Assessment of acute kidney injury in neurologically and traumatically injured intensive care patients receiving large vancomycin doses

BACKGROUND: Previous reports note that in a mixed patient population, vancomycin doses >4 g/day are associated with increased rates of acute kidney injury (AKI). OBJECTIVE: The objective of the study is to determine if vancomycin regimens >4 g/day are associated with a higher incidence of AKI in neurocritical care unit (NCCU) and trauma/burn Intensive Care Unit (TBICU) patients. MATERIALS AND METHODS: This single-centered, retrospective study enrolled adult patients initiated on vancomycin in the NCCU and TBICU at an academic medical center during 2016. Based on maximum steady-state dose exposure, patients were separated into two groups: ≤4 g/day and >4 g/day. The primary outcome of incidence of AKI was defined by the AKI Network criteria. RESULTS: A total of 284 patients were screened for eligibility; 165 patients met inclusion criteria, 98 patients received ≤4 g/day and 67 patients received >4 g/day. The >4 g/day group had a lower mean age (32.6±11.1 vs. 47.8±16.2, P < 0.001), included more male patients (81% vs. 60%, P = 0.008), were more often treated for a central nervous system infection (31% vs. 11%, P = 0.001), had, on average, more concomitant use of nephrotoxic drugs (2.2±1.2 vs. 1.8±0.9, P = 0.02) and had a higher exposure to contrast (94% vs. 79%, P < 0.001). The primary outcome of AKI occurred in 14 patients receiving ≤4 g/day and five patients receiving >4 g/day which was not statistically significant (14% vs. 7%, P = 0.22). CONCLUSIONS: Our results indicate that administering >4 g/day of vancomycin to achieve therapeutic vancomycin troughs does not appear to lead to an increased incidence of AKI in a mixed NCCU and TBICU population.