Nosocomial infections in a medical-surgical intensive care unit

Abstract

Objective: We aimed to describe the pattern of nosocomial infections in an adult medical-surgical intensive care unit (ICU).

Subjects and methods: A 2-year prospective cohort study of nosocomial infection surveillance in a 15-bed adult combined medical and surgical ICU of Farwaniya Hospital, Kuwait, was carried out. Data were collected between January 2004 and December 2005 using the standard surveillance protocols and nosocomial infection site definitions of the National Nosocomial Infections Surveillance System's ICU surveillance component.

Results: Of 1,173 patients hospitalized in the ICU for an aggregate duration of 6,855 days, 89 patients acquired a total of 140 nosocomial infections; 46 (33%) ventilator-associated pneumonia (VAP), 33 (24%) central-line-associated bloodstream infection and 15 (11%) catheter-associated urinary tract infection, 22 (16%) cutaneous infection and 24 (17%) other infections. The overall patient day rate was 20.6/1,000 patient days. The patient infection rate was 10.6/100 patients at risk. The mean VAP rate was 9.1/1,000 ventilator days (95% CI, 5-13.2), the central-line-associated bloodstream infection rate 5.5/1,000 central line days (95% CI, 3.2-7.8) and the catheter-associated urinary tract infection rate 2.3/1,000 catheter days (95% CI, 1.2-3.4). Of all nosocomial infections, 119 (85%) were culture-confirmed and 21 (15%) were clinically defined culture-negative infections. Of the culture-confirmed nosocomial infections, 81 (68%) were Gram-negative, 32 (27%) Gram-positive and 6 (5%) fungal. The most frequent organism was Pseudomonas aeruginosa (20, 17%), followed by Acinetobacter baumannii (15, 13%), Klebsiella spp. (13, 11%) and Escherichia coli (10, 8%). The crude mortality was 27% among ICU-infected patients.

Conclusion: VAP was the most common nosocomial infection in our ICU. Gram-negative organisms were more commonly reported as etiologic agents of ICU infections.