Associations of lactate-to-hematocrit ratio with short- and long-term prognoses in critically ill patients with respiratory failure: A retrospective cohort study

Multiple studies have confirmed that the lymphocyte-to-high-density Lipoprotein ratio (LHR) is associated with disease outcomes. However, the prognostic value of LHR in critically ill patients with respiratory failure remains unclear. This study aimed to investigate the association between LHR and clinical outcomes in critically ill patients with respiratory failure. Hospitalized patients with severe respiratory failure were identified from the MIMIC-IV database and categorized into tertiles according to LHR. The outcomes included short-term and long-term mortality after admission. Cox proportional hazards regression and restricted cubic spline analyses were used to evaluate the association between LHR and clinical outcomes in critically ill patients with respiratory failure. A total of 10,379 patients were included in the analysis. The 30-day, 120-day, and 360-day mortality rates were 31.59%, 34.90%, and 35.49%, respectively. Multivariable Cox proportional hazards analysis demonstrated that elevated LHR was significantly associated with increased all-cause mortality. After adjustment for confounding factors, elevated LHR remained significantly associated with 30-day, 120-day, and 360-day mortality. Restricted cubic spline analyses demonstrated a progressively increasing risk of short-term and long-term all-cause mortality with increasing LHR. LHR is significantly associated with both short-term and long-term mortality in critically ill patients with respiratory failure. These findings suggest that LHR may help identify critically ill patients with respiratory failure who are at high-risk of all-cause mortality.