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

ABSTRACT

OBJECTIVE: To evaluate the impact of methicillin resistance in Staphylococcus aureus bacteremia (SAB) on mortality and length of stay in burn patients. DESIGN: Retrospective cohort study. SETTING: A 750-bed tertiary care university hospital in Cologne, Germany. PATIENTS Patients registered in the database of the burn intensive care unit (BICU) between 1989 and 2009 with complete data sets (n=1688). RESULTS: 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. CONCLUSION: Our data suggest that methicillin resistance is not associated with significant increases in mortality and length of BICU stay among burn patients with SAB.