Postoperative Pain Management

Quick Answer

Postoperative pain management is a core anaesthetic competency affecting 30-50% of patients in the immediate postoperative period, with 10-20% developing chronic postoperative pain. The multimodal analgesia approach — combining different drug classes and non-pharmacological techniques — reduces opioid consumption by 30-50% and improves outcomes. Preemptive analgesia (medication administered before surgical incision) demonstrates superior efficacy compared to treatment-only approaches. Regional anaesthesia techniques (epidural, spinal, paravertebral block) provide superior analgesia for specific procedures (abdominal, thoracic, orthopaedic) with opioid-sparing effects. Non-opioid adjuvants — paracetamol, NSAIDs, gabapentinoids, TCAs, dexmedetomidine, ketamine, lidocaine infusions — reduce opioid requirements and target different pain mechanisms. Multimodal pathway management includes preoperative optimisation (PACU pathway), patient education, regular assessment with validated tools (NRS, VAS, BPI), and early intervention for poorly controlled pain. Enhanced Recovery After Surgery (ERAS) protocols improve patient satisfaction and reduce hospital length of stay by 1-2 days. Indigenous patients have higher postoperative pain scores (related to communication barriers, cultural beliefs about pain expression, higher rates of comorbidities), requiring culturally sensitive pain assessment, involvement of Aboriginal Health Workers, and adaptation of communication strategies to ensure effective pain management. [1-10]

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Pathophysiology

Postoperative Pain Mechanisms

Postoperative pain results from multiple mechanisms that often coexist:

1. Nociceptive Pain (Somatic and Visceral)

Somatic Pain:

• Tissue injury from surgical incision and manipulation
• Mediators: Bradykinin, histamine, prostaglandins, substance P, serotonins
• Receptors: Aδ and C fibers (Aδ: sharp, localized; C: dull, aching)
• Transmission: Via spinothalamic tracts to somatosensory cortex
• Characteristics: Well-localized, described as "sharp," "sore," "aching"
• Examples: Incision pain, orthopaedic postoperative pain

Visceral Pain:

• Organ manipulation and distension
• Mediators: Prostaglandins, histamine, cytokines
• Receptors: C fibers (poorly localized, diffuse distribution)
• Transmission: Via sympathetics and spinothalamic tracts
• Characteristics: Poorly localized, often referred, described as "deep," "pressure," "cramping"
• Examples: Abdominal pain, renal colic, shoulder pain from diaphragmatic irritation

2. Neuropathic Pain

Peripheral Nerve Injury:

• Direct nerve trauma (surgical transection, crush injury)
• Nerve ischemia (compression from edema, hematoma)
• Chemical irritation from local anaesthetics, antiseptics
• Inflammatory response releasing algogenic substances

Characteristics:

• Quality: Burning, tingling, "electric shock," lancinating
• Distribution: Dermatomal or peripheral nerve pattern
• Associated sensory changes: Allodynia (pain from non-painful stimuli), hyperalgesia (increased pain sensitivity)
• Motor changes: Weakness, atrophy

Examples:

• Thoracotomy pain (intercostal nerve injury)
• Phantom limb pain
• Causalgia (nerve crush injury)

3. Inflammatory Pain

Mechanism:

• Surgical trauma releases inflammatory mediators
• Key mediators: Prostaglandin E2, substance P, bradykinin, histamine, serotonin, cytokines (IL-1β, IL-6, TNF-α)
• Sensitizes nociceptors to mechanical and chemical stimuli
• Promotes extravasation of leukocytes and inflammatory cells

Peak Inflammatory Pain:

• Onset: Within 1-2 hours postoperatively
• Duration: 24-48 hours (correlates with inflammatory mediator release)
• Characteristics: Dull, aching, diffuse

Management Implications:

• NSAIDs effective (reduce prostaglandin synthesis)
• Steroids modulate inflammatory response
• Regional anaesthesia blocks peripheral sensitization

4. Visceral Hyperalgesia

Definition: Increased pain sensitivity occurring in body regions distant from the surgical site, often due to central sensitization.

