ABSTRACT
The predictors of prolonged mechanical ventilation and subsequent morbidity after cardiac surgery are ill defined. Our aim was to evaluate them. Four hundred and seventy consecutive patients undergoing coronary artery bypass grafting on cardiopulmonary bypass (CPB) between January and June 2002 were retrospectively analysed for preoperative predictors of prolonged ventilation, which included age, gender, ejection fraction (EF), renal function, diabetes, angina status, severity of the disease (New York Heart Association class), number of vessels diseased and chronic lung disease. Intraoperative variables such as prolonged CPB, aortic cross clamp time, intra-aortic balloon pump (IABP) usage, inotropes and postoperative variables like temperature on arrival at intensive care unit(ICU), IABP usage, organ dysfunction, inotropes and reintervention (reintubation and re-exploration) were also analysed. Prolonged ventilation was defined as > or = 24 hours and these patients were included in group I (n=22). Patients requiring less than 24 hours ventilation (n=448) were included in group II. Stepwise logistic regression analysis was performed. The average age of patients was 56.9 +/- 8.8 years with male predominance (88.4%). The overall perioperative mortality was 2.1% (10 patients) with Group I showing mortality rate of 36.3% (8 patients). In multivariate analysis, predictors of prolonged ventilation were found to be EF <40% (odds ratio, (OR) 13.38), preoperative renal dysfunction [OR 4.06 (serum creatinine > 1.2 mg%)], prolonged CPB, > 120 min (OR 9.6) and reintervention in the form of re-exploration or reintubation in the ICU (OR 13.8). Identification of perioperative variables, which may lead to prolonged ventilation may allow the development of strategies to optimize the patient's condition and ICU management.
ABSTRACT
BACKGROUND: A cardiac homograft valve bank with cryopreservation facility was established at the Institute of Cardiovascular Diseases, Madras Medical Mission, Chennai in July 1995. METHODS AND RESULTS: During the last 7 1/2 years of its existence, from July 1995 to March 2003, 588 hearts were processed. The valves harvested were 390 aortic, 400 pulmonary and 39 others including mitral valve, aortic conduits, pericardium etc.; 176 (29.9%) hearts were discarded for various reasons which included failure to sterilize, HBV, HIV, HCV, treponema pallidum hemagglutination test positivity, atheromatous/fatty streaks, incompetent valves, and dissection mistakes. The valves were sterilized using an antibiotic cocktail of vancomycin, amikacin, streptomycin, cefotaxime and amphotericin B in Hank's balanced salt solution. Of the 585 valves issued for clinical use, 247 were aortic, 323 pulmonary and 15 others (mitral valve, pericardium, conduits). Gram negative bacilli were the predominant contaminants from the hearts during the first half (July 1995 to February 1999) and gram positive organisms were the predominant contaminants during the later half (March 1999 to March 2003) of the study period. A variety of fungal contaminants like candida, aspergillus, penicillium and other fungi were also isolated from the homograft hearts at procurement. The valves were used most commonly for Rastelli procedure/right ventricular-pulmonary artery conduit (48.71%) followed by Ross procedure (23.41%). The other procedures were aortic valve replacement (6.15%), truncus repair (5.81%), unifocalization with conduit repair (6.49%), aortoplasty (0.512%), left ventricular-pulmonary artery conduit (0.512%), pulmonary valve replacement (0.512%), aneurysm repair (0.34%), Norwood repair (0.34%), mitral valve replacement (0.17%) and other procedures (7%). CONCLUSIONS: We have established a viable and functioning cardiac homograft valve bank to suit Indian conditions and till date, have issued 585 homograft valves for clinical use.