Lung Volume Reduction Surgery

Reviewed and revised 10 March 2014; Cowritten by Chris Poynter and Jeremy Fernando

OVERVIEW

• Lung volume reduction surgery is performed on a high risk population with an associated mortality of 5-10%
• The goal of the operation is to eliminate the most diseased areas of lung to reduce overall lung volume and improve respiratory mechanics
• Admission to ICU postoperatively is for initial stabilization, close monitoring and respiratory support
• Success of the operation is dependent on patient selection, preparation, surgical skill and ICU care

Types of operations

• wedge resection
• lobectomy
• pneumonectomy

Usual indications

• Cancer (20% of bronchogenic carcinomas have resectable disease and even in this group mortality is high; if incidental finding -> do well, symptoms from cancer -> do poorly)
• Tb
• COPD (less commonly performed as often do poorly)

HISTORY

From anaesthetist:

• Indication
• Pre-op work up – ie. Functional status, relevant tests (e.g. spirometry, DLCO, Echo, ABGs)
• Comorbidities (e.g. cancer syndromes (e.g. Eaton-Lambert, carcinoid, ACTH secretion), OSA, empyema, esophageal or airway obstruction)
•  usual meds/allergies
• Pre-operative discussion with patient and family re:expectations
• Intraoperative events of note
• Current status eg. Sedatives on board, ABCs etc., fluid status
• Analgesia – local/regional techniques used, systemic analgesics, analgesic plan
• Any specific instructions? Concerns?

From surgeon:

• Specifics of operation including complications, drains, bleeding, lung state
• Specific instructions eg. Antibiotics, drains and suction

EXAMINATION

• AIRWAY – standard assessment + signs of SVC obstruction (Pembertons sign, face and arm venous congestion, JVP)
• BREATHING – unilateral chest signs (consolidation, effusion, pneumothorax), RR, position of trachea, sputum quality, SpO2 on RA
• CIRCULATION – signs of right heart failure (pulmonary hypertension) – elevated JVP, RV thrill, oedema, murmurs signs of left heart failure, murmur (TR ?carcinoid), liver enlargement.
• Walk patient up 2 flights of stairs if possible (50 stairs)

INVESTIGATIONS

STAGE 1

1. Spirometry

• Surgery Minimum Preoperative % of predicted FEV1

Pneumonectomy >60%
Lobectomy >40%
Wedge Resection >30%

• Predicted post-operative PFTs = Preop Value (5 – number of lobes resected)/5
• Goal = preoperative FEV1 >2L and >60% and postoperative FEV1 > 800mL

2. ABG

• hypoxia or hypercarbia on RA bad prognostic sign

3. DLCO

• diffusion capacity of lungs
• Goal = postoperative DLCO >40% of predicted normal

STAGE 2

4. Xe or Technetium V/Q scan

• works out regional blood flow to both lungs -> and then we can calculate a more accurate FEV1 and DLCO

STAGE 3

5. CPX Testing

• VO2 max >20mL/kg/min -> they will usually tolerate lung reduction surgery well

OTHER TESTS

• FBC – polycythaemia from chronic hypoxia, WCC for infection
• CXR – sizing of DLT, gross pathology
• CT – assessment of airway and degree of pathology
• unilateral pulmonary artery occlusion test; blocking off of one pulmonary artery and pressure measured in PA (if PAP >35mmHg or PaO2 < 45mmHg -> cancel surgery)

MANAGEMENT

PRE-OPERATIVE

• stop smoking 4 weeks prior
• preoperative physio and incentive spirometry
• bronchodilators and anti-cholinergics
• may need post operative ventilation if:
  1. DLCO <40% predicted normal
  2. estimated postop FEV1 <800mL
  3. estimated post op FVC <15mLkg

INTRA-OPERATIVE

• ateral position with broken table
• lung protective ventilation (PAP < 30cmH2O, prolonged expiratory phase = short I:E ratio) – aim for extubation post op as mechanical ventilation -> stress stitches and increases risk of infection
• art line in dependent arm
• blood loss 200-800mL
• CVL generally not used and are unrealiable
• OLV cares

POST-OPERATIVE

Priorities

• early extubation and rapid commencement of post operative rehabilitation
• this can usually be achieved with initial stabilization and monitoring and attention to adequate analgesia and careful fluid balance

Immediate assessment and stabilization

• As patient returns from theatre, they should be met and immediately assessed for stability
• Airway – are they extubated? If not, why not?
• Breathing – O2 requirements, how is their ventilation? SpO2? What are the ventilator settings if intubated? What are the pressures?
• Circulation – What is the pulse rate and BP? What lines and monitoring do they have?
• Disability – Are they awake? What sedation have they had?

Monitoring

• ECG, Arterial BP, CVP, SpO2, Consider PiCCO for fluid balance

Specific therapy and supportive care

• extubate as soon as possible
• minimize fluid intake
• set reasonable targets for pO2 and pCO2 (look at old ABGs)
• watch for gas trapping and/or tension pneumo esp. with PPV
• humidified O2
• early Physio and mobilization
• watch for blood loss
• careful fluid balance – ensure perfusion of organs but don’t overhydrate as high risk for pulm. Oedema
• Analgesia – ensure able to breath, cough and mobilize. Careful balance as respiratory depression with systemic analgesia. Local anaesthetic techniques are useful, ideally thoracic epidural. Ensure pain team involvement and follow-up.
• Pulmonary rehabilitation – involve physiotherapists and rehab team early
• perioperative antibiotic prophylaxis as per protocol
• Drains underwater usually no suction

Seek and treat complications

• Complicated recovery – with prolonged intubation or post-op repiratory failure/weaning difficulty, may need to discuss with patient, family and surgeon re: treatment goals and limits

References and Links

Journal articles

• Benzo R. Lung volume reduction surgery: nonpharmacological approach. Curr Opin Anaesthesiol. 2011 Feb;24(1):44-8. PMC3390016.
• Sharafkhaneh A, Falk JA, Minai OA, Lipson DA. Overview of the perioperative management of lung volume reduction surgery patients. Proc Am Thorac Soc. 2008 May 1;5(4):438-41. PMC2645316.