2024.1 Day 1 VIVA 5

Regional Anaesthesia

A 64-year-old woman is having an elective left total knee replacement (TKR) in 2 weeks. You are seeing her in the pre-admission clinic.

She has a background history of hypertension, COPD and Type 2 diabetes mellitus. She takes metformin, dapagliflozin, salmeterol / fluticasone (Seretide), tiotropium (Spiriva) and ramipril. She is 95kg and 160cm tall (BMI = 37).

She had a previous right TKR under spinal + sedation which worked well, and she is keen for the same anaesthetic again.

How would you assess this patient for this procedure?

• Cardiovascular:

  • Assess HTN control - check recent BP readings and end-organ damage

  • Review ECG for LVH/ischemia given her risk factors

  • Calculate METs - specifically ask about climbing stairs or walking distance

• Respiratory:

  • Document COPD severity using GOLD criteria - exacerbation frequency, home oxygen use

  • Auscultate for wheeze/crackles - optimize bronchodilators pre-op

• Endocrine:

  • Check HbA1c - aim <8% for elective surgery

  • Plan SGLT2i cessation (dapagliflozin) 3 days preoperatively

Consent

• Discuss risks specific to her profile: higher spinal failure rate in obesity

• Explain possible need for GA conversion

Airway:

• Full airway exam despite planned spinal - document Mallampati, thyromental distance

• Review previous anaesthetic chart for airway management details

Her clinic BP is 158/92 today. How does this affect your plan?

This represents stage 2 hypertension - I would:

1. Check for symptoms of end-organ damage (headache, visual changes)

2. Review her medication adherence - consider increasing ramipril dose if compliant

3. Order basic investigations (UEC, urinalysis for proteinuria)

4. If asymptomatic, proceed but ensure careful BP monitoring perioperatively

5. Discuss with surgeon about potential benefit of delaying 1-2 weeks for better control

She reports using her salmeterol/fluticasone inhaler twice daily but still gets breathless climbing one flight of stairs. What's your concern?

This functional limitation (METs ~4) raises several considerations:

1. Likely moderate COPD - I'd want to:

   • Verify inhaler technique

   • Consider adding tiotropium if not already prescribed

   • Request CXR to exclude infection/pneumonia

2. Assess for other causes:

   • Cardiac ischemia (stress test if high suspicion)

   • Anaemia (check FBC)

3. For perioperative management:

   • Plan for spinal to reduce pulmonary complications

   • Consider HDU post-op if severe compromise

The surgeon asks if we should cancel due to her BMI. What's your view?

Obesity alone isn't an absolute contraindication, but we should consider:

1. Technical factors:

   • Higher spinal failure rates (15-20% vs 5% in non-obese)

   • May need longer spinal needle/Tuohy for epidural conversion

2. Physiological challenges:

   • Increased aspiration risk if converting to GA

   • Higher thromboembolic risk

3. My recommendation would be:

   • Proceed with spinal attempt by most experienced operator

   • Have low threshold for ultrasound assistance

   • Ensure full GA backup preparations

How would you modify her diabetic medications perioperatively?

For her T2DM management:

1. Dapagliflozin:

   • Stop 3 days pre-op due to SGLT2i-associated DKA risk

   • Check ketones if unwell perioperatively

2. Metformin:

   • Hold morning of surgery (risk of lactic acidosis if renal impairment)

   • Restart when eating/drinking post-op

3. Intraoperative:

   • Monitor BGL hourly

4. Postoperative:

   • Early diabetic review when eating

   • Temporary insulin regimen if require

Describe your planned spinal anaesthetic technique for this patient.

Preparation:

• Large-bore IV access (16G) + 500ml crystalloid coload

• Standard monitoring + invasive BP if cardiac compromise

• Positioning:

  • Sitting position with pillow support

  • Assistant to help maintain flexion

• Technique:

  • Ultrasound identification of L3/4 interspace

  • 25G pencil-point needle with 1% lidocaine infiltration

  • Hyperbaric bupivacaine 12mg + fentanyl 20mcg

• Sedation:

  • Propofol TCI 0.5-1.0mcg/ml

  • Titrate to maintain verbal contact

• Confirmation:

  • Cold test to confirm T10 sensory level

  • Document Bromage 3 motor block before positioning

Why choose hyperbaric bupivacaine 12mg rather than your usual dose?

