Shaoxing Wu,1,* Haipeng Li,2,* Junhao Xu,2 Junxiang Cai,1 Lei Wu,1 Yinji Xu1 

1Department of Pulmonary and Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine (The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, The Second Clinical Medical College of Guangzhou University of Chinese Medicine), Guangzhou, Guangdong, People’s Republic of China; 2The Second Clinical Medical College of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Yinji Xu, Department of Pulmonary and Critical Care Medicine, Guangdong Provincial Hospital of Chinese Medicine, No. 111, Dade Road, Yuexiu District, Guangzhou, Guangdong, People’s Republic of China, Email xuyinji@gzucm.edu.cn

Purpose: Increasing evidence suggests that mechanical power (MP) is associated with mortality among patients undergoing invasive mechanical ventilation. However, the relationship between MP and mortality in chronic obstructive pulmonary disease (COPD) patients undergoing invasive ventilation remains uncertain. The aim of this study was to investigate the association between MP and 28-day all-cause mortality among COPD patients undergoing invasive ventilation.
Patients and Methods: Data were obtained from the Medical Information Mart for Intensive Care (MIMIC-IV) database. COPD patients undergoing invasive ventilation were categorized into three categories based on MP tertiles to further assess the robustness of our results. The primary outcome was 28-day all-cause mortality. The relationship between MP and 28-day all-cause mortality in COPD patients undergoing invasive ventilation was performed to evaluate restricted cubic splines and Cox proportional hazards regression analysis. Receiver operating characteristic (ROC) curves and Kaplan-Meier survival analysis were employed to evaluate and visualize the predictive value of MP for 28-day all-cause mortality. Additionally, the optimal cut-off value of MP was determined. Finally, subgroup analysis was conducted to assess the robustness of the findings.
Results: 1704 COPD patients undergoing invasive ventilation (56.92% male) were included in the study. Based on the Cox regression analysis, MP was significantly associated with 28-day all-cause mortality risk in the unadjusted model (Model 1) [HR (95% CI) 1.04 (1.03– 1.05), p< 0.001]. However, as this is an observational study, causality cannot be inferred. Restricted cubic spline regression models revealed a linear rise in the risk of 28-day mortality as MP increased (P for non-linearity = 0.967). The area under the curve (AUC) for MP was 0.602. This study also identified an optimal cut-off value of 17.38 J/min for MP. Kaplan-Meier survival analysis demonstrated statistically significant differences in survival among invasive ventilation patients stratified by MP tertiles. Subgroup analysis of potential confounding factors indicated no significant interaction between MP and any subgroup (P for interaction: 0.114– 0.967).
Conclusion: MP is associated with 28-day all-cause mortality in COPD patients undergoing invasive ventilation. The cut-off value of 17.38 J/min may serve as a reference point for clinicians in assessing disease severity. However, further research is needed to investigate the causal relationship between MP and mortality.

Keywords: mechanical power, chronic obstructive pulmonary disease, invasive ventilation, mortality, MIMIC-IV