Not every ones ball game – they are different

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The Pediatric Airway:

Challenges and Solutions

Prof S Moied Ahmed

PhD, MD, FICCM, FCCP, MNAMS

Chairman Editor CJISA

Dept. of Anaesthesiology & Critical Care JN Medical College

AMU, Aligarh

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Not every ones ball game – they are different

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• The ASA closed claims analysis and

• Pediatric Perioperative Cardiac Arrest (POCA) registry show that pediatric cardiac arrest and brain death are the mainly due airway problems,

• Laryngospasm has been the most common cause of respiratory-related arrests

Cardiac Arrests

Age 5

10 15 20 25 30 35 40

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• Problems are more common occur with non-paediatric anaesthesiologist,

• 5 times more common in Anaesthesiologists who perform less than 100

pediatric cases per year as compared to 200 cases per year.

(Auroy Y, Ecoffey C, Messiah A, et al.Anesth Analg. 1997;84(1):234-235)

• A review on 4,000 infants less than 12 months of age found that one of the

four main risk factors for bradycardia was actually whether there was a non-

pediatric versus pediatric anesthesiologist

(Keenan RL, Shapiro JH, Kane FR, et al. Anesthesiology. 1994;80(5):976-982.)

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• Major airway complications in almost 115,000 patients

• Children comprised a small proportion of the total population, only 7-8%

• Poor AIRWAY ASSESSMENT

• Poor PLANNING

• Failure to HAVE BACKUP PLAN (Key Finding)

• In Difficult intubation MULTIPLE REAPETED ATTEMPTS (Key finding)

• Failure to use devices when required like SUPRAGLOTTICS, FIBREOPTICS etc

• Lack of MONITORING (oxygen saturation and capnography)

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Incidence

• Unexpected difficult bag-mask ventilation is almost 7% (Valois-Gomez T, et al.

Paediatr Anaesth 2013;23:920-6.

• The incidence of impossible mask ventilation is reported as 0.15%

• Difficult DL ranges from 0.06% to 3% (Heinrich et al. Paediatr Anaesth 2012;22:729-36)

• Unanticipated difficult intubation was 0.03%,

• The most important constant threat is irreversible hypoxic damage which occurs more quickly in children if there is an airway problem

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Challenges - Assessment (BMV, DL, DI, E-Crico)

• There is no validated scoring system in infants and young children,

• The anaesthetist must still make a risk assessment

• Consider as many predictors for assessment

• COPUR

• Age <1 year, cardiac surgery, ASA status III and IV, Mallampati III or IV, and low body mass index

• Short thyromental distance or micrognathia - an independent risk factor

• Narrow inter-incisor distance and mandibular hypoplasia

• Bilateral Microtia associated with 42% DI

• Craniofacial syndromes are the most common reason for difficult airways in the paediatric population.

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Assessment for Risk factors

• The PeDI registry study found four independent risk factors associated with the risk of complications

(Lancet Respir Med 2016;4:37-48)

• Weight less than 10 kg

• Micrognathia (mandibular hypoplasia)

• Greater than two tracheal intubation attempts

• Three DL attempts before an indirect technique

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Strategy - Assessment

• Plan according to the difficulty assessed

• Know your limitations

• Your expertise

• The predicted risk of your patient

• Availability of Equipment

• Don’t hesitate to refer to high volume paediatric centres

• Though unanticipated DA is rare but keep DA cart ready at hand

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• Immature nervous system

• Bradycardia induced

• Lower TV

• Decrease oxygen reserve

• Decreased FRC (75% less O2 tank)

• Higher dead space

• Increase oxygen consumption

• Increase CO2 production

• They Compensate with:

• Increase heart rate

• Increase Respiratory rate

• So apnoea would rapidly lead to hypoxia

Challenge – Oxygenation

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Strategy – Pre-oxygenation

• Consider various methods of passive oxygenation

• Preoxygenate / Peri-oxygenation with 100% oxygen before induction of anaesthesia

• Establish a reservoir of oxygen in the lungs by displacing nitrogen

• Nasal oxygen to be administered with nasal prongs/catheter during attempts at laryngoscopy and intubation for apnoea ventilation.

• The flow rate of oxygen should be adjusted targeting oxygen saturation more than 95%.

