DCAS Airway Management & Intubation 2 — Questions and Answers
Question 1: Sellick's manoeuvre (cricoid pressure) in RSI is designed to:
- Compress the oesophagus against the vertebral body to reduce regurgitation risk during intubation (Correct answer)
- Lift the larynx into a more favourable view
- Reduce the patient's gag reflex
- Stabilise the trachea during intubation
Correct answer: Compress the oesophagus against the vertebral body to reduce regurgitation risk during intubation
Cricoid pressure compresses the oesophagus between the cricoid ring and vertebral body, theoretically preventing passive regurgitation of gastric contents during induction; its routine use is now controversial as it may worsen laryngoscopic view.
Question 2: Succinylcholine (suxamethonium) as an RSI agent is contraindicated in:
- Hyperkalaemia, crush injuries, burns >24 hours old, and known or suspected pseudocholinesterase deficiency (Correct answer)
- All trauma patients
- Patients with asthma
- Patients receiving beta-blockers
Correct answer: Hyperkalaemia, crush injuries, burns >24 hours old, and known or suspected pseudocholinesterase deficiency
Succinylcholine causes potassium release (∼0.5mEq/L normally); in hyperkalaemic states, or conditions with upregulated acetylcholine receptors (burns, crush, denervation), this can cause fatal cardiac arrest.
Question 3: The correct depth of insertion for a nasopharyngeal airway (NPA) approximates:
- Distance from the tip of the nose to the earlobe (7-9cm in most adults) (Correct answer)
- 10cm for all adults
- 5cm universally
- Determined solely by resistance during insertion
Correct answer: Distance from the tip of the nose to the earlobe (7-9cm in most adults)
The NPA is sized by measuring from the nostril to the tragus of the ear (approximately 7-9cm in adults), ensuring the tube reaches the posterior pharynx without entering the larynx or oesophagus.
Question 4: During RSI, the typical induction dose of ketamine for a haemodynamically compromised patient is:
- 1-2mg/kg IV (reduced dose for haemodynamic compromise vs 1-2mg/kg standard) (Correct answer)
- 4-5mg/kg IV regardless of haemodynamics
- 0.1mg/kg IV
- 10mg fixed dose for all patients
Correct answer: 1-2mg/kg IV (reduced dose for haemodynamic compromise vs 1-2mg/kg standard)
Ketamine 1-2mg/kg IV provides dissociative anaesthesia with haemodynamic preservation (sympathomimetic properties) — doses at the lower end are used in haemodynamically compromised patients to avoid catecholamine depletion.
Question 5: A 'difficult airway' algorithm should include which rescue device if intubation fails?
- Supraglottic airway (SGA) such as laryngeal mask airway (LMA) or i-gel as a bridge to oxygenation (Correct answer)
- Immediate cricothyrotomy after the first failed intubation attempt
- Continuing repeated intubation attempts until successful
- Immediate transport without airway management
Correct answer: Supraglottic airway (SGA) such as laryngeal mask airway (LMA) or i-gel as a bridge to oxygenation
Failed intubation should trigger a 'can't intubate, can ventilate' response using an SGA as a rescue device for oxygenation; cricothyrotomy is reserved for 'can't intubate, can't oxygenate' (CICO) scenarios.
Question 6: Video laryngoscopy (VL) compared to direct laryngoscopy (DL) in pre-hospital intubation:
- Provides an improved glottic view, especially for anticipated difficult airways, but may require a bougie for tube delivery (Correct answer)
- Is inferior to DL in all pre-hospital situations
- Requires a non-intubating assistant at all times
- Cannot be used in hypoxic patients
Correct answer: Provides an improved glottic view, especially for anticipated difficult airways, but may require a bougie for tube delivery
VL consistently improves the glottic view (Grade I-II on most patients regardless of DL grade), improving first-pass success particularly in difficult airways, though tube delivery through the visualised glottis may require a bougie.
DCAS Airway Management & Intubation 2
Sellick's manoeuvre (cricoid pressure) in RSI is designed to: