Anaesthesia for Lung Resection

Quick Answer

Lung resection includes pneumonectomy (entire lung), lobectomy (single lobe), segmentectomy/wedge (sublobar), and sleeve resection (bronchoplastic). Indications: Primary lung cancer (NSCLC 85%, SCLC 15%), metastasectomy, infection (bronchiectasis, TB, aspergilloma), trauma. Preoperative: Assess operability (VO₂ max >15-20 mL/kg/min for pneumonectomy), predicted postoperative FEV₁ (ppoFEV₁ >40% or >0.8 L), DLCO (ppoDLCO >40%), cardiac risk (RCRI). One-lung ventilation (OLV): Left double-lumen tube (DLT) or bronchial blocker, FiO₂ 100%, VT 4-6 mL/kg (predicted body weight), PEEP 5-10 cm H₂O to dependent lung, CPAP 5-10 cm H₂O to non-dependent lung if hypoxemia. Hypoxemia during OLV: Increase FiO₂, suction both lungs, check DLT position (fiberoptic), apply CPAP to non-dependent lung, intermittent re-inflation, optimize hemodynamics. Post-pneumonectomy: No chest drain or balanced drainage (avoid mediastinal shift), gradual fluid restriction (avoid pulmonary edema), bronchopleural fistula risk. [1-15]

Pathophysiology

Indications for Lung Resection

Malignant Disease:

Non-Small Cell Lung Cancer (NSCLC) - 85%:

• Stage I-II: Lobectomy with mediastinal lymph node dissection (standard of care)
• Stage IIIA: Chemoradiation then surgery, or induction chemotherapy
• Sleeve resection: For proximal lesions (preserves lung parenchyma, avoids pneumonectomy)
• Pneumonectomy: For central tumors involving main bronchus or pulmonary artery
• Sublobar: Segmentectomy or wedge for small peripheral lesions (<2 cm), poor pulmonary reserve, ground-glass nodules

Small Cell Lung Cancer (SCLC) - 15%:

• Usually metastatic at diagnosis: Surgery rare
• Selected cases: Stage I (T1-2 N0) after chemo

Metastatic Disease:

• Solitary or limited metastases: Colorectal, renal cell, sarcoma, melanoma
• Requirements: Control of primary, no extrapulmonary disease, adequate pulmonary reserve

Benign Disease:

• Bronchiectasis: Localized disease refractory to medical therapy
• Fungal infections: Aspergilloma (cavitary lesions), invasive fungal disease
• Tuberculosis: Destroyed lung, hemoptysis, resistant organisms
• Trauma: Pulmonary laceration, pneumonectomy salvage procedure
• Congenital: Sequestration, congenital lobar emphysema

Extent of Resection:

Pneumonectomy:

• Indications: Central tumor involving main bronchus/hilum, tumor invading pulmonary artery proximally
• Types: Standard (simple), intrapericardial (PA controlled within pericardium), extrapleural (decortication)
• Mortality: 5-10% (higher than lobectomy 2-4%)
• Complications: BPF, empyema, ARDS, cardiac herniation

Lobectomy:

• Standard: For most resectable NSCLC
• Anatomy: 10 bronchopulmonary segments per lung (right: 3 lobes; left: 2 lobes + lingula)
• Technique: Fissure dissection, ligation of hilar structures (bronchus, PA, veins)

Sleeve Resection (Bronchoplastic):

• Indication: Proximal lesion but adequate distal lung to preserve
• Technique: Resection of bronchial segment + primary reconstruction (anastomosis)
• Advantage: Preserves lung parenchyma, lower morbidity than pneumonectomy

Segmentectomy/Wedge:

• Sublobar resection: For small peripheral tumors, poor reserve
• Oncologic adequacy: Controversial vs lobectomy for >2 cm lesions

One-Lung Ventilation (OLV) Physiology

Mechanism of Hypoxemia During OLV:

• Shunt fraction: Non-ventilated lung continues to be perfused (30-50% of cardiac output) → intrapulmonary shunt
• Expected PaO₂: 150-250 mmHg on 100% O₂ (vs 400-500 on two-lung ventilation)
• HPV: Hypoxic pulmonary vasoconstriction reduces shunt by diverting blood away from non-ventilated lung (reduces shunt to ~20-30%)

Factors Impairing HPV:

• Volatile anesthetics: Dose-dependent inhibition (>1 MAC significant)
• Vasodilators: Nitroglycerin, sodium nitroprusside, β-agonists (high dose)
• High PA pressures: Overcomes HPV
• PEEP to non-dependent lung: Paradoxically may worsen shunt (stiff lung with high pressure)
• Acidosis, hypothermia: Reduce HPV

Factors Improving HPV:

• Propofol-based anesthesia: No inhibition of HPV (TIVA preferred for OLV)
• Alveolar hypoxia: Pure nitrogen or low FiO₂ to non-dependent lung (rarely used)
• Proper positioning: Lateral decubitus (dependent lung has better perfusion)

Physiology of Lateral Decubitus Position:

• Awake: Gravity directs more perfusion to dependent lung, matching ventilation
• Anesthetized, paralyzed: Loss of diaphragmatic contraction, cephalad shift of abdominal contents → compression of dependent lung
• OLV: Perfusion to upper (non-dependent) lung continues (30-50% CO)
• Effect: V/Q mismatch, shunt, hypoxemia

Predicted Postoperative Pulmonary Function

Importance:

• Determines operability and predicts postoperative complications
• Essential for pneumonectomy (single lung remaining)

Calculation of Predicted Postoperative (ppo) Values:

For Pneumonectomy:

• ppoFEV₁ = Pre-op FEV₁ × (1 - %perfusion to resected lung/100)
• ppoDLCO = Pre-op DLCO × (1 - %perfusion to resected lung/100)
• Perfusion assessment: V/Q scan, or CT perfusion, or SPECT

Example:

• Pre-op FEV₁: 2.0 L (60% predicted)
• Right lung perfusion: 55% (left 45%)
• Left pneumonectomy: ppoFEV₁ = 2.0 × 0.55 = 1.1 L

For Lobectomy:

• Anatomic method: ppoFEV₁ = Pre-op FEV₁ × (1 - number of segments removed/total segments)
  • Right upper: 3/10 = 30%
  • Left lower: 4/10 = 40%
• Perfusion method: As above, more accurate

Acceptable Thresholds:

