[Nosocomial infections in a neurosurgical intensive care unit]

The occurrence of nosocomial infections in 1017 consecutive patients seen in a neurosurgical intensive care unit (ICU), over a period of 18 months is reported. The frequency of infections is low, which may possibly be due partly to the short stay in the ICU. Close interdisciplinary cooperation is stressed as an important factor in limiting infections. BACKGROUND. The aim of this study was to analyse the nosocomial infections in a neurosurgical intensive care unit over a period of 18 months, emphasizing localization and cause of infection, in order to adapt treatment and to take preventive measures. From 15% to 27% of patients treated in ICUs acquire nosocomial infections. In Germany this means 500,000-800,000 patients a year, and the annual costs related to nosocomial infections are estimated at 1.7 billion Deutschmarks. PATIENTS AND METHODS. In all, 1017 consecutive patients were evaluated. The patients were divided into two groups, depending on the duration of treatment in the ICU: Patients who remained for less than 48 h (1017 patients) Patients who were treated for a period exceeding 48 h (314 patients) The evaluation was performed retrospectively from the medical documentation. Criteria for registration are those of the Centers for Disease Control (Atlanta 1988). When more than one infection was diagnosed, each was considered as a new infection, regardless of the bacteria involved. Among the 314 patients who were in the ICU for more than 48 h a total of 114 nosocomial infections were recorded. The frequency of infection referred to all patients treated during that time (n = 1017) was 11.2%, while the frequency among those who were treated for longer than 48 h was 36.3%. Most infections (38.6%) affected the respiratory tract, followed by infections of the urinary tract. Of the bacteria determined 56.7% were gram-negative. In this group E. coli was the most frequently found (29.8%). In the group of gram-positive bacteria, S. aureus was diagnosed in 56.3% of cases. Twelve (16%) of the infected patients died and lethality referred to all patients was 8.6%. DISCUSSION. Compared with other studies, this study revealed a low the infection rate, at 11.2%. This can be explained partly by the short stay in this ICU (mean 3.7 days) and partly by the retrospective method of registration and the particular medical characteristics of neurosurgical patients. The well-known general risk factors for infection, such as age, mechanical ventilation, continuous catheterization of the bladder, and long duration of stay, are also found in neurosurgical ICUs. It is quite difficult to determine to what extent nosocomial infections prolong the treatment necessitated by the primary neurosurgical disease. We were not able to extrapolate the influence of immunosuppressant treatment on the appearance of nosocomial infections, as almost all patients in this study were receiving steroids. This study underlines the necessity of interdisciplinary cooperation between neurosurgeons, anaesthesiologists, microbiologists and nurses in neurosurgical ICUs, where most patients staying longer than 48 h are immunosuppressed and ventilated and thereby particularly at risk of nosocomial infections.