Hemodynamic and respiratory effects of dexmedetomidine sedation in critically ill Covid-19 patients: A retrospective cohort study.

Introduction: Dexmedetomidine has been suggested to be a promising sedative for patients with Covid-19 infection (CV19). However, use of dexmedetomidine is limited by its heart rate (HR) and arterial blood pressure lowering effects. Moreover, CV19 is associated with cardiac manifestations including bradyarrythmias. The hemodynamic effects of dexmedetomidine have not been previously studied in CV19 patients. We evaluated the effects of dexmedetomidine on hemodynamic and respiratory parameters of CV19 patients.

Methods: In this single center study, all CV19 patients receiving dexmedetomidine for sedation during a one year period were included. Our primary outcomes included changes in HR, mean arterial pressure (MAP), respiratory rate (RR), partial oxygen pressure of arterial blood/fraction of inspired oxygen-ratio (PF-ratio), and Richmond Agitation and Sedation Score (RASS) during dexmedetomidine administration.

Results: We identified 39 patients with a mean (SD) age of 58.3 (12.7) years. After initiation of dexmedetomidine, HR decreased by 16.9 (3.3) beats/min (95% CI 9.5-22.4; p < 0.001). During the 12-hour follow-up period, HR decrease was significant at 2 to 12 h. Incident bradycardia (<45/min) was reported in 12 (30.8%) patients and it was associated with lower plasma C-reactive protein, Pro-calcitonin, and troponin T levels. There was no change in MAP compared to baseline. Dexmedetomidine administration was associated with improvement of PF-ratio (p < 0.001) and with decrease of RASS (p = 0.004).

Conclusions: Dexmedetomidine is an effective sedative for CV19 patients and may improve their oxygenation. However, dexmedetomidine administration is associated with marked decline in HR and with a high incidence of bradycardia in patients with CV19.