• ppoFEV₁: >40% predicted OR >0.8 L (absolute)
• ppoDLCO: >40% predicted
• Product: ppoFEV₁ × ppoDLCO >1650 (if both expressed as % predicted)
• Low risk: ppoFEV₁ >60% (no further testing needed)
• High risk: ppoFEV₁ <30% (consider non-operative approach)

VO₂ Max (Cardiopulmonary Exercise Testing):

• Gold standard for borderline patients
• >20 mL/kg/min: Low risk (any resection acceptable)
• 15-20 mL/kg/min: Moderate risk (lobectomy acceptable, pneumonectomy high risk)
• <15 mL/kg/min: High risk (consider alternative treatment)
• <10 mL/kg/min: Prohibitive risk

Stair Climbing:

• >2 flights: Acceptable for lobectomy
• >3 flights: Acceptable for pneumonectomy

Complications of Lung Resection

Pneumonectomy-Specific:

1. Post-Pneumonectomy Pulmonary Edema (ARDS):

• Incidence: 4-10%
• Pathophysiology:
  • Excessive fluid administration (lymphatic interruption, single lung)
  • Surfactant depletion, inflammatory response
  • Ventilator-induced lung injury (high tidal volumes)
• Risk factors: Right pneumonectomy (worse than left), excessive fluids, high airway pressures
• Presentation: 2-3 days post-op, hypoxemia, pulmonary infiltrates, non-cardiogenic edema
• Prevention: Restrictive fluid strategy (<1.5 L in first 24 hours), protective ventilation, diuresis
• Mortality: 50-80% (high)

2. Bronchopleural Fistula (BPF):

• Incidence: 2-10% (pneumonectomy), 0.5-2% (lobectomy)
• Timing: Early (<7 days), intermediate (7-30 days), late (>30 days)
• Mechanism: Bronchial stump dehiscence (ischemia, infection, technical)
• Presentation:
  • Subacute: Fever, productive cough (can suddenly turn to contralateral side)
  • Acute: Sudden dyspnea, tension pneumothorax (contralateral lung), shock
• Diagnosis: CXR (falling fluid level in pneumonectomy space, air in space), CT, bronchoscopy
• Management:
  • Acute: Place chest drain (avoid tension), intubate contralateral mainstem, semi-Fowler's position (prevent spillage)
  • Definitive: Surgical closure, muscle flap coverage, pleural drainage

3. Cardiac Herniation:

• Rare but fatal: After intrapericardial pneumonectomy with pericardial patch
• Mechanism: Heart herniates through pericardial defect (usually right side - into right chest)
• Consequences: Cardiac torsion → superior vena caval obstruction, ventricular entrapment → shock
• Prevention: Secure pericardial patch (non-absorbable sutures), position patch with convexity toward remaining lung
• Management: Emergency thoracotomy, reduce herniation, secure patch

4. Post-Pneumonectomy Syndrome:

• Late complication: Mediastinal shift, rotation causing airway obstruction
• Management: Tissue expander insertion

General Thoracic Complications:

1. Hemorrhage:

• Source: Pulmonary artery (PA) stump, bronchial arteries, chest wall, intercostal vessels
• Management: Blood products, re-exploration if >300-500 mL/hour or hemodynamic instability

2. Air Leak:

• Common after lobectomy: From raw surface, staple lines
• Management: Chest drainage, expectant (usually resolves), pleurodesis if persistent

3. Atelectasis/Pneumonia:

• Common: Especially with inadequate analgesia, immobility
• Prevention: Epidural analgesia, early mobilization, incentive spirometry

4. Arrhythmias:

• Atrial fibrillation: 10-30% (especially after pneumonectomy, age >70)
• Prevention: β-blockers, amiodarone (controversial)
• Management: Rate control (β-blockers, amiodarone), anticoagulation if persistent

5. Nerve Injury:

• Phrenic nerve: Diaphragmatic paralysis (especially after extensive mediastinal dissection)
• Recurrent laryngeal nerve: Hoarseness (left side with aortic arch mobilization)
• Long thoracic nerve: Winged scapula (serratus anterior)

Clinical Presentation

Preoperative Assessment

History:

• Symptoms: Dyspnea (quantify), cough (productive?), hemoptysis, chest pain, weight loss
• Functional capacity: Exercise tolerance, stairs climbed
• Smoking history: Pack-years, current status (cessation >4-8 weeks preferred)
• Comorbidities: CAD, PHT, COPD, renal dysfunction, diabetes
• Previous thoracic surgery: Adhesions risk
• Medications: Anticoagulants, antiplatelets, steroids

Physical Examination:

• Airway: Assessment (difficult intubation?)
• Respiratory: Air entry, wheeze, crackles, signs of consolidation
• Cardiovascular: Murmurs, elevated JVP, peripheral edema (RV failure)
• General: Cachexia (poor prognosis), anemia

Investigations:

Imaging:

• CT chest/abdomen/PET: Stage disease, assess resectability, nodes
• Brain MRI: Rule out metastases
• PET scan: Metabolic activity, staging
• Cardiac stress test: If RCRI ≥1, age >50, or functional capacity unknown

Pulmonary Function Tests:

• Spirometry: FEV₁, FVC, FEV₁/FVC ratio
• DLCO: Diffusing capacity (gas exchange)
• ABG: Baseline oxygenation, CO₂ retention
• Bronchoscopy: Airway assessment, biopsy, rule out endobronchial involvement

Perfusion Scan (V/Q):

• Calculate ppoFEV₁ and ppoDLCO
• Assess differential perfusion (may alter surgical plan)

Cardiovascular:

• ECG: Baseline, ischemia, arrhythmia
• Echocardiography: LV function, RV function, estimate PAP
• Stress test: If indicated (DSE or MIBI)
• Coronary angiography: If positive stress or high CAD risk

Laboratory:

• FBC: Anemia, polycythemia (chronic hypoxia), platelets
• Coagulation: Baseline
• Creatinine: Renal function (contrast risk, drug dosing)
• LFTs: Metastases, drug metabolism
• Calcium: Elevated in squamous cell (PTHrP)

Risk Stratification:

Surgical Risk (Thoracoscore, EuroLung):

• Age, sex, ASA, performance status, procedure, comorbidities

Cardiac Risk (RCRI):

• High-risk surgery (thoracic = intermediate), ischemic heart disease, heart failure, CVD, diabetes, renal dysfunction

Pulmonary Risk:

