Association of sedation level and 28-day mortality: a COVID-19 cohort multicentre study sub analysis

ABSTRACT

Introduction: COVID-19 started in Wuhan (China) in December 2019 [1]. World pandemic was declared by the WHO in March 2020 [2]. Since then, millions of patients have been infected worldwide. Our group published in March 2021 a multicentre study analysing the prevalence and risk factors for delirium in critically ill patients with COVID-19 infection [3]. In this sub analysis of the main study, the primary outcome was the association of sedation level since ICU admission with 28-day mortality in patients admitted to ICU due to COVID-19. Methods: The exposure tested against mortality was excessive sedation (in the coma range) defined as 'Did patients have a documented sedation score in the coma range at any point this day? RASS = - 4 or - 5;SAS = 2 or 1;MAAS = 0 or 1;Ramsay 5 or 6'. Data from 2017 patients was available for analysis, collected after patients' admission to ICU. Other covariates analyzed were baseline patient characteristics, medical history and treatment applied in the ICU. Logistic regression was used in all analyses and results presented as odd ratios (OR) with 95% confidence intervals. Results: Deep sedation (RASS = - 4 or - 5, SAS = 2 or 1, MAAS = 0 or 1, Ramsay 5 or 6) was positively and significantly associated to mortality within 28 days since ICU admission. P value was 0.012 and the OR was 2.00 with a 95% confidence interval of 1.16-3.45. Conclusions: As shown by this sub analysis, deep sedation increases mortality rates in critically ill COVID 19 patients. We should try to decrease sedation levels to avoid RASS of - 4 and - 5 to favor patients' outcomes admitted to the ICU.