2024.2 Day 1 VIVA 10

Peri-operative Medicine

You are called to the ED to provide procedural sedation for a 75-year-old male who presented following a fall at home. He has a dislocated left shoulder requiring relocation. His weight is 90kg (BMI=30). His past history includes Ischaemic Heart Disease, Hypertension, and Hyperlipidaemia. His medications are: Aspirin 100mg, Irbesartan 150mg, Rosuvastatin 40mg daily. His vital signs are: Alert and talking but disoriented, Heart Rate = 150, Respiratory Rate = 25, Blood pressure = 80/50, Oxygen saturation = 100% on Hudson mask at 6 L/min. ECG – ventricular tachycardia, rate 150 bpm. He has already received 150mg of Amiodarone.

What are the key elements of your assessment of this patient?

Primary Survey (ABCDE):

• Airway: Patent but at risk (disoriented, potential aspiration)

• Breathing: Tachypnoeic (RR 25) but SpO₂ 100% - monitor for fatigue

• Circulation:

  • Unstable VT (HR 150, BP 80/50) → prepare for synchronized DC cardioversion (200J)

  • Large bore IV access, draw bloods (FBC, UEC, troponin, VBG)

  • Fluid challenge (250ml crystalloid) + vasopressor ready (metaraminol)

• Disability: GCS assessment (disoriented - consider head injury)

• Exposure: Check for trauma (pelvis, long bones)

Secondary Assessment:

• Cardiac: Ischaemia? (IHD history, check ECG for STEMI)

• Sedation Risk: Elderly, unstable, polypharmacy → high risk for complications

• Shoulder Relocation: Can wait until haemodynamically stable

Common Pitfalls:

• Delaying cardioversion for more amiodarone

• Missing occult bleeding (especially with aspirin use)

• Underestimating aspiration risk

Walk me through your decision-making process for managing this unstable VT

This is a time-critical emergency requiring immediate intervention. The key features making this unstable VT are:

• SBP <90 mmHg with evidence of poor perfusion (tachycardia, disorientation)

• Failed chemical cardioversion with amiodarone 150mg

My immediate actions would be:

1. Prepare for synchronized DC cardioversion at 200J while continuing CPR as needed

2. Ensure adequate IV access and draw emergency bloods

3. *Administer 100% oxygen via non-rebreather mask*

4. *Have vasopressors drawn up (metaraminol 0.5mg boluses) for post-cardioversion hypotension*

I would not delay cardioversion for further amiodarone in this unstable patient

How would you comprehensively assess for potential causes of this patient's instability?

I would consider:

• Cardiac causes:

  • Acute coronary syndrome (check ECG for STEMI, troponin)

  • Structural heart disease (known IHD)

• Hypovolaemia:

  • Trauma from fall (pelvic/abdominal bleeding)

  • GI bleed (on aspirin)

• Other causes:

  • PE (unlikely with this presentation)

  • Sepsis (check temperature, WCC)

In Scenarioville, without immediate CT availability, I would rely on:

• Clinical examination for trauma

• Bedside ultrasound if available

• Trend in Hb and lactate

Discuss your approach to airway management in this scenario

This patient has multiple risk factors for airway compromise:

• Elderly

• Reduced GCS

• Full stomach (recent trauma)

• Potential for hemodynamic collapse

My approach would be:

• Prepare for RSI with backup plan for failed intubation

• Have suction ready and position optimally

• *Choose induction agents carefully (e.g., ketamine 1-2mg/kg for hemodynamic stability)*

• Have second operator available for cricoid pressure

In Scenarioville's resource-limited setting, I would:

• Ensure all emergency airway equipment is checked and ready

• Have a plan for surgical airway if needed

How would you modify your management knowing retrieval to tertiary care takes 2 hours?

This significantly impacts my decision-making:

• I would be more aggressive with initial stabilization

• Have lower threshold for intubation given prolonged transfer times

• Ensure all necessary interventions are done before transfer (e.g., adequate vascular access, stable airway)

• Administer any time-critical medications (e.g., antibiotics for open fracture) before retrieval team arrives

I would also:

• Contact retrieval team early for advice

• Prepare comprehensive handover including all interventions and responses

What specific challenges does this patient's age and comorbidities present?

