Staphylococcus aureus bacteremia after thermal injury: the clinical impact of methicillin resistance.

Abstract

To evaluate the impact of methicillin resistance in Staphylococcus aureus bacteremia (SAB) on mortality and length of stay in burn patients. Retrospective cohort study. A 750-bed tertiary care university hospital in Cologne, Germany. Patients registered in the database of the burn intensive care unit (BICU) between 1989 and 2009 with complete data sets (n=1688). Over the 21-year study period, 74 patients with SAB were identified; 33 patients had methicillin-resistant S. aureus (MRSA) and 41 methicillin-susceptible S. aureus (MSSA). Comparing the MRSA with the MSSA population the following parameters were significantly different in the univariate analysis: BMI (27.2 kg/m(2) vs. 23.6 kg/m(2); P=0.05), extent of deep partial thickness burns (17.8% vs. 9.0% of total body surface area; P=0.007), antibiotic requirement on admission (45.5% vs. 22.0%; P=0.046), median length of hospitalization prior SAB (24 days vs. 7 days; P<0.001), packed red blood cells administration (47.6 units vs. 26.1 units; P=0.003), intubation requirement (100% vs. 80.5%; P=0.007), intubation period (43.5 days vs. 26.8 days; P=0.008), catecholamine requirement (90.9% vs. 61.0%; P=0.004), sepsis (60.6% vs. 34.1%; P=0.035) and organ failures (81.8% vs. 39.0%; P<0.001). Regarding outcome parameters, methicillin resistance was not significantly related with mortality (adjusted OR 1.55, 95% CI 0.56-4.28; P=0.40) and length of BICU stay after SAB (Kaplan-Meier analysis log-rank test P=0.32; Cox's proportional hazards regression HR 1.22, 95% CI 0.65-2.27, P=0.535) in the univariate and multivariate analyses. Our data suggest that methicillin resistance is not associated with significant increases in mortality and length of BICU stay among burn patients with SAB.