Base excess serves as a mediator in the hemoglobin-intensive care unit stay length relationship in neonatal respiratory distress syndrome.

Background: Neonatal respiratory distress syndrome (NRDS) is a leading cause of neonatal respiratory failure and mortality. This study investigated risk factors for intensive care unit (ICU) length of stay in newborns with NRDS. Methods: The data were collected from the MIMIC-III database. Baseline characteristics were recorded. Machine learning methods were used to identify key factors associated with ICU stay length. The nonlinear associations of hemoglobin and base excess (BE) with ICU stay length were assessed using generalized additive model (GAM) analysis and threshold effect analysis. Mediation analysis explored the relationship between hemoglobin, BE, and length of ICU stay. Results: We enrolled 1,241 NRDS-diagnosed newborn infants. Four key variables (height, weight, hemoglobin, and BE) were correlated with the length of ICU stay. Specifically, hemoglobin levels (≥12.1 g/dL) and BE (≥-8.3 mmol/L) were negatively correlated with ICU stay length. Hemoglobin was an independent predictor for shorter ICU stay (β=-0.503, 95% CI: -0.958 to -0.049) (P<0.05), and its level was positively associated with BE (P<0.05). Mediation analysis revealed that BE partially mediated the relationship between hemoglobin and ICU stay length. Conclusions: Hemoglobin level was a crucial independent predictor for ICU stay duration in NRDS patients, with BE as a mediator. These findings highlight the importance of maintaining adequate hemoglobin levels to improve NRDS outcomes.