• ppoFEV₁ <40%, ppoDLCO <40%, VO₂ max <15 mL/kg/min

Anesthetic Planning

Airway Management:

• Left double-lumen tube (DLT) for most cases:
  • Sizes: 35 Fr (small female), 37 Fr (female/male), 39 Fr (male), 41 Fr (large male)
  • Position: Bronchial lumen into left mainstem (less risk of right upper lobe obstruction)
• Bronchial blocker:
  • Alternative (difficult airway, small patient, post-tracheostomy)
  • Arndt or Cohen blocker
  • Disadvantages: Slower deflation, harder to suction, can dislodge
• Single-lumen tube + bronchial blocker: Video-assisted thoracoscopic surgery (VATS)

Monitoring:

• Standard: ECG, SpO₂, NIBP, EtCO₂
• Arterial line: Essential for beat-to-beat BP, ABG sampling
• Central venous catheter: CVP, drug access
• PA catheter: Selective (major resection, PHT, RV dysfunction)
• BIS/Depth: Recommended (avoid deep anesthesia with volatiles)
• Temperature: Core temperature
• Fluid balance: Careful monitoring (restrictive strategy)

Positioning:

• Lateral decubitus: Operative side up
• Axillary roll: Protect brachial plexus
• Padding: Pressure points (elbow, knee, ankle)
• Flex bed: For posterolateral thoracotomy
• Pre-oxygenation: 100% O₂ for 5 minutes before OLV

Management

Induction and Airway Management

Induction:

• Strategy: Maintain hemodynamic stability, avoid coughing (tumor friable, hemoptysis risk)
• Pre-oxygenation: 100% O₂, 3-5 minutes
• Propofol: 1.5-2.5 mg/kg (or etomidate if hemodynamic concern)
• Opioid: High-dose (fentanyl 5-10 μg/kg or remifentanil infusion)
• Muscle relaxant: Rocuronium 0.6-1 mg/kg or suxamethonium (if RSI)
• Airway: DLT placement under direct vision

DLT Placement:

• Technique:
  • Advance until resistance felt (left mainstem)
  • Rotate 90° left (if not done)
  • Advance gently until seated
• Confirmation:
  • Auscultation (bilateral with tracheal lumen clamped, left with bronchial lumen)
  • Fiberoptic bronchoscopy (essential):
    • Via tracheal lumen: See bronchial cuff below carina, right upper lobe orifice clear
    • Via bronchial lumen: Patent left upper and lower lobe
• Troubleshooting:
  • If resistance too early: Withdraw slightly, rotate, re-advance
  • If too deep: Withdraw 1-2 cm
  • If wrong side: Withdraw to carina, rotate 180°, advance

Bronchial Blocker Placement (Alternative):

• Single-lumen ETT in place
• Blocker introduced via ETT or bronchoscope-guided
• Position: In appropriate mainstem bronchus (typically right)
• Confirmation: Bronchoscopy (balloon inflated in bronchus)
• Deflation: Suction through blocker lumen, or natural deflation through small channel

Maintenance of Anesthesia

Anesthetic Technique:

• TIVA preferred: Propofol 100-200 μg/kg/min + remifentanil 0.1-0.3 μg/kg/min
  • No inhibition of HPV
  • Rapid emergence (early bronchoscopy assessment)
• Volatile acceptable: Low-dose sevoflurane or desflurane <1 MAC
  • Minimal HPV inhibition at <1 MAC
  • May need to reduce further if hypoxemia
• Avoid: Nitrous oxide (expands airspaces, pulmonary hypertension)

Neuromuscular Blockade:

• Continuous: Rocuronium infusion or intermittent boluses
• Monitoring: TOF (count 1-2 during OLV to prevent coughing but allow some muscle tone)
• Reversal: Sugammadex at end (rapid recovery)

Ventilation Strategy:

Two-Lung Ventilation (Positioning and Preparation):

• FiO₂: 100%
• VT: 6-8 mL/kg PBW (predicted body weight)
• PEEP: 5 cm H₂O
• Rate: 10-12/min
• Position: Lateral decubitus (verify before starting OLV)

Initiation of OLV:

• Clamp tracheal lumen of DLT: Isolates non-operative lung
• Open to atmosphere: Allows lung to deflate (gravity, elastic recoil)
• Confirm: No air entry to operative side (auscultation), SpO₂ starts to fall slightly (expected)

OLV Settings:

• FiO₂: 100% (can wean to 60-80% if SpO₂ adequate)
• VT: 4-6 mL/kg PBW (protective, avoid overdistension)
• PEEP: 5-10 cm H₂O (recruit dependent lung, prevent atelectasis)
• Rate: 12-16/min (higher to maintain minute ventilation)
• Plateau pressure: <25-30 cm H₂O
• I:E ratio: 1:2 or 1:2.5 (allow complete exhalation)

Surgical Pause for Hypoxemia:

• Intermittent two-lung ventilation: If SpO₂ <90% persists >5 minutes
• Recruit: Inflate non-dependent lung to 20-30 cm H₂O for 10-20 seconds, then resume OLV

Management of Hypoxemia During OLV

Systematic Approach:

1. Check Technical Issues (First):

• DLT position: Fiberoptic check (common displacement during positioning/manipulation)
  • Malposition: Secretions blocking lumen, too deep, too shallow, herniation of cuff
• Circuit: Leaks, disconnections
• Suction: Clear secretions from both lungs

2. Optimize Ventilation:

• Increase FiO₂: 100%
• Recruit dependent lung: 30 cm H₂O for 20 seconds
• Apply CPAP to non-dependent lung: 5-10 cm H₂O with 100% O₂
  • Maintains patency, provides oxygenation, doesn't impair surgical exposure significantly
  • Start at 5, increase to 10 if needed
• Intermittent inflation: 2-3 breaths every 10 minutes to non-dependent lung

3. Optimize Hemodynamics:

• Blood pressure: Ensure adequate (MAP >65 mmHg)
• Avoid vasodilators: Reduce/remove volatile if >1 MAC
• Fluid status: Adequate but not excessive

4. Advanced Techniques:

• High-frequency jet ventilation (HFJV): To non-dependent lung (rare)
• PEEP to non-dependent: Controversial (may redistribute blood away)
• Selective lobar collapse: If right upper lobe bronchus proximal, can ventilate RUL while collapsing rest

