2024.2 Day 1 VIVA 1
Airway Management
A 30-year-old man presented to the emergency department with a dental abscess in his right lower molar. He weighs 70 kg, is drooling, has swelling in the right lower side of his face, and has been unable to eat or drink overnight. His observations are: RR 25, SaO2 94% on room air, HR 110, BP 140/90, Temp 38°C, GCS 15. He has a patent 20G IV cannula in his right hand. The retrieval service estimates it will take over 4 hours to arrive, and they recommend securing the patient’s airway in the meantime.
What preparations do you make before securing his airway?
Immediate Preparation:
Call for senior anaesthetic support + surgical backup (ENT or general surgeon for FONA).
Prepare difficult airway trolley: videolaryngoscope (VL), bougie, 2nd-gen SGA, scalpel-bougie FONA kit.
Position patient head-up 30° → improves FRC, venous drainage from airway, reduces oedema.
Preoxygenation with HFNO at 60L/min even if not fully cooperative → provides oxygenation during apnoea (apnoeic oxygenation).
Medical Optimisation:
IV dexamethasone (8 mg): reduces mucosal and submucosal oedema (onset 1–2 hrs).
IV co-amoxiclav 1.2 g for early source control (sepsis bundle).
Nebulised adrenaline (5 mg in 5 mL) to vasoconstrict mucosa + reduce swelling.
Analgesia: Paracetamol 1 g + small dose fentanyl (25–50 mcg IV) to reduce agitation, but avoid oversedation.
Airway Assessment:
LEMON:
Look: Facial swelling, trismus, oral secretions.
Evaluate: Likely <3-finger mouth opening; thyromental distance may be shortened.
Mallampati: Difficult or ungradeable.
Obstruction: Positive – drooling, muffled voice = red flags.
Neck mobility: May be impaired by pain/swelling.
Planned Strategy:
Awake FOI preferred (preserves spontaneous breathing) → safer than RSI in high obstruction risk.
Backup: VL + RSI → if FOI not feasible.
FONA readiness essential.
AMData: BMI = 42 → anticipate rapid desaturation → maximise apnoeic oxygenation.
How would you preoxygenate if he’s agitated?
Start HFNO at 60 L/min in head-up position.
If tolerates, add non-rebreather mask for 3–5 min.
If severely distressed: ketamine 0.25–0.5 mg/kg IV (dissociative dose without apnea).
Justification:
Agitation = reduced preoxygenation effectiveness.
Ketamine preserves spontaneous respiration and airway reflexes.
HFNO offers PEEP and buys time during apnoea — critical in morbid obesity (BMI 42 → ↓ FRC).
Avoid midazolam/propofol which risk apnea.
Why not use standard RSI here?
Facial/airway swelling → high risk of "can’t intubate, can’t oxygenate" (CICO) after paralysis.
RSI removes protective reflexes and spontaneous breathing → may cause total obstruction.
Justification:
RSI is standard in most emergencies — but contraindicated in high-risk obstructed airways.
Awake FOI maintains patient’s own ventilation, allowing better visualization and safer progression.
In a patient who can’t lie flat (due to airway threat), RSI becomes even more dangerous.
What if he deteriorates during preparation?
If SpO₂ <90% or GCS drops → abandon FOI, call CICO, proceed to FONA.
Team roles clearly allocated.
Verbalise: “This is a CICO – proceeding to scalpel-bougie cricothyroidotomy.”
Justification:
Delayed decision-making = fatal.
CICO declaration is a cognitive switch → ensures all attention turns to oxygenation, not intubation.
SpO₂ <90% is an objective threshold for abandoning current strategy.
How does sepsis alter your plan?
Start with IV fluid bolus 500 mL (guided by MAP/UO).
Have metaraminol or noradrenaline ready.
Sepsis → vasodilation, hypovolemia → risk of post-induction hypotension.
Justification:
Airway drugs (especially induction agents) → vasodilation.
Sepsis reduces vascular tone → need volume + vasopressors to prevent crash.
AMData: Initial MAP 64 → supports fluid + vasopressor prep.
Describe your approach to intubation.
First-line: Awake FOI
Topicalisation:
Lidocaine 4% spray + nebulised 4% x 10 mins.
Transtracheal injection of 2% lidocaine if tolerated.
Sedation:
Ketamine 20–30 mg IV → anxiolysis, preserves breathing.
Avoid benzodiazepines/propofol.
Route:
Oral preferred (less trauma); nasal only if absolutely required and no coagulopathy.
