Intensive care acquired infection is an independent risk factor for hospital mortality: a prospective cohort study

Ohtonen Pasi, Syrjälä Hannu, Ylipalosaari Pekka, Ala-Kokko, Laurila Jouko, Syrjälä

Description

The aim of this study was to elucidate the impact of intensive care unit (ICU)-acquired infection on hospital mortality. Methods Patients with a longer than 48 hour stay in a mixed 10 bed ICU in a tertiary-level teaching hospital were prospectively enrolled between May 2002 and June 2003. Risk factors for hospital mortality were analyzed with a logistic regression model. Results Of 335 patients, 80 developed ICU-acquired infection. Among the patients with ICU-acquired infections, hospital mortality was always higher, regardless of whether or not the patients had had infection on admission (infection on admission group (IAG), 35.6% versus 17%, p = 0.008; and no-IAG, 25.7% versus 6.1%, p = 0.023). In IAG ( n = 251), hospital stay was also longer in the presence of ICU-acquired infection (median 31 versus 16 days, p < 0.001), whereas in no-IAG ( n = 84), hospital stay was almost identical with and without the presence of ICU-acquired infection (18 versus 17 days). In univariate analysis, the significant risk factors for hospital mortality were: Acute Physiology and Chronic Health Evaluation (APACHE) II score >20, sequential organ failure assessment (SOFA) score >8, ICU-acquired infection, age ≥ 65, community-acquired pneumonia, malignancy or immunosuppressive medication, and ICU length of stay >5 days. In multivariate logistic regression analysis, ICU-acquired infection remained an independent risk factor for hospital mortality after adjustment for APACHE II score and age (odds ratio (OR) 4.0 (95% confidence interval (CI): 2.0–7.9)) and SOFA score and age (OR 2.7 (95% CI: 2.9–7.6)). Conclusion ICU-acquired infection was an independent risk factor for hospital mortality even after adjustment for the APACHE II or SOFA scores and age.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2006
• Nombre de lectures: 8
• Langue: English

Extrait

Available onlinehttp://ccforum.com/content/10/2/R66

Vol 10 No 2 Open Access Research Intensive care acquired infection is an independent risk factor for hospital mortality: a prospective cohort study 1 22 31 Pekka Ylipalosaari, Tero I AlaKokko, Jouko Laurila, Pasi Ohtonenand Hannu Syrjälä

1 Department of Infection Control, Oulu University Hospital, FIN90029 OYS, Finland 2 Department of Anesthesiology, Division of Intensive Care, Oulu University Hospital, FIN90029 OYS, Finland 3 Departments of Anesthesiology and Surgery, Oulu University Hospital, FIN90029 OYS, Finland

Corresponding author: Pekka Ylipalosaari, [e-mail]

Received: 14 Dec 2005Revisions requested: 13 Feb 2006Revisions received: 7 Mar 2006Accepted: 23 Mar 2006Published: 20 Apr 2006

Critical Care2006,10:R66 (doi:10.1186/cc4902) This article is online at: http://ccforum.com/content/10/2/R66 © 2006 Ylipalosaariet al., licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract IntroductionThe aim of this study was to elucidate the impact of intensive care unit (ICU)acquired infection on hospital mortality.

MethodsPatients with a longer than 48 hour stay in a mixed 10 bed ICU in a tertiarylevel teaching hospital were prospectively enrolled between May 2002 and June 2003. Risk factors for hospital mortality were analyzed with a logistic regression model.

ResultsOf 335 patients, 80 developed ICUacquired infection. Among the patients with ICUacquired infections, hospital mortality was always higher, regardless of whether or not the patients had had infection on admission (infection on admission group (IAG), 35.6% versus 17%,p= 0.008; and noIAG, 25.7% versus 6.1%,p= 0.023). In IAG (n= 251), hospital stay was also longer in the presence of ICUacquired infection (median 31 versus 16 days,p< 0.001), whereas in noIAG (n=

Introduction Patients admitted into intensive care units (ICUs) are at great risk for acquiring nosocomial infections. They are susceptible to infection because of their underlying diseases or conditions associated with impaired immunity as well as several violations of their immune system or risks of aseptic mistakes in patient management during invasive monitoring and they are prone to secondary infections after exposure to broadspectrum antimi crobials [1].

Prevalence or prospective cohort studies have earlier shown ICUacquired infections to be associated with high mortality, excessive length of ICU and hospital stay, and high hospital costs [25]. However, the significance of ICUacquired infec

84), hospital stay was almost identical with and without the presence of ICUacquired infection (18 versus 17 days). In univariate analysis, the significant risk factors for hospital mortality were: Acute Physiology and Chronic Health Evaluation (APACHE) II score >20, sequential organ failure assessment (SOFA) score >8, ICUacquired infection, age≥65, community acquired pneumonia, malignancy or immunosuppressive medication, and ICU length of stay >5 days. In multivariate logistic regression analysis, ICUacquired infection remained an independent risk factor for hospital mortality after adjustment for APACHE II score and age (odds ratio (OR) 4.0 (95% confidence interval (CI): 2.0–7.9)) and SOFA score and age (OR 2.7 (95% CI: 2.9–7.6)).

Conclusion ICUacquiredinfection was an independent risk factor for hospital mortality even after adjustment for the APACHE II or SOFA scores and age.

tion for patient outcome is controversial. In one earlier case control study, after adjustment for risk factors, ICUacquired catheterrelated infection was not a significant risk factor for mortality [6]. In other studies on catheterrelated infections, the patients with infection had longer hospital stays than the controls, with no difference in mortality [7]. In studies based on large sets of register data [8] and a casecontrol design [9], ventilatorassociated pneumonia (VAP) was associated with longer hospital stay but no effect on mortality. A recent meta analysis of VAP, however, showed that the cases with VAP had a two fold mortality rate compared to matched controls [10]. Increased mortality has also been reported among ICU patients with Gramnegative bacteremia [11,12] or intra abdominal infections [13].

APACHE = Acute Physiology and Chronic Health Evaluation; CI = confidence interval; ICU = intensive care unit; LOS = length of stay; OR = odds ratio; SOFA = Sequential Organ Failure Assessment; TISS = Therapeutic Intensity Scoring System; VAP = ventilatorassociated pneumonia.

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