(1775) Acetazolamide Versus Metolazone in Volume Overload

Introduction: The ADVOR trial assessed whether utilizing acetazolamide to augment the effects of loop diuretics could lead to quicker decongestion in patients with acute decompensated heart failure with volume overload versus placebo. Metolazone has also been used as an adjunctive agent for sequential nephron blockade in patients experiencing edema or general volume overload. The primary objective of this retrospective cohort study is to compare the incidence of output attained among patients with acute volume overload receiving IV loop diuretics with acetazolamide versus metolazone. The secondary objectives are to assess incidences of hypotension (SBP < 90 or MAP < 65), acute kidney injury (AKI), hypokalemia, metabolic acidosis, and hospital length of stay (LOS).

Methods: This study was conducted by a retrospective chart review of patients that received either acetazolamide or metolazone as add on therapy to high dose IV loop diuretics from June through December 2023. Patients included received at least one dose of acetazolamide or metolazone. Specific lab values reviewed included serum creatinine, potassium, and blood gas levels. Hospital LOS was assessed and collected upon. The results were analyzed using appropriate statical tests for categorical and continuous data.

Results: 120 patients were included in this study. The primary outcome analysis showed a statistical difference between the output attained from adding acetazolamide versus metolazone to IV loop diuretics (11,333.7 mL versus 6,095.3 mL, respectively) (p=0.0278). No difference was found for the secondary outcomes of hypotension, AKI, hypokalemia, or metabolic acidosis; however, hospital LOS was found to have a statistical difference (p=0.0444).

Conclusions: The results of this study show that the addition of acetazolamide to high dose IV loop diuretics resulted in a greater amount of output and a shorter hospital LOS versus patients who received metolazone. The rates of common side effects such as hypotension, AKI, hypokalemia, and metabolic acidosis were not statistically or clinically significant. Due to the variety of doses used in this study, further research should be done to further optimize diuresis through sequential nephron blockade in volume overloaded patients.