Microbiologically confirmed infections are common among patients requiring medical intensive care for 48 h. Despite the administration of adequate antimicrobial therapy, microbiologically confirmed infections appear to be an important cause of hemodynamic instability and increased hospital mortality. These data suggest that clinical efforts aimed at the prevention of infections and improvements in the medical management of patients with severe infections, especially those associated with hemodynamic instability and the need for vasopressors, are required to achieve further improvements in patient outcomes.
Bacterial infections are common among patients requiring intensive care. In a 1-day point-prevalence study conducted in European ICUs, a total of 10,038 patients were reviewed, of whom 4,501 (44.8%) had a microbiologically confirmed infection. Pneumonia (46.9%), lower respiratory tract infection (17.8%), urinary tract infection (17.6%), and bloodfrequent types of infections described in these ICUs. The Enterobacteriaceae (34.4%), Staphylococcus aureus (30.1%), and Pseudomonas aeruginosa (28.7%) were the most common pathogens associated with infection. Similarly, among 181,993 patients admitted to medical ICUs in the United States, urinary tract infections were the most frequent nosocomial infection (31%), followed by pneumonia (27%) and primary bloodstream infection (19%). Bacterial infections were the most common cause of hospital-acquired infection with coagulase-negative staphylococci (36%), enterococci (16%), and S aureus (13%) being the most common blood isolates. P aeruginosa (21%) and S aureus (20%) were the most common isolates from pneumonia, and Candida albicans was the most common single pathogen isolated from the urine.
Despite the common occurrence of infections among patients requiring intensive care, there are few clinical data describing the overall impact of infections on patient outcomes, especially hospital mortality. Most recently, the influence of inadequate or delayed antimicrobial treatment of serious infections on hospital mortality has been well-described. Therefore, we performed a prospective cohort study with two main goals. The first goal was to establish the frequency of microbiologically confirmed infections among patients requiring 48 h of medical intensive care. Our second goal was to describe the relationship between microbiologically confirmed infections and hospital mortality in this patient cohort.