• Studies have shown that THRIVE delays hypoxia who are apneic.

• All these techniques are done to delay hypoxia and prolong the apnoea time

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Challenges – Obstruction / Positioning

• Prone to develop Airway obstruction

• Large head, Rounded occiput,

• Large tongue, and

• Larynx anterior & high C2-3

• Funnel Shaped Larynx

• Soft Larynx and Trachea

• Narrowest at cricoid

• Adenoids

• Kissing tonsils

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Strategy - Positioning

A. CRITERIA:

• 1. Align the Glabella horizontally with the Chin

• 2. Open the anterior neck space

• 3. Align the external auditory meatus (EAM)

horizontally with the suprasternal notch (SN)

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• B. STEPS (assess criteria after each step. Move to next step if criteria are met)

• FOR NEONATES, INFANTS AND TODDLERS

• STEP 1: Simply extend the neck with the child on a flat surface (No shoulder roll or head rest)

• Check and see if all the criteria are met (Sometimes this is all that is required)

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STEP 2: Place a shoulder and check if the criteria are met

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STEP 3: Add a headrest – adjust headrest – shoulder roll combination until criteria are best met

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STEP 2: Add a shoulder roll if needed to bring the plane in the best possible alignment

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Challenge: Mask ventilation

• Patient Factors:

• Anatomical Factors -

• Facial Anomaly - Congenital malformation, Syndromes

• Adenoids and Kissing tonsils

• Micrognathia

• Large tongue

• Poor head position

• Functional may appear in upper and lower airways

• Inadequate depth of anaesthesia and

• Laryngospasm

• Inflation of the stomach

• bronchospasm or

• chest wall rigidity

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• Equipment Factors:

• Check the mask,

• Circuit, and

• Oxygen supply

• Technique:

• Pressing the soft submandibular tissue

• AMBU bag

Challenge: Mask ventilation

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• Correct size, correct placement, correct positioning, and correct technique

• Adjust the head position – does the child need a head roll (or should the head roll be removed)

• Ventilate using simple airway opening manoeuvres (chin lift, jaw thrust, CPAP)

• Apply positive end expiratory pressure (PEEP)

• Adjust cricoid pressure if it has been used

• Insert an oropharyngeal airway (if the patient is deep enough)

• Increase depth of anaesthesia

• Ventilate using a two-person technique

• Pass a nasogastric tube to deflate the stomach.

Strategy: Mask ventilation

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• If mask ventilation is impossible despite all the measures or the child’s oxygen saturation begins to fall:

• EITHER insert an SAD (if available)

• OR deepen anaesthesia, attempt to visualise the vocal cords and intubate the trachea

• There is no randomised controlled trial to assess which is the best response, but insertion of an SAD is recommended first, and then intubation

• If oxygenation and ventilation is satisfactory through the SAD or tracheal tube then it is safe to proceed with surgery.

• If in doubt, wake the child up.

Strategy: Mask ventilation

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• The epiglottis is long, narrow, omega-shaped, hanging over larynx

• Location of the larynx is high and anterior

• So this makes visualisation very difficult by conventional laryngoscope

• Further the sniffing position’ is of no benefit in small children,

• Pillow under the large head only makes airway management more difficult by flexing the Neck

• The airway at the level of the cricoid cartilage is narrowest and rigid

• The vocal cords are angled more anteriorly

• So ETT gets caught in the anterior commisure

Challenge – Endotracheal intubation

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Challenge – Endotracheal Tubes

• Recent research say that cricoid ring is more elliptical in shape than round.

• More pressure and trauma on the mucosa may be created due to placement of round, uncuffed ETT

• As a result uncuffed ETTs are now being replaced by ciffed tubes.

• In addition, pediatric cuffs are now mostly the low-pressure type.

• It’s therefore becoming much more common to use cuffed, low-pressure tubes

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Strategy - Endotracheal Intubation

• Choose the correct Type of Blade for Children?

• Choose the Correctly Sized Endotracheal Tube

• Cuffed Versus Uncuffed Endotracheal Tube?

