EVALUATION OF HIGH-RISK LUNG RESECTION CANDIDATES - PULMONARY HEMODYNAMICS VERSUS EXERCISE TESTING - A SERIES OF 5 PATIENTS

We compared the value of exercise testing and measurement of pulmonary haemodynamics (PH) in the pre-operative assessment of 5 patients (mea n age: 64 years, 3 men) with clinical stage I or II bronchogenic carci noma and severe chronic obstructive pulmonary disease. They were consi dered at high risk due to poor pulmonary function tests (PFT); (one or more of the following): (1) radionuclide calculated postlobectomy FEV (1) <30% predicted, (2) diffusion capacity or transfer factor <60% pre dicted, combined with a fall in PaO2 on maximal exercise of >5 mm Hg, (3) a PaCO2 at rest of >45 mm HE. Maximal oxygen uptake (VO2max) durin g symptom-limited cycle ergometry and PH were measured in these 5 pati ents. They were considered eligible for lobectomy if they fulfilled at least one of the two criteria: (1) mean pulmonary artery pressure (PA P) of <35 mm Hg and pulmonary vascular resistance of <190 dyn.s.cm(-5) at moderate exercise (40 W), (2) a VO2max of greater than or equal to 15 ml/kg/min. Six months postoperatively PFT and VO2max were measured again. PAP(40W) was 21, 38, 38, 46 and 52 mm Hg, respectively, which would have excluded 4/5 patients from surgery, VO2max was 21.7, 14.9, 13.4, 19.2 and 18.6 ml/kg/min, respectively, which would have excluded 2/5 patients. Expressed in percent predicted, however, VO2max was gre ater than or equal to 69% in all 5 patients, indicating only mild impa irment of exercise capacity in the 2 patients with <15 ml/kg/min VO2ma x. Therefore all 5 patients were offered surgery and underwent lobecto my. Apart from 1 prolonged air leak no complications occurred, the mea n hospital stay was 16 days (13-21). At 6 months their PFT and VO2max were unchanged. In conclusion, in our series of patients with marginal pulmonary function, exercise testing with the determination of VO2max was superior to PH measurements for the prediction of operability. It seems that VO2max should be expressed as a percent of predicted; howe ver, our findings will need confirmation by future studies with bigger sample sizes.