2024.2 Day 1 VIVA 4

Paediatric Anaesthesia

It is 1 pm on the weekend at Scenarioville Hospital. A 5-year-old girl presents to the Emergency Department accompanied by her mother with a supracondylar fracture after falling off a trampoline.

The surgeon would like to take her to the theatre immediately, as her hand is cold and pulseless. She had lunch 1 hour ago and is very distressed. I

ntravenous access has not been obtained. She has a past history of asthma.

What are your main concerns?

Immediate threats:

• Vascular compromise:

  • Cold, pulseless hand = limb ischemia risk → urgent reduction required within 6 hours to prevent permanent damage.

• Full stomach aspiration risk:

  • Ate lunch 1 hour ago → high risk for regurgitation/aspiration under GA.

• Asthma history (PAData confirms mild asthma):

  • High stress + GA → increased risk of bronchospasm.

Scenarioville resource limitations:

• No paediatric ICU or HDU.

• Retrieval delay (~2 hours).

• Only basic post-op monitoring available (SpO₂, HR).

Consent priorities:

• Discuss aspiration risk explicitly with family.

• Explain need for RSI despite recent food.

• Explain possible escalation to retrieval if respiratory complications arise.

How would you balance the urgency of surgery against aspiration risk?

• Proceed immediately with RSI — limb salvage > aspiration risk.

• Risk of permanent disability or amputation if delayed >6 hours.

• Mitigate aspiration risk with RSI, cricoid pressure, and preoxygenation.

Justification:

• NPO guidelines are suspended in time-critical emergencies.

What preoperative assessments are essential given her asthma?

• Auscultate chest for wheeze or crackles.

• Confirm recent bronchodilator use (salbutamol MDI or nebuliser).

• Check for recent exacerbations or steroid use (indicates poor control).

• Consider pre-treatment with salbutamol nebuliser before GA.

Justification:

• Airway reactivity increases aspiration + bronchospasm risk.

How does Scenarioville’s lack of ICU affect your decision-making?

• Full recovery prior to extubation is essential → awake extubation only.

• Ensure robust spontaneous ventilation before leaving theatre.

• Plan for overnight monitoring in SCU even if stable.

Justification:

• No facility for post-intubation ventilation → must prevent complications rather than rescue.

What consent points would you prioritise with the mother?

• Immediate surgery to save the limb.

• Aspiration risk: despite precautions, regurgitation could occur.

• Possibility of prolonged recovery → escalation to retrieval if needed.

• Risks of bronchospasm, pneumonia, re-intubation if complications occur.

Justification:

• Informed consent must focus on emergency-specific risks.

Would you delay for fasting? If so, how long?

• No delay — urgent limb salvage is the priority.

• RSI minimises risk; cricoid pressure and airway suction readiness further mitigate aspiration risk.

Justification:

• Delaying compromises limb viability; aspiration risk can be actively managed.

Outline your induction plan, including drug dosing and airway strategy.

Pre-induction preparation:

• 2x IV cannulas if possible (16–20G based on child's size).

• Preoxygenation:

  • 100% O₂ for 3 minutes if compliant.

  • 8 vital capacity breaths if distressed.

• Salbutamol nebuliser pre-op if wheezy.

Induction drugs:

• Ketamine 1–2 mg/kg IV:

  • Preserves airway reflexes, causes bronchodilation, maintains haemodynamics.

• Rocuronium 1.2 mg/kg IV:

  • Provides rapid muscle relaxation for RSI.

• Fentanyl 1–2 mcg/kg IV if no hypovolemia, for blunting response to intubation.

• Atropine 20 mcg/kg IV optional if bradycardia concern.

Airway equipment:

• Size 5.0 cuffed ETT (age/4 + 3.5 or 4).

• Videolaryngoscope available.

• Size 2 LMA backup ready.

• Bougie, suction prepped.

• Cricoid pressure:

  • Apply gently (10 N) after LOC; avoid distortion of airway anatomy.

Positioning:

• Supine with injured arm supported.

• Avoid over-traction → worsens vascular injury.

Why avoid succinylcholine in this case?

• Risk of hyperkalemia with muscle trauma — theoretical but avoidable.

• Rocuronium 1.2mg/kg achieves RSI conditions safely.

Justification:

• Succinylcholine reserved for rare 'can't intubate, can't oxygenate' situations where fastest onset is critical.

How would you modify dosing if she were obese?

• Use ideal body weight for rocuronium dosing.

• Use lean body weight for ketamine (high lipophilicity → reduced overdose risk).

Justification:

• Overdosing paralytics risks prolonged apnea; underdosing risks failed RSI.

What if you couldn’t secure IV access?

• IM ketamine 5 mg/kg + IM atropine 20mcg/kg.