Mechanism:

• Central sensitization: Enhanced responsiveness of spinal and supraspinal neurons
• Neuroplastic changes: Reorganization of somatosensory cortex
• Descending inhibition failure: Reduced endogenous pain control

Characteristics:

• Distribution: Beyond surgical incision site
• Intensity: May be severe and disproportionate to surgical stimulus
• Quality: Diffuse, poorly localized

Contributing Factors:

• Severe acute pain in immediate postoperative period
• Inadequate analgesia during surgery and emergence
• Pre-existing chronic pain with central sensitization
• Psychological factors (anxiety, catastrophizing)

Management:

• Preemptive analgesia (reduces central sensitization)
• N-methyl-D-aspartate (NMDA) receptor antagonists: Ketamine, magnesium
• Early aggressive pain control

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Clinical Presentation

Pain Assessment in Postoperative Period

Assessment Domains:

1. Pain Characteristics:

• Location and distribution
• Intensity at rest and with movement
• Quality (sharp, dull, aching, burning)
• Temporal pattern (constant, intermittent, movement-related)
• Aggravating and relieving factors

2. Functional Impact:

• Mobility (bed rest vs. ambulation)
• Deep breathing and coughing effectiveness
• Ability to perform ADLs (dressing, feeding, toileting)
• Sleep quality and duration

3. Psychological State:

• Anxiety level
• Pain catastrophizing
• Coping strategies
• Patient expectations

4. Medication Efficacy and Side Effects:

• Current analgesic regimen
• Pain relief achieved
• Adverse effects (nausea, sedation, respiratory depression)
• Opioid requirements

Validated Assessment Tools

Pain Intensity Measures:

Numeric Rating Scale (NRS):

• Scale: 0-10 (0 = no pain, 10 = worst pain imaginable)
• Assess: At rest and with movement/activity
• Advantages: Simple, rapid, familiar
• Use: Routine postoperative assessment, every 1-2 hours initially
• Target: NRS ≤4 at rest, ≤7 with movement

Visual Analog Scale (VAS):

• Scale: 100-mm line (0 = no pain, 100 = worst pain)
• Advantages: Visual, continuous scale
• Use: Particularly useful for patients with cognitive impairment
• Target: VAS ≤30 mm at rest, ≤50 mm with movement

Verbal Descriptor Scale (VDS):

• Scale: "No pain," "Mild," "Moderate," "Severe," "Worst possible"
• Advantages: Qualitative descriptors
• Use: Quick assessment, patients with language barriers
• Target: "Mild" or "Moderate" (not "Severe" or "Worst possible")

Functional Assessment:

Quality of Recovery Score (QoR-40):

• Assesses: Recovery quality in 40 domains (5 categories × 8 aspects)
• Categories: Patient support, comfort, emotions, physical independence, pain
• Score: 40-200 (higher = better recovery)
• Advantages: Comprehensive recovery assessment
• Use: Discharge planning, postoperative audit

Postoperative Quality of Recovery Scale (PQRS):

• Assesses: 18 items across 5 dimensions (comfort, emotions, physical independence, psychological support, pain)
• Score: 9-18 per dimension (lower = better recovery)
• Advantages: Quick administration (5-10 minutes)
• Use: Routine postoperative assessment

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Management

Multimodal Analgesia Principles

Definition: Multimodal analgesia is the concurrent use of two or more analgesic medications or techniques with different mechanisms of action, targeting different points in the pain pathway.

Key Components:

1. Preemptive Analgesia

Definition: Administration of analgesics before surgical incision.

Mechanism:

• Prevents peripheral and central sensitization
• Reduces neuroplastic changes
• Attenuates inflammatory response

Evidence:

• 30-50% reduction in acute postoperative pain scores
• Reduced opioid consumption by 20-40%
• Lower incidence of chronic postoperative pain

Preemptive Regimens:

2. Regional Anaesthesia

Advantages:

• Superior analgesia compared to systemic opioids
• Opioid-sparing effect: 30-50% reduction in opioid requirements
• Reduced side effects: Nausea, vomiting, sedation, respiratory depression
• Improved respiratory function: Better deep breathing, cough
• Earlier ambulation: Pain control without sedation
• Facilitates early discharge: Pain managed, recovery enhanced

Types:

Epidural Analgesia:

• Indications: Abdominal, thoracic, lower limb surgery
• Medications: Local anaesthetic ± opioid
• Advantages: Bilateral analgesia, prolonged duration (12-24 hours)
• Disadvantages: Urinary retention, hypotension, motor block

Paravertebral Block:

• Indications: Abdominal, hip, lower limb surgery
• Medications: Local anaesthetic ± opioid ± clonidine
• Advantages: Unilateral, longer duration (up to 24 hours), less hypotension than epidural
• Techniques: Paramedian, transforaminal, sagittal (Pecs 1 and 2)

Peripheral Nerve Blocks:

• Brachial Plexus: Upper limb surgery
• Neuraxial Block: Lower limb surgery
• Transversus Abdominis Plane (TAP) Block: Abdominal surgery
• Femoral Nerve Block: Knee surgery
• Sciatic Nerve Block: Foot and ankle surgery

3. Systemic Pharmacological Management

Opioids:

Mechanism: μ-opioid receptor agonism in CNS and PNS.

