A Protocolized Approach for Dexmedetomidine Use in The Cardiac Intensive Care Unit

Abstract

Introduction Dexmedetomidine is one of the sedative agents recommended by the Society of Critical Care Medicine (SCCM) as a preferred option over benzodiazepines in critically ill, mechanically ventilated patients. Its use has been associated with increased hypotension and bradycardia compared to alternative sedative agents, which may be particularly dangerous in patients in acute decompensated heart failure (ADHF). No recommendations exist for appropriate use of this agent in the cardiac intensive care unit (CICU) for which many patients may be vulnerable to its side effect profile. Hypothesis A CICU sedation protocol will reduce use of dexmedetomidine in patient populations at risk for adverse events. Methods We performed a retrospective cohort study on patients 18 years of age and older admitted to the University of Michigan cardiac intensive care unit (CICU) from June 2014 to March 2020 who received dexmedetomidine. Baseline comorbidities, medication data, and adverse events were extracted from the electronic medical record. The CICU sedation guideline was implemented in September 2019. Before and after cohorts were defined based on this date. The primary endpoint was use of dexmedetomidine in acute systolic heart failure, cardiogenic shock, or severely depressed left ventricular ejection fraction (LVEF). Severely depressed LVEF was defined as ≤15%. Results Two-hundred thirteen patients were included, with 187 in the before group and 27 in the after cohort. There was no difference in median age (62 vs 66 years; p=0.26), baseline median LVEF (50 vs 35%; p=0.23), or baseline systolic blood pressure (124 vs 126 mmHg; p=0.69). After implementation, there were fewer patients with ADHF, cardiogenic shock or severely depressed LVEF (79 vs 6; p=0.047) who received dexmedetomidine. The median duration was shorter after implementation (18 vs 16 hours; p=0.16) and the median maximum dosage was lower (0.8 vs 0.5; p=0.007). The incidence of rebound hypertension and tachycardia was lower (14 vs 0; p=0.22) after implementation potentially due to maximum duration of therapy in the guideline of 48 hours. Conclusions A CICU sedation guideline led to fewer patients with ADHF, cardiogenic shock, or severely depressed LVEF receiving dexmedetomidine for sedation. Future studies should investigate the safety of alternative agents to determine optimal sedative strategies in these patients.