Continuous infusions (CI) of loop diuretics provide constant delivery of drug to site of action in the kidney, resulting in a continuous natriuretic effect. Data supporting the efficacy/safety of CI of high dose bumetanide (CIHDB) are sparse. A detailed review of a single institution’s experience will help fill the gap in literature.
CIHDB are effective in inducing diuresis and achieving dry weight in critically ill cardiac and cardiothoracic (CT) surgery patients (pts) with significant volume overload without causing new-onset acute renal failure.
A retrospective electronic/paper chart review of all pts treated with a CIHDB at a single institution was performed. Pts receiving an infusion of 1-2 mg/hr bumetanide with sufficient data were included. Pts were excluded if the infusion rate remained <1 mg/hr or if receiving concomitant renal replacement therapy (RRT) or aquaphoresis. Data collected included weights, dosing of intermittent loop diuretics and CIHDB, urine output (UOP), serum creatinine, need for RRT. Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to stage severity of acute kidney injury (AKI).
Thirty-eight pts treated for a mean of 53 hours were included. All pts received at least one dose of IV loop diuretics in the 24 hours preceding CIHDB, while 74% received a bolus of bumetanide IV 2-4 mg within 2 hours preceding CIHDB. Prior to initiation of CIHDB, mean volume overload was +6.2 kg (-1.8 to 11.8 kg) above dry weight; mean UOP was 0.9 cc/kg/hr (0.2-3 cc/kg/hr). After the first 24 hours, UOP increased to 1.6 cc/kg/hr (p<0.001) and to 1.9 cc/kg/hr (p<0.001) after the second 24 hours. Mean weight loss following CIHDB was 5.2 kg. At baseline, 16 (42%) had stage 1-2 AKI. Following CIDHB, 6 (38%) of these pts progressed to stage 3 AKI, but were maintained on CIHDB for 3-48 hours prior to RRT. After CIHDB, an additional 12 pts had stage 1-2 AKI, 10 of which were new onset.
CIHDB is effective at improving UOP and achieving significant weight loss in critically ill cardiac and CT surgery pts. Optimizing diuretic therapy may potentially delay/avoid RRT. Further randomized, controlled studies are needed to support these results.