midazolam: an effective anti-emetic

agent for cytotoxic chemotherapy. The

Medical Journal of Australia 1989; 150:

466.

4 Ewalenko P, Janny S, Dejonckheere M,

Aandry G, Wyns C. Antiemetic effect

of subhypnotic doses of propofol after

thyroidectomy. British Journal of Anaes-

thesia 1996; 77: 463–7.

Positioning for radial arterycannulation

I read with interest the recent corre-spondence (Coates. Anaesthesia 2002;

57: 311–12) in which is described atechnique to position the arm for radialartery cannulation by hanging a bag of

fluid onto the patient’s index finger,especially when no help is available. Iappreciated the idea and tried it on afew patients in the ITU where there is

less chance of nursing help due to theirother commitments. I admit I found itextremely helpful, but there is a prob-

lem with the technique. It can causeischemia of the finger when arterialcannulation is difficult and prolonged. It

becomes a particular problem when youwish to secure the cannula with suturesin the same extended position.

I think this technique is not as benignas it appears, especially in high-risk

patients with poor peripheral circulationand you may end up writing an incidentform and calling a vascular surgeon. Isuggest reserving the technique for

desperate situations, first checking cap-illary refill, and keeping the time of theprocedure to a minimum or give the

finger a rest if it is taking longer thanexpected.

N. Zafar

Queens Medical Centre,

Nottingham, UK

Old wine in a new bottle?

I read with interest the recent corre-spondence (Morton & Mahon. Anaes-

thesia 2002; 57: 501–2) describing a newsign in chronic aortic regurgitationwhich they named as the �facial flash-ing�. It seems that they have reported

the same peripheral sign previouslydescribed by more imaginative peers asthe �Lighthouse sign�. (As the repeated

flushing and blanching with each pulsebeat resembles the flashing of a light-house.) Aortic regurgitation is classically

described as a disease of peripheral signsand I would like to add three more tothe list of 11 signs described in theprevious correspondence. The �dancing�carotids, also called Corrigan’s sign (tobe differentiated from Corrigan’s pulse).Pistol shot sound, heard on auscultation

over the femoral arteries. Ophthalmos-copy – systolic reddening and diastolicpaling of the optic disc due to capillary

pulsation (only seen in aortic regurgita-

tion). Though interesting, they areprobably of no significance in assessingthe severity and in the management ofaortic regurgitation.

A. Ghori

Northern General Hospital,

Sheffield, UK

Foreign language drug labelling

I have read the correspondence (Wearne

G. Anaesthesia 2002; 57: 207) raisingconcerns about non-English informa-tion on drug packaging with interest and

can report that this occurs in our hospitaltoo. Italian seems to be the most popularnon-English language in use. For those

of us not too far beyond �buongiorno�and �due cappuccini prego�, our boxesare also helpfully labelled in Braille asFig. 7 demonstrates. I am unable to

determine whether this is in English orItalian, but I hope it reads �Englishinformation sheet enclosed�.

S. Grewal

Northampton General Hospital,

Northampton NN1 5BD, UK

Penicillin kills

In response to a recent letter (Barclay &

King. Anaesthesia 2002; 57: 625), apatient was recently admitted to ITUfollowing a road traffic accident in whichhe received a significant head injury and

was unconscious from the time of theincident. A tattoo on his right arm

Figure 7



showed a skull and crossbones with thewords �Penicillin Kills�. Unfortunately,his mental state did not recover fullyenough to explain whether the reference

was to his knowledge of fatal anaphylac-tic reactions or in fact his own allergy.Obviously we decided not to give any

penicillin just in case it was the latter.We are unable to provide a photo of

the tattoo as the patient is not compe-

tent to give consent for this.

P. Baumgartner

Walsgrave Hospital,

Coventry, UK


A talisman to ward off the badanaesthetics

I was interested to read the recent letter(Barclay & King. Anaesthesia 2002; 57:

625) describing recognition of a tattoomedi-alert for scoline apnoea. I wasreminded of an incident regarding an

elderly lady, whom I was asked to

anaesthetise for an urgent hemicolecto-my, as she had intestinal obstructionsecondary to a mass. I was having a busyday as the CEPOD list was growing

rapidly and my frustration was nothelped by the fact that this 82-year-oldlady was a very vague historian and I did

not seem to be able to gain any relevanthistory from her. At the end of my visitshe then told me that she had a talisman

to �ward off the bad anaesthetics� and Ileft the bed-side thinking her slightlysuperstitious and I’m embarrassed to say,

slightly mad!I then turned to the notes to try and

glean any relevant information regard-ing results and I noted in the corres-

pondence that there was a mentionof malignant hyperthermia (MH). Thepenny then dropped, although extre-

mely slowly, that she in fact possessed aMedic-Alert necklace (a �talisman to wardoff the bad anaesthetics�) warning of her

possible malignant hyperthermia. Ontalking to her GP, I learnt that two ofher male relatives had died from MH

whilst having an anaesthetic. She was arather cantankerous lady and hadrefused to receive the appropriate test-ing when offered, so was given the

Medic-Alert necklace to caution againstthe use of MH triggers.

She therefore underwent an unevent-

ful anaesthetic using the vapour freemachine and a modified rapid sequenceinduction avoiding the use of suc-

cinylcholine.Do our patients really understand

the significance of the information

that we give them? Maybe this ladybelieved that the necklace itself wasenough to prevent any dangers from�bad� anaesthetics. I would also caution

other readers to listen carefully tocomments made by seemingly vague,cantankerous historians, as careful pre-

assessment may alert to potential avoid-able disasters!

C. A. Mearns

Queen Victoria Hospital,

East Grinstead, UK



positioning for radial artery cannulation

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