Common Postoperative Opioids:

Principles:

• Start low, go slow: Begin with low dose, titrate to effect
• Avoid undertreatment: Titrate to adequate analgesia (NRS ≤4 at rest)
• Use patient-controlled analgesia (PCA): Allows patient titration, improves satisfaction
• Avoid excessive sedation: Maintain airway, respiratory drive
• Monitor for side effects: Nausea, vomiting, pruritus, respiratory depression

NSAIDs:

Mechanism: Cyclo-oxygenase (COX) inhibition → reduced prostaglandin synthesis.

Common NSAIDs:

Paracetamol as Core Adjuvant:

• Mechanism: Central COX inhibition (different from NSAIDs)
• Opioid-sparing: Reduces opioid requirements by 20-30%
• Safety: Minimal side effects, no GI toxicity, renal safe
• Maximum dose: 4 g/day (adults), reduced to 3 g/day in chronic use or hepatic impairment

Paracetamol + Opioid Combination:

• Improved analgesia compared to opioid alone
• Synergistic effect: Different mechanisms of action
• Allows lower opioid dose (reduced side effects)
• Examples: Endone (oxycodone 5 mg + paracetamol 325 mg), Targinact (tramadol 37.5 mg + paracetamol 325 mg)

Gabapentinoids (Neuropathic Pain Modifiers):

Mechanism: α2δ subunit of voltage-gated calcium channels → reduced excitatory neurotransmission.

Indications:

• Chronic neuropathic pain (diabetic neuropathy, postherpetic neuralgia)
• Postoperative neuropathic pain (nerve injury during surgery)

Common Agents:

Opioid-Sparing Effect:

• 20-30% reduction in opioid requirements
• Particularly effective for neuropathic components
• Requires preloading for effect (start 12-24 hours pre-op or immediate post-op)

NMDA Receptor Antagonists (Ketamine):

Mechanism: Non-competitive NMDA receptor antagonism → central sensitization prevention.

Indications:

• Major surgery with anticipated severe pain
• Opioid tolerance (reduced opioid efficacy)
• Neuropathic pain components

Dosing:

• Low-dose infusion: 0.1-0.3 mg/kg/hour (subanesthetic doses)
• Duration: 24-48 hours postoperatively
• Can be continued as oral or IV

Benefits:

• Opioid-sparing: 20-30% reduction in requirements
• Prevents central sensitization: Reduces hyperalgesia
• Reduces opioid tolerance: May reduce postoperative opioid requirements

Side Effects:

• Psychomimetic effects: Hallucinations, vivid dreams (mitigate with benzodiazepine)
• Nausea: Anti-emetic prophylaxis
• Hemodynamic changes: Usually minimal at low doses

Dexamethasone:

Mechanism: Potent glucocorticoid → anti-inflammatory, anti-edema, reduced nociceptor sensitization.

Benefits:

• Anti-emetic effect: Reduces PONV (postoperative nausea and vomiting)
• Anti-inflammatory: Reduces tissue edema and inflammatory pain
• Opioid-sparing: May reduce postoperative opioid requirements
• Improved pain scores: 30-40% reduction at 24 hours

Dosing:

• 0.1-0.2 mg/kg IV (typical postoperative dose)
• 8 mg IV for 70 kg adult
• Single dose (occasionally repeated dose 12-24 hours)

Contraindications:

• Infection: Active infection at surgical site (delayed wound healing)
• Recent vaccination: Live vaccines within 4-6 weeks
• Uncontrolled diabetes: May worsen hyperglycaemia

Lidocaine Infusions:

Mechanism: Sodium channel blockade → peripheral nerve analgesia.

Indications:

• Thoracic surgery (thoracotomy, VATS, cardiac surgery)
• Upper abdominal surgery with epidural analgesia
• Nerve injury during surgery (intercostal nerves)

Dosing:

• 1-2 mg/kg/hour IV infusion
• Duration: 24-72 hours postoperatively
• Usually via epidural catheter

Benefits:

• Excellent analgesia for somatic pain
• Opioid-sparing: 50-80% reduction in opioid requirements
• Reduced neuropathic pain: Nerve injury analgesia
• Facilitates coughing: Pain-free deep breathing

Risks:

• Toxicity: Dose-related (tinnitus, perioral numbness, seizures)
• Motor block: Weakness with higher doses
• Catheter-related: Infection, displacement

4. Non-Pharmacological Techniques

Patient Education and Expectation Setting:

Key Components:

• Pain as expected: Normalizing pain experience
• Functional expectations: "Some discomfort is expected"
• Active participation: Encourage deep breathing, early ambulation
• Goal setting: Pain NRS ≤4 at rest, return to normal activities

Early Ambulation:

• Benefits: Reduced pulmonary complications, shorter hospital stay, faster recovery
• Timing: Within 6-8 hours postoperatively when pain controlled
• Requirements: Adequate analgesia, hemodynamic stability, nausea/vomiting controlled

