Study objectives: To describe the clinical features and outcome of patients with invasive group A streptococcal (GAS) infections admitted to the ICU.
Design: Prospective, population-based surveillance for invasive GAS infections was conducted in Ontario from January 1992 until June 2002. All 62 patients meeting clinical and/or histopathologic criteria for invasive GAS who were admitted to the ICUs of four university-affiliated hospitals in Toronto, Canada were included. Demographic and clinical information were obtained retrospectively by chart review. ICU morbidity data included the occurrence of organ dysfunction (renal, hepatic, coagulation, ARDS), treatment, and interventions such as hemodialysis and mechanical ventilation.
Measurements and results: ARDS developed in 34%, renal dysfunction developed in 55%, hepatic dysfunction developed in 64%, and coagulopathy developed in 69% of patients. A total of 56% of patients were treated with IV polyspecific IgG (IVIG), 81% were intubated and placed on mechanical ventilation, and 21% required renal replacement therapy. The median durations of ICU and hospital stay were 5.3 days and 15.0 days, respectively. The overall mortality was 40%. Mortality correlated directly with acute physiology and chronic health evaluation II score and the number of dysfunctional organs. Survivors were younger, had lower severity of illness scores, fewer dysfunctional organs, and were less likely to have shock or to receive treatment with vasopressors, mechanical ventilation, or pulmonary artery catheters. There was no association between the use of IVIG, surgical intervention, or clindamycin, and survival. Variables independently associated with mortality on multivariable analysis were the presence of coagulopathy (p = 0.0005) and liver dysfunction (p = 0.0123).
Conclusions: Patients with invasive GAS infection admitted to the ICU have a high mortality rate. In this group of patients, coagulopathy and liver failure were independently associated with mortality. We did not observe any association between the use of IVIG, surgical intervention, or clindamycin, and survival.