Management and outcomes in women and men weaning from invasive mechanical ventilation: insights from the WEAN SAFE study

Objective To understand the differences in the weaning process and outcomes in men and women enrolled in the WorldwidE AssessmeNt of Separation of pAtients From ventilatory assistancE (WEAN SAFE) study. Methods We analysed patients in the WEAN SAFE cohort who commenced weaning from invasive ventilation, stratified by biological sex. The primary outcome was the effect of sex on delayed weaning and failed weaning from invasive mechanical ventilation. Secondary outcomes included the influence of sex on ventilatory management, ICU/hospital survival and decisions to limit life-sustaining interventions. Results Of 4,523 patients who entered the weaning process, 1,754 (38.8%) were women and 2,769 (61.2%) were men. Women were shorter, had higher P/F ratios, and received higher tidal volumes and lower PEEP than men. Women on controlled ventilation received higher driving pressures, while women on assisted ventilation received higher inspiratory pressures than men. Both female sex and shorter stature were independently associated with higher tidal volume ventilation, with shorter females at particular risk. In univariate analyses, women were less likely to successfully wean from invasive ventilation. When adjusted for factors such as height, age, and frailty profile, there was no independent association between sex and weaning success. In patients with more severe respiratory failure (P/F ratios <200), there were no sex differences in ventilatory support, weaning management and outcomes. Conclusions Women weaning from ventilation were shorter and had less severe respiratory failure but received less protective lung ventilation and more frequent ventilatory over-assistance. When adjusted for height and age, female sex was not independently associated with failed weaning from invasive ventilation. Trial registration ClinicalTrials.gov, NCT03255109.