Resistance in gram-negative bacilli in a cardiac intensive care unit in India: risk factors and outcome.

The objective of this study was to compare the risk factors and outcome of patients with preexisting resistant gram-negative bacilli (GNB) with those who develop sensitive GNB in the cardiac intensive care unit (ICU). Of the 3161 patients ( n=3,161) admitted to the ICU during the study period, 130 (4.11%) developed health care-associated infections (HAIs) with GNB and were included in the cohort study. Pseudomonas aeruginosa (37.8%) was the most common organism isolated followed by Klebsiella species (24.2%), E. coli (22.0%), Enterobacter species (6.1%), Stenotrophomonas maltophilia (5.7%), Acinetobacter species (1.3%), Serratia marcescens (0.8%), Weeksella virosa (0.4%) and Burkholderia cepacia (0.4%). Univariate analysis revealed that the following variables were significantly associated with the antibiotic-resistant GNB: females (P=0.018), re-exploration (P=0.004), valve surgery (P=0.003), duration of central venous catheter (P<0.001), duration of mechanical ventilation (P<0.001), duration of intra-aortic balloon counter-pulsation (P=0.018), duration of urinary catheter (P<0.001), total number of antibiotic exposures prior to the development of resistance (P=0.014), acute physiology and age chronic health evaluation score (APACHE II), receipt of anti-pseudomonal penicillins (piperacillin-tazobactam) (P=0.002) and carbapenems (P<0.001). On multivariate analysis, valve surgery (adjusted OR=2.033; 95% CI=1.052-3.928; P=0.035), duration of mechanical ventilation (adjusted OR=1.265; 95% CI=1.055-1.517; P=0.011) and total number of antibiotic exposure prior to the development of resistance (adjusted OR=1.381; 95% CI=1.030-1.853; P=0.031) were identified as independent risk factors for HAIs in resistant GNB. The mortality rate in patients with resistant GNB was significantly higher than those with sensitive GNB (13.9% vs. 1.8%; P=0.03). HAI with resistant GNB, in ICU following cardiac surgery, are independently associated with the following variables: valve surgeries, duration of mechanical ventilation and prior exposure to antibiotics. The mortality rate is significantly higher among patients with resistant GNB.

Predictors of operative mortality following primary coronary artery bypass surgery.

BACKGROUND: Although quality assessment of coronary artery patients can be done by 30 days risk-adjusted operative mortality, it is still insufficient to study the outcome after primary coronary artery bypass graft surgery (CABG). In our study, we attempted to determine the factors, which can help predict operative mortality before and after CABG. METHODS: The study population consisted of 1000 prospective patients who underwent primary isolated CABG. Assessment was done by dividing the patients into two groups, i.e. non-survivors ( n= 12) and survivors ( n= 988). Data were analyzed using both univariate and multivariate models. RESULTS: On univariate analysis, recent acute myocardial infarction, intra-aortic balloon counterpulsation (IABC), left ventricular ejection fraction (LVEF) <25%, ventilator-associated pneumonia (VAP), tracheostomy, re-exploration, ventricular arrhythmias, low cardiac output (CO), multiple blood transfusions, post-operative renal dysfunction and longer intensive care unit and hospital stay were found as risk factors for mortality. Multivariate analysis showed that LVEF <25%,VAP, ventricular arrhythmias and low CO independently predicted mortality. Prior knowledge of these risk factors can help not only in predicting the outcome and the risks but also helps to plan the surgical and post-operative course of the patients to improve the morbidity and mortality. CONCLUSION: Our data suggest that operative mortality can be predicted prior to and after surgery considering factors such as LVEF, use of IABC, onset of ventricular arrhythmias and low CO.