Evaluation of pulmonary complications in patients with valvular heart surgery: Clinical and laboratory significances

Background: Pulmonary complications following cardiac valvular surgery are common and contribute to increased rate of hospital stay, morbidity and mortality. This study was conducted to determine the incidence of pulmonary complications after cardiac valvular surgery and to investigate perioperative clinical factors for postoperative pulmonary complications at a tertiary university hospital. Methods: Overall, 180 consecutive adult patients (> 18 years), whounderwent nonemergency aortic, mitral, pulmonary or tricuspid valvular surgery were enrolled. Before surgery, lung function and gas exchange were measured. Complete history taking, vital signs and clinical examination was done and Chest X-Ray, Electrocardiogram (ECG), echocardiography, blood gas analysis, and complete blood tests were obtained and patients were followed throughout surgery and after that, till discharge from the hospital for detection of respiratory complications. The relevant pre-, intra-, and post-operative data of all patients were investigated and analyzed. Results: The cumulative incidence of pulmonary complications was 50 (90 of 180) with a mortality rate of 6.6% (6 of 90) and the overall mortality among all patients was 3.3% (6 of 180). Type of valvular surgery was significantly associated with postoperative pulmonary complications (POPC). With regards to cardiac risk factors, Hypertension (HTN) and smoking had a significant relationship with POPC (P < 0.0001, P 0.003 respectively). Bivariate analyses showed that older patients were more susceptible to POPC (P < 0.0001). There was no significant difference in POPC (P = 0.55) between males and females. Prolongation of operation time (P = 0.03), cross clamp time (P = 0.04) and pump time (P < 0.0001) were associated with POPC. There was a significant relationship between PaO2 in AIR and 100% FIO2, and POPC (P = 0.02, P = 0.007, respectively).There was a significant relationship between death and POPC (P = 0.01). Conclusions: Type of valvular surgery, hypertension, smoking, older age, pump time, operation time, cross clamp time and Pao2 in air and 100% O2 were the most important factors associated with postoperative pulmonary complications.