The reduced dose (from standard 15mg) is because:

1. Patient factors:

   • Obesity increases cephalad spread

   • Combined with sedation reduces requirement

2. Safety benefits:

   • Lower risk of high spinal

   • More stable haemodynamics

3. Adequacy for surgery:

   • TKR only requires T10 level

   • Can supplement with femoral nerve block if inadequate

4. Evidence:

   • Supported by recent RA-UK guidelines for obese patients

The spinal seems slow to establish. Your management?

Systematic approach:

1. First confirm intrathecal placement:

   • Check for free CSF flow

   • Consider test dose with lignocaine

2. If confirmed but inadequate:

   • Wait full 15 minutes before supplementing

   • Consider epidural top-up if catheter placed

   • Femoral nerve block as plan B

3. If failed:

   • GA with RSI precautions

   • Post-op pain team referral for catheter

4. Documentation:

   • Clearly record level achieved

   • Note any technical difficulties

She becomes restless during the case. How would you proceed?

Stepwise management:

1. Assess:

   • Check block level (cold test)

   • Ask specifically about pain vs anxiety

2. Pain management:

   • Small fentanyl boluses (25-50mcg)

   • Consider ketamine 10-20mg if refractory

3. Anxiety/sedation:

   • Increase propofol TCI by 0.2mcg/ml increments

   • Consider midazolam 1mg if very anxious

4. Surgical factors:

   • Discuss tourniquet time with surgeon

   • Ensure adequate padding/pressure points

The surgeon requests muscle relaxation. Your options?

Balanced approach considering:

1. Without intubation:

   • Limited options - deepen sedation carefully

   • Communicate limitations to surgeon

2. If converting to GA:

   • RSI with suxamethonium

   • Consider sugammadex for reversal

3. Compromise:

   • Small dose rocuronium (10mg) if maintaining spontaneous ventilation

   • Must have reversal available

4. Documentation:

   • Clearly record all discussions

   • Note muscle relaxant use if given

15 minutes after spinal administration, her BP drops to 70/40, HR 38, and she reports tingling in her fingers. What's happening?

• Diagnosis:

  • High spinal (tingling at C8/T1 indicates ascending block)

  • Differentials: MI, PE, anaphylaxis, vasovagal

• Immediate Actions:

  • Call for help (ANA Crisis Handbook algorithm)

  • Trendelenburg position + 100% O2

  • Rapid 500ml fluid bolus

  • Glycopyrrolate 200mcg IV

  • Phenylephrine 100mcg boluses

• Monitoring:

  • Continuous ECG for arrhythmias

  • Check sensory level (likely above T1)

  • Prepare for intubation if respiratory failure

She's now unconscious with agonal breathing. What's your management?

Escalated resuscitation:

1. Airway:

   • Immediate bag-valve-mask ventilation

   • RSI with ketamine 1-2mg/kg + suxamethonium

2. Circulation:

   • Adrenaline 50-100mcg boluses

   • Noradrenaline infusion (start at 0.05mcg/kg/min)

3. Monitoring:

   • Arterial line placement

   • ABG for acidosis/CO2 retention

4. Team coordination:

   • Assign roles (airway, drugs, scribe)

   • Prepare for prolonged resuscitation

How would you determine whether to continue surgery after stabilisation?

Multifactorial decision:

1. Patient factors:

   • Haemodynamic stability >20 minutes

   • Neurological status

2. Surgical factors:

   • Urgency (infection vs elective)

   • Current progress (bone cuts made?)

3. Team discussion:

   • Surgeon's assessment of viability

   • Anaesthetic team's comfort

4. Documentation:

   • Clear record of decision-making

   • Consultant involvement documented

What follow-up would you arrange post-crisis?

Comprehensive follow-up plan:

1. Medical:

   • 24hr neurology obs for any deficits

   • Cardiology review given haemodynamic instability

2. Documentation:

   • Incident report per hospital policy

   • Anaesthetic alert for future procedures

3. Patient communication:

   • Open disclosure meeting

   • Written summary for GP

4. Departmental:

   • M&M meeting presentation

   • Review of high spinal protocols

The surgeon insists on continuing. What factors would make you agree?

Conditional agreement requires:

1. Patient stability:

   • Normotensive without vasopressors >30 mins

   • Normal neurological exam

2. Surgical imperatives:

   • Prosthesis already implanted

   • High infection risk if aborted

3. Safety measures:

   • GA with controlled ventilation

   • Invasive monitoring (A-line, CVP)

   • HDU post-op

4. Documentation:

   • Clear consent for continued surgery

   • Consultant-to-consultant discussio

Critical Phrases Examiners Expect:

1. "High spinal requires immediate vasopressor therapy, not just fluid resuscitation"

2. "Obese patients need reduced spinal doses but heightened monitoring"