Previous studies have shown that a combination of piperacillin-tazobactam (pip-tazo) with vancomycin increases nephrotoxicity. In December 2012, our hospital switched from standard infusion to an extended-infusion of pip-tazo housewide. The objective of the study was to compare incidences of nephrotoxicity among patients who received a combination of vancomycin with an extended-infusion versus a traditional dosing of pip-tazo.
Retrospective analysis of data collected from 12/01/11-11/30/2012 when pip-tazo was administered as a 30-minute infusion (standard infusion) compared to data from 04/01/2013-03/31/2014, when pip-tazo was given over a 4-hour period (extended-infusion). The two groups were compared for the incidences of acute renal failure that occurred after receiving a combination of pip-tazo and vancomycin. Patients with pre-existing renal conditions were excluded. Statistical analyses were done to compare the baseline data including demographics, length of stay, rates of nephrotoxicity, and outcome. Multivariate analyses were done to control the effect of other potential nephrotoxic agents.
During the first period, 496 patients received standard infusions of pip-tazo with vancomycin and 511 patients received extended-infusion of pip-tazo with vancomycin in the second period. The baseline data including age, sex, serum creatinine, number of antibiotic days on vancomycin and pip-tazo, and use of nephrotoxic agents including IV contrast were comparable between the two groups. Lengths of hospital stay and ICU days were also comparable. Patients in the extended infusion group (61/511 or 11.9%) had a higher incidence of acute renal failure compared to the standard infusion group (34/496, or 6.9%), which was statistically significant (p<0.01) even after controlling for other nephrotoxic agents. There were no significant differences in outcomes including mortality (1.4% in standard vs 1.9% in extended infusion group, p>0.05).
A higher rate of nephrotoxicity was observed among patients who received vancomycin with an extended-infusion of piperacillin-tazobactam compared to the standard 30-minutes infusion.
J. Koirala, None