Physical Therapy:

• Incentive spirometry: Improves lung volumes, reduces pulmonary complications
• Early mobilization: Prevents stiffness, venous thromboembolism
• Exercise prescription: Gradual return to normal activity

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ANZCA Final Exam Focus

SAQ Patterns

Postoperative pain management features regularly in ANZCA Final Written Examination. Common SAQ themes include:

Management-Focused Questions:

• "A 65-year-old man undergoing laparoscopic colectomy has severe postoperative pain (NRS 8/10). Outline your management." (2020)
• "Describe multimodal analgesia for major abdominal surgery." (2021)
• "How would you manage a patient with inadequate postoperative analgesia?"

Pharmacology-Focused Questions:

• "Explain the mechanism of action and clinical use of paracetamol in postoperative pain."
• "Compare the pharmacology of gabapentin and pregabalin."
• "What are the side effects and monitoring requirements for PCA?"

Regional Anaesthesia Questions:

• "Describe the benefits of epidural analgesia for abdominal surgery."
• "What are the contraindications for paravertebral block?"
• "Compare epidural vs. paravertebral block for lower limb surgery."

Complication-Focused Questions:

• "A patient develops respiratory depression with postoperative opioid use. How would you manage this?"
• "Describe PONV (postoperative nausea and vomiting) prophylaxis."
• "What are the red flags in postoperative period that require urgent intervention?"

Marking Scheme Priorities:

• Multimodal analgesia principles (different mechanisms)
• Regional anaesthesia use where appropriate
• Opioid sparing strategies
• Preemptive analgesia
• Validated pain assessment tools
• Side effect management
• Patient education and expectation setting
• Early ambulation
• Red flag recognition

Clinical Viva Themes

The Clinical Viva frequently includes postoperative pain scenarios:

Scenario Types:

• Inadequate postoperative analgesia
• Postoperative respiratory depression
• PONV management
• Epidural complications
• Regional anaesthesia placement
• Chronic postoperative pain development

Examiner Expectations:

• Systematic pain assessment approach
• Knowledge of analgesic mechanisms and doses
• Understanding of multimodal principles
• Regional anaesthesia techniques and benefits
• Management of analgesic complications
• Team communication and leadership
• Patient-centered care

Common Viva Questions:

• "How would you assess postoperative pain?"
• "What are the components of multimodal analgesia?"
• "When would you use epidural analgesia?"
• "What are the opioid-sparing strategies?"
• "How would you manage respiratory depression from opioids?"
• "What is PONV prophylaxis?"
• "How does preemptive analgesia work?"
• "What are the red flags postoperatively?"

Medical Viva Considerations

The Medical Viva may include postoperative pain within broader discussions:

• Pain physiology and classification
• Pharmacology of analgesics
• Evidence for multimodal analgesia
• Regional anaesthesia techniques
• Postoperative pain outcomes research

Key Points for Examination Success

1. Multimodal is foundational — know all components (regional + systemic + non-pharmacological)
2. Opioid sparing is critical — paracetamol, gabapentinoids, regional anaesthesia
3. Validated assessment tools — NRS, VAS, BPI
4. Regional anaesthesia benefits — superior analgesia, opioid sparing, earlier recovery
5. Preemptive analgesia evidence — reduces central sensitization
6. Side effect management — anticipate and treat nausea, sedation, respiratory depression
7. Red flag recognition — respiratory depression, ileus, uncontrolled pain
8. Patient education — set expectations, encourage early ambulation

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Assessment Content

SAQ Practice Question 1 (20 marks)

Question:

A 72-year-old woman (65 kg) undergoing laparoscopic sigmoid colectomy. In PACU, patient reports severe pain (NRS 8/10) despite receiving morphine 4 mg SC q4h and paracetamol 1 g q6h. She is reluctant to deep breathe due to pain and refuses to ambulate.

(a) What assessment domains would you evaluate? (5 marks)

(b) Describe your multimodal analgesia plan. (8 marks)

(c) How would you manage this patient's reluctance to mobilize? (7 marks)

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Model Answer:

(a) Assessment Domains (5 marks)

1. Pain Characteristics [1 mark]

• Location: Abdominal (laparoscopic port sites, midline incision)
• Intensity: NRS 8/10 (severe) — inadequate current analgesia
• Quality: Not specified (would ask: sharp, dull, aching, burning, etc.)
• Temporal: Constant vs. intermittent
• Aggravating: Movement, deep breathing

2. Functional Impact [1 mark]

• Mobility: Reluctant to ambulate → severe impairment
• Deep breathing: Inability due to pain
• ADLs: Impaired (cannot perform normal activities)

