moderator – prof anjan trikha presenter - priya anaesthesia.co.in@gmail.com

Anaesthetic management of patient with Maxillofacial injury

Moderator – Prof Anjan TrikhaPresenter - Priya

www.anaesthesia.co.in

anaesthesia.co.in@gmail.com

Krishna 25years/male Student Resident of Delhi

Pain and difficulty in chewing × 1 week Restriction of mouth opening ×1 week

Chief complaints :

History of present illness : H/O fall from tree one week back Following which patient developed Pain and swelling on left side of jaw Pain on opening mouth Difficulty in chewing food No H/O loss of consciousness No H/O oral, nasal or ear bleed

Past history No H/O any previous GA exposure No H/O asthma, TB,DM & any drug allergy Personal history : Non smokerTreatment history : Inter maxillary wiring was done after

traumaFamily history : Not significant

Alert, conscious &oriented No pallor, icterus, clubbing, cyanosis,

edema and lymphadenopathyVitals PR- 70 beats/min all peripheral pulses

palpable BP – 124/78mm Hg R, upper arm, supine Weight – 58 kg

General physical examination

Inter incisor gap – wiring present Length of upper incisor -<1.5 cm No buck teeth or loose teeth MMP class – could not be assessed Upper lip bite – unable to do because of

wiring Thyromental distance = 6.5 cm Sub mandibular compliance - normal

Airway examination :

Neck movements Flexion - adequate Extension - adequate Neck thickness normal No short neck Nasal patency – equally patent, no deviation

or growth seen

B/L vesicular breath sounds present No adventitial sounds

Cardiovascular system: First and second heart sound heard, no

murmur present

Respiratory system :

Higher mental functions normal No sensory and motor weakness

Abdomen : No visible swelling No organomegaly

Central nervous system :

Hb – 12gm% Platelets – 2 lakhs/mm3 TLC – 8400/mm3 Na/K – 140/4.2meq/l Urea/creatinine – 20/0.9mg/dl LFT - WNL

Investigations:

OPG X-ray – fracture in ramus of mandible left side with inter maxillary fixation (IMF) in situ

Fracture mandible left ramus with reduced mouth opening posted for open reduction and internal fixation

Provisional diagnosis

Open reduction and internal fixation of mandible fracture with plating

Surgical procedure planned

25 year old male with left mandibular fracture with interdental wiring in situ posted for open reduction and internal fixation

Summary :

Nasal intubation laryngoscopy guided after removal of wiring

Plan

Nasal intubation – its inherent risks Sharing of airway Access to airway Extubation issues PONV prophylaxis Post operative airway obstruction

Problems :

Inform about procedure & risk Written consent Premedication

aspiration prophylaxis- oral ranitidineantisialogogue – Glycopyrrolate i.m nasal decongestant – xylometazoline

drops Pre op fasting Wiring was removed on the day of surgery

Preoperative prepration

Check machine and emergency equipments Standard monitoring – ECG, NIBP, pulse

oximetry,capnography iv access secured – extension tubing Nasal prepration with xylometazoline drops Softening of nasal tube Preoxygenation for three minutes

Ot prepration

Sniffing position Induction – fent 2mcg/kg, propofol 2-3mg/kg Mask ventilation assessed ->Vecuronium –

0.1mg/kg Lubricated 7.5 size nasal RAE tube

introduced through rt nostril Tube guided into glottis under laryngoscopy Equal air entry confirmed

Eye padding, oral packing done Positioning for surgery Maintainence – oxygen, air and isoflurane,

vecuronium, fentanyl Antiemetics – dexamethasone and

ondensetron Monitor airway pressure

Reversal – neostigmine and glycopyrrolate Removal of pack and thorough suctioning Extubation – fully awake, adequate tidal

volume, following commands Postoperative- Oxygen by face mask Pulse oximetry Beware of vomiting aspiration

RAE (nasal) tube, naso pharyngeal airways, warm saline, magill forceps & LA jelly

Fibreoptic bronchoscopy, suction apparatus Lidocaine preprations- 2% viscous,2%

injectable solution,10 or 15% spray,4% topical solution

Eye pads, throat pack, small pillows & rolls

Intravenous accesses secured

Specific equipments & tools

Fibreoptic guided intubation after i.v induction,paralysis & IPPV awake with sedation Blind nasal intubation- awake post induction and paralysis Light wand guided Retrograde intubation tracheostomy