Key considerations for this 75-year-old with multiple comorbidities:

• Reduced physiological reserve: Less tolerant of hypotension/hypoxia

• Polypharmacy: Potential drug interactions (especially with amiodarone)

• Atherosclerosis: Higher risk of end-organ damage from hypotension

• Reduced drug clearance: More sensitive to sedatives/analgesics

My modifications would include:

• More cautious fluid administration

• Lower dosing of sedatives/analgesics with careful titration

• Enhanced monitoring for end-organ perfusion

The VT has resolved after cardioversion (SR, BP now 110/70). How will you proceed with shoulder reduction?

Sedation Plan (ANZCA PS08):

• Goal: Minimal effective sedation - titrate to response

• Agents:

  • Fentanyl 25-50mcg aliquots + midazolam 0.5-1mg (caution in elderly)

  • Alternative: Ketamine 0.5mg/kg (haemodynamically neutral)

• Monitoring:

  • ECG, SpO₂, NIBP, ETCO₂ (capnography essential)

  • Consider arterial line if ongoing instability

Airway Management:

• Have RSI kit ready (unpredictable responses in elderly)

• Avoid deep sedation → risk of aspiration

Reduction Technique:

• Coordinate with ED team for quick, efficient reduction

• Consider intra-articular lidocaine if sedation inadequate

Common Pitfalls:

• Over-sedating elderly patients

• Omitting capnography → missing respiratory depression

• Failing to prepare for GA conversion

Detail your pharmacological approach to sedation in this high-risk patient

For this elderly patient with recent cardiac instability, I would use:

• Opioid: Fentanyl 25mcg aliquots (max 1-1.5mcg/kg) - titrated to effect

  • Rationale: Short-acting, less histamine release than morphine

• Sedative: Midazolam 0.5mg aliquots (max 2mg total)

  • Rationale: Titratable, reversible with flumazenil

• Alternative: Ketamine 0.5mg/kg bolus + 10mg aliquots

  • Advantages: Maintains airway reflexes, hemodynamic stability

  • Disadvantages: Potential emergence phenomena

Critical monitoring would include:

• Capnography for early detection of respiratory depression

• Continuous ECG for arrhythmia detection

• Frequent BP measurements (at least every 3 minutes)

Discuss the pros and cons of different reduction techniques in this context

Traditional sedation + reduction:

• Pros: Familiar to ED staff, doesn't require paralysis

• Cons: Higher risk of respiratory depression in elderly

Intra-articular lidocaine:

• Pros: Avoids systemic sedation

• Cons: May be insufficient analgesia for reduction

GA with muscle relaxation:

• Pros: Optimal conditions for reduction

• Cons: Requires intubation, higher risk in unstable patient

For this patient, I would recommend:

• Titrated sedation with fentanyl/ketamine

• Have GA backup available

• Consider adding intra-articular lidocaine as adjunct

How would you manage a scenario where the patient becomes hypotensive during reduction?

Immediate actions:

1. Stop procedure and call for help

2. Administer 100% oxygen

3. Fluid bolus (250ml crystalloid)

4. Vasopressor (metaraminol 0.5mg IV)

Simultaneously assess for:

• Over-sedation (check respiratory rate, ETCO₂)

• Occult bleeding (check surgical site, Hb trend)

• Arrhythmia recurrence (check ECG)

If unresolved:

• Consider GA with intubation

• Prepare for transfer to higher level care

What specific equipment checks would you perform before starting?

Essential equipment checks:

• Working suction tested

• Airway trolley with all difficult airway equipment

• Emergency drugs drawn up (including flumazenil, naloxone)

• Defibrillator charged and pads attached

• Oxygen supply checked (adequate for procedure + potential transfer)

In Scenarioville's resource-limited setting, I would additionally:

• Confirm backup power sources

• Check availability of senior help

• Ensure retrieval team is aware of impending procedure

How would you modify your approach if the shoulder was open/dislocated for >6 hours?

This changes the urgency and risk-benefit analysis:

• Higher risk of:

  • Neurovascular injury

  • Avascular necrosis

  • Reduction difficulty

My modified approach would include:

• More comprehensive neurovascular exam pre-reduction

• Lower threshold for GA with muscle relaxation

• Consider orthopedic consultation

• Post-reduction X-ray mandatory

• Admission for observation likely needed

Post-reduction, the patient is agitated and confused. How will you manage this?

