Abstract
Purpose. The use of routine microbiological monitoring in the intensive care unit (ICU) setting has been controversially discussed in the past. Therefore, the primary goal of this study was to evaluate the efficiency and value of both laboratory and microbiological monitoring as useful diagnostic tools for nosocomial infections, particularly in patients with severe sepsis. Materials and methods. Between 2000 and 2002, 60 consecutive patients with severe sepsis and tertiary peritonitis on a surgical ICU were retrospectively analysed for this study. All nosocomial infections that occurred during ongoing treatment as well as parameters that finally initiated screening for infections were registered. The time course of serum inflammatory parameters (C-reactive protein, leucocyte count, procalcitonin, interleukin-6) and core temperature (fever > =38.0°C) for 72 h before definite diagnosis of an infection as well as their predictive value were analysed. The results of a routine microbiological monitoring were evaluated with special regards to their potential for the isolation of causative pathogens and, thus, the early identification of nosocomial infection with subsequent initiation of adequate therapy. Results. Clinical and laboratory diagnosis of subsequent ICU-acquired infections in this particular patient population was complicated by recurrent acute inflammatory reactions. Overall, 205 definite infections (pneumonia, tracheobronchitis, catheter-related infections, peritonitis) were analysed regarding the diagnostic value of laboratory tests and microbiological monitoring. The sensitivity of serum inflammatory parameters varied broadly, from 35 to 57%. C-reactive protein was found to be the most predictive marker (57.1%). Successful screening for infectious focus was most frequently initiated by the results of microbiological investigations (45.9%) or by clinical signs and symptoms (23.4%). Additional routine microbiological monitoring (endotracheal aspirate, urine and blood cultures) allowed the early diagnosis of 134 of 205 infections (65.4%) and adequate antimicrobial treatment of 127 infections (62%) during the study period. Conclusions. Nosocomial infections and related complications occur frequently in patients with severe sepsis. These infections, as well as the necessity of recurrent surgical interventions, may complicate the course and have a significant negative impact on patient outcome. A routine microbiological monitoring for patients with severe sepsis or septic shock is a helpful additional tool for the early diagnosis and adequate treatment of subsequent ICU-acquired infections in the setting of a surgical ICU. Thus, mortality rates of these debilitated and critically ill patients can be effectively improved.