• Then inhalation induction with sevoflurane if needed.

• Once sedated → place IV.

Justification:

• Delaying surgery for IV access risks limb loss → sedation facilitates urgent access.

Would you use cricoid pressure? What are its pitfalls?

• Yes — high aspiration risk.

• Pitfalls:

  • Distortion of airway anatomy → difficult intubation.

  • Overpressure (>20N) collapses airway.

Justification:

• Cricoid pressure must be skillfully applied and can be released if intubation is difficult.

How would you position her given the fracture?

• Supine with affected arm padded and supported, avoiding traction or compression.

• Arm draped carefully to avoid compromise during surgery.

Justification:

• Further movement can worsen vascular compromise or cause nerve injury.

The child vomits on induction. What are your next steps?

Immediate Management:

• Place head down and lateral if possible.

• Continuous suction of oropharynx.

• Maintain cricoid pressure if feasible.

• Rapid sequence intubation immediately if not yet intubated.

Post-Intubation Management:

• Confirm ETT placement with EtCO₂.

• Suction via ETT if large volumes aspirated.

• Post-op:

  • Chest X-ray (if clinical signs warrant).

  • Start co-amoxiclav empirically.

  • Monitor for hypoxia/fever signs of aspiration pneumonitis.

Escalation/Contingency:

• SCU admission for close observation.

• Early retrieval activation if SpO₂ persistently <90% or respiratory failure develops.

What clinical signs suggest significant aspiration?

• Desaturation (<92%).

• New wheeze or crackles on auscultation.

• Increased airway pressures on ventilator.

• Radiographic infiltrates on CXR.

Justification:

• Need to identify early to prevent respiratory failure.

How would you ventilate her if she develops bronchospasm?

• Low tidal volumes (5–6 mL/kg).

• Increase expiratory time (I:E 1:3–1:4).

• Increase PEEP cautiously (5cmH₂O).

• Administer salbutamol puffs via ETT or inline nebuliser.

Justification:

• Avoid dynamic hyperinflation and barotrauma.

What if she remains hypoxic despite intubation?

• Exclude tube obstruction/malposition.

• Rule out tension pneumothorax (unilateral absence of breath sounds → needle decompression).

• Administer adrenaline bolus 1 mcg/kg IV if hypotension and severe bronchospasm.

Justification:

• Early identification and treatment of critical complications improves survival.

When would you request retrieval to a tertiary centre?

• Persistent hypoxia despite optimal ventilation.

• Hemodynamic instability.

• Need for prolonged ventilation >6hr post-op.

Justification:

• Scenarioville lacks capacity for advanced ventilation or inotropes.

How would you manage her postoperatively in Scenarioville?

• SCU admission with continuous SpO₂ and cardiorespiratory monitoring overnight.

• Chest physiotherapy if secretions accumulate.

• Careful fluid management → avoid pulmonary edema.

Justification:

• Maximise early detection of deterioration without access to ICU.

Critical Phrases:

• • “Limb salvage outweighs fasting guidelines — RSI is mandatory.”

  • “Ketamine ensures haemodynamic stability and bronchodilation.”

  • “Cricoid pressure must be applied gently — not at the expense of intubation success.”

  • “Persistent hypoxia post-aspiration mandates early retrieval activation.”

Key Learning Points

1. Urgency > Fasting Status:

   • In limb-threatening emergencies, proceed to surgery immediately despite NPO violations.

   • RSI with cricoid pressure is mandatory to manage aspiration risk.

2. Ketamine is the Ideal Induction Agent:

   • Provides bronchodilation, maintains airway reflexes, and preserves haemodynamic stability — perfect for asthmatic, distressed children.

3. Scenarioville = Prevent Complications, Don’t Rescue Them:

   • No ICU or advanced ventilation → awake extubation, fully reversed, and stable before leaving theatre.

4. Succinylcholine Should Be Avoided in Acute Trauma:

   • Risk of hyperkalaemia due to upregulated acetylcholine receptors after trauma, even in children.

5. Positioning Must Protect the Fractured Limb:

   • No traction or torsion during induction/transport → could worsen vascular compromise or cause nerve injury.

6. Aspiration Requires Immediate Aggressive Management:

   • Head down, suction, rapid intubation, minimal bagging until airway secured.

   • Monitor for aspiration pneumonitis post-op with chest X-ray and SpO₂ monitoring.

7. Early Activation of Retrieval Services if Deterioration:

   • If persistent hypoxia, bronchospasm, or haemodynamic instability → contact retrieval early (retrieval time ~2 hours).

8. Paediatric-Specific Dosing Principles:

   • Ketamine and fentanyl based on lean body weight,

   • Rocuronium based on ideal body weight,

   • Always have drug calculations pre-checked before induction.