Effects of Adjunct Ketamine Sedation in Critically Ill Patients with Covid-19 Ards

ABSTRACT

INTRODUCTION: Ketamine is an NMDA receptor antagonist which has had a resurgence in sedation for critically ill patients. During the COVID-19 pandemic, there was an increase in acute respiratory distress syndrome (ARDS) where deep sedation was required. Ketamine has a lenient hemodynamic profile, opioid sparing properties, bronchodilating and anti-inflammatory effects. These characteristics make it a desirable agent for sedation in COVID-19 ARDS. METHOD(S) This is a single-center retrospective study where time-to-event data of 144 patients admitted to the ICU was analyzed. Kaplan-Meier curves were applied to summarize time from ICU admission to death. Competing risks regression analysis was performed to test the association between ketamine use and ICU-to-floor time, time-to-transfer or discharge to LTAC. RESULT(S) 58 of 144 patients who received ketamine were younger, had higher BMI, and lower APACHE II (median age 59 years, BMI 34.4, APACHE II Score 14) compared to 86 patients who did not receive ketamine. A higher percentage of patients receiving ketamine were on extracorporeal membrane oxygenation (ECMO) (25.9% vs 5.8%). There was no significant difference in time-to-death between the two groups (p=0.124). Patients on ketamine had a lower incidence of being transferred to acute care floors (SHR0.45, 95% CI) and had prolonged intubation (SHR 0.24, 95% CI). Ketamine was not associated with increased incidence of reintubation. CONCLUSION(S) Among COVID-19 ARDS patients requiring sedation, there was no significant change in time to death in those sedated with ketamine when compared to those without. Patients who required Ketamine had a more prolonged course of invasive mechanical ventilation and required ECMO. It is likely that they had been already on high amounts of sedation at the previous institution leading to higher tolerance to ketamine. However, patients sedated with ketamine in our sample had a higher predicted mortality since admission. Ketamine might still have role in sedation for ARDS COVID-19, but the effects are still unknown and further trials are needed to elucidate its role and possible benefits.