3. Psychological State [1 mark]

• Anxiety: High (refusing ambulate due to pain)
• Catastrophizing: Possible (fear of movement)
• Coping: Maladaptive (avoidance behavior)
• Expectations: May be unrealistic (expecting pain-free)

4. Medication Review [1 mark]

• Current regimen:
  • Morphine 4 mg SC q4h (suboptimal dose for severe pain)
  • Paracetamol 1 g q6h (appropriate)
• Effectiveness: Inadequate (NRS 8/10)
• Side effects: Not specified but assess for sedation, nausea, pruritus

5. Red Flag Screening [1 mark]

• Respiratory depression: Assess RR, SpO₂
• Ileus: Assess bowel sounds, abdominal distension
• Surgical complications: Bleeding, anastomotic leak, infection
• Cardiac events: Ischaemia, arrhythmias

(b) Multimodal Analgesia Plan (8 marks)

1. Optimize Systemic Pharmacology [2 marks]

Opioid Optimization:

• Morphine: Increase from 4 mg SC q4h → 6-8 mg SC q4h or convert to PCA
  • SC route: Poor bioavailability, consider IV for rapid titration
  • PCA: 1 mg bolus, 5 min lockout, basal 1-2 mg/hour
• Target: NRS ≤4 at rest, ≤6 with movement

Paracetamol Optimization:

• Current dose: 1 g q6h (appropriate)
• Ensure regular timing: q6h around the clock
• Consider IV paracetamol: If NPO or poor oral absorption

Gabapentinoid Addition:

• Indication: Major abdominal surgery + neuropathic pain likely
• Pregabalin: 75 mg bd (starting dose)
  • Titrate to 150 mg bd over 1-2 weeks if needed
  • Start preoperatively or immediate post-op for preemptive effect
• Opioid-sparing: Expect 20-30% reduction in requirements

2. Regional Anaesthesia [2 marks]

Epidural Analgesia:

• Indication: Major abdominal surgery (sigmoid colectomy)
• Placement: Lumbar epidural (T10-T12 level)
• Medication: Ropivacaine 0.1-0.2% with fentanyl 2 μg/mL
• Benefits:
  • Superior analgesia for abdominal surgery
  • Opioid-sparing: 30-50% reduction
  • Facilitates early ambulation (pain control without sedation)
  • Improves respiratory function

3. NSAID/Anti-inflammatory [1 mark]

• Celecoxib: 200 mg PO (first dose)
  • COX-2 selective (lower GI risk)
  • Reduces inflammatory pain component
• Paracetamol: 1 g IV/PO q6h (continued)
  • Synergistic with opioids, opioid-sparing

4. Dexamethasone [1 mark]

• 0.15-0.2 mg/kg IV (10-13 mg for 65 kg patient)
• Anti-emetic: Reduces PONV
• Anti-inflammatory: Reduces tissue edema and inflammatory pain
• Opioid-sparing: May reduce postoperative opioid requirements

5. Non-Pharmacological Strategies [1 mark]

• Patient education: Set realistic expectations (some discomfort expected)
• Encourage early ambulation: Once pain controlled to NRS ≤4-6
• Incentive spirometry: Improves respiratory function
• Physiotherapy: Early mobilization, exercises

6. Side Effect Management [1 mark]

• Anti-emetic prophylaxis:
  • Ondansetron 4 mg IV pre-induction + 8 mg q8h post-op
  • Dexamethasone 8 mg IV (already planned)
  • Consider droperidol 1.25 mg if high PONV risk
• Monitor for respiratory depression: SpO₂, respiratory rate, sedation score
• Treat pruritus: If morphine-related, consider antihistamine

(c) Managing Reluctance to Mobilize (7 marks)

1. Assess and Understand Barriers [1 mark]

• Specific fears: What exactly does patient fear? (pain, wound opening, falling)
• Beliefs: Concerns about damaging incision
• Past experiences: Previous bad postoperative recovery?
• Misconceptions: Believes rest is better than movement

2. Validate and Reassure [1.5 marks]

• Acknowledge pain: "I can see this is very severe"
• Validate feelings: "It's completely understandable to be worried about moving"
• Reassure about wound integrity: "Your incision is secure, opening it won't cause damage"
• Explain benefits: "Movement actually helps healing, prevents blood clots, improves lung function"

3. Optimize Analgesia FIRST [1.5 marks]

• Current analgesia inadequate: NRS 8/10 despite morphine 4 mg q4h
• Escalate aggressively:
  • Increase morphine dose (PCA preferred for rapid titration)
  • Add gabapentinoid (pregabalin) if not already started
  • Ensure epidural functioning optimally (if present)
  • Consider additional boluses before mobilization attempts
• Goal: Reduce pain to acceptable level (NRS ≤4) before asking patient to move

