Preoperative Pulmonary Function Evaluation in Lung Resection Ri 李佩蓉 / 王奐之 CR 顏郁軒

Pulmonary Function Test Preoperative pulmonary evaluation of patients with lung cancer concerns both resectability and operability. –resectability: TNM staging –operability: how much tissue can be safely removed

Commonly Used Parameters FEV 1 (Forced Expiratory Volume in 1 second) –FVC (Functional Vital Capacity) –FEV 1 /FVC MVV (Maximum Voluntary Ventilation) = MBC (Maximum Breathing Capacity) DLCO (Diffusing Capacity of Carbon Monoxide) VO 2 max (Maximum Oxygen Consumption)

FEV 1 best parameter to predict risk of post-op complications (including death) ppoFEV 1 (predicted postoperative FEV 1 ) Am J of Med (2005) 118, 578–583 Chest (2003) 123, Resp Med (2004) 98,

MVV (MBC) largest volume breathed voluntarily in 1 min an estimate of the peak ventilation available to meet physiological demands represents respiratory muscle strength and correlates with post-op morbidity Am J of Med (2005) 118, 578–583 Chest (2003) 123, Resp Med (2004) 98,

DLCO independent predictor for risk of post-op complications (including death) reflects alveolar membrane integrity and pulmonary capillary blood flow low DLCO implies significant emphysema, and reduced pulmonary capillary vascular bed Am J of Med (2005) 118, 578–583 Chest (2003) 123, Resp Med (2004) 98,

VO 2 max (Exercise Test) exercise capacity (measured as VO 2 max) predictor of post-op complications (including death) –exercise oximetry –stair climbing –shuttle walking –6-minute walk test helps to identify high-risk patients who can safely undergo lung resection Am J of Med (2005) 118, 578–583

VO 2 max Eugene et al VO 2 max > 1 L/min  little complications Smith et al VO 2 max > 20 ml/kg/min  post-op complications 10% VO 2 max = 15~20 ml/kg/min  post-op complications 66% VO 2 max < 15 ml/kg/min  post-op complications 100% Markos et al oxygen desaturation during a 12-min walk, ppoDLCO and ppoFEV 1 were more reliable predictors of post-op mortality Chest (2003) 123,

Other Parameters FEF 25-75% : highly variable ABG: hypercapnia (>45 mmHg) PPP (predicted postoperative product) –product of ppoFEV 1 and ppoDLCO Am J of Med (2005) 118, 578–583

Postoperative Lung Function Pulmonary function is affected by lung resection, extent varies: –pneumonectomy: FEV 1 : 34~36%↓ FVC: 36~40%↓ VO 2 max: 20~28%↓ –lobectomy: FEV 1 : 9~17%↓ FVC: 7~11%↓ VO 2 max: 0~13%↓ Am J of Med (2005) 118, 578–583

Lung Resection may undergoes up to 3 testing phases: 1 st phase (whole-lung tests): room-air ABG, simple spirometry, lung volume, (DLCO, exercise test) i. PaCO 2 > 45 mmHg ii. FEV 1 or MVV 50% if any combination of the above exists → proceed to 2 nd phase Chapter 49, Miller’s Anesthesiology, 6th Edition

Lung Resection 2 nd phase (single-lung tests): ventilation/perfusion of each lung quantitative CT scanning i. ppoFEV 1 70% blood flow to the diseased lung if any of the above exists → proceed to 3 rd phase Chapter 49, Miller’s Anesthesiology, 6th Edition

Prediction of Post-op Lung Function Methods to predict postoperative pulmonary function: –segment method –radionuclide scanning techniques –quantitative computed tomography

Segment Method 19 total segments (right 10, left 9) estimated post-op pulmonary function = (pre-op pulmonary function) * (post-op remaining segments) / 19 subsegments also being used (total of 42 subsegments) Am J of Med (2005) 118, 578–583

Radionuclide Scanning Techniques inhaled 133 Xe or intravenous 99 Tc-labeled macroaggregates estimation by quantifying the perfusion to a specific area: ppoFEV 1 = preoperative FEV 1 * % of radioactivity contributed by nonoperated lung Am J of Med (2005) 118, 578–583

Quantitative Computed Tomography -500~-910 Hounsfield unit is used to estimate functional lung volume correlates better than radionuclide scanning method AJR (2002) 178, 667–672

Lung Resection 3 rd phase (mimic post-op condition): –temporary balloon occlusion (with or without exercise) → skill-demanding, rarely performed Chapter 49, Miller’s Anesthesiology, 6th Edition Ann Thorac Cardiovasc Surg (2004) 10,

Testing Phases Chapter 49, Miller’s Anesthesiology, 6th Edition

Pulmonary Function Test Chapter 49, Miller’s Anesthesiology, 6th Edition

Pre-opPredicted Post-op FVC (L) FEV 1 (L)1.66 (>1.2~1.0)1.40 (>1) FEV 1 /FVC (%)51.9 (>40) RV/TLC (%)55.0 MVV (L/min) % predicted (%) 53.3 (>40) 69.9 (>40) VO 2 max (L/min) VO 2 max (ml/kg/min) ( 15, <20) Oxy-Hb drop in exercise (%)None (<5%) Case The patient should therefore be safe to undergo RUL lobectomy.

Reference 1. Anesthesia for thoracic surgery, Miller: Miller’s Anesthesiology (2005) 6th Edition, chapter Pulmonary function testing, Miller: Miller’s Anesthesiology (2005) 6th Edition, chapter Mazzone et al., Lung cancer: preoperative pulmonary evaluation of the lung resection candidate. Am J of Med (2005) 118, 578– Datta et al., Preoperative evaluation of patients undergoing lung resection surgery. Chest (2003) 123, Wang et al., Pulmonary function tests in preoperative pulmonary evaluation. Resp Med (2004) 98, Tanita et al., Review of preoperative functional evaluation for lung resection using the right ventricular hemodynamic functions. Ann Thorac Cardiovasc Surg (2004) 10, Wu et al., Prediction of postoperative lung function in patients with lung cancer: comparison of quantitative CT with perfusion scintigraphy. AJR (2002) 178,

Thank you for your attention!

predicted VO 2 = 5.8 * weight in kg (W of workload)