2023.1 Day 1 VIVA 5

You will be doing an elective dental list in SCENARIOVILLE next week. The first patient on the list is a 10 year old boy, who is ~25kg, for a dental examination under anaesthesia +/- restorations as required. He has had limited medical or dental care due to behavioural issues.

Past Medical:

• Autism (non-verbal)

• ADHD

• Mild asthma

Allergies: Nil

Medications:

• Melatonin 5 mg nocte

• Ritalin 10 mg bd (mane, midi)

• Salbutamol PRN

How will you plan in advance for his anaesthetic?

Issues/concerns:

• Severe autism & ADHD: Likely non-cooperative, high anxiety → difficult IV access & induction.

• Limited medical/dental care: No prior anaesthesia exposure, unknown airway risks.

• Asthma history: Risk of bronchospasm during induction or emergence.

• Behavioural management: Need for pre-medication & careful environment control.

Q: How would you engage the parents/caregivers in the preoperative period?

• Detailed discussion about child’s usual behaviours, triggers & comfort strategies.

• Parental presence for induction (if beneficial to child).

• Familiar objects (e.g., blanket, toy) to ease anxiety.

• Prepare child for hospital environment with pictures/social stories if possible.

What are your options for pre-medication, and how do you choose? 📃(Notes)

• Midazolam (0.5 mg/kg PO or 0.2 mg/kg IN) → rapid onset, sedation, amnesia.

• Clonidine (4 mcg/kg PO or 2 mcg/kg IN) → sedation, reduces agitation/emergence delirium.

• Dexmedetomidine (2 mcg/kg IN or IV) → excellent sedation with minimal respiratory depression.

• Ketamine (3-5 mg/kg PO) → for highly uncooperative children, maintains airway reflexes.

• Choice depends on severity of behavioural issues and expected cooperation.

The dentist requests a nasal tube. What are the advantages and disadvantages? 📃(Notes)

• Advantages:

  • Better surgical access to the oral cavity.

  • More secure airway (less displacement than oral ETT).

  • Reduced risk of intra-op obstruction (compared to LMA).

• Disadvantages:

  • Risk of epistaxis during insertion.

  • More difficult passage in small children (narrow nasal passages).

  • Increased airway resistance (can increase work of breathing if spontaneously ventilating).

How would you induce anaesthesia in this child?

• If cooperative after pre-med → IV induction with propofol 2-3 mg/kg + fentanyl.

• If uncooperative → inhalational induction:

  • Sevoflurane in oxygen/nitrous oxide via face mask in a calm environment.

  • Gradual deepening until IV cannulation possible, then proceed with IV agents.

• If severe resistance → ketamine IM (4-5 mg/kg) as a last resort.

Monitoring and Airway Emergencies

You notice a sudden loss of end-tidal CO₂ trace. What are your differentials? ✏️(Notes)

• Circuit disconnection or leak → most common cause, check entire breathing circuit.

• ETT displacement → check breath sounds, chest rise, tube position.

• Kinked or obstructed tube → suction the tube, consider bronchospasm.

• Equipment failure → check monitor calibration, change capnography sensor.

• Cardiac arrest (rare but serious) → check pulse, BP, SpO₂ immediately.

Q: The issue is a simple circuit disconnection. What do you do?

• Reconnect the circuit immediately.

• Confirm capnography return and ensure stable ventilation.

• Reassess airway and vitals to rule out secondary complications

How would you plan extubation for this child?

• Awake extubation (preferred in this case):

  • Ensure fully awake, airway reflexes intact.

  • Avoid deep extubation due to risk of laryngospasm & airway obstruction.

• Deep extubation (alternative in highly reactive patients):

  • Only if smooth, non-irritable emergence is needed (e.g., history of emergence delirium).

  • Must be fully monitored with ability to rapidly reintubate if needed.

What are your criteria for proceeding with the next patient?

• Ensure full recovery from anaesthesia (stable vitals, patent airway).

• Assess for agitation or emergence delirium (common in autism/ADHD).

• Confirm adequate pain & nausea control.

• Confirm safe discharge criteria are met before starting the next case

Bonus Question

If the child becomes severely agitated post-op, how would you manage it?

• Reduce stimuli (quiet room, dim lights, parental presence).

• Medications if needed:

  • Dexmedetomidine (0.5 mcg/kg IV) → sedation without respiratory depression.

  • Midazolam (0.05 mg/kg IV) → short-acting anxiolysis.

• Ensure adequate analgesia (pain can exacerbate agitation).