Epidemiology of intensive care unit (ICU)-acquired infections in a 14-month prospective cohort study in a single mixed Scandinavian university hospital ICU.

Abstract

Our aim was to evaluate the epidemiology of intensive care unit (ICU)-acquired infections in a prospective cohort study. Patients with longer than a 48-h stay in an adult mixed medical-surgical ICU in a tertiary level teaching hospital were included. The incidence (per cent) and incidence density (per 1000 patient days) of ICU-acquired infections and the device-associated infection rates per 1000 device days were analysed prospectively in a 14-month study. Eighty (23.9%) of 335 patients, whose ICU stay was longer than 48 h, acquired a total of 107 infections (1.3 per patient) during their ICU stay, with an infection rate of 48 per 1000 patient days. The most common infections were ventilator-associated pneumonia (VAP) [33.8% (18.8 per 1000 respiratory days)], other lower respiratory tract infections (LRTIs) (20%) and sinusitis (13.8%). The rate of central catheter-related (CRI) or primary bloodstream infections was 6.3% (2.2 per 1000 central venous catheter days), and the rate of urinary tract infections was 1.3% (0.5 per 1000 urinary catheter days). The first ICU infection was observed in 58.8% (47/80) of cases within 6 days after admission. The median time from admission to the diagnosis of an ICU-acquired infection was 4 days (25th-75th percentiles, 4.0-6.0) for VAP, 6.0 days (4.5-7.0) for LRTIs and 9.5 days (6.5-13.0) for CRIs. The rates of urinary tract infections and bloodstream infections were lower than reported previously, differentiating our results from the classic pattern of ICU-acquired infections, with the exception of the predominance of VAP.