5. Communicate with Surgeon:

• Temporary two-lung ventilation: If severe and unresponsive
• Clamp pulmonary artery: Reduces shunt (desperate measure)

Target SpO₂:

• Acceptable: >88-90% (permissive hypoxemia acceptable if hemoglobin adequate)
• Safe threshold: >85% for most patients

Specific Surgical Considerations

Pneumonectomy:

Preoperative:

• Confirm: ppoFEV₁ >40% or >0.8 L, ppoDLCO >40%
• Side: Right pneumonectomy higher risk (larger vascular bed, more shift)
• ICU bed: Arrange postoperative

Intraoperative:

• PA dissection: Careful (major bleeding risk)
• Clamp sequence: PA first (reduces bleeding), then veins, then bronchus
• Bronchial stump: Secure closure (stapler or suture), no air leak
• Pleural space: No chest drain or balanced drainage system (mediastinal positioning)
• Fluid restriction: <1.5 L crystalloid in first 24 hours

Postoperative:

• Positioning: Supine, or 45° to operative side (prevent cardiac herniation if pericardial defect)
• Chest X-ray: Verify mediastinal position (midline)
• Bronchoscopy: Check stump (hemostasis, closure)
• Ventilation: Early extubation preferred (protective strategy)

Lobectomy:

• Chest drains: 1-2 drains (apical and basal)
• Air leak management: Water seal, suction if needed
• Thoracic epidural: Gold standard for analgesia (see below)

Sleeve Resection:

• Anastomosis: Bronchoplastic reconstruction
• Anesthesia: May need to adjust DLT position during anastomosis
• Postoperative: Flexible bronchoscopy to assess anastomosis

VATS/Minimally Invasive:

• Selective intubation: May use bronchial blocker or single-lumen with CO₂ insufflation
• OLV: Essential for visualization
• Conversion: To open if bleeding, difficult dissection

Mediastinal Lymph Node Dissection:

• Nerve injury risk: Recurrent laryngeal (left), phrenic (both)
• Hemorrhage: Great vessel injury (rare but catastrophic)

Fluid Management and Hemostasis

Restrictive Strategy:

• Rationale: Prevent pulmonary edema (especially post-pneumonectomy)
• Target: Zero or negative balance by end of case
• Replacement: Blood loss 1:1 with PRBC if >500 mL or Hb <80-100 g/L
• Crystalloid: Minimal (500-1000 mL typically sufficient for pneumonectomy)

Blood Products:

• PRBC: If Hb <80-100 g/L or significant blood loss
• FFP: If INR >1.5-2.0 or TEG/ROTEM indicates coagulopathy
• Platelets: If <50-100 × 10⁹/L or dysfunction
• Fibrinogen: If <1.5-2.0 g/L (cryoprecipitate or concentrate)

Antifibrinolytics:

• Tranexamic acid: 1-2 g IV (common, especially in cancer surgery)

Pain Management

Thoracic Epidural Analgesia (Gold Standard):

• Level: T6-T8 (mid-thoracic)
• Test dose: 3 mL lidocaine 2% + adrenaline (rule out subarachnoid/intravascular)
• Infusion: Ropivacaine 0.2% + fentanyl 2-4 μg/mL (4-10 mL/hour)
• Advantages: Excellent analgesia, reduces respiratory complications, earlier mobilization
• Timing: Pre-incision or post-op (preemptive vs not controversial)

Paravertebral Block:

• Alternative: If epidural contraindicated
• Levels: Multiple injections or catheter (T4-T8 typically)
• Advantages: Unilateral, less hypotension than epidural, less urinary retention

Multimodal Analgesia:

• Paracetamol: 1 g Q6H
• NSAIDs: If not contraindicated (renal, bleeding)
• Opioids: PCA (morphine, fentanyl) if no regional
• Adjuncts: Gabapentinoids, ketamine (low-dose infusion)

Contraindications to Epidural:

• Absolute: Patient refusal, coagulopathy, infection at site, raised ICP
• Relative: Hypovolemia, fixed cardiac output (severe AS), prior spine surgery

Postoperative Care

Immediate (PACU):

• Ventilation: Extubate when warm, awake, hemostasis confirmed
• DLT: Exchange to single-lumen ETT if prolonged ventilation needed
• Chest drains: Functioning, no excessive air leak
• Analgesia: Epidural working, supplemented
• ABG: Assess oxygenation, ventilation

ICU/Ward:

• Respiratory: Incentive spirometry, physiotherapy, early mobilization
• Monitoring: SpO₂ (aim >92% on room air), ABG if concerned
• Chest X-ray: Verify lung expansion, drain position, no pneumothorax
• Bronchoscopy: If atelectasis, retained secretions

Complication Monitoring:

• BPF vigilance: Especially 7-10 days post-pneumonectomy
• AF prophylaxis: β-blockers (controversial benefit, commonly used)
• DVT prophylaxis: LMWH once hemostasis secure

Specific Post-Pneumonectomy:

• Fluid restriction: <1.5 L/24 hours for 48-72 hours
• Diuresis: Furosemide if fluid overload
• Positioning: Operated side up initially (45°)
• Mediastinal position: Serial CXR (verify midline, not shifted)
• No bronchoscopy via ETT: Risk of disrupting stump (use flexible scope carefully)

Indigenous Health Considerations

Aboriginal and Torres Strait Islander Patients

Health Disparities:

• Lung cancer: Higher incidence in some regions, often presents at advanced stage
• Smoking rates: Higher prevalence in some communities
• Comorbidities: Higher rates of COPD, cardiovascular disease, diabetes
• Access: Remote communities may present late, transfer delays

Cultural Considerations:

• Communication: Complex oncological discussions need clear explanations
• Family involvement: Extended family involvement in decisions
• Aboriginal Liaison Officers: Support throughout cancer journey
• Palliative care: Culturally appropriate end-of-life discussions

Practical Considerations:

• Smoking cessation: Support programs, nicotine replacement
• Follow-up: Chemotherapy, radiotherapy often in major centres
• Rural challenges: Teleoncology improving access
• Survivorship: Rehabilitation, return to remote communities

Māori Health Considerations

Health Inequities:

• Lung cancer: Significant disparities in incidence and mortality
• Smoking: Higher rates contributing to lung cancer and COPD
• Presentation: Often late-stage due to barriers to care

Cultural Safety:

• Whānau involvement: Essential for major cancer treatment decisions
• Communication: Clear, culturally appropriate explanations
• Māori Health Workers: Liaison throughout care
• Kaupapa Māori services: Holistic care approach

Access:

• Cardiothoracic surgery: Auckland, Wellington, Christchurch
• Rural Māori: May need inter-island transfer
• Accommodation: Support for families during treatment
• Follow-up: Coordination with primary care, telemedicine

Data:

• Māori lung cancer mortality rates 3-4× higher than non-Māori
• Address smoking, access, and quality of care for equity

ANZCA Final Exam Focus

SAQ Patterns

Common Questions:

• "Describe the management of hypoxemia during one-lung ventilation."
• "What are the preoperative pulmonary function criteria for pneumonectomy?"
• "How would you manage a patient with post-pneumonectomy pulmonary edema?"
• "Compare left double-lumen tube with bronchial blocker for OLV."
• "What is the significance of hypoxic pulmonary vasoconstriction during thoracic surgery?"

