Neurological outcome after coronary artery bypass surgery

Neurological dysfunction is a common complication after cardiac surgery. Despite significant advances in cardiopulmonary bypass [CPB] technology, surgical techniques and anaesthetic management, central nervous system complications occur in a large number of patients undergoing surgery requiring CPB. The objective of this study was to determine neurocognitive status of the patients undergoing coronary artery bypass grafting [CABG] and to find any causative or associated factor. We evaluated 1000 consecutive patients undergoing primary isolated coronary artery bypass grafting [CABG] at a tertiary care cardiac institute from July 2000 to December 2001 to determine the neurological outcome after CABG and risk factors involved. The demographic and perioperative data were analyzed by X2 analysis. A history of diabetes, hypertension, increased age, preoperative neurological event, aortic atheromatous / calcific disease, bilateral carotid artery disease, intermittent aortic cross clamping and evidence of mural thrombi are all co-related with increased risk of neurological damage after CABG. When analyzed in a stepwise logistic regression model, diabetes mellitus, aortic disease increased age and mural thrombi carried a higher probability that the patient would have a postoperative neurological deficit. Conclusions: We conclude that although these factors are individually involved in the adverse neurological outcome after CABG but the combination of these factors greatly increases the risk of postoperative neurological consequences and only few of them are avoidable

Acute renal failure after cardiopulmonary bypass surgery

Acute renal failure [urine output <0.5ml/kg/hr.] following cardiopulmonary bypass is an uncommon but highly lethal complication which arises in the setting of inadequate cardiac function and may be associated with multi-organ failure. Acute renal failure [ARF] after cardiopulmonary bypass occurs in about 8% of adult cardiac surgical patients with some preoperative renal impairment and in about 3-4% of patients with normal preoperative renal parameters. This study was conducted to determine the frequency of acute renal failure after cardiopulmonary bypass operations and to find possible risks factors. We analyzed the data of 500 consecutive patients who survived the first 24 hours after open heart surgery at Punjab Institute of Cardiology, Lahore as this is the minimum time to evaluate post-operative renal function, their morbidity, mortality and the main contributing risk factors, from July 2000 to Dec. 2000. The association between preoperative, intra-operative and postoperative variables and the development of ARF was assessed by multivariate logistic regression. Of the 500 consecutive patients 35 [7%] patients developed acute renal failure [serum creatinine>2.5 mg/dl] and 102 [20.4%] patients developed acute renal dysfunction [serum creatinine 1.6-2.4 mg/dl]. Positive risk factors noted in the development of ARF were age, raised preoperative blood urea and creatinine, diabetes mellitus, low cardiac output state, oligurea, total CPB time, total cross clamp time and significant hypotension during the procedure or during intensive care unit [ICU] stay. Mortality rate for established ARF was extremely poor [88.8%] and there were only four [4] survivors among those requiring dialysis. Conclusions: Prevention of this disastrous complication appears to be better than treatment once it is fully established. However newer aggressive forms of early renal replacement / transplant therapies may have some promise