Preoperative Pulmonary Function Preoperative Pulmonary Function Evaluation in Lung ResectionEvaluation in Lung Resection

Ri 李佩蓉 / 王奐之CR 顏郁軒

Pulmonary Function TestPulmonary 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 ParametersCommonly Used Parameters

• FEV1 (Forced Expiratory Volume in 1 second)– FVC (Functional Vital Capacity)

– FEV1/FVC

• MVV (Maximum Voluntary Ventilation)= MBC (Maximum Breathing Capacity)

• DLCO (Diffusing Capacity of Carbon Monoxide)

• VO2 max (Maximum Oxygen Consumption)

FEVFEV11

• best parameter to predict risk of post-op complications (including death)

• ppoFEV1 (predicted postoperative FEV1)

Am J of Med (2005) 118, 578–583Am J of Med (2005) 118, 578–583Chest (2003) 123, 2096-2103Chest (2003) 123, 2096-2103

Resp Med (2004) 98, 598-605Resp Med (2004) 98, 598-605

MVV (MBC)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, 578–583Am J of Med (2005) 118, 578–583Chest (2003) 123, 2096-2103Chest (2003) 123, 2096-2103

Resp Med (2004) 98, 598-605Resp Med (2004) 98, 598-605

DLCODLCO

• 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, 578–583Am J of Med (2005) 118, 578–583Chest (2003) 123, 2096-2103Chest (2003) 123, 2096-2103

Resp Med (2004) 98, 598-605Resp Med (2004) 98, 598-605

VOVO22 max (Exercise Test) max (Exercise Test)

• exercise capacity (measured as VO2 max)• predictor of post-op complications (includin

g death)– exercise oximetry– stair climbing– shuttle walking– 6-minute walk test

• helps to identify high-risk patients who can safely undergo lung resection

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VOVO22 max max

Eugene et al

• VO2 max > 1 L/min little complications

Smith et al

• VO2 max > 20 ml/kg/min post-op complications 10%

• VO2 max = 15~20 ml/kg/min post-op complications 66%

• VO2 max < 15 ml/kg/min post-op complications 100%

Markos et al • oxygen desaturation during a 12-min walk, ppoDLCO and pp

oFEV1 were more reliable predictors of post-op mortality

Chest (2003) 123, 2096-2103Chest (2003) 123, 2096-2103

Other ParametersOther Parameters

• FEF25-75%: highly variable• ABG: hypercapnia (>45 mmHg) • PPP (predicted postoperative product)

– product of ppoFEV1 and ppoDLCO

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Postoperative Lung FunctionPostoperative Lung Function

• Pulmonary function is affected by lung resection, extent varies:– pneumonectomy:

• FEV1: 34~36%↓• FVC: 36~40%↓• VO2 max: 20~28%↓

– lobectomy:• FEV1: 9~17%↓• FVC: 7~11%↓• VO2 max: 0~13%↓

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Lung ResectionLung Resection

• may undergoes up to 3 testing phases:• 1st phase (whole-lung tests):

• room-air ABG, simple spirometry, lung volume, (DLCO, exercise test)

i. PaCO2 > 45 mmHgii. FEV1 or MVV < 50% predictediii. RV/TLC > 50%

• if any combination of the above exists→ proceed to 2nd phase

Chapter 49, Miller’s Anesthesiology, 6th EditionChapter 49, Miller’s Anesthesiology, 6th Edition

Lung ResectionLung Resection

• 2nd phase (single-lung tests):• ventilation/perfusion of each lung• quantitative CT scanning

i. ppoFEV1 < 0.85 Lii. > 70% blood flow to the diseased lung

• if any of the above exists→ proceed to 3rd phase

Chapter 49, Miller’s Anesthesiology, 6th EditionChapter 49, Miller’s Anesthesiology, 6th Edition

Prediction of Post-op Lung FunctionPrediction of Post-op Lung Function

• Methods to predict postoperative pulmonary function:– segment method– radionuclide scanning techniques– quantitative computed tomography

Segment MethodSegment 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)

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Radionuclide Scanning TechniquesRadionuclide Scanning Techniques

• inhaled 133Xe or intravenous 99Tc-labeled macroaggregates

• estimation by quantifying the perfusion to a specific area:

ppoFEV1 = preoperative FEV1 * % of radioactivity contributed by nonoperated lung

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Quantitative Computed TomographyQuantitative Computed Tomography

• -500~-910 Hounsfield unit is used to estimate functional lung volume

• correlates better than radionuclide scanning method

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Lung ResectionLung Resection

• 3rd phase (mimic post-op condition):– temporary balloon occlusion (with or without exe

rcise) → skill-demanding, rarely performed

Chapter 49, Miller’s Anesthesiology, 6th EditionChapter 49, Miller’s Anesthesiology, 6th EditionAnn Thorac Cardiovasc Surg (2004) 10, 333-339Ann Thorac Cardiovasc Surg (2004) 10, 333-339

Testing PhasesTesting Phases

Chapter 49, Miller’s Anesthesiology, 6th EditionChapter 49, Miller’s Anesthesiology, 6th Edition

Pulmonary Function TestPulmonary Function Test

Chapter 49, Miller’s Anesthesiology, 6th EditionChapter 49, Miller’s Anesthesiology, 6th Edition

Pre-op Predicted Post-opFVC (L) 3.20 2.69FEV1 (L) 1.66 (>1.2~1.0) 1.40 (>1)

FEV1/FVC (%) 51.9 (>40)

RV/TLC (%) 55.0MVV (L/min)% predicted (%)

53.3 (>40)69.9 (>40)

VO2 max (L/min)VO2 max (ml/kg/min)

0.944 (<1)15.9 (>15, <20)

Oxy-Hb drop in exercise (%) None (<5%)

CaseCase

The patient should therefore be safe to undergo RUL lobectomy.

ReferenceReference1. Anesthesia for thoracic surgery, Miller: Miller’s Anesthesiology (2005) 6th Edition, chapte

r 492. Pulmonary function testing, Miller: Miller’s Anesthesiology (2005) 6th Edition, chapter 263. Mazzone et al., Lung cancer: preoperative pulmonary evaluation of the lung resection ca

ndidate. Am J of Med (2005) 118, 578–5834. Datta et al., Preoperative evaluation of patients undergoing lung resection surgery. Chest

(2003) 123, 2096-21035. Wang et al., Pulmonary function tests in preoperative pulmonary evaluation. Resp Med

(2004) 98, 598-6056. Tanita et al., Review of preoperative functional evaluation for lung resection using the rig

ht ventricular hemodynamic functions. Ann Thorac Cardiovasc Surg (2004) 10, 333-339

7. Wu et al., Prediction of postoperative lung function in patients with lung cancer: comparison of quantitative CT with perfusion scintigraphy. AJR (2002) 178, 667-672

Thank you for your attention!Thank you for your attention!

predicted VO2 = 5.8 * weight in kg + 151 + 10.1 (W of workload)