4. Gradual Mobilization Plan [1.5 marks]

• Step-wise approach:
  • Sit at edge of bed → dangle legs → stand → take 2-3 steps
  • Each step only after pain acceptable at current level
  • Provide physiotherapy/assistant support throughout
• Positive reinforcement: "Excellent! You're doing great, just a few more steps"
• Rest breaks: Return to bed when pain increases, try again later

5. Fear Exposure with Graded Activity [1.5 marks]

• Education: Explain pain increases with movement initially but improves
• Graded activities:
  • Deep breathing in bed (assess pain tolerance)
  • Cough and deep breathe (vital for lung function)
  • Sitting up (gradual)
  • Standing with support
• Goal: Demonstrate that movement doesn't worsen pain or damage

(Total: 20 marks)

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Viva Scenario (25 marks)

Opening Stem:

You are the consultant anaesthetist responsible for the care of a 58-year-old man (80 kg) who is 2 days post-laparoscopic prostatectomy with an ileal conduit. The patient reports severe pain (NRS 8/10) despite receiving oxycodone 10 mg q6h PO and ibuprofen 400 mg q6h PO. He describes the pain as burning and shooting down his right leg. He has not ambulated since surgery due to pain and anxiety. On examination, he is haemodynamically stable with SpO₂ 96% on room air. His epidural catheter was removed POD 2.

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Expected Viva Progression:

Examiner: What are your immediate concerns and priorities?

Candidate Response: [4 marks]

"My immediate concerns are:

1. Inadequate Analgesia [1 mark]

• Pain NRS 8/10 (severe) despite moderate opioid dose (oxycodone 10 mg q6h ≈ morphine 20 mg/day)
• Burning/shooting quality in right leg suggests neuropathic pain component
• Poor functional status: Not ambulated for 2 days post-major surgery
• This represents treatment failure requiring urgent reassessment

2. Red Flags to Exclude [1 mark]

• Ileus: Has not passed stool/flatus in 2 days → assess bowel sounds, abdominal distension
• Surgical complication: Leak from ileal conduit (urosepsis risk), anastomotic breakdown
• Infection: Fever, leukocytosis, wound erythema
• Deep vein thrombosis: Unilateral leg swelling, DVT signs
• Compartment syndrome: Leg pain, swelling, tense compartments

3. Neuropathic Pain Indicators [1 mark]

• Burning/shooting quality: Classic neuropathic descriptor
• Right leg distribution: May indicate obturator nerve injury during prostatectomy
• Epidural removed: Lost regional analgesia that may have been masking neuropathic component
• Requires neuropathic pain modifiers (gabapentinoids, TCAs, SNRIs)

4. Psychological Distress [0.5 mark]

• Anxiety about pain and movement
• Catastrophizing thoughts (fear of damage)
• Avoidance behavior (not ambulating)
• Requires psychological support alongside analgesic optimization

5. Medication Inefficacy [0.5 mark]

• Oxycodone dose: 10 mg q6h PO (suboptimal for severe postoperative pain)
• Consider PCA: IV opioid for rapid titration
• No gabapentinoid: Neuropathic pain component untreated
• Multimodal analgesia inadequate: Missing key components

Priorities:

1. Exclude red flags (urgent imaging, surgical consult)
2. Optimize analgesia (increase opioid, add gabapentinoid)
3. Address neuropathic component
4. Provide psychological support
5. Facilitate gradual ambulation"

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Examiner: What specific interventions would you implement?

Candidate Response: [5 marks]

"I would implement a comprehensive multimodal approach:

1. Urgent Red Flag Exclusion [1.5 marks]

Surgical Consult:

• Urgent review by urology/surgical team
• Assess for: Ileal conduit leak, anastomotic breakdown
• CT abdomen with contrast if leak suspected

DVT/PE Screen:

• Bilateral lower limb doppler ultrasound
• D-dimer if DVT suspected
• Consider CT pulmonary angiogram if PE suspected

2. Analgesic Optimization [2 marks]

Opioid Optimization:

• Convert to PCA: Morphine or hydromorphone PCA
  • Initial settings: 1 mg bolus, 5 min lockout, 1-2 mg/hour basal
  • Titrate to effect (NRS ≤4 at rest)
• Consider methadone: If long-acting opioid preferred for stability
  • Starting 5-10 mg PO bd (methadone 10:1 morphine equivalent)
  • Once-daily dosing, more stable plasma levels

Add Neuropathic Pain Modifiers:

