ARTICLE IN PRESS+ModelBJANE-82; No. of Pages 5

Rev Bras Anestesiol. 2013;xxx(xx):xxx---xxx

REVISTABRASILEIRA DEANESTESIOLOGIA Official Publication of the Brazilian Society of Anesthesiology

www.sba.com.br

SCIENTIFIC ARTICLE

Comparison of the effects of remifentanil and remifentanil pluslidocaine on intubation conditions in intellectually disabledpatients�

Can Eyigor, Esra Cagiran ∗, Taner Balcioglu, Meltem Uyar

Department of Anaesthesiology, Faculty of Medicine, Ege University, Izmir, Turkey

Received 1 March 2012; accepted 22 March 2013

KEYWORDSRemifentanil;Lidocaine;Endotrachealintubation;Withoutneuromuscularblockade

AbstractBackground and objectives: This is a prospective, randomized, single-blind study. We aimed tocompare the tracheal intubation conditions and hemodynamic responses either remifentanilor a combination of remifentanil and lidocaine with sevoflurane induction in the absence ofneuromuscular blocking agents.Methods: Fifty intellectually disabled, American Society of Anesthesiologists I---II patients whounderwent tooth extraction under outpatient general anesthesia were included in this study.Patients were randomized to receive either 2 �g kg−1 remifentanil (Group 1, n = 25) or a combi-nation of 2 �g kg−1 remifentanil and 1 mg kg−1 lidocaine (Group 2, n = 25). To evaluate intubationconditions, Helbo-Hansen scoring system was used. In patients who scored 2 points or less inall scorings, intubation conditions were considered acceptable, however if any of the scoreswas greater than 2, intubation conditions were regarded unacceptable. Mean arterial pressure,heart rate and peripheral oxygen saturation (SpO2) were recorded at baseline, after opioidadministration, before intubation, and at 1, 3, and 5 min after intubation.Results: Acceptable intubation parameters were achieved in 24 patients in Group 1 (96%) andin 23 patients in Group 2 (92%). In intra-group comparisons, the heart rate and mean arterialpressure values at all-time points in both groups showed a significant decrease compared tobaseline values (p = 0.000)Conclusion: By the addition of 2 �g/kg remifentanil during sevoflurane induction, successfultracheal intubation can be accomplished without using muscle relaxants in intellectually dis-abled patients who undergo outpatient dental extraction. Also worth noting, the addition of1 mg/kg lidocaine to 2 �g/kg remifentanil does not provide any additional improvement in the

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intubation parameters.© 2013 Sociedade Brasileira dereserved.

� The study was conducted in Department of Anaesthesiology, Ege Univ∗ Corresponding author.

E-mail: esrayuksel73@yahoo.com (E. Cagiran).

0104-0014/$ – see front matter © 2013 Sociedade Brasileira de Anestesiohttp://dx.doi.org/10.1016/j.bjane.2013.03.006

parison of the effects of remifentanil and remifen-tually disabled patients. Rev Bras Anestesiol. 2013.

Anestesiologia. Published by Elsevier Editora Ltda. All rights

ersity Faculty of Medicine.

logia. Published by Elsevier Editora Ltda. All rights reserved.

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2 C. Eyigor et al.

Table 1 Intubating condition scoresa

1 2 3 4

Jaw relaxation Complete Slight tone Stiff RigidLaryngoscopy Easy Fair Difficult ImpossibleVocal cords Open Moving Closing ClosedCoughing None Slight Moderate SevereLimb movement None Slight Moderate Severe

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ntroduction

racheal intubation is usually facilitated with a muscle relax-nt that is administered following anesthesia induction.uring intubation, anesthesia should be deep enough to

nhibit the reflex activity and complete muscle relaxationhould be accomplished.1 The use of hypnotics and opioidst induction doses can be sufficient for tracheal intubationithout the need for muscle relaxants, where use of a mus-le relaxant is not preferred as is the case for day surgeryatients, short surgical procedures, motor neuron diseasend drug allergy.2,3