Airway management choices

A clinical situation in which a conventionally trained anaesthesiologist experiences difficulty with mask ventilation, difficulty with tracheal intubation or both

Difficult airway:

It is not possible for unassisted anaesthesiologist to maintain the SpO2 > 90% using 100% O2 and positive pressure mask ventilation in a patient whose SpO2 was > 90% before

or It is not possible for the unassisted

anaesthesiologist to prevent or reverse signs of inadequate ventilation during mask ventilation

Difficult mask ventilation

Difficult laryngoscopy It is not possibe to see any portion of the

vocal cords after multiple attempts at conventional laryngoscopy

Difficult tracheal intubation A clinical situation in which intubation

requires more than three attempts or ten minutes using conventional laryngoscopic techniques

Performance by a reasonably experienced laryngoscopist

The use of the optimal sniffing position The use of OELM One change in length/type of blade

Optimal laryngoscopy attempt

History Specific tests for assessment

◦ Difficult mask ventilation

◦ Difficult laryngoscopy

◦ Difficult surgical airway access

Radiologic / photographic assessment

Assessment

Congenital difficult airways

Acquired◦ Rheumatoid arthritis, Acromegaly, tumors of tongue,

larynx

Iatrogenic◦ radiotherapy, Laryngeal/tracheal/TMJ surgery

Reported previous anaesthetic problems◦ Database

History

Inter-incisor gap : >3cm Buck teeth + Length of incisor: <1.5cm Upper lip Bite MMP class Palate: arching / narrowing TMD: >6cm Mandibular compliance Neck length: sufficient Neck diameter: thin or thick Neck movement

11 point scoring

Mouth opening

Evaluation of tongue size relative to pharynx

Mandibular space

Mobility of the joints

◦ TMJ

◦ Neck mobility

Specific Tests

With maximal mouth opening Acceptable value > 4 cm Positive results: Easy insertion of a 3

cm deep flange of the laryngoscope blade

< 3 cm: difficult laryngoscopy < 2 cm: difficult LMA insertion Affected by TMJ and upper cervical

spine mobility

Inter-incisor Gap

Samsoon-Young’s modification of Mallampati Test

Patient in sitting position Maximal mouth opening in neutral position Maximal tongue protrusion without arching No phonation

Evaluation of tongue size relative to pharynx

Class III or IV: signifies that the angle between the base of tongue and laryngeal inlet is more acute and not conducive for easy laryngoscopy

Limitations◦ Poor interobserver reliability◦ Limited accuracy

73%

19%8%

Correlation between MMP score and laryngoscopy grade

MMP class

Cormack and Lehane grade

Grade 1 Grade 2 Grade 3 Grade 4

Class I (73%) 59% 14% - -

Class II (19%) 5.7% 6.7% 4.7% 1.9%

Class III & IV (8%)

- 0.5% 5% 2.5%

Airway Management, Jonathan Benumof

Thyromental distance (Patil test) Distance from the tip of thyroid cartilage to

the tip of mandible Neck fully extended Minimal acceptable value – 6.5 cmSignificance Negative result – the larynx is reasonably

anterior to the base of tongue Very low sensitivity-20%

Mandibular space

Modification to improve the accuracy Ratio of height to thyromental distance

(RHTMD) Useful bedside screening test RHTMD < 25 or 23.5 – very sensitive

predictor of difficult laryngoscopy

Sternomental Distance (Savva Test) >12.5cm

Patient is asked to hold the head erect, facing directly to the front maximal head extension angle traversed by the occlusal surface of upper teeth

Grade I : > 35° Grade II : 22-34° Grade III : 12-21° Grade IV : < 12°

Evaluation of Neck Mobility

Placing one finger on the patient’s chin One finger on the occipital protuberance

Result Finger on chin higher than one on occiput

normal cervical spine mobility Level fingers moderate limitation Finger on the chin lower than the second

severe limitation

Angle traversed by the vertex or forehead > 90° from max flexion to max extension is a specific +ve test for atlanto-occipital joint.

