Failure to maintain or protect airway Comatose (prevents aspiration) Airway trauma Failure of ventilation or oxygenation Ventilation failure not reversible Deteriorating oxygenation even with supplemental O2 Cardiac arrest

In emergencies there is about a 1 - 2% failure to intubate Therefore: Need to identify the difficult airway: So that you can make plans for the event of possible failure to intubate Neuromuscular paralysis should be used with extreme caution

Assessment 1. External markers of difficulty 2. Neck mobility of bag-mask ventilation of intubation 2. Neck mobility 3. Mouth opening 4. Oral access (Mallampati) 5. Estimate difficulty for direct laryngoscopy 6. Laryngoscopic view (Cormack and Lehane)

1. External markers No teeth Obesity History of snoring Beard Difficult bag-mask ventilation No teeth Obesity History of snoring Beard Age > 55years Anatomically abnormal facies Facial or neck trauma Obstructive airways disease Third trimester pregnancy

1. External markers Difficult intubation Anatomically abnormal facies Neck trauma Prominent incisors or passion gap Receding mandible Short thick neck Obesity Neck immobilisation

2. Neck mobility 3. Mouth opening Flex and extend through full range of motion 3. Mouth opening Open mouth as wide as possible Should insert 3 fingers between upper and lower incisors

4. Oral access = Mallampati scale (sitting up, not saying “Ah”) Class 1: Full visibility of tonsils, uvula and soft palate Class 2 : Visibility of hard and soft palate, upper portion of tonsils and uvula Class 3 : Soft and hard palate and base of the uvula are visible Class 4 : Only hard palate visible

5. Estimate difficulty for direct laryngoscopy Distance - Chin to hyoid Estimates size of mandible 3 fingers Distance - Thyroid cartilage to mandible Estimates position of larynx in neck 2 fingers

Laryngoscopic view = Cormack and Lehane Grade I : Most of glottis is seen Grade II : Only posterior portion of glottis can be seen Grade III : Only epiglottis may be seen (none of glottis seen) Grade IV : Neither epiglottis nor glottis can be seen

The mneumonic “LEMON” L = Look externally (facial trauma, large incisors, beard or moustache, and large tongue) E = Evaluate the 3 - 3 - 2 rule (incisor distance < 3 fingers hyoid / chin distance < 3 fingers thyroid-to-mandible distance < 2 fingers) M = Mallampati (Mallampati score 3 or more) O = Obstruction (presence of any condition that could cause an obstructed airway) N = Neck mobility (limited neck mobility)

Bag-mask ventilation Oxygen source We use a self inflating resuscitator (e.g. Ambu®-, Laerdal®- bag) Reservoir bag O2 at 15 L min-1 straight from regulator not through humidifier Oxygen source

Suction Yankauers Magills forceps

Laryngoscope Types Consists of blade varying sizes (000 - 0 - 4) Handle Types MacIntosh (curved blade) Miller (straight blade)

Endotracheal tubes (ETT) Different types Cuffed vs. uncuffed Average size of ETT’s for Adult male = 8 Adult female = 7,5 Child = (Age / 4) + 4 Maintain sterility Syringe to inflate cuff

Secondary confirmation devices Introducer / bougie KY jelly Stethoscope Tie / tape to secure ETT Secondary confirmation devices Oesophageal detector device (ODD) Capnography

If unconscious then easy If awake / semi-conscious then need a RSI RSI = Rapid Sequence Intubation Rapid placement of ETT into trachea Pre-oxygenation After administering a sedative / induction agent Apply cricoid pressure (Sellick’s manoeuvre) Followed by the muscle relaxant, suxamethonium ('scoline') Prevents regurgitation and aspiration

Pre-oxygenate for 5 min or 6 vital capacity breaths Prepare equipment Pre-oxygenate for 5 min or 6 vital capacity breaths FIO2 = 0,8 - 1,0 Paralysis with induction Induction agent Cricoid pressure Paralysing agent - Suxamethonium Pass ETT once fasciculated or 60 sec (whichever is first) Confirm position and then release cricoid pressure Post-intubation care

Head positioning Sniffing morning air Allows a straight line of vision from mouth to vocal cords Neck extension, head flexion

Laryngoscope introduced into right side of mouth (held in left hand) Tongue swept to left Tip of blade advanced until epiglottis seen

Tip of blade into the vallecula Entire laryngoscope lifted in direction of the handle. (Do not pivot or lever on the teeth!)

Tip of ETT advanced through the cords under direct vision Depth: Black line at cords / cuff just through cords Approx. ETT size x 3 Note marking at lip Confirm with ODD Then inflate balloon Check placement Secure ETT

'Major signs' of endotracheal placement (Reliable) Direct visualisation of ETT through cords End-tidal CO2 Oesophageal detector device 'Minor signs' of endotracheal placement (False positives) Absent sounds on auscultation over the epigastrium, with breath sounds in axillae and bases (i.e. 5 point auscultation) Fogging / misting of tube Equal rise and fall of chest Pulse oximetry (Late sign! esp. with pre-oxygenation) Exclude endobronchial placement Clear and equal bilateral breath sounds in axillae and bases NB. Auscultation is not a reliable sign of correct endotracheal placement

Squeeze, attach to ETT and release, then allow to re-expand If in the oesophagus, it will not re-expand as the oesophagus will collapse round the ODD Done before any bagging False positive May falsely re-expand if stomach is filled with air due to ventilation False negatives May falsely not re-expand if a small child (<20kg) or obese

Want to look at end-tidal CO2 to assess if in trachea Qualitative = Capnodisc Yellow = yes pH sensitive filter paper Turns yellow if >2 - 5 kPa PETCO2 Only qualitative Quantitative = Capnography Infrared detection Waveform analysis

Problems with qualitative: False positives Gassy cooldrinks Gastric distension from mouth-to-mouth ventilation False negatives Cardiac arrest Massive pulmonary embolus Massive obesity

Pulse oximeter detects haemoglobin oxygen saturation peripherally Is a delayed response Especially if pre-oxygenated Remember to be careful if: Nail polish High ambient light Carbon monoxide poisoning No pulse in patient Hypotensive Hypothermic

Laryngospasm / bronchospasm Oesophageal intubation Trauma Lips Teeth Airway Vocal cords Infection Laryngospasm / bronchospasm Oesophageal intubation Right main bronchus intubation Tension pneumothorax

DOPES check D = Displacement of ETT (right bronchus/oesophagus) O = Obstruction of ETT / circuit P = Pneumothorax E = Equipment failure S = Stomach full of air (especially children)

Go back to basics and bag-mask ventilate If cannot intubate, but can ventilate then Ventilate Stay calm, call for help Try to intubate later If still cannot then rescue device: LMA Combitube If cannot intubate, cannot ventilate Rescue device Last resort → Surgical airway (cricothyroidotomy)