2024.2 Day 2 VIVA 14

Peri-operative Medicine

A 69-year-old female presents to your Scenarioville Pre-Anaesthetic Clinic for a wide local excision of a right breast lump.

She has a past history of:

  • Atrial fibrillation (AF)

  • Permanent pacemaker (PPM)

  • Hypercholesterolaemia

  • Glaucoma

  • Severe post-operative nausea and vomiting (PONV) after a previous laparoscopic cholecystectomy

Her medications are: Apixaban, Atenolol, Atorvastatin, and Timolol eye drops.

Outline your preoperative assessment and optimisation priorities.

Cardiovascular Assessment:

  • History of AF: rate vs rhythm control, anticoagulation status, symptoms of decompensation (syncope, palpitations, SOB).

  • PPM: assess for dependency, pacing mode, last interrogation (<6 months), underlying rhythm, battery status, MRI compatibility.

  • Functional capacity: METs >4? Exercise tolerance? Investigate if <4 METs or symptoms.

PPM-Specific Considerations:

  • Confirm type: dual vs single chamber; rate responsiveness.

  • Plan for intraoperative interference: diathermy type, site proximity, need for reprogramming or magnet.

Medication Review:

  • Apixaban: assess bleeding vs thromboembolic risk (CHA2DS2VASc).

  • Beta-blocker continuation.

  • Statin continuation.

  • Timolol eye drops: avoid systemic beta-blocker stacking (atenolol + timolol).

Other Priorities:

  • PONV history: implement aggressive triple prophylaxis.

  • Glaucoma: avoid mydriatic/anticholinergic agents.

  • Airway and fasting assessment.

Her pacemaker is a dual chamber MRI compatible pacemaker last reviewed 4 months ago. What are your next steps for surgical planning?

  • Dual chamber MRI-compatible device = reduced diathermy risks.

  • Check report, no need for recheck unless > 6 months ago.

  • Need to determine whether she is pacemaker-dependent (e.g. CHB vs SSS).

  • If monopolar diathermy unavoidable and device within 15cm: consider temporary reprogramming to asynchronous (VOO/DOO) mode or magnet application strategy.

  • Ensure availability of magnet, external pacing, and defib.

She reports walking 500 metres before getting breathless. How would you evaluate her cardiac risk further?

  • Functional capacity likely <4 METs: needs workup.

  • Arrange ECG, consider recent echo (within 6–12 months).

  • BNP or troponin if any decompensation signs.

  • If LVEF <40% or significant valvular disease: refer cardiology for optimisation

  • If angina symptoms: defer surgery, consider stress testing.

  • ANZCA PS12: cardiac disease must be stable preoperatively.

Apixaban was taken this morning. What is your management plan?

  • For low bleeding risk surgery: continue if timing safe (>12h pre-op).

  • For intermediate/high risk surgery (e.g. breast): generally stop 48h prior.

  • Consider renal function (CrCl <30 requires longer delay).

  • No bridging unless high thromboembolic risk.

  • If urgent: consider reversal agents (andexanet alfa not available generally, use PCCs).

The surgeon plans to use monopolar diathermy. What specific precautions would you take intraoperatively?

  • Use lowest effective power, short bursts (<5s).

  • Place return electrode far from device (e.g. left thigh).

  • Continuous ECG and SpO2 monitoring.

  • Have magnet available and test before induction.

  • Ensure access to defibrillator and external pacing pads.

  • Post-op interrogation within 24–48h.

Preoperative work-up is completed, what is the anaesthetic plan?

MAIDE

  • Monitoring:

    • 5-lead ECG (detect pacer spikes).

    • Non-invasive BP; arterial line if haemodynamic instability risk.

      BIS monitor for depth of anaesthesia (especially with TIVA).

    • TOFR

  • Assistant:

    • Airway assistant - Brief plan ABC

    • Surgical team - discuss surgical plan and duration.

  • IV access:

  • Drugs:

    • Induction/Maintenance:

      • TIVA with propofol + remifentanil (reduced PONV, avoids IOP rise).

      • Avoid suxamethonium and ketamine (IOP/glaucoma risk).

      • Rocuronium + sugammadex for reversibility.

  • Equipment:

    • Airway equipement

    • Arrest trolley

    • Magnet

In addition to MAIDE I would consider:

  • PPM Strategy:

    • Magnet tested and taped near chest.

    • If high diathermy use: request asynchronous pacing pre-op.

    • Continuous rhythm monitoring throughout.

  • PONV Prophylaxis:

    • Dexamethasone + ondansetron + cyclizine (triple therapy).

