Safety of Digoxin Loading in Patients Undergoing Continuous Renal Replacement Therapy.

Abstract

Background: Atrial fibrillation with rapid ventricular response (Afib-RVR) is a hemodynamically unstable arrythmia encountered in the critically ill patient. Digoxin, a cardiac glycoside, may be an appropriate treatment option for managing Afib-RVR with contraindications or unresponsiveness to traditional agents. Currently, there is limited guidance for the use of digoxin supported with continuous renal replacement therapy (CRRT). Aim: The primary outcome of this study is the incidence of bradycardia (Heart rate less than 60 beats per minute) within 48 hours following digoxin initiation. Secondary outcomes include the time to achieve rate control after digoxin initiation and the proportion of time rate controlled within the first 48 hours of digoxin therapy. Methods: This was a retrospective study of patients admitted to an intensive care unit between March 2018 and October 2021 with a diagnosis of Afib-RVR, received a digoxin loading dose while supported with CRRT. Exclusion criteria included prior digoxin use, use other than Afib-RVR concurrent beta-blocker or calcium-channel blocker therapy. Results: Nine patients met the inclusion criteria, there were no incidences of bradycardia within the first 48 hours following digoxin initiation. The median digoxin loading dose, time to rate control and proportion with rate control was 9.01 ± 2.04 mcg/kg, 7±13 hours and 54 ± 23% respectively. Conclusions: In our cohort of patients in Afib-RVR loaded with digoxin while supported on CRRT did not experience any bradycardic episodes. This data supports a cautious approach to digoxin use in this patient population and serves as a platform for future studies for the optimal dosing regimen.