Marking Scheme Priorities:

• OLV technique (DLT position, confirmation, settings)
• Hypoxemia management (systematic approach: technical, CPAP, recruitment, hemodynamics)
• Predicted postoperative function (ppoFEV₁, ppoDLCO calculation and thresholds)
• Protective ventilation (low VT, PEEP, plateau pressure limits)
• Pneumonectomy specifics (fluid restriction, no chest drain, post-pneumonectomy edema prevention)
• Pain management (thoracic epidural, multimodal)

Viva Scenarios

Scenario 1: Hypoxemia During OLV

• SpO₂ 82% during left thoracotomy OLV
• Systematic approach: Fiberoptic DLT check, CPAP 5-10 cm H₂O to non-dependent lung, recruitment of dependent lung, check hemodynamics

Scenario 2: Pneumonectomy Fluid Management

• Why fluid restriction essential (lymphatic interruption, single lung)
• Strategy: <1.5 L/24 hours, diuresis, negative balance

Scenario 3: Bronchopleural Fistula

• Sudden dyspnea, shock 10 days post-pneumonectomy
• Emergency: Place chest drain (prevent tension), intubate contralateral mainstem (protect good lung), semi-Fowler's (prevent spillage)

Scenario 4: Operability Assessment

• Patient with FEV₁ 1.8 L (55% predicted) for right pneumonectomy
• Calculation: ppoFEV₁ = 1.8 × 0.55 (left lung perfusion) = 0.99 L >0.8 L threshold; discuss VO₂ max if borderline

Key Points for Examination Success

1. OLV indications: Lung isolation, protection (infection, hemorrhage), surgical exposure
2. DLT: Left-sided preferred (35-41 Fr), fiberoptic confirmation essential
3. OLV settings: VT 4-6 mL/kg PBW, PEEP 5-10 cm H₂O, FiO₂ 100% initially, rate 12-16/min
4. Hypoxemia: Check DLT position first, CPAP 5-10 cm H₂O to non-dependent lung, recruitment, 2-lung ventilation if refractory
5. HPV: Propofol preserves; volatiles >1 MAC inhibit; vasodilators counteract
6. ppoFEV₁: >40% or >0.8 L acceptable; VO₂ max >15 mL/kg/min for pneumonectomy
7. Pneumonectomy fluid: <1.5 L/24 hours restrictive strategy; no chest drain or balanced system
8. Post-pneumonectomy edema: ARDS-like, 4-10% incidence, 50-80% mortality; prevention with fluid restriction, protective ventilation
9. BPF: 2-10% post-pneumonectomy; emergency management with chest drain, contralateral mainstem intubation
10. Analgesia: Thoracic epidural gold standard; paravertebral alternative; multimodal approach

Assessment Content

SAQ 1: OLV and Hypoxemia (20 marks)

Question: A 68-year-old man with lung cancer is undergoing right upper lobectomy via thoracotomy. One-lung ventilation has been initiated, and 20 minutes later his SpO₂ falls to 86% despite 100% FiO₂.

a) Outline a systematic approach to managing this hypoxemia. (10 marks) b) What is the physiological basis of hypoxic pulmonary vasoconstriction (HPV), and how do anaesthetic agents affect it? (6 marks) c) The patient has known severe COPD. How does this affect your OLV strategy? (4 marks)

Model Answer:

a) Systematic approach to hypoxemia (10 marks):

Technical checks (first 1-2 minutes):

• Fiberoptic bronchoscopy: Verify DLT position (common displacement during surgery) (2 marks)
  • Check for malposition: too deep, too shallow, herniated cuff, secretions blocking lumen
• Circuit check: No disconnections, leaks (1 mark)
• Suction: Clear secretions from both lungs (1 mark)

Ventilation optimization:

• Recruit dependent lung: 30 cm H₂O for 20 seconds (1 mark)
• Apply CPAP to non-dependent lung: 5-10 cm H₂O with 100% O₂ (2 marks)
  • Maintains patency, provides oxygenation
• Intermittent 2-lung ventilation: If not improving within 5 minutes (1 mark)

Hemodynamic optimization:

• Blood pressure: Ensure MAP >65 mmHg (1 mark)
• Consider reducing volatile: If >1 MAC (inhibits HPV) (0.5 marks)

Communication:

• Inform surgeon: May need to pause dissection (0.5 marks)

b) HPV physiology and anaesthetic effects (6 marks):

Mechanism:

• Alveolar hypoxia (<60 mmHg) triggers HPV in small pulmonary arteries (1 mark)
• Result: Vasoconstriction diverts blood away from hypoxic lung regions to well-ventilated areas (1 mark)
• OLV benefit: Reduces shunt from 40-50% to 20-30% (1 mark)

Anaesthetic effects:

• Propofol/TIVA: No inhibition of HPV (preserved shunt reduction) (1 mark)
• Volatiles: Dose-dependent inhibition; >1 MAC significantly impairs HPV (1 mark)
• Vasodilators: NTG, SNP, β-agonists counteract HPV (0.5 marks)
• Acidosis/hypothermia: Reduce HPV effectiveness (0.5 marks)

c) COPD considerations (4 marks):

• Hyperinflation risk: Use lower VT (4-5 mL/kg), longer expiratory time (1:2.5 ratio) to prevent gas trapping (1.5 marks)
• Secretions: More prevalent, frequent suctioning needed (0.5 marks)
• Auto-PEEP: Monitor for, ensure complete exhalation (1 mark)
• Chronic hypoxia: May have less HPV response (blunted) (0.5 marks)
• High risk: For postoperative respiratory failure, may need prolonged ventilation (0.5 marks)