• Raising the Shoulders Can Help Position a Baby for Intubation

• Don’t Block the Mouth as You Open It

• Control of the Tongue Is Key to Seeing the Larynx

• Passing the Tube May Be Challenging

• Avoid repeated attempts

• Esophageal Intubation and Mainstem Intubation Occur Easily

• Cricoid Pressure Must Be Light

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• When the view is, ‘as good as it gets’, keep the hands still, move your head out of the way, and let the assistant introduce the endotracheal tube

• If, despite using this technique, only the epiglottis is seen, then

• Fibre-optic intubation or ‘look-around-corner- devices’ like Video Laryngoscopes

Strategy - Endotracheal Intubation

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• Occasionally an SAD won’t seat easily, especially if there are large tonsils in the posterior pharynx.

• The SAD is usually easy to insert in children, but in infants the long epiglottis is frequently caught and down-folded by the tip of the SAD

• Displacement and airway obstruction occur most frequently with the smallest LMA, and size #1 should probably only be used for short procedures by

experienced users

(Park C, Bahk JH, Ahn WS, Do SH, Lee KH Can J Anaesth 2001; 48: 413–7.)

• SAD slipped very often in pts < 1 yr be prepared for advanced techniques

Challenge – Supraglottic Airway (SAD)

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• Consider inserting a partially inflated SAD laterally against the side of the tongue, advancing until resistance is met and then rotating back into midline.

• This technique is associated with the highest success rate of insertion and lowest incidence of complications.

• It could be the technique of first choice for SAD insertion in children

• Nakayama S, Osaka Y, Yamashita M. Paediatr Anaesth. 2002;12(5):416-419.

• Ghai B, Makkar JK, Bhardwaj N, et alPaediatr Anaesth. 2008;18(4):308-312

Strategy – Supraglottic Airway (SAD)

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• Partly inflated LMA in a reverse fashion of the mask against the palate, and then rotate it in place when it is fully inserted

• Inserted with a rigid tube inside it

• Ghai B, Makkar JK, Bhardwaj N, Wig J. Pediatr Anesth 2008; 18: 308–12.

Strategy – Supraglottic Airway (SAD)

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• Extubation strategy depends on

• The type of surgery

• The difficulties faced during intubation

• The experience of the anaesthesiologists

• Deep anaesthesia or in the awake state is probably a matter of preference anaesthesiologist has less paediatric experience,

• OR if the airway was difficult to handle during induction, extubating in the awake patient is preferable

• Extubate during inspiration with forced volume through the ETT

Strategy – Extubation

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• Challenges:

• Identification of Cricothyroid membrane is difficult

• The space is very narrow

• The preferred technique is different than in adult

• Strategy:

• It is easier to locate the space between the tracheal rings rather than the cricothyroid membrane

• Prefer needle crico as the first choice depending upon the age

Strategy – Surgical Airway

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Always be prepared for laryngospasm

• Avoid Laryngospasm

• Recognize Laryngospasm

• Break Laryngospasm

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• The incidence of laryngospasm during anesthesia is higher in children than in adults, and ranges from 1.7% to 25%.26 Of cardiac arrests found in the POCA registry,

• 27% resulted from respiratory events. Laryngospasm was the most common cause of respiratory-related events,

(Bhanankar SM, Ramamoorthy C, Geiduschek JM, et al. Anesth Analg.2007 (105)2:344-50)

Complication – Laryngospasm

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• The first treatment should be oxygen delivered by a tight-fitting face mask applied with moderate

intermittent pressure

• During induction, an incomplete spasm will also allow anaesthetic gases to deepen the level of anaesthesia.

• If the laryngospasm is complete, no air will enter the lungs

• Oxygen is still to be given to be ready as soon the spasm alleviates.

Strategy – Laryngospasm

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• If a high-pitched stridor is heard, it means that the spasm is partial and some oxygen can enter the Lungs

• A firm jaw-trust may stretch the larynx and

• A firm jaw-trust may stretch the larynx and help alleviate the spasmhelp alleviate the spasm

• Propofol in small doses has been shown to alleviate the spasm in 75% of cases

• If it is ready in a syringe 1–2 mg/kg is given i.v., depending on whether the spasm occurs during induction or awakening

Strategy - Laryngospasm

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• .Otherwise, the most effective treatment is succinylcholine i.v.

• Doses as small as 0.1 mg/kg i.v. have been shown to relieve the spasm and 0.25–0.3 mg/kg i.v. will quickly relieve the spasm while allowing the child to continue spontaneous breathing.