ABSTRACT
INTRODUCTION: Previous studies suggest that delayed initiation of extracorporeal membrane oxygenation (ECMO) is associated with higher patient mortality. Hence, we hypothesized that prolonged invasive mechanical ventilation (IMV) prior to ECMO was associated with higher mortality in patients with COVID-19. METHOD(S): The COVID-19 Critical Care Consortium, a prospective international multicenter registry, was queried for all patients with COVID-19 infection who received IMV and ECMO. Patients who were intubated prior to transfer to a study site were excluded. The primary variable was number of days on IMV prior to ECMO initiation and study endpoint was death or discharge from the study site. Cox proportional hazards model for the time between ECMO initiation and death was built using covariates including age, gender, selected comorbidities, and time intervals from ICU admission to IMV and IMV to ECMO initiation. RESULT(S): Between 1/1/2020 and 6/6/2022, A total of 593 patients from 107 study sites and 25 countries were included in the analysis. In this cohort, the median age was 50 (Interquartile range [IQR]: 40-58) years. Obesity and hypertension were prevalent among 220 (38.4%) and 223 (38.8%) of the patients, respectively. Twenty-four (4.2%) patients had chronic pulmonary disease. Prior to ECMO initiation, patients spent a median of 3.68 (IQR: 1.36-8.07) days in the ICU and a median of 2.49 (IQR: 0.88-5.65) days on IMV. Overall mortality was 47.2% with 3.9% patients' status not finalized or unknown. According to the final survival model, the number of days on IMV prior to ECMO initiation was not associated with mortality. The hazard ratios for 0, 3, 7, and 14 days of pre-ECMO IMV were 0.94 (95% confidence interval [CI]: 0.83 to 1.07), 1.02 (95% CI: 0.97 to 1.08), 1.09 (95% CI: 0.92 to 1.3) and 1.09 (95% CI: 0.83 to 1.42), respectively. Other noticeable contributory factors in the model included age and gender. CONCLUSION(S): Among patients with COVID-19 who received ECMO, the length of pre-ECMO IMV was not associated with hospital mortality. Further studies evaluating the ventilator settings before and after ECMO initiation are needed.
ABSTRACT
Background: The virus responsible for COVID-19 enters human cells by binding angiotensinconverting enzyme 2. The influence of renin-angiotensin-aldosterone system (RAAS) inhibitors, including angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs), remains uncertain. Aim: To examine the role of ACEi / ARB exposure on outcomes in COVID-19 patients with preexisting hypertension (HTN) admitted to intensive care units (ICU). Methods: The COVID-19 Critical Care Consortium is a prospective, observational cohort study of patients requiring ICU admission for active COVID-19 spanning 354 participating sites in 54 countries. Patients >18 years old with pre-existing HTN requiring antihypertensive therapy were analysed. Length of stay and in-hospital mortality to 90 days post ICU admission were analysed as time-to-eventoutcomes by multistate survival analysis, and the influence of ACEi / ARB use on the hazards of death and discharge by multi-state Cox proportional hazard modelling and sensitivity analysis. Results: From December 1, 2019 through December 30, 2020, 663 eligible patients were registered. Of these, 480 patients had received ACEi and / or ARB therapy (median age 65 years, 67% male) in the 2 weeks before ICU admission, while 183 had not (66 years, 61% male). Average lengths of ICU and general ward stays were longer in the ACEi / ARB than non-ACEi / ARB group (20.8 days and 6.5 days vs. 15.5 and 6.0 days, respectively). ACEi / ARB use was associated with a decreased hazard of death (HR, 0.69, 95% CI, 0.54 -0.88) that persisted after adjusting for propensity scores (0.67, 0.53 -0.86). Cumulative probabilities (unadjusted for baseline characteristics) for death and discharge post ICU admission are depicted in the figure for ACEi/ARB (red) and non-ACEi / ARB (blue) patients. Conclusions: In 663 critically ill COVID-19 patients with pre-existing HTN, RAAS inhibition pre-ICU admission was linked to reduced in-hospital mortality.