Analysis Of Risk Factors For Postoperative Respiratory Failure After Pulmonary Resection

Introduction: Pulmonary resection remains the important options for patients with pulmonary diseases especially for those with non small cell carcinoma presenting as localized nodules. Acute postoperative respiratory failure(PRF) is among the most serious of the postoperative pulmonary complications and is believed to be a major contributor to the morbidity and mortality after pulmonary resection . More importantly, the in-hospital death rate for patients with PRF is 40% to 42% versus 6% for those without PRF. We sought to the risks of pre-, intra-, and post-operative factors that lead to its occurrence and make efforts to prevent it from happening so as to reduce the morbidity , mortality , in-hospital costs and improve the effect of operation.The main objective of this study was to determine the preoperative predictors of PRF in a large subjects undergoing pulmonary resection retrospectively. Specific goals included identifying predictors of PRFthat are easily obtained and commonly accessible to care providers before surgery.Material and Methods: The clinical data of 600 consecutive patients who underwent pneumonectomy, lobectomy or segmental resection from Jan. 1996 to Jan. 2004 were analysed retrospectively. 17 patients who developed PRF postoperatively served as respiratory failure group (study group), another 49 patients sampled randomly during the same period without respiratory failure postoperatively served as non respiratory failure group (control group). The following possible risk parameters were measured for all patients: Preoperative variables include age, smoking index, body mass index, Alb, TP, Hb, abnormal ECG, accompanied with circulatory system disease or another respiratory system disease, spirometry, and ASA scoring; Intraoperative variables include anesthetic and operation time, intubation method, blood loss, and fluid infusion volume; Postoperative variables include cytology, fluid infusion volume in the operation day, fluid infusion volumn after operation , blood transfusion volumn. The related factors for acute respiratory failure after pneumonectomy , lobectomy or segmental resection were assessed with univariate analysis and followed by binary logistic regression analysis. In the univariate analysis, categorical variables were analyzed using a Pearson's x test or Fisher's exact test, and continous variables were compared by using the student's unpairedt-test. Data are presented as x±s for continuous variables and as percentage for categorical variables. Differences were considered significant with P values less than 0.05. Those variables with P values less than 0.05 in the univariate analysis were included in the multivariate analysis. The risk of postoperative respiratory failure was evaluated by using a binary forward stepwise logistic regression analysis to estimate odds ratios (OR) and their 90% confidence intervals (CI). The statistical analysis was performed with SPSS 10.0 for Windows software system. Results: Univariate analysis of Preoperative clinical factors associated with higher risk for postoperative respiratory failure were: age exceed 60 (65% vs 16%, P=0.0035), accompanied with respiratory disease (35% vs 4%, P=0.0007), more ASA above grade 1 patients(59% vs 22%, P=0.0055). But the smoking index(>400) (59% vs 33%, P=0.0571), BMI(21.06 ±2.79 vs 21.76 ± 2.63, P=0.3586), Alb(37.53 ±4.86 vs 36.73 ± 6.76, P=0.6612), Hb(12.84 ± 1.39 vsl2.21 + 1.88, P=0.2182), accompanied with abnormal ECG (53% vs 35%, P=0.1846), accompanied with circulatory system disease(24% vs 14%, P=0.6146) did not have an increased risk for postoperative respiratory failure (P>0.05) .Univariate analysis of spirometry associated with higher risk forpostoperative respiratory failure were: FVC(2.44±0.78 L vs 2.90±0.62 L,P = 0.0196), FEV₁ (1.49±0.57 L vs 2.20±0.59 L, P=0.0011), PPO-FEV₁(1.17±0.48 L vs 1.68±0.54 L, P=0.0018) , FVC(<80%) (24% vs 2%, P=0.0105),FEV₁(<1.5L)(59% vs 14% , P=0.0002) , FEV₁/FVC(<70%) (35% vs6%, P=0.0040) , FEF50% (<70%) (82% w55%,P= 0.0208).ButFIF50%(<7...