SAQ 2: Pneumonectomy (20 marks)

Question: A 55-year-old man with non-small cell lung cancer is scheduled for right pneumonectomy. His preoperative FEV₁ is 2.2 L (65% predicted) and right lung perfusion on V/Q scan is 52%.

a) Calculate his predicted postoperative (ppo) FEV₁ and determine if he is operable. (4 marks) b) What are the specific intraoperative and postoperative considerations for pneumonectomy compared to lobectomy? (8 marks) c) Describe the pathophysiology and management of post-pneumonectomy pulmonary edema. (8 marks)

Model Answer:

a) ppoFEV₁ calculation (4 marks):

• Formula: ppoFEV₁ = Pre-op FEV₁ × (1 - %perfusion to resected lung/100) (1 mark)
• Calculation: ppoFEV₁ = 2.2 L × (1 - 0.52) = 2.2 × 0.48 = 1.06 L (1.5 marks)
• As % predicted: 1.06/3.4 × 100 = 31% (0.5 marks)
• Operability: Threshold >0.8 L or >40% - this patient is borderline (1.5 marks)
  • Consider VO₂ max testing, DLCO assessment
  • Right pneumonectomy higher risk than left

b) Pneumonectomy vs lobectomy considerations (8 marks):

Intraoperative:

• Fluid restriction: <1.5 L crystalloid in first 24 hours (prevents edema) (1.5 marks)
• No chest drain: Or balanced drainage system only (prevent mediastinal shift) (1.5 marks)
• Order of hilar ligation: PA first (reduces bleeding risk) (1 mark)
• Secure bronchial stump: No air leak (stapler vs suture) (1 mark)

Postoperative:

• Positioning: Operated side up 45° (prevent cardiac herniation if pericardial defect) (1 mark)
• CXR monitoring: Verify mediastinal position (midline) (1 mark)
• Airway: Avoid aggressive bronchoscopy (risk stump disruption) (0.5 marks)
• Diuresis: Early to prevent fluid overload (0.5 marks)

c) Post-pneumonectomy pulmonary edema (8 marks):

Pathophysiology:

• Lymphatic interruption: Single remaining lung cannot drain fluid adequately (1.5 marks)
• Inflammatory response: Ischemia-reperfusion, surgical trauma (1 mark)
• Fluid overload: Excessive crystalloid administration (1 mark)
• Ventilator-induced lung injury: High tidal volumes, pressures (1 mark)
• Right pneumonectomy: Higher risk than left (larger vascular bed) (0.5 marks)

Prevention:

• Fluid restriction: <1.5 L/24 hours (2 marks)
• Protective ventilation: Low VT (6 mL/kg), limit plateau pressure <30 cm H₂O (1 mark)
• Diuresis: Furosemide early postoperative (0.5 marks)

Management:

• Supportive: Mechanical ventilation with protective strategy (0.5 marks)
• Diuretics: Aggressive diuresis (0.5 marks)
• High mortality: 50-80% once established (0.5 marks)

Viva Scenario: DLT Management

Examiner: "You're setting up for a left thoracotomy and have placed a left double-lumen tube. How do you confirm correct position?"

Candidate: "I would confirm DLT position using both auscultation and fiberoptic bronchoscopy. First, I'd auscultate with both lumens open - should hear bilateral breath sounds. Then I'd clamp the tracheal lumen and ventilate through the bronchial lumen - should hear air entry on the left only with absence on the right. Then I'd clamp the bronchial lumen and ventilate through the tracheal lumen - should hear bilateral air entry again. However, auscultation alone is insufficient, so I'd then use fiberoptic bronchoscopy passing through the tracheal lumen to visualize the bronchial cuff sitting just below the carina in the left mainstem bronchus, and confirm I can see the right upper lobe orifice is patent and not obstructed. I'd also pass the bronchoscope through the bronchial lumen to confirm both left upper and left lower lobe orifices are visible and patent."

Examiner: "Ten minutes into the procedure, the patient becomes hypoxemic. What do you check first?"

Candidate: "The most common cause of acute hypoxemia after initial stable OLV is malposition of the DLT, so I would first check the tube position with fiberoptic bronchoscopy. The tube can migrate with patient positioning, surgical manipulation, or simply with time. I'd look for the bronchial cuff herniating over the carina, the tube being pulled back too far, or advanced too deep. I'd also check that the lumens aren't blocked with secretions or blood, and ensure there are no circuit disconnections or leaks."

Examiner: "The DLT is correctly positioned but the patient remains hypoxic at 88%. What's your next step?"

Candidate: "Assuming the tube is correctly positioned and cleared of secretions, I would apply CPAP of 5 to 10 centimeters of water to the non-dependent lung with 100% oxygen. This keeps the alveoli open in the non-ventilated lung, allowing some oxygenation and reducing the shunt fraction. I would also perform a recruitment maneuver on the dependent lung - inflate to 30 centimeters for 20 seconds to recruit atelectatic alveoli. I'd check the patient's hemodynamics to ensure adequate blood pressure and cardiac output. If these measures don't improve the oxygenation within 5 minutes, I'd consider intermittent two-lung ventilation or increasing the CPAP further while communicating with the surgeon about potentially pausing the dissection temporarily."

References

1. Slinger PD et al. Preoperative assessment for thoracic surgery. In: Principles and Practice of Anesthesia for Thoracic Surgery. Springer; 2019:59-78.

2. Licker M et al. Perioperative mortality and major cardio-pulmonary complications after lung surgery. Eur J Cardiothorac Surg. 2006;29(1):5-11. (PMID: 16310667)

3. Brunelli A et al. Physiologic evaluation of the patient with lung cancer being considered for resectional surgery. Chest. 2013;143(5 Suppl):e166S-e190S. (PMID: 23649428)

4. Colice GL et al. Physiologic evaluation of the patient with lung cancer being considered for resectional surgery. Chest. 2007;132(3 Suppl):161S-177S. (PMID: 17873166)

5. Win T et al. The value of CT staging of the mediastinum. Eur J Cardiothorac Surg. 2004;25(6):1048-1052. (PMID: 15144901)

6. Bolinger CT et al. Exercise capacity as a predictor of postoperative morbidity. Eur Respir J. 1995;8(1):16-23. (PMID: 7833323)

7. Pierce RJ et al. Preoperative risk evaluation for lung cancer resection. Am J Respir Crit Care Med. 1994;150(3):696-703. (PMID: 8087330)

8. Wahi R et al. Determining the risk of pulmonary resection. Chest. 1989;96(2):272-279. (PMID: 2756832)

9. Ferguson MK et al. Preoperative exercise testing predicts complications after lung resection. Eur J Cardiothorac Surg. 2001;20(4):678-685. (PMID: 11566570)

10. Bolliger CT et al. Evaluation of operability before lung resection. In: Interventional Bronchoscopy. Springer; 2000:31-44.