Tracheal intubation without muscle relaxants may be aife-saving measure to maintain spontaneous respiration inatients with difficult airways. According to the previousedical literature, intubation can be carried out without

he use of a muscle relaxant.4---6Sevoflurane, a nonirritatingnhalational anesthetic agent with low blood/gas solubility,as also been used for intubation without neuromuscu-ar blocking agents, either alone or in combination withemifentanil.7,8

In addition, one may improve tracheal intubating con-itions through the use of additional drugs, such asemifentanil and lidocaine, which may potentiate depres-ion of the laryngeal reflexes.4,9

The aim of the present study was to compare theffects of remifentanil and remifentanil plus lidocaine usingevoflurane induction without muscle relaxants on trachealntubating conditions in intellectually disabled patientsdmitted for outpatient dental treatment.

aterials and methods

he present study was designed as a prospective, random-zed, and single-blind study. The study was approved byhe ethics committee, and written informed consents werebtained from the parents and guardians of the patients.

Fifty intellectually disabled American Society of Anes-hesiologists (ASA) I and II patients, who were scheduled forental surgery requiring general anesthesia, were includedn the study. Patients with ASA physical status III or higher,n expectance of difficult intubation, limited head andeck movement, reactive airway disease, gastroesophagealeflux, renal or hepatic impairment, allergies to any of

Please cite this article in press as: Eyigor C, et al. Comtanil plus lidocaine on intubation conditions in intellechttp://dx.doi.org/10.1016/j.bjane.2013.03.006

he study drugs were excluded from the study. Mallampatilassification10 of airway anatomy higher than class II, mouthpening <3 cm, sternomental distance <12.5 cm, tiromentalistance <6 cm, Cormack---Lehane classification11 higher than

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rade II, and body mass index ≥3012 were considered as thendicators of difficult intubation.

Standard intraoperative monitoring included electrocar-iography, pulse oximetry, respiratory rate and noninvasivelood pressure measurements (Datex-Ohmeda, Helsinki,inland). Capnography, and inspired and end-tidal partialressures of sevoflurane and O2 were also monitored. A faceask with a semi-closed anesthetic circuit was primed with

% sevoflurane in 100% O2. Then, anesthesia was inducedsing this mask for 2 min, where a fresh flow of gas at

L min−1 was supplied to the circuit. Once an adequate levelf anesthesia was achieved, an intravenous (IV) line wasstablished and 0.01 mg kg−1 atropine was given. After base-ine measurements, the patients were randomly allocatedo one of two groups on the basis of a computer-generatedandom table. Patients in Group 1 (n = 25) received 2 �g kg−1

emifentanil + 5 mL saline whereas Group 2 (n = 25) received �g kg−1 remifentanil + 1 mg kg−1 lidocaine. Tracheal intu-ation was performed 90 s after remifentanil administrationy a single, experienced anesthesiologist. Intubation waserformed and assessed by an anesthesiologist who waslinded to the remifentanil dose used.

The quality of intubation was graded by an independentnesthesiologist using the scoring system devised by Helbo-ansen Raulo and Trap-Andersen13 (Table 1).

Ease of laryngoscopy Position of vocal cords Degree of coughing Jaw relaxation Limb movement

Intubating conditions were deemed acceptable if aatient had ≤2 points in all categories or unacceptable ifhe patient had >2 points in any single category.

Mean arterial pressure (MAP), heart rate (HR) anderipheral oxygen saturation (SpO2) were recorded at base-ine, after opioid administration, before intubation, andt 1, 3, and 5 min following intubation. Side effects asso-iated with remifentanil use including muscle rigidity,ypotension, bradycardia and arterial oxygen desatura-

parison of the effects of remifentanil and remifen-tually disabled patients. Rev Bras Anestesiol. 2013.

ion below 91% were recorded and treated accordingly.ypotension (MAP < 25% from baseline) was managed with---10 mg ephedrine IV and bradycardia (HR < 50 beat/min)as treated with 0.5 mg atropine.

ARTICLE IN+ModelBJANE-82; No. of Pages 5

Tracheal intubation without muscle relaxants

Table 2 Patient characteristics.

