Peri-operative determinants of prolonged CICU stay after coronary artery bypass graft surgery in elderly at a private tertiary care hospital: A case control study

Objective: To explore peri-operative risk factors associated with prolonged stay in cardiac intensive care unit among patients undergoing isolated coronary artery bypass grafting. Methods: This retrospective case control study was conducted at the Aga Khan University Hospital, Karachi, comprised medical records of patients who had undergone cardiothoracic revascularisation surgery from January 2006 to December 2013. The patients were grouped into cases and controls at a ratio of 1: 2 on the basis of length of stay at cardiac intensive care unit, i.e. >= 72 hours and <72 hours. Independent risk factors for prolonged cardiac intensive care unitstay were evaluated. SPSS 20 was used for data analysis. Results: Of the 999 patients, 333(33.3%) were cases and 666(66.6%) were controls. The mean age of cases was 62.5 +/- 9.7 years and that of controls was 60.8 +/- 9.6 years (p=0.007). The number of males was 280(84.1%) among the cases and 489(73.4%) among the controls. Adjusted odds ratio and 95% confidence interval for age and male gender were 1.02 (1.0,1.03) and [1.90 (1.32,2.74)]; diabetics were at high risk of staying longer [1.51 (1.13,2.02)]; previous cardiovascular interventions [1.65 (1.05,2.59)], intra-aortic balloon pump insertion [1.45 (1.01,2.08)], initial ventilation time and post-operative bleeding tamponade were independently associated with prolonged cardiac intensive care unit stay [1.01 (1.00, 1.01)] and [1.9 (1.13,3.2)], respectively. The risk of dying among the cases was three times more after adjusting for all covariates in the model [3.1 (1.52,6.31)]. Conclusion: Advanced age, male gender, diabetes, previous cardiovascular interventions, post-operative intra-aortic balloon pump insertion, initial ventilation support and post-op bleeding tamponade were found to be the independent risk factors for prolonged cardiac intensive care unit stay.