• Pregabalin: 75 mg bd (starting dose)
  • Titrate to 150-150 mg bd over 1-2 weeks as tolerated
  • Load immediately for preemptive effect: 300 mg PO load
  • Particularly effective for burning/shooting neuropathic pain
• Consider TCA: Amitriptyline 10-25 mg nocte (if gabapentinoid insufficient)
  • Neuropathic pain modulation
  • Improves sleep (patient has not ambulated)

Continue Paracetamol + NSAID:

• Paracetamol: 1 g IV q6h (more reliable than oral)
• Celecoxib: 200 mg PO daily (COX-2 selective, lower GI risk)
• Anti-inflammatory effect: May reduce inflammatory component of pain

3. Non-Pharmacological Interventions [1.5 marks]

Patient Education:

• Explain neuropathic component: "Burning/shooting pain is from nerve injury, not wound itself"
• Reassure about movement: "Walking won't damage your incision, prevents complications"
• Set expectations: Some discomfort expected with movement, will improve over time

Physiotherapy:

• Early mobilization assistance: Gradual ambulation program
• Desensitization techniques: Touch, tapping, rubbing around incision
• Graded exercises: Starting in bed, progressing to ambulation
• Incentive spirometry: Hourly, 10 breaths each, record volumes

Psychology Referral:

• Cognitive-behavioral therapy: Address pain catastrophizing, fear of movement
• Graded exposure: Systematic approach to feared activities
• Relaxation techniques: Breathing exercises, mindfulness

4. Complication Management [1 mark]

Monitor for:

• Ileus: Continue bowel sounds, NG tube if symptomatic
• Wound infection: Daily dressing changes, erythema, purulent discharge
• Anastomotic leak: Drain output monitoring, CT if concerned
• UTI symptoms: Dysuria, fever (catheter-related risk)

5. Regional Anaesthesia Reconsideration [1 mark]

Options if pain remains severe:

• Reinsert epidural: If still within postoperative period (POD 4-7)
• Consider paravertebral block: For somatic component
• Consider celiac plexus block: For visceral component
• Would provide superior analgesia for abdominal pain

6. Team Communication [1 mark]

Inform:

• Surgical team: Of analgesia plan, need for surgical review
• Nursing staff: Of new medication regimen, monitoring requirements
• Physiotherapy: Of mobilization plan
• Psychology team: Of referral and need for CBT"

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Examiner: The surgical review finds no leak or obstruction, DVT ultrasound is negative. Patient reports pain now NRS 5/10 after PCA + pregabalin. How would you manage this transition?

Candidate Response: [4 marks]

"This represents successful transition from severe pain to moderate pain:

1. Acknowledge and Reinforce Progress [1 mark]

• Validate improvement: "Your pain has reduced from 8/10 to 5/10 — this is excellent progress"
• Reinforce coping: "You're doing great with deep breathing and walking"
• Set realistic expectations: "Some pain is normal after major surgery"

2. Optimize Current Regimen [1 mark]

• PCA settings: May titrate lockout to 10 min (allows more patient control, reduces bolus frequency)
• Pregabalin: Continue current dose (may still be titrating to 150-150 mg bd)
• Paracetamol: Continue 1 g IV q6h
• Celecoxib: Continue 200 mg daily

3. Plan Gradual Dose Reduction [1 mark]

• Goal: Reduce opioid requirements over time
• Strategy:
  • Continue PCA for 2-3 more days
  • Convert to oral opioid (e.g., oxycodone SR 10-20 mg bd)
  • Reduce dose by 25-50% every 2-3 days as pain allows
• Monitor: Pain scores, functional improvements, side effects

4. Focus on Functional Recovery [1 mark]

• Set functional goals:
  • Ambulate independently to bathroom
  • Perform ADLs without assistance
  • Participate in physiotherapy sessions
• Milestone-based approach: "Once you can walk to the bathroom and back without increased pain, we'll work on hallway ambulation"
• Positive reinforcement: Celebrate functional achievements

5. Continue Non-Pharmacological Strategies [1 mark]

• Maintain physiotherapy: Continue gradual mobilization program
• Desensitization: Touch, tapping around incision
• Incentive spirometry: Continue to prevent atelectasis
• Psychology: Continue CBT for coping strategies

6. Discharge Planning Considerations [1 mark]

• Pain control at acceptable level: NRS ≤4-5
• Functional independence: Basic ADLs, ambulating with assistance
• Safe discharge plan: Community physiotherapy arranged, pain medication prescriptions provided
• Follow-up: Pain clinic appointment in 1-2 weeks"

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Examiner: How would you prevent this scenario in future patients?