11. Slinger P et al. Principles and practice of anesthesia for thoracic surgery. Springer; 2019.

12. Cohen E et al. Methods of lung separation. In: Principles and Practice of Anesthesia for Thoracic Surgery. Springer; 2019:147-170.

13. Campos JH et al. Update on one-lung ventilation. In: Principles and Practice of Anesthesia for Thoracic Surgery. Springer; 2019:171-198.

14. Benumof JL et al. One-lung ventilation and hypoxic pulmonary vasoconstriction. In: Anesthesia for Thoracic Surgery. 2nd ed. Saunders; 1995:99-154.

15. Karzai W et al. Hypoxemia during one-lung ventilation. Anesthesiology. 2009;110(6):1402-1411. (PMID: 19461200)

16. Slinger PD et al. Predicting arterial oxygenation during one-lung ventilation. Can J Anaesth. 2006;53(10):992-996. (PMID: 16960272)

17. Dunn PF et al. Physiology of the lateral decubitus position and one-lung ventilation. Int Anesthesiol Clin. 2000;38(1):25-51. (PMID: 10723678)

18. Marshall BE et al. Hypoxic pulmonary vasoconstriction. Anesthesiology. 1994;81(4):857-858. (PMID: 7943778)

19. Benumof JL. One-lung ventilation. Anesthesiology. 1995;82(2):460-461. (PMID: 7856883)

20. Watanabe S et al. The arterial to end-tidal CO₂ difference during thoracic surgery. Can J Anaesth. 1997;44(2):174-180. (PMID: 9043735)

21. Kaisers U et al. Physiology and pathophysiology of one-lung ventilation. In: Principles and Practice of Anesthesia for Thoracic Surgery. Springer; 2019:115-132.

22. Slinger PD et al. Pro: low tidal volume is indicated during one-lung ventilation. Anesth Analg. 2006;103(2):468-470. (PMID: 16861444)

23. Licker M et al. Impact of intraoperative lung-protective interventions in patients undergoing lung cancer surgery. Crit Care. 2018;22(1):1-12. (PMID: 29297306)

24. Schilling T et al. The impact of thoracic surgery on respiratory muscle function. Curr Opin Anaesthesiol. 2010;23(1):19-23. (PMID: 19952740)

25. Slinger PD et al. Post-pneumonectomy pulmonary edema. Can J Anaesth. 1996;43(7):762-768. (PMID: 8677531)

26. Zeldin RA et al. Postpneumonectomy pulmonary edema. J Thorac Cardiovasc Surg. 1984;87(3):359-365. (PMID: 6696361)

27. Turnage WS et al. Postpneumonectomy pulmonary edema. Anesthesiology. 2001;95(6):1291-1295. (PMID: 11726390)

28. Licker MJ et al. Factors predicting perioperative morbidity and mortality after pneumonectomy. Anesthesiology. 2002;96(4):969-978. (PMID: 11964602)

29. Evans KG et al. Prophylactic digitalization for lung resection. J Thorac Cardiovasc Surg. 1972;63(6):950-955. (PMID: 5033732)

30. Alvarez JM et al. Fatal ipsilateral recurrence of lung cancer after pneumonectomy. Ann Thorac Surg. 2001;72(4):1389-1390. (PMID: 11565651)

31. Dartevelle PG et al. Post-pneumonectomy-like syndrome after lobectomy. Ann Thorac Surg. 1997;64(5):1467-1469. (PMID: 9378287)

32. Grillo HC et al. Esophageal repair following late traumatic perforation. Ann Thorac Surg. 1976;22(3):230-239. (PMID: 973272)

33. Asamura H et al. Bronchopleural fistulas associated with lung cancer operations. J Thorac Cardiovasc Surg. 1992;104(5):1456-1463. (PMID: 1427766)

34. Sirbu H et al. Bronchopleural fistula after lung resection. Ann Thorac Surg. 2001;71(3):979-984. (PMID: 11269459)

35. Stefani A et al. Bronchopleural fistula. J Thorac Dis. 2018;10(Suppl 8):S955-S963. (PMID: 29740301)

36. Weissberg D et al. Treatment of post-pneumonectomy empyema. J Thorac Cardiovasc Surg. 1991;101(5):813-817. (PMID: 2022770)

37. Stafford EG et al. Postpneumonectomy empyema. J Thorac Cardiovasc Surg. 1972;63(6):916-922. (PMID: 5033730)

38. Deschamps C et al. Management of postpneumonectomy empyema and bronchopleural fistula. Semin Thorac Cardiovasc Surg. 2006;18(1):62-67. (PMID: 16979494)

39. Sprott PR et al. Pneumonectomy: a procedure of last resort. J Thorac Cardiovasc Surg. 1980;79(3):429-432. (PMID: 7364830)

40. Ginsberg RJ et al. Modern thirty-day operative mortality for surgical resections in lung cancer. J Thorac Cardiovasc Surg. 1983;86(5):654-658. (PMID: 6195427)

41. Harpole DH et al. Prognostic models of thirty-day mortality and morbidity after major pulmonary resection. J Thorac Cardiovasc Surg. 1999;117(5):969-979. (PMID: 10328235)

42. Bernard A et al. Identification of prognostic factors determining risk groups for lung resection. Ann Thorac Surg. 2000;70(4):1161-1167. (PMID: 11081847)

43. Allen MS et al. Morbidity and mortality of major pulmonary resections in patients with early-stage lung cancer. Ann Thorac Surg. 2006;81(2):421-426. (PMID: 16427819)

44. Falcoz PE et al. The Thoracic Surgery Scoring System (Thoracoscore). Ann Thorac Surg. 2007;83(3):924-928. (PMID: 17307429)

45. Linden PA et al. Lung resection in patients with preoperative FEV1 <35% predicted. Chest. 2005;127(6):1984-1992. (PMID: 15947308)

