NOSOCOMIAL INFECTION IN AN INTENSIVE-CARE UNIT - MULTIVARIATE-ANALYSIS OF RISK-FACTORS

BACKGROUND: Nosocomial infections, especially in the intensive care un it, are a very important problem due to their frequency and important consequences (morbility and mortality). On the other hand there are so me risk factors and some preventive measures which are involved in the appearance of the nosocomial infections. The purpose of this work was to recognize these risk factors and to identify the preventive measur es which are effective, and also to quantify the participation of each risk factors/preventive measures in the development of the nosocomial infections. PATIENTS AND METHODS: Follow-up of a cohort of patients a dmitted to the intensive care unit of the General Hospital of La Pat ( Madrid, Spain) during a year and with a stay of at least 48 hours. RES ULTS: We have found a cummulative incidence of patients with nosocomia l infection of 32.8%. More than 80% of the patients received antibioti c treatment during their stay in the intensive care unit. The stay of the patients not infected was 4 days while the stay of infected patien ts was 20 days. We have found a mortality of 29.5%, which was greater in the patients who were infected (42%). In the multivariate analysis we have developed an equation to predict the development of the nosoco mial infection. The following variables were identified: six or more i nstrumentations (OR, 4.75; 95% Cl, 2.75-8.19), more of ten days of hos pitalization previous to the appearance of the first nosocomial infect ion (OR, 4.17; 95% CI, 2.60-6.70), administration of muscle relaxing d rugs (OR, 2.25; 95% Cl, 1.43-3.55), nasogastric tube (OR, 2.19; 95% Cl , 1.25-3.84), and altered consciousness (OR, 2.19; 95% Cl, 1.25-3.84). Therefore, those patients who present some of these characteristics s hould be monitored in a special way due to their high risk of developm ent of a nosocomial infection. CONCLUSIONS: Several factors play an im portant role in the development of a nosocomial infection in the inten sive care unit; these are not only intrinsec (especially the altered c onsciousness) but also extrinsec (instrumentations and drugs), as well as the stay at the hospital previous to the appearance of the first n osocomial infection.