Class A: able to protrude the lower incisors anterior to the upper incisors

Class B: lower incisors just reach the margin of upper incisors

Class C: lower incisors cannot reach the margin of upper incisors

Significance Class B and C: difficult laryngoscopy

Mandibular Protrusion Test

Class I: Lower incisors can bite the upper lip above vermilion line

Class II: can bite the upper lip below vermilion line Class III: can not bite the upper lip

Upper Lip Bite Test

Less inter-observer variability

Age > 55 years

BMI > 26 kg/m2

History of snoring

Beard

Edentulous

Predictors of Difficult Mask Ventilation

Difficult LMA Insertion Mouth opening < 2 cm Intraoral/pharyngeal masses (e.g. lingual tonsils)

Difficult Direct Tracheal Access Gross obesity Goitre Deviated trachea Previous radiotherapy Surgical collar

Diagnostic test

•MMP•TMD•Sternomental distance•Mouth opening•Wilson score•MMP+TMD

Sensitivity

•49%•20%•62%•22%•46%•56%

Specificity

•86%•94%•82%•97%•89%•97%

Statistical Significance

Wilson Score 5 factors

◦ Weight, upper cervical spine mobility, jaw movement, receding mandible, buck teeth

Each factor: score 0-2 Total score > 2 predicts 75% of difficult

intubations

Combination of predictors

Difficult mask ventilation Mask fit Obesity Age No teeth Snoar

Quick look back

Difficult laryngoscopy Look Evaluate…3.3.2 Mallampati Obstruction Neck movement

L - Look externally (facial trauma, large incisors,

beard, large tongue)E - Evaluate 3-3-2 rule

3 - inter incisor gap3 - hyomental distance2 - hyoid to thyroid distance

M - MMP scoreO- Obstruction (epiglottitis, quinsy)N- Neck mobility

Ron and Walls’ Emergency Airway Management

“LEMON” Assessment

Difficult EGD insertion Restricted mouth opening Obstruction of upper airway Disrupted/distorted anatomy Stiff lungs/cervical spine

Difficult cricothyrotomy Surgery Hematoma Obese Radiation / burn Tumor

Awake intubation

Why awake?

Patent airway Spontaneous breath Larynx-No anterior displacement Aspiration-protection Neck movement-minimal Neurological monitoring

Who needs?

H/o difficult intubation & Predicted difficult airway

May be considered in the following situations (usually with a coexisting difficult airway):

High risk of aspiration Hemodynamically very unstable Respiratory failure

Where not to?

Patient refusal Uncooperative 1.child 2. mentally retarded 3. intoxicated 4. combative Allergic to all LA

What to inform?

Need for alternative intubation Difficult, time consuming but safer Slightly uncomfortable but pain-free Injections required for better tolerance Recall ± LA complications rarely Experienced physician-extra safety measures Pt may opt for conventional - last resort

Do you premedicate?

BZD…Midazolam 20-40mcg/kg i.v bolus Opioid…fentanyl 0.5-2.0mcg/kg i.v bolus remifentanil 0.05-0.5mcg/kg/min Ketamine…0.2-0.5mg/kg i.v Propofol…0.25mg/kg i.v bolus 50-100mcg/kg/min infusion Dexmedetomidine…1mcg/kg i.v followed by 0.2-0.7mcg/kg/hr Inhalations…Sevo / Des …pediatric DA

Anti-anxiety : Options

Adequate fasting H2 blocker Metoclopramide Sodium citrate

Anti-sialogogue

Atropine 10-20mcg/kg i.v or i.m Glycopyrollate 5-10mcg/kg i.v or i.m Scopolamine 0.3-0.6mg i.v or i.m or s.c

Aspiration prophylaxis

0.025% to 0.05% oxymetazoline nasal drops in each nostril; once before shifting from ward & once in holding area.

4% cocaine + 2% lidocaine + 1% phenylephrine

Mucosal vasoconstictors

Any preparation?

Staff to assist Monitors : ECG, BP, EtCO2, SpO2 Supplemental oxygen Airway equipments-Difficult airway cart Surgeon ready for tracheostomy 1. Pt in extremes 2. Airway catastrophy

Airway Anesthesia:

What are the options?

Flexible fibrescope guided Blind nasotracheal Rigid fibrescope guided Trachlight / light wand guided ILMA guided Other SGA guided Retrograde intubation Direct laryngoscopy

Supine sniffing position

Guided by breath sound or capnography

Lubricated tube Patent nare Gently advance

Blind nasotracheal intubation

Five response positions: •Position T (Trachea): Goal position! Breath sound +; tube advances, patient coughs

•Position A (Anterior): breath sounds+; the tube stops , and the patient coughs

•Response A:withdrawal and re-advance; neck gradually flexed

•Position L or R (Left or Right pyriform sinus): breath sounds STOP, unable to advance tube, NO coughing; tube may be palpable on one side of the neck.

