Causes of death in intensive care surgical patients. A prospective study

Infection and sepsis are generally considered as causally related to death in intensive care unit (ICU) patients, but in several studies a decrease in infection rates was not associated with lower mortality. We therefore investigated the causes of death in surgical ICU patients, with special regard to the relationship between infection and mortality. MATERIAL AND METHODS. During the investigation period of 6 months, 502 patients were treated in the ICU (cardiac surgery: 222, thoracoabdominal surgery: 125, vascular surgery: 84, others: 14). In all patients each antibiotic therapy and infection was documented, as was the sepsis score. Definitions of infection and bacteriological monitoring were described in detail previously. In all deaths, attention was paid to an infection that was causally related to or contributed to death. In unclear cases a postmortem examination was performed. RESULTS. Forty-two patients died (8.4%). During the first 4 days 23 patients died, 11 within 24 h, because of severe trauma with severe underlying disease (main reason for death: cardiac 30%, cerebral 32%). Infections were not significant in these patients. Nineteen patients suffered from 1 or more infections (total 30). They died after a median of 16 days. The leading cause of death was multiple organ failure. In 7 of these patients a life-threatening infection was the reason for admission and, later, death. In 8 patients a nosocomial infection was causally related to or contributed to death. In the 4 other patients a postmortem examination excluded an infection as being responsible for death. DISCUSSION. More than one-half of the deaths were caused by severe trauma or severe underlying disease. Nosocomial infections could only be related to death in 1.6% of the 502 treated ICU patients. The influence of new therapeutic regimens on infection and mortality can therefore only be investigated in multicenter trials.