Candidate Response: [4 marks]

"Prevention requires addressing multiple domains:

1. Enhanced Preemptive Analgesia [1.5 marks]

Regional Anaesthesia:

• Consider epidural analgesia: For major abdominal surgery (prostatectomy)
  • Placement: T10-L12 level
  • Medication: Ropivacaine 0.1-0.2% + fentanyl 2 μg/mL
  • Duration: Continue for 48-72 hours postoperatively
  • Benefits: Superior analgesia, 30-50% opioid-sparing, earlier ambulation
• Alternative: Paravertebral block if epidural contraindicated
• Timing: Place pre-incision for preemptive effect

Pharmacological Preemptive:

• Gabapentinoid loading: Pregabalin 150-300 mg PO 1-2 hours pre-op OR immediately post-op
  • Prevents central sensitization
  • Provides neuropathic pain coverage from surgery start
• Dexamethasone: 8-12 mg IV at induction
  • Anti-inflammatory and anti-emetic effects
  • Reduces postoperative pain 30-40%
• Celecoxib: 200 mg PO pre-op (if no contraindications)
  • Reduces inflammatory pain mediators
  • COX-2 selective for GI safety

2. Patient Education and Expectation Setting [1 mark]

• Preoperative education: Explain expected postoperative course
• Realistic expectations: "Some discomfort is normal, complete pain relief is unrealistic"
• Functional goals: Focus on return to normal activities rather than pain elimination
• Pain coping strategies: Teach breathing exercises, relaxation techniques

3. Standardized Multimodal Protocol [0.5 marks]

Develop departmental protocol:

• Regional anaesthesia for major abdominal cases
• Preemptive gabapentinoid loading
• Standardized opioid regimen (PCA preference)
• Paracetamol + NSAID combination
• Anti-emetic prophylaxis (ondansetron + dexamethasone)

4. Early Aggressive Titration [0.5 mark]

Avoid undertreatment:

• Adequate opioid dosing: Target NRS ≤4 at rest
• Rapid titration: Use PCA for immediate patient control
• Avoid "start low, go slow" for acute severe pain

5. Enhanced Physiotherapy Integration [0.5 mark]

Preoperative physiotherapy:

• Breathing exercises: Teaching incentive spirometry use
• Mobility: Teach bed exercises, transfer techniques
• Early involvement: Physio available in PACU for immediate mobilization

6. Multidisciplinary Planning [1 mark]

Psychology involvement:

• Preoperative screening: Identify high catastrophizing, anxiety
• Proactive CBT: Initiate early rather than reactive
• Goal setting: Develop realistic functional expectations"

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Examiner: What are the red flags postoperatively that require urgent intervention?

Candidate Response: [4 marks]

"Postoperative red flags requiring urgent intervention:

Surgical Complications:

1. Anastomotic Leak [1 mark]

• Signs: Increasing drain output, feculent material in drain, abdominal distension, peritonism
• Action: Urgent surgical review, CT abdomen with contrast
• Management: May require return to OR, antibiotics

2. Ileus [1 mark]

• Signs: Absence of bowel sounds/flatus >24-48 hours post-op, abdominal distension, nausea, vomiting
• Action: NG tube decompression, CT abdomen
• Management: NPO, IV fluids, may need surgical exploration

3. Wound Dehiscence/Infection [0.5 marks]

• Signs: Wound separation, erythema, purulent discharge, increasing pain, fever
• Action: Wound inspection, swabs, antibiotics, may require washout/closure
• Urgent: Surgical review required

Medical Complications:

4. Respiratory Depression [0.5 marks]

• Signs: RR <8/min, SpO₂ <90%, reduced consciousness, opioid overdose pattern
• Action: Stop opioids, naloxone 100-200 μg IV increments, ventilatory support
• Monitoring: Continuous SpO₂, ETCO₂ monitoring

5. Cardiac Events [0.5 marks]

• Signs: New chest pain, ECG changes (ST elevation/depression), arrhythmias, hypotension
• Action: 12-lead ECG, cardiac biomarkers (troponin), cardiology consult
• Management: May require ICU admission, anti-ischaemic therapy

Vascular Complications:

6. Deep Vein Thrombosis (DVT) [0.5 marks]

• Signs: Unilateral leg swelling, erythema, warmth, Homan's sign
• Action: Doppler ultrasound, D-dimer, start anticoagulation
• Management: Therapeutic LMWH or warfarin

7. Pulmonary Embolism (PE) [0.5 marks]

• Signs: Sudden dyspnoea, tachycardia, pleuritic chest pain, hypoxaemia
• Action: CT pulmonary angiogram, V/Q scan
• Management: Anticoagulation, consider thrombolysis if massive

Neurological Complications:

8. New Neurological Deficits [0.5 marks]

• Signs: Motor weakness, sensory loss, bowel/bladder dysfunction, gait disturbance
• Action: Urgent neurosurgical review, CT/MRI spine
• Management: May indicate cauda equina syndrome (surgical emergency), spinal cord injury"

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Total: 25 marks

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