•Response L or R: slight withdrawal till breath sounds resume; slow rotation of head to opposite side and re-advance.

Position E (Esophagus): Breath sounds STOP, tube advances, NO coughing.

Response E: withdrawing until breath sounds resume and then :1. Extend patient's head and re-advance.

2. Largely inflate cuff, advance tube until resistance is felt, maintain some advancing pressure on tube while cuff is slowly deflated.

3. Apply posterior pressure on the larynx and re-advance tube.

4. Leave one ETT inside esophagus to block it and insert another ETT to intubate the trachea.

Beck Airway Airflow Monitor(BAAM)-(Tracheal Whistle) disposable device that magnifies the patients respirations with a whistle sound.

Bougie guided blind intubation NG tube guided blind intubation

Assisted methods

Explicit descriptions of DA◦ Difficult face mask ventilation◦ Difficult laryngoscopy◦ Difficult tracheal intubation◦ Failed intubation

Purpose- facilitate mx. of DA, ↓adverse outcomes

Focus on anaesthesia care All locations, all ages

ASA task force on management of DA (Anesthesiology May 03;98)

Basic preparation◦ Inform◦ Ascertain help◦ Preoxygenation◦Supplemental

oxygenation throughout

Portable storage unit Rigid laryngoscope

blades ETTs ETT guides LMAs FFOI equips RI Em NI a/w vent Em invasive a/w Exhaled CO2 detector

ASA task force on management of DA

Strategy depending on◦ Anticipated surgery◦ Patient condition◦ Skill & preference of anaesthesiologist

4 basic problems 3 basic management choices Primary approach Alternative approach Exhaled CO2 to confirm tracheal

intubation

ASA task force on management of DA

LMA in ASA DA algorithm

Strategy for extubation of DA◦ Awake?◦ Adverse impacts on ventilation◦ Further A/w management plan◦ Guide for reintubation

Follow up

ASA task force on management of DA

Open ended, wide choice of techniques Emphasis on prediction of difficult airway No stratification of available a/w devices No expression of strength of

recommendation

Limitations of ASA guidelines

Management of un-anticipated difficult intubation in an adult non-obstetric patient

Paediatric, obstetric patients & patients with upper a/w obstruction excluded

Flow charts based on series of plans Careful planning with backup plans Maintenance of oxygenation takes priority Seek the best assistance available

DAS guidelines(Anaesthesia.2004.59)

• Complete explanation of the reason for performing the airway nerve blocks, is essential

• Consider (a) an alternative plan, i.e the direct spray of LA or

spray with a nebulizer (b) the time available (c) the patient's condition

• Use of appropriate sedation to maintain patient comfort

• These techniques should be practiced in nonemergency situations so that when their success is required for a difficult intubation they can be performed appropriately

Points to be considered prior to the performance of airway blocks

Topical ◦ Spray◦ Jel◦ Injection◦ nebulization

Nerve blocksindividual multiple

Airway anaesthesia

Available Lidocaine Preparations

Preparation Dose

Injectable/topical solution 1% , 2%,4%

Viscous solution 1%, 2%

Ointment 2%,5%

Aerosol 10%

• Amount of LA absorbed varies• Systemic absorption of topically applied lidocaine is

limited• 5 mcg/ ml , toxic limit of blood lidocaine• Chinn and colleagues found plasma lidocaine levels of

0.44 μg/mL after inhalation of 400 mg of nebulized lidocaine

• Baughman and associates found that patients breathing 4 mg/kg aerosolized lidocaine developed plasma levels of less than 0.5 μg/mL

• Oral lidocaine produced even lower plasma levels

because much of the dose is swallowed & subjected to first-pass metabolism by the liver

• Swallowed lidocaine in the setting of topical airway anesthesia can cause nausea and vomiting

Systemic Absorption and Toxicity

• Lidocaine applied directly to the trachea and bronchi results in higher plasma levels

• Viegas and Stoelting found plasma levels of 1.7 μg/mL 9 minutes after tracheal installation of 2 mg/kg lidocaine

• Sutherland and Williams in their study found that despite a total dose of lidocaine (5.3 ± 2.1 mg/kg), the mean peak arterial plasma lidocaine concentration was low (0.6 ± 2.1 μg/mL)

