Risk of acute kidney injury in critically ill surgical patients with presumed pneumonia is not impacted by choice of methicillin-resistant staphylococcus aureus therapy

BACKGROUND: Vancomycin and linezolid are standard treatment options for nosocomial methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. While acute kidney injury (AKI) is commonly attributed to vancomycin, existing data has not definitely confirmed vancomycin as an independent risk factor for AKI. AIMS: This study aimed to quantify the incidence of AKI in Surgical Intensive Care Unit (ICU) patients receiving empiric vancomycin or linezolid for nosocomial pneumonia and to identify risk factors for AKI with a focus on MRSA antibiotic therapy. MATERIALS AND METHODS: A retrospective cohort analysis of surgical ICU patients who received at least 48 h of vancomycin or linezolid for pneumonia was performed. Patients who received vancomycin were compared to those who received linezolid with a primary endpoint of AKI as defined by the risk/injury/failure/loss/end-stage renal disease (RIFLE) criteria. A modified RIFLE criteria assessing only changes in serum creatinine was also used. RESULTS: One hundred one patients were evaluated (63 vancomycin and 38 linezolid). AKI occurred in 51 (81.0%) and 32 (84.2%) patients in the vancomycin and linezolid groups (P = 0.79), respectively. Using the modified RIFLE criteria, AKI occurred in 19 (30.2%) and 14 (36.8%) patients in the vancomycin and linezolid groups (P = 0.448). After adjustment for age, diabetes mellitus, Charlson comorbidity index, and concomitant nephrotoxins, there was no difference in risk of AKI between groups (P = 0.773). CONCLUSIONS: Patients who received empiric vancomycin or linezolid for nosocomial pneumonia experienced high, but similar rates of AKI. The results suggest MRSA antibacterial therapy in this setting may not be independently indicative of AKI risk, rather the risk is likely multifactorial.