Analysis of risk factors for weaning failure from mechanical ventilation in critically ill older patients with coronavirus disease 2019

Objective: This study aimed to investigate the factors influencing weaning failure from invasive mechanical ventilation (IMV) in critically ill older patients with coronavirus disease 2019 (COVID-19). Methods: We enrolled critically ill older patients with COVID-19 who were admitted to the medical intensive care unit (ICU) and received IMV between December 2022 and June 2023. Results: We included 68 critically ill older patients with COVID-19 (52 male [76.5 %] and 16 female individuals [23.5 %]). The patients' median age (interquartile range) was 75.5 (70.3-82.8) years. The median length of ICU stay was 11.5 (7.0-17.8) days; 34 cases (50.0 %) were successfully weaned from IMV. The successfully weaned group had a higher proportion of underlying chronic obstructive pulmonary disease [6 (17.6 %) vs. 0, P = 0.033] and fewer cases of diabetes [7 (20.6 %) vs. 16 (47.1 %), P = 0.021] compared with the weaning failure group. Serum lactate levels [1.5 (1.2-2.3) vs. 2.6 (1.9-3.1) mmol/L, P < 0.001], blood urea nitrogen [8.2 (6.3-14.4) vs. 11.4 (8.0-21.3) mmol/L, P = 0.033], Acute Physiology and Chronic Health Evaluation (APACHE) II score [19.0 (12.0-23.3) vs. 22.5 (16.0-29.3), P = 0.014], and hospitalization days before endotracheal intubation [1.0 (0.0-5.0) vs. 3.0 (0.0-11.0), P = 0.023] were significantly decreased in the successfully weaned group, whereas PaO2/FiO(2) [148.3 (94.6-200.3) vs. 101.1 (67.0-165.1), P = 0.038] and blood lymphocyte levels [0.6 (0.4-1.0) vs. 0.5 (0.2-0.6) 10(9)/L, P = 0.048] were significantly increased, compared with the weaning failure group. Multivariate logistic regression analysis showed that diabetes (OR= 3.413, 95 %CI 1.029-11.326), P = 0.045), APACHE II Score (OR = 1.089, 95 % CI 1.008-1.175), P = 0.030), and hospitalization days before endotracheal intubation (OR = 1.137, 95 % CI 1.023-1.264), P = 0.017) were independent risk factors for weaning failure. Conclusion: In critically ill older patients with COVID-19 with diabetes, higher APACHE II Score, and longer hospitalization days before endotracheal intubation, weaning from IMV was more challenging. The study could help develop strategies for improving COVID-19 treatment.