• Gargling of large volumes (0.3 mL/kg) of 2% lidocaine may be associated with peak lidocaine concentrations approaching a potentially toxic level

Systemic Absorption and Toxicity

Total dose of lidocaine should be limited to 8.2 mg/kg in adult pts

Take extra care in elderly & pts with liver, cardiac impairment

Minimum amount of lidocaine necessary should be used when installed through FOB

Thorax 2001;56 (suppl 1)

British Thoracic society guidelines on FOB

Predominant nerve supply of airway

Anterior ethmoidal nerve Anterior 2/3 of nasal septumLateral wall of nose

Sphenopalatine N Posteroir 1/3 of septumFloor of nose

Glossopharyngeal N Posterior 1/3 of tonguePosterior & lateral pharyngeal wallAnteror surface of epiglottis

Internal br of superior laryngeal N Larynx includ. Vocal cords

Recurrent laryngeal N Below the level of vocal cordstrahea

Sensory innervations of airway

Plethora of sensory fibers Multiple origins Topical application – the best and safe Nerve blocks

Sphenopalatine NAnterior ethmoidal N

Nasal cavity and nasopharynx

Method of packing nasal cavity

Atomizer

Sphenopalatine & Ant Ethmoidal N block

Vagus, facial, glossopharyngeal N Topical anaesthesia sufficient in majority Gag reflex difficult to suppress by topical

alone

Oropharynx

Deep ,sub mucosal pressure receptors Postrerior 1/3 of tongue Gag happens more on oral intubation Glossopharyngeal nerve (GPN) – the

afferent arc

Gag reflex

Glossopharyngeal nerve block

GPN block

GPN block

The use of a tongue blade facilitated by application of a topical LA to mouth

If air is aspirated, needle needs to be withdrawn

If blood is aspirated, it is arterial (carotid artery), the needle is too posterior and too lateral. It needs to be redirected medially

Clinical Tips

Topical spray Atomiser Spray as you go Transcricoid injection

Nebulized lidocaine Superior laryngeal nerve block

Anesthesia of Larynx

Innervations of Larynx

External approach ◦ Cornu of hyoid◦ Cornu of thyriod◦ Thyroid notchInternal approach

piriform fossa

SLN block

SLN block – Hyoid landmark

Superior laryngeal nerve block- thyroid cornu as landmark

• Caution not to insert the needle into the thyroid cartilage, injection of LA into vocal cords cause edema

• If air is aspirated, the needie pierced laryngeal mucosa & to be retrieved

• If blood is aspirated (superior laryngeal artery or vein), needle to be redirected more anteriorly

• For evaluation of vocal cord movement, only the internal laryngeal nerve needs to be blocked

• For awake intubation, SLN and RLN need to be blocked

Clinical tips

SLN block – piriform fossa

SLN block – Piriform fossa

Translaryngeal injection Spray as you go Labat’s technique

Trachea and vocal cords

Cricothyroid membrane

Technique of transcricoid injection

Transcricoid injection

• Pt needs to be informed that the injection of LA solution make him or her cough

• Contraindicated in patients with unstable neck

• During the block, pt should not talk, swallow, or cough

• Catheter left in place until the intubation is completed for injecting more LA if necessary& to decrease the likelihood of subcutaneous emphysema

Clinical tips

Non invasive Useful in pts at risk of aspiration Injecting LA through suction port of FOB Wait 30- 60 sec before advancing to deeper

structure and repeat the maneuver Two methods

oxygen spray techniqueCatheter technique

“Spray as you go”

Attach three-way stopcock to suction port Connect oxygen tubing with flow@2-4 l /min Through other port of 3 way inject LA Advantages

high Fio2 deliveryclean lensdisperse mucous awayaids innabulizing LA

Oxygen spray technique

Pass a angiographic or epidural catheter into suction port of FOB

Till it project 5 mm beyond FOB lens Inject LA through proximal connection Allows accurate placement of LA

Catheter technique

Safe, non invasive technique Useful in pts with unstable neck, ↑IOP &ICP Needs pt’s cooperation 5ml of 4% lidocaine @oxygen flow of

6L/min, ultrosonic nebulizer over 10- 15 min period

O2 flow < 6L/min yields droplet size of 30- 60 microns

Nebulizing LA

Le fort classification

Sub mental intubation

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