Avoid nasal route if abscess extends into nasopharynx.
Backup Plan:
RSI with VL if awake FOI fails.
Drugs: Ketamine 1–2 mg/kg + rocuronium 1.2 mg/kg.
Avoid suxamethonium → possible acidosis/hyperkalaemia in sepsis.
Plan B: i-gel if cannot intubate.
FONA Ready:
Scalpel-bougie kit open, cricothyroid membrane marked.
ENT aware and scrubbed if available.
Why avoid nasal intubation here?
Nasal route risks abscess rupture, bleeding, and aspiration.
Infected tissue → fragile vessels → higher bleeding risk.
Sepsis = hyperdynamic state → amplifies risk of haemorrhage.
Justification:
Nasal intubation is generally less preferred in active oral/maxillofacial infection.
If violated, can lead to systemic bacteraemia or sudden loss of airway.
How would you adjust if he has a BMI of 40?
Preoxygenate longer with HFNO + NRB.
Ramped position (external auditory meatus aligned with sternal notch) improves VL view.
Anticipate faster desaturation and difficult mask seal.
Justification:
Obesity → reduced FRC, increased O₂ consumption → rapid desaturation.
Proper positioning improves glottic view and decreases intubation time.
AMData confirms BMI 42 → higher vigilance needed.
What’s your tube size and why?
Use 6.0–6.5 mm ETT → easier passage in edematous or distorted anatomy.
Avoid nasal tubes unless absolutely needed.
Avoid too small (↑ resistance, difficult suctioning) unless swelling mandates.
Justification:
Smaller tubes = higher resistance, but better tolerance in narrowed or inflamed airway.
6.0 ETT is a safe compromise in distorted airway management.
When would you abandon awake FOI?
If patient becomes uncooperative, GCS drops, or desaturates <90%, transition to RSI or FONA.
Awake FOI requires conscious cooperation and airway patency.
Justification:
Delay = danger.
Objective desaturation or altered mental status precludes safe FOI.
Must be ready to switch to Plan B rapidly.
He becomes hypoxic (SpO₂ 70%) during intubation attempts. What next?
Immediate Declaration:
"This is a CICO. I am proceeding to FONA."
Scalpel-Bougie Technique (ANZCA standard):
4–5 cm vertical incision midline.
Horizontal stab through cricothyroid membrane.
Insert bougie caudally.
Railroad 6.0 ETT over bougie.
Confirm EtCO₂ + bilateral chest rise.
Post-Procedure Care:
Secure airway, call ENT for formal tracheostomy.
Broad-spectrum antibiotics.
Check ABG + CXR.
Why choose scalpel-bougie over cannula technique?
Needle techniques have lower first-pass success, especially in obese/edematous necks.
Cannot provide effective ventilation in adult males.
High failure rate + barotrauma.
Justification:
Male, BMI 42 → challenging anatomy.
Scalpel-bougie has faster time to oxygenation and higher success.
How would you manage bleeding obscuring landmarks?
Continuous suction, use finger to palpate laryngeal structures.
Make wide vertical incision → improves exposure.
If unable to locate → consider ENT trach or alternative access.
Justification:
Visualisation can be impaired in infection/bleeding.
Tactile feedback often more reliable than sight.
Delay increases hypoxic injury risk.
What if EtCO₂ isn’t detectable post-FONA?
Reassess ETT position.
If misplaced: remove, reattempt.
Consider tension pneumothorax if ventilation fails → needle decompression.
Justification:
Capnography confirms placement → no waveform = misplacement or obstruction.
Tension PTX is rare but possible with bagging in traumatic airway.
How does sepsis impact FONA outcomes?
Sepsis → increased risk of wound infection, cellulitis, or even necrotising fasciitis.
Requires post-procedure antibiotics + close monitoring.
Tissues friable → careful technique needed.
Justification:
FONA is lifesaving, but introduces new infection risk in already septic patient.
Early source control + coverage avoids worsening sepsis.
Key phrases:
“This is a potentially obstructed airway — I will maintain spontaneous ventilation.”
“I will pre-mark the cricothyroid membrane and have FONA equipment ready.”
“My first-line approach is awake fibreoptic intubation to avoid losing the airway.”
“If oxygen saturations fall or the patient deteriorates, I will abandon and escalate to FONA.”
“This is a CICO situation — I am proceeding to scalpel-bougie cricothyroidotomy.”
“EtCO₂ confirmation is essential after intubation or front-of-neck access.”
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