    • Avoid nitrous oxide and volatiles.

  • Other:

    • Avoid atropine/glycopyrrolate.

During surgery, BIS rises to 85. What are your priorities and actions?

  • First assess IV integrity: check for tissued or occluded cannula.

  • Assess clinical signs: movement, HR/BP rise, lacrimation, diaphoresis.

  • Bolus propofol 20–30mg; increase target concentration.

  • Add remifentanil or fentanyl bolus for analgesia.

  • Confirm ventilation and EtCO2 – hypoventilation can increase awareness risk.

  • Check depth of neuromuscular blockade.

  • Consider rescue midazolam 1–2mg if recall suspected.

She begins moving her arms under drapes. What steps do you take?

  • Immediately stop surgery, call for help.

  • Confirm airway: mask ventilate or intubate if not already.

  • Administer induction bolus: propofol 50–100mg, rocuronium 1mg/kg.

  • Secure airway and deepen anaesthesia.

  • Once stable: discuss timing and consent of re-starting.

You notice loss of pacer spikes on the ECG. What’s your differential and next step?

  • Potential electromagnetic interference from diathermy: check pad placement, power settings.

  • Displacement or battery failure: check physical leads.

  • Immediate: apply magnet to force asynchronous pacing.

  • Administer atropine 600mcg and prepare for external pacing.

The IV line is tissued and you have no access. BIS is high, BP 190/100. What’s your management?

  • Transition to sevoflurane to deepen anaesthesia.

  • Cease surgery and alert team.

  • Urgently establish new IV access (ultrasound or intraosseous if needed).

  • Give GTN sublingual (400mcg) or labetalol 5mg IV once access regained.

  • Consider arterial line for ongoing monitoring.

  • Document all events meticulously.

Post-op, the patient reports hearing voices during surgery. How would you manage this?

  • Provide immediate supportive reassurance.

  • Conduct structured debrief and timeline review (📃 Notes ✏️Notes)

  • Offer psychological support or referral.

  • Document event and report as critical incident.

  • Check BIS, propofol logs, IV charting.

  • Discuss findings and follow-up plan with patient and team.

PPM interrogation reveals potential EMI-related failure. What’s your plan?

  • Continuous ECG and haemodynamic monitoring.

  • Cardiologist review for interrogation and reprogramming.

  • Assess for any intraoperative compromise.

  • Delay discharge until stable device function confirmed.

What would you include in your written handover to PACU or ward team?

  • Operative course including awareness event and PPM concern.

  • Monitoring needs (telemetry, neuro checks).

  • Pain plan and PONV coverage.

  • Cardiologist pending review.

  • Alert for any signs of delayed haemodynamic changes.

The surgeon wants to now perform a contralateral biopsy. How would you respond?

  • Patient is not currently fit for further procedure.

  • Device malfunction + intraop awareness = unacceptable risk.

  • Re-book after full cardiology evaluation and psychological follow-up.

  • Reconsent patient at later date with appropriate planning.

Key Phrases

  1. “TIVA with BIS monitoring is my preferred approach due to this patient’s severe PONV and glaucoma.”

  2. “Magnet application must be tested prior to induction and available throughout the case.”

  3. “Any intraoperative awareness must be managed with reassurance, documentation, and psychological support.”

  4. “Apixaban cessation must balance bleeding risk and CHA₂DS₂-VASc score — often requiring 48-hour withholding.”

  5. “Surgery must be paused immediately if the patient moves or awareness is suspected — depth must be re-established urgently.”

📚 Key Learning Points

  1. Understand Pacemaker Fundamentals

    • Know the model, date of implantation, dependency, last interrogation, and EMI planning including whether asynchronous reprogramming or magnet use is required.

  2. Diathermy Requires Device-Specific Strategy

    • Monopolar diathermy near a pacemaker demands detailed planning — including pad placement, low-energy bursts, magnet readiness, and post-op interrogation.

  3. TIVA Is the Optimal Technique for Severe PONV & Glaucoma

    • Propofol-based TIVA avoids IOP elevation and minimises emetogenic potential but depends on reliable IV access and BIS monitoring.

  4. Intraoperative Awareness Requires Immediate, Structured Response

    • Ensure IV access, secure airway if necessary, deepen anaesthesia, and follow with post-event support, documentation, and incident reporting.

  5. High BIS or Movement During Surgery Must Trigger a Depth & Device Review

    • Check for IV issues, PPM interference, analgesic failure, and neuromuscular block status before assuming awareness.

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