Safety of dexmedetomidine in the cardiac intensive care unit

Comparison of Standard-Dose Versus High-Dose Dexmedetomidine in Extracorporeal Membrane Oxygenation

BACKGROUND

Dexmedetomidine is commonly used to achieve light sedation in patients on extracorporeal membrane oxygenation (ECMO) despite minimal evidence. In vivo studies have shown dexmedetomidine sequestration in ECMO circuits, and higher doses may be used to overcome sequestration.

OBJECTIVE

The purpose of this study was to compare safety and efficacy of dexmedetomidine at standard versus high doses in ECMO.

METHODS

A retrospective analysis of adult ECMO patients was performed. Patients were compared as receiving either standard-dose (≤1.5 µg/kg/h) or high-dose (>1.5 µg/kg/h) dexmedetomidine. Safety outcomes included new onset bradycardia or hypotension. Efficacy was compared by the addition of concomitant sedative and analgesic agents.

RESULTS

One hundred five patients were evaluated, with 20% of patients in the high-dose group. Comparing standard and high dosing, no significant differences were seen in primary safety outcomes including bradycardia (49% vs 38%, P = 0.46), hypotension (79% vs 71%, P = 0.56), or addition of vasopressors (75% vs 71%, P = 0.78). Need for concomitant analgesic agents and propofol was similar between groups.

CONCLUSION AND RELEVANCE

This represents the first evaluation of use of high-dose dexmedetomidine in ECMO. Rates of dexmedetomidine higher than 1.5 µg/kg/h were commonly used in patients on ECMO, with similar rates of adverse effects and need for concomitant propofol and analgesic agents. While high-dose dexmedetomidine may be as safe as standard dose, no additional efficacy was found.

Liberation From Mechanical Ventilation in the Cardiac Intensive Care Unit

The prevalence of respiratory failure is increasing in the contemporary cardiac intensive care unit (CICU) and is associated with a significant increase in morbidity and mortality. For patients that survive their initial respiratory decompensation, liberation from invasive mechanical ventilation (IMV) and the decision to extubate requires careful clinical assessment and planning. Therefore, it is essential for the CICU clinician to know how to assess and manage the various stages of IMV liberation, including ventilator weaning, evaluation of extubation readiness, and provide post-extubation care. In this review, we provide a comprehensive approach to liberation from IMV in the CICU, including cardiopulmonary interactions relative to withdrawal from positive pressure ventilation, evaluation of readiness for and assessment of spontaneous breathing trials, sedation management to optimize extubation, strategies for patients at a high risk for extubation failure, and tracheostomy in the cardiovascular patient.