Group 1a Group 2a

Age (years) 17.88 ± 7.1 21.20 ± 7.1Weight (kg) 50.44 ± 18.1 58.76 ± 12.5

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Gender (M/F) 13/12 11/14a Values are presented as mean ± SD.

Statistical analysis

Statistical analysis was performed with the StatisticalPackage for the Social Sciences (SPSS) for Windows (version13.0; SPSS Inc., Chicago, IL, USA). Descriptive statistics wereexpressed as mean. Variables with normal distribution wereanalyzed using the Student’s t-test while non-normally dis-tributed variables were analyzed using the Mann---Whitneyrank sum test. Categorical data were analyzed using theFisher’s exact test. Hemodynamic responses were analyzedusing the repeated measures analysis of variance (ANOVA).A value p < 0.05 was considered statistically significant.

Results

Each group contained 25 patients. Demographic variableswere similar in both groups (p > 0.05) (Table 2).

According to the Helbo-Hansen scoring system, there wasno significant difference between the groups in terms of jawrelaxation (p = 0.57), ease of laryngoscope (p = 0.31), vocalcord position (p = 0.09), degree of coughing (p = 0.14) andlimb movement (p = 0.42). One patient in Group 1 scored 3points for jaw relaxation. One patient in Group 2 scored 4points for jaw relaxation and 3 points for the position ofvocal cords, while another patient scored 3 points for vocalcord position.

Intubation was successful in all patients, and no furtherintervention was necessary. According to the Helbo-Hansenscoring system, acceptable intubating conditions were

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achieved in 24 patients in Group 1 (96%) and 23 patientsin Group 2 (92%) (Fig. 1).

The mean basal HR was 107.84 ± 19.2/min in Group 1 and100.72 ± 16.2/min in Group 2, and there was no significant

25

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Unacceptable Acceptable

Figure 1 Overall intubating conditions of two groups.

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ifference between the groups (p = 0.16). The MAP at base-ine was significantly lower in Group 2 than that in Group

(p = 0.002). In intra-group comparisons, the HR and MAPalues at all-time points in both groups showed a significantecrease compared to baseline values (p = 0.000).

Cardiovascular responses to induction and intubation arehown in Figs. 2 and 3.

No patient had clinically significant bradycardia,ypotension, rigidity or hypoxemia. However, 1 patient inroup 2 developed laryngeal spasm for a short time.

iscussion

n the present study, we found that, when used withevoflurane, both remifentanil and remifentanil lidocaineombination secured acceptable intubating conditions inentally retarded patients undergoing outpatient dental

reatment when muscle relaxants were not used during intu-ation.

The risk of an unexpectedly difficult intubation is con-iderably higher in mentally retarded patients due tonadequate airway examination before anesthesia and theresence of possible anatomical deformities.14 Machotta andoeve15 successfully performed intubation without muscleelaxants using sevoflurane and remifentanil in mentallyetarded children with Marshall---Smith syndrome. Similarly,akazawa and coworkers16 presented an 11-year-old patientith Down’s syndrome to whom they successfully per-

ormed tracheal intubation without using a muscle relaxantespite the risk of a difficult intubation estimated duringre-anesthesia examination. In the present study, we didot encounter difficult intubating conditions in any of ourentally retarded cases and all patients were successfully

ntubated.The improvement in intubating conditions, in case of

emifentanil use in combination with sevoflurane inductionithout neuromuscular blocking drugs, may be due to thenalgesic effects of these drugs.4,6 Cros et al.17 suggestedhat opioids might block afferent nerve impulses resultingrom stimulation of the pharynx, larynx and trachea dur-ng intubation and cuff inflation. In a study by Joo et al.,7

he authors reported good to optimal conditions for trachealntubation in 89% and 100% of their patients when 1 �g kg−1

nd 2 �g kg−1 remifentanil, respectively, was used. In theirtudy, where Weber et al.18 used 1 �g kg−1 of remifentanilith 4% end-tidal sevoflurane concentration, all of the chil-ren included in the study had acceptable (excellent orood) intubating conditions. Woods et al.19,20 achieved goodr ideal intubating conditions in 80---90% of the patients with

�g kg−1 of remifentanil. In agreement with the literature,e achieved acceptable (excellent or good) intubating con-itions in 96% of the patients in Group 1 and in 92% of theatients in Group 2, when we used 2 �g kg−1 of remifentanilith 4% sevoflurane without a muscle relaxant for intuba-

ion. Intubation was completed successfully in all patientsithout the need for any other intervention.

