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

• Main Authors: Pawar Mandakini, Mehta Yatin, Purohit Apoorva, Trehan Naresh, Daniel Rosenthal
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2008-01-01
• Series: Annals of Cardiac Anaesthesia
• Subjects: Cardiac surgery; gram-negative bacilli; intensive care unit; nosocomial infection; resistance
• Online Access: http://www.annals.in/article.asp?issn=0971-9784;year=2008;volume=11;issue=1;spage=20;epage=26;aulast=Pawar

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 (<i> n</i> = 3,161) admitted to the ICU during the study period, 130 (4.11&#x0025;) developed health care-associated infections (HAIs) with GNB and were included in the cohort study. <i> Pseudomonas aeruginosa</i> (37.8&#x0025;) was the most common organism isolated followed by Klebsiella species (24.2&#x0025;), <i> E. coli</i> (22.0&#x0025;), Enterobacter species (6.1&#x0025;), <i> Stenotrophomonas maltophilia</i> (5.7&#x0025;), Acinetobacter species (1.3&#x0025;), <i> Serratia marcescens</i> (0.8&#x0025;), <i> Weeksella virosa</i> (0.4&#x0025;) and <i> Burkholderia cepacia</i> (0.4&#x0025;). Univariate analysis revealed that the following variables were significantly associated with the antibiotic-resistant GNB: females (<i> P</i> = 0.018), re-exploration (<i> P</i> = 0.004), valve surgery (<i> P</i> = 0.003), duration of central venous catheter (<i> P</i> &lt; 0.001), duration of mechanical ventilation (<i> P</i> &lt; 0.001), duration of intra-aortic balloon counter-pulsation (<i> P</i> = 0.018), duration of urinary catheter (<i> P</i> &lt; 0.001), total number of antibiotic exposures prior to the development of resistance (<i> P</i> &lt; 0.001), duration of antibiotic use prior to the development of resistance (<i> P</i> = 0.014), acute physiology and age chronic health evaluation score (APACHE II), receipt of anti-pseudomonal penicillins (piperacillin-tazobactam) (<i> P </i> = 0.002) and carbapenems (<i> P</i> &lt; 0.001). On multivariate analysis, valve surgery (adjusted OR = 2.033; 95&#x0025; CI = 1.052-3.928; <i> P</i> = 0.035), duration of mechanical ventilation (adjusted OR = 1.265; 95&#x0025; CI = 1.055-1.517; <i> P</i> = 0.011) and total number of antibiotic exposure prior to the development of resistance (adjusted OR = 1.381; 95&#x0025; CI = 1.030-1.853; <i> P</i> = 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&#x0025; vs. 1.8&#x0025;; <i> P</i> = 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.