The relationship between mechanical power normalized to dynamic lung compliance and weaning outcomes in mechanically ventilated patients

Abstract

Background Prolonged mechanical ventilation is associated with an increased risk of mortality in these patients. However, there exists a significant clinical need for novel indicators that can complement traditional weaning evaluation methods and effectively guide ventilator weaning. Objectives To investigate the specific relationship between mechanical power normalized to dynamic lung compliance (Cdyn-MP) and weaning outcomes in patients on mechanical ventilation for more than 24 hours, as well as those who underwent a T-tube weaning strategy. Methods A retrospective cohort study was conducted using the Medical Information Mart for Intensive Care-IV v1.0 database (MIMIC-IV v1.0). Patients who received invasive mechanical ventilation for more than 24 hours and underwent a T-tube ventilation strategy for weaning were enrolled. Patients were divided into two groups based on their weaning outcome: weaning success and failure. Ventilation parameter data were collected every 4 hours during the first 24 hours before the first spontaneous breathing trial (SBT). Results Of all the 3,695 patients, 1,421 (38.5%) experienced weaning failure. Univariate logistic regression analysis revealed that the risk of weaning failure increased as the Cdyn-MP level rose (OR 1.34, 95% CI 1.31–1.38, P<0.001). After adjusting for age, body mass index, disease severity, and pre-weaning disease status, patients with high Cdyn-MP quartiles in the 4 hours prior to the SBT had a significantly greater risk of weaning failure than those with low Cdyn-MP quartiles (odds ratio 10.37, 95% CI 7.56–14.24). These findings were robust and consistent in both subgroup and sensitivity analyses. Conclusion The increased Cdyn-MP before SBT was independently associated with a higher risk of weaning failure in mechanically ventilated patients. Cdyn-MP has the potential to be a useful indicator for guiding the need for ventilator weaning and complementing traditional weaning evaluation methods.