The use of remifentanil for tracheal intubation without

parison of the effects of remifentanil and remifen-tually disabled patients. Rev Bras Anestesiol. 2013.

uscle relaxants, has been reported to cause hypotension,n many studies.16,21 Batra et al.21 observed hypotensionith 2 �g kg−1 and 3 �g kg−1 of remifentanil administra-

ion. Similar results were reported by Joo et al.7 with

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4 C. Eyigor et al.

140

120

100

80

60

40

20

0Baseline Following

opiateadministration

Beforeintubation

1 min followingintubation

Group 1

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* * * * **

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Group 2

3 min followingintubation

5 min followingintubation

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igure 2 Mean (SD) changes in heart rate (HR), observations: min following intubation. *p = 0.000 compared with baseline v

�g kg−1 of remifentanil. However, in both studies lowlood pressure values were within the clinically acceptableange and did not require treatment. In the present study,n agreement with the literature, hypotension developedfter 2 �g kg−1 of remifentanil, but blood pressure measure-ents were within clinically acceptable limits and none of

he patients needed treatment. Lidocaine is known to benvolved in the suppression of airway reflexes. While numer-

Please cite this article in press as: Eyigor C, et al. Comtanil plus lidocaine on intubation conditions in intellechttp://dx.doi.org/10.1016/j.bjane.2013.03.006

us studies reported improvement in intubating conditionsith lidocaine,9,22,23 there are also studies with conflicting

esults.24,25 Munholland and colleagues 24 designed a double-lind study to compare the intubating conditions with

erew

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80

60

40

30

20

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opiateadministration

Beforeintubation

Group 1

*+* *

*

50

90

70

igure 3 Mean (SD) changes in mean arterial pressure (MAP), obntubation; 1, 3, 5 min following intubation. *p = 0.000 significant diffroups.

line; following opiate administration; before intubation; 1, 3,

.5 mg kg−1 of propofol or a similar volume of isotonic salinefter intravenous lignocaine pretreatment, and found noignificant difference between the groups. Similar findingsere observed in a study by Grange et al.25 who also foundo significant difference between the effects of lignocainend alfentanil pre-treatment on orotracheal intubation con-itions following induction with propofol, but without these of muscle relaxants. Several studies also examined the

parison of the effects of remifentanil and remifen-tually disabled patients. Rev Bras Anestesiol. 2013.

ffectiveness of intravenous lidocaine to suppress the cougheflex.26,27 In our study, lidocaine offered no additional ben-fit on cough reflex. In our study, lidocaine, when givenith remifentanil, did not improve the tracheal intubating

1 min followingintubation

* ** * * *

Group 2

3 min followingintubation

5 min followingintubation

servations: baseline; following opiate administration; beforeerences from baseline. +p < 0.05 significant difference between

IN+Model

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ARTICLEBJANE-82; No. of Pages 5

Tracheal intubation without muscle relaxants

conditions when a muscle relaxant was not used. Most plau-sible explanation of the failure of lidocaine to improve theintubating conditions may be the fact that acceptable intu-bating conditions were achieved in as high as 96% of thepatients, even when only remifentanil was used.

In conclusion, we found that both remifentanil andremifentanil + lidocaine under sevoflurane induction pro-vided acceptable intubating conditions in mentally retardedpatients who had outpatient dental extraction when a mus-cle relaxant was not used during intubation. In our facultyof dentistry, the rate of mentally retarded patients is lessthan that of the general population. Thus, the number ofpatients was limited in the present study. The present studymay constitute an example of the design of further studieswith higher patient numbers.

Conflicts of interest

The authors declare no conflicts of interest.

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