Preoperative Evaluation For Chronic Respiratory Dysfunction And Exploration Of Its Mechanism

Objective To assess the applicability of cardiac pulmonary exercise test on judging the indications of lung resection on COPD patients.Methods 20 COPD patients presenting lung resection, who were diagnosed moderate to server obstructive respiratory dysfunction by spirometer(FEVl% = 40.1 ± 11.9, FEV1/FVC = 50.9± 10.4%) were enrolled in this study. They were scheduled cardiac pulmonary exercise(CPX). Ergometer was adopted as our CPX tool, and the protocol is riding the bicycle at the speed of 50-60 rpm under zero load for 3 min, then increase the load by 15Watt every 2 min, till the patient could not maintain the riding speed. ECG, SpO2, NBP were monitored during the CPX and artery blood gas were analyzed before and after CPX. Those people whose VO2peak > 10ml/min/kg were admitted operation. All the patients were arranged preoperative training including bronchodilator therapy, incentive spirometer training, physical training and adaptable none invasive positive pressure ventilation (NPPV) training for 1 -2 weeks. The operation was under epidural block combined with general anesthesia. All the patients were sent to ICU after operation. EPCA was adopted for postoperative analgesia. The parameters from the spiromter test and CPX are compared between the patients who developed server postoperative pulmonary complications(PPCs) and those who didn't develop PPCs.Result 19 patients, whose VO2peak>10ml/min/kg were admitted for operation. All the patients were extubating in PACU. 3 patients experienced PPCs, and were ventilated noninvasively for 5-7days. 2 of them were aspired with fiberoptic bronchoscope at third and forth postoperative day because of sputum retention. All the patients were cured and perioperative motility is zero. Only FEV1 (870.00 ± 70.71ml vs 1225.55 ?88.04ml P<0.05 ) and VO2AT/BW (9.87±0.78ml/min/kg vs 12.32±1.87ml/min/kg P<0.05 ) show significant difference between patients with and without PPCs. Using Logistic regression to assess the risk rate of FEVI <900ml and VO2AT/BW<10ml/min/kg over PPCs, we find only VO2AT/BW< 10ml/min/kg has the OD (34.1) with stastic significant.Conclusion CPX is applicable in judging the indications of lung resection in COPD patients. VO2AT/BW< 10ml/min/kg has the predictive value on PPCs.