(125) Milrinone Use and Complications in Critically Ill Adults

Introduction: Milrinone (MIL) is an inotrope used in adult intensive care units (ICUs) for cardiogenic shock (CS). Due to its primary renal elimination, impaired renal function can prolong MIL’s half-life, increasing the risk of adverse effects. Current dosing guidelines are not well established for impaired renal function. This study aims to evaluate the incidence of new-onset arrhythmias (NOA), cardiac arrest (CA), and hypotension among patients receiving MIL with varying levels of renal function.

Methods: This retrospective study conducted at a large academic center, included adult patients with CS. Patients were grouped based on renal function: poor creatinine clearance (CrCl mL/min) < 30, moderate CrCl 30-50, and adequate CrCl >50. The primary outcome was incidence of NOA lasting >30 seconds or requiring intervention. Secondary outcomes included hospital and ICU length of stay (LOS), number of patients alive and ICU-free at day 28, CA, mortality and hypotension.

Results: 302 patients on MIL were included: age 61±13; 63% male sex; weight 94±23kg; BMI 31±10; 134 (44%) underwent cardiac surgery. Over half (n=154, 51%) presented with renal dysfunction at admission and 60 patients (20%) CKD stage 4/5 or ESRD. Initial MIL rate was 0.210 ±0.110 mcg/kg/min; max rate 0.264±0.125 and duration 5±6 days. NOA occurred in 38% of patients, typically 48 hours after initiation. NOA occurred in 32% of patients with adequate renal function vs. 43% with moderate or poor renal function. Those with poor renal function had significantly higher rates of NOA (52% vs. 39%, p< 0.001); higher mortality (37% vs. 15%, p< 0.001), longer hospital and ICU LOS (20±20 vs. 14±17, p=0.04, & 23±20 vs. 19±18, p=0.026), fewer days alive and free of ICU at day 28 (8±12 vs.15±15, p< 0.001), and more hypotension as evidenced by a higher vasoactive-inotropic score (9±5 vs. 14±8, p=0.002).

Conclusions: This study found that patients receiving MIL with poor renal function had significantly worse clinical outcomes than those with adequate renal function. Patients with NOA had longer hospital and ICU stays, fewer ICU-free and alive days at day 28, and required more vasopressor support. Based on this study we recommend, if possible avoiding MIL in patients with poor renal function or to restrict use to the lowest feasible infusion rate and duration.