The association of arterial partial oxygen pressure with mortality in patients with severe acute pancreatitis: a retrospective cohort study

Intensive Care Med Exp. 2025 Dec 18;13(1):131. doi: 10.1186/s40635-025-00843-8.

ABSTRACT

BACKGROUND: Patients with severe acute pancreatitis (SAP) frequently develop hypoxic acute respiratory failure (AHRF), with a mortality rate as high as 37%. However, the optimal partial pressure of oxygen (PaO₂) for SAP patients remains unclear to date. This study aims to investigate whether partial pressure of oxygen is associated with mortality in SAP patients.

METHODS: A retrospective cohort study was conducted on patients with severe acute pancreatitis (SAP) admitted to the First Affiliated Hospital of Nanchang University from 2015 to 2024. Propensity score matching (based on whether arterial oxygen partial pressure PaO₂ ≥ 80 mmHg during the first 3 days after ICU admission, assigning patients to the liberal PaO₂ group or conservative PaO₂ group), univariate logistic regression analysis, Cox regression analysis, subgroup analysis, Kaplan-Meier (K-M curve) survival analysis, and sensitivity analysis were employed to thoroughly evaluate the association between PaO₂ and mortality in SAP patients. The primary outcome was 28-day mortality.

RESULTS: The study included 1585 patients. We found that higher PaO₂ was associated with lower 28-day mortality rates. In logistic regression analysis after propensity score matching, the incidence rates of adverse outcomes such as persistent circulatory failure (OR 0.50; 95% CI 0.35-0.69; P < 0.001) and persistent multiple organ failure (OR 0.60; 95% CI 0.47-0.78; P < 0.001) significantly decreased. The K-M curve demonstrated significant reductions in 28-day mortality (P = 0.02), 90-day mortality (P = 0.0079), and overall mortality (P = 0.008) in the liberal PaO₂ group, with all P values showing statistical significance. Subgroup analysis revealed that the association between higher PaO₂ and mortality in SAP patients varied across different age groups, BMI values, SIRS and APACHE II scores, and smoking status. Sensitivity analysis demonstrated stable results after excluding specific populations. On the third day of ICU admission (P = 0.016), higher PaO₂ correlated with improved outcomes compared to the conservative group, particularly when PaO₂ stabilized around 100 mmHg.

CONCLUSIONS: Early maintenance of higher PaO₂ (≥80 mmHg) during the initial ICU period was associated with lower mortality.

PMID:41408473 | DOI:10.1186/s40635-025-00843-8