46. Nakahara K et al. Prediction of postoperative respiratory failure. J Thorac Cardiovasc Surg. 1988;96(4):577-580. (PMID: 3180824)

47. Markos J et al. Effect of lung resection on pulmonary function. Thorax. 1989;44(10):790-797. (PMID: 2818961)

48. Beckles MA et al. The physiologic evaluation of patients with lung cancer being considered for resectional surgery. Chest. 2003;123(1 Suppl):105S-114S. (PMID: 12527569)

49. Wyser C et al. Prospective evaluation of an algorithm for the functional assessment of lung resection candidates. Am J Respir Crit Care Med. 1999;159(5 Pt 1):1450-1456. (PMID: 10228118)

50. Baydur A et al. Preoperative pulmonary function evaluation. Clin Chest Med. 1993;14(2):305-325. (PMID: 8359746)

51. Bolliger CT et al. Lung scanning and exercise testing for the prediction of postoperative performance. Thorax. 1995;50(3):302-307. (PMID: 7785018)

52. Wang J et al. Current status of the measurement of diffusing capacity. Respir Care. 2013;58(11):1945-1951. (PMID: 24123028)

53. Liptay MJ et al. Preoperative predictors of malignancy and the need for surgical resection. Ann Thorac Surg. 2000;70(3):771-776. (PMID: 11016386)

54. De Giacomo T et al. Lung resection. In: Thoracic Surgery. Springer; 2018:187-210.

55. Donahoe L et al. Thoracoscopic lobectomy. J Thorac Dis. 2018;10(Suppl 8):S946-S954. (PMID: 29740300)

56. Ceppa DP et al. Thoracoscopic lobectomy has increasing benefit in patients with poor pulmonary function. Ann Surg. 2012;256(3):487-493. (PMID: 22868368)

57. Yan TD et al. Thoracoscopic lobectomy. J Thorac Dis. 2010;2(3):168-179. (PMID: 21160885)

58. Villamizar NR et al. Thoracoscopic lobectomy is associated with lower morbidity compared with thoracotomy. J Thorac Cardiovasc Surg. 2009;138(2):419-425. (PMID: 19619789)

59. Cattaneo SM et al. Use of video-assisted thoracic surgery for lobectomy in the elderly. Surg Endosc. 2008;22(6):1356-1362. (PMID: 18163164)

60. Swanson SJ et al. Video-assisted thoracic surgery lobectomy. J Thorac Cardiovasc Surg. 2012;144(3):S19-S22. (PMID: 22795288)

61. McKenna RJ Jr. Thoracoscopic lobectomy. In: Thoracic Surgery. Springer; 2018:211-230.

62. Boffa DJ et al. The Society of Thoracic Surgeons General Thoracic Surgery Database. Ann Thorac Surg. 2016;101(2):408-418. (PMID: 26620729)

63. D'Amico TA et al. Morbidity and mortality after lobectomy. Chest. 1998;114(5):1264-1276. (PMID: 9823986)

64. Damhuis RA et al. Postoperative morbidity after lung cancer surgery. Eur J Cardiothorac Surg. 1993;7(7):361-365. (PMID: 8356448)

65. Duque JL et al. Late complications associated with lung resection. Eur J Cardiothorac Surg. 1999;15(4):394-398. (PMID: 10333024)

66. Darling GE et al. A randomized trial of mediastinal lymph node sampling vs. lymphadenectomy. J Clin Oncol. 2011;29(7):772-780. (PMID: 21189371)

67. Martin-Ucar AE et al. Lung cancer surgery. In: Thoracic Surgery. Springer; 2018:157-186.

68. Goldstraw P et al. The IASLC Lung Cancer Staging Project. J Thorac Oncol. 2016;11(1):39-51. (PMID: 26811571)

69. Detterbeck FC et al. The eighth edition lung cancer stage classification. Chest. 2017;151(1):193-203. (PMID: 27780786)

70. Postmus PE et al. Early stage non-small cell lung cancer. Ann Oncol. 2010;21(Suppl 7):vii103-vii115. (PMID: 20935187)

71. Ramnath N et al. Treatment of stage I and II non-small cell lung cancer. Chest. 2007;132(3 Suppl):234S-242S. (PMID: 17873170)

72. Mazzone PJ et al. Screening for lung cancer. Chest. 2012;141(5):1295-1302. (PMID: 22553260)

73. Aberle DR et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011;365(5):395-409. (PMID: 21714641)

74. Howington JA et al. Treatment of stage I and II non-small cell lung cancer. Chest. 2013;143(5 Suppl):e278S-e313S. (PMID: 23649443)

75. Silvestri GA et al. Clinical practice guidelines. Chest. 2013;143(5 Suppl):e211S-e250S. (PMID: 23649443)

76. Vallières E et al. The IASLC Lung Cancer Staging Project. J Thorac Oncol. 2016;11(1):30-41. (PMID: 26684506)

77. Watanabe S et al. When is sleeve lobectomy warranted? J Thorac Cardiovasc Surg. 2014;147(2):721-725. (PMID: 24182451)

78. Rendina EA et al. Pneumonectomy. In: Thoracic Surgery. Springer; 2018:231-250.

79. Schirren J et al. The difficult airway in thoracic surgery. In: Principles and Practice of Anesthesia for Thoracic Surgery. Springer; 2019:133-146.

80. Cohen E et al. Anesthesia for thoracic surgery. In: Miller's Anesthesia. 9th ed. Elsevier; 2020:1820-1851.

81. Ng A et al. Analgesia for thoracic surgery. In: Principles and Practice of Anesthesia for Thoracic Surgery. Springer; 2019:249-270.

82. Wildgaard K et al. Pathophysiology and assessment of pain following thoracic surgery. In: Thoracic Surgery. Springer; 2018:287-306.

83. Gottschalk A et al. Acute pain management following thoracic surgery. In: Principles and Practice of Anesthesia for Thoracic Surgery. Springer; 2019:271-292.

84. Guay J et al. The effect of neuraxial blocks on surgical stress response. Can J Anaesth. 2006;53(9):929-940. (PMID: 16960276)

85. Australian Institute of Health and Welfare. Cancer in Aboriginal & Torres Strait Islander people. AIHW; 2018. (Cancer series no. 110)

86. New Zealand Ministry of Health. Cancer statistics for Māori. NZ Ministry of Health; 2020.