Differential Diagnosis:

• Hypoxia (check SpO₂, ABG)

• Drug effects (opioids/benzodiazepines)

• Metabolic (hypoglycaemia, electrolytes)

• Intracranial injury (fall history)

Management:

• Immediate:

  • Check glucose, SpO₂

  • Consider naloxone 40mcg aliquots if opioid toxicity suspected

• Pharmacological:

  • Haloperidol 0.5mg IV (avoid benzodiazepines in elderly)

• Investigations:

  • CT head if focal signs (Scenarioville may need retrieval for this)

Discharge Planning:

• Must have responsible adult escort

• Document delirium for future procedures

• Follow-up arranged for cardiac review

Common Pitfalls:

• Assuming "just delirium" without excluding life threats

• Discharging without proper escort

• Over-sedating with benzodiazepines

Take me through your systematic approach to post-procedural agitation

My approach would be:

1. Primary survey (ABCDE): Ensure no immediate life threats

2. Focused history:

   • Timeline of agitation onset

   • Recent medication administration

   • Any witnessed seizure activity

3. Targeted examination:

   • Neurological exam (focal signs?)

   • Signs of opioid toxicity (pinpoint pupils, respiratory depression)

   • Evidence of trauma

4. Investigations:

   • Bedside glucose

   • ABG/VBG (pH, lactate)

   • ECG (QT prolongation?)

5. Management:

   • Treat reversible causes first

   • Pharmacological intervention only if necessary

How would you differentiate between drug-induced delirium and intracranial pathology?

Key differentiating features:

• Drug-induced:

  • Temporal relationship to medication administration

  • Associated signs (miosis with opioids, nystagmus with ketamine)

  • Improves with reversal agents

• Intracranial pathology:

  • Focal neurological signs

  • Persistent/recurrent vomiting

  • Progressive deterioration

• In Scenarioville, without immediate CT:

  • I would have low threshold for retrieval if any red flags present

  • Monitor closely for signs of herniation

Discuss your pharmacological options for managing agitation in this elderly patient

First-line: Non-pharmacological measures (reorientation, family presence)

If pharmacological treatment needed:

• Haloperidol 0.5mg IV:

  • Advantages: Minimal respiratory depression

  • Risks: QT prolongation, extrapyramidal effects

• Avoid:

  • Benzodiazepines (paradoxical agitation in elderly)

  • Typical antipsychotics in Parkinson's disease

Special considerations:

• Reduced dosing in elderly

• Cardiac monitoring (especially with haloperidol)

• Frequent reassessment

What would be your absolute contraindications to discharge in this patient?

Absolute contraindications would include:

• Ongoing confusion/disorientation

• Unstable vital signs

• Inadequate pain control

• No responsible adult available for escort

• Concerns about intracranial pathology

• Recurrent arrhythmias

In Scenarioville's context, I would be particularly cautious about:

• Patients living alone in remote areas

• Lack of follow-up options

• Limited access to emergency care

How would you document and communicate this event to prevent future complications?

Comprehensive documentation should include:

• Detailed timeline of events

• All medications administered (doses, times)

• Patient response to interventions

• Differential diagnosis considered

• Discharge instructions and follow-up plan

Communication strategies:

• Clear handover to receiving team

• Documentation in "alert" section of medical record

• Discussion with patient's GP

• Consider medicolegal documentation if adverse outcome

For future procedures:

• Flag in records as "high risk for delirium"

• Recommend pre-op geriatric assessment

• Suggest alternative sedation strategies

Key Learning Points

1. Life-threatening arrhythmias require immediate cardioversion in unstable patients

2. Elderly patients need modified sedation approaches (lower doses, careful titration)

3. Post-procedural agitation requires systematic assessment to exclude serious causes

4. Resource-limited settings demand pragmatic solutions without compromising safety

5. Comprehensive documentation is essential for medicolegal protection and future care

Critical Phrases for Examiners

• "This meets criteria for immediate synchronized cardioversion"

• "Capnography is non-negotiable for procedural sedation in high-risk patients"

• "I would not discharge without ensuring adequate supervision given this patient's risk factors"