Incidence and risk factors of weaning-induced pulmonary oedema: results from a multicentre, observational study

During the weaning process, the transition from positive to negative pressure ventilation may induce cardiac dysfunction, which may lead to pulmonary oedema. The incidence of weaning-induced pulmonary oedema (WIPO) is poorly documented and shows huge variations. Our study aims to investigate the incidence and risk factors for WIPO during weaning from mechanical ventilation in general critically ill patients. This multicentre study was conducted in France, Italy, and India. Adult critically ill patients receiving invasive ventilation were included once a spontaneous breathing trial (SBT) was performed. The SBT technique could be either T-piece or pressure support mode with (PSV-PEEP) or without positive end expiratory pressure (PEEP) (PSV-ZEEP). A consensual diagnosis of WIPO was made a posteriori by five experts who analysed changes observed during the SBT that were retrospectively recorded. From July 2019 to February 2021, 634 SBTs were performed in 500 patients from 13 ICUs. Weaning success occurred in 417 patients (66%) and weaning failure in 217 (34%). Weaning was short in 414 (83%) of SBTs, difficult in 47 (9%) SBTs, and prolonged in 39 (8%) SBTs. WIPO was diagnosed in 79 (12%) cases, which accounted for 36% of the 217 weaning failures. WIPO occurred in 54/358 (15%) of T-piece SBT, in 7/84 (8%) of PSV-PEEP SBT (p = 0.072 vs. T-piece), and in 18/192 (9%) of PSV-ZEEP SBT (p = 0.002 vs. T-piece). In multilevel logistic regression analysis including 202 weaning failures from 149 different patients, COPD, and previous cardiomyopathy were identified as independent risk factors associated with WIPO. In general ICU patients, WIPO accounts for 36% of weaning failure cases. Previous heart disease and COPD are two independent risk factors for developing WIPO during the weaning process. gov identifier (retrospectively registered on 2022-03-31): NCT05318261.