(945) Ketamine Infusion Effects on Sedation Requirements in Acute Respiratory Distress Syndrome

Introduction: Acute respiratory distress syndrome (ARDS) is a life-threatening clinical syndrome characterized by poor oxygenation and impaired lung compliance. Patients with ARDS commonly require invasive ventilation and deep sedation to facilitate therapies including prone positioning, lung-protective ventilation, and to decrease respiratory drive. Commonly utilized sedative agents pose adverse effects that may limit their utility, necessitating the need for additional options. Ketamine has limited impact on respiratory drive and provides a favorable hemodynamic profile compared to other sedatives. Its utility in ARDS has not been well defined, therefore the purpose of this study is to evaluate the effects of ketamine utilization on overall sedation requirements in patients with ARDS.

Methods: This was a single-center retrospective study including patients with ARDS requiring mechanical ventilation that received ketamine for sedation for > 24 hours. Patients were excluded if they received simultaneous neuromuscular blockade infusions, received ketamine for other indications, or were cannulated for extracorporeal membrane oxygenation. The primary endpoint was the difference in sedation requirements 24-hours pre- and post-ketamine infusion initiation. Key secondary endpoints included difference in vasopressor requirements, ratio of partial pressure of oxygen in arterial blood to fraction of inspired oxygen concentration, and minute ventilation after ketamine initiation.

Results: Eighty-five patients were included. The median age was 57, 72% of patients were male. Seventy-nine percent of patients had ARDS secondary to COVID-19 pneumonia, and most patients had mild (54%) or moderate (41%) ARDS. There was a significant reduction in cumulative propofol administration following ketamine initiation (p = 0.001); however, this trend was not observed with other sedatives or opiates. There were no differences in ventilatory parameters or vasopressor requirements.

Conclusions: Ketamine utilization was associated with a reduction in overall propofol requirements; however, was not associated with a reduction in other sedative agents, improvements in ventilatory parameters, or a reduction in vasopressor requirements.