Combined prognostic value of the neutrophil-to-lymphocyte ratio and serum lactate for 28-day mortality in patients with sepsis-induced pulmonary dysfunction.

OBJECTIVE: To investigate the predictive value of the neutrophil-to-lymphocyte ratio (NLR) combined with serum lactate (Lac) in patients with sepsis-induced pulmonary dysfunction (SIPD) for early evaluation and personalized treatment. METHODS: A total of 230 SIPD patients were retrospectively screened from January 2018 to December 2023. After exclusions, 226 patients were classified into the survivor group (154 cases) and the non-survivor group (72 cases) based on their 28-day survival status. Receiver operating characteristic (ROC) curves assessed NLR-Lac combined prognostic value for 28-day mortality in SIPD, with logistic regression screening risk factors. RESULTS: In the non-survivor group, levels of NLR, serum Lac, sequential organ failure assessment (SOFA) score, acute physiology and chronic health evaluation II (APACHE II) score, C-reactive protein (CRP), procalcitonin (PCT), white blood cells (WBC), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine (Cr) were higher (all P < 0.05), whereas partial pressure of arterial oxygen/fraction of inspired oxygen (PaO2/FiO2) was lower (P = 0.041) than in the survivor group. ROC curve analysis showed the area under the curve (AUC) of combined NLR-Lac model for predicting SIPD patients' 28-day mortality was 0.803 (95% CI: 0.746, 0.860), higher than that of NLR alone (0.727, 95% CI: 0.649, 0.804) and serum Lac alone (0.734, 95% CI: 0.661, 0.808). Logistic regression indicated elevated NLR and serum Lac were independent predictors for 28-day mortality in SIPD patients (both P < 0.001). Additionally, the non-survivor group had longer mechanical ventilation duration (P < 0.001). CONCLUSION: Combined NLR and Lac detection may improve prognostic accuracy in SIPD patients.