Abstract
Sepsis remains a leading cause of mortality and healthcare burden, necessitating improved diagnostic and therapeutic strategies. Observational studies suggest that hyperoxemia may improve postoperative sepsis outcomes, but evidence remains limited. This study aims to explore the optimal range of oxygen partial pressure (PaO2) in postsurgical sepsis patients and its impact on prognosis. Clinical data of adult sepsis patients were extracted from the medical information mart for intensive care-IV database. Patients were categorized into control (PaO2 ≤ 100 mm Hg) and hyperoxemia (PaO2 > 100 mm Hg) groups. Primary outcome was 90-day mortality, while secondary outcomes included 1-year mortality, intensive care unit (ICU)/hospital length of stay, and invasive ventilation duration. Restricted cubic spline analysis stratified postsurgical PaO2 into normal (≤128.7 mm Hg), mild hyperoxemia (128.7-162.1 mm Hg), and severe hyperoxemia (≥162.1 mm Hg). Kaplan-Meier survival analysis and multivariate regression were conducted. Among 1220 patients, hyperoxemia patients were younger, had lower disease severity, and received more aggressive treatment. They had lower rates of acute respiratory failure and acute kidney injury. After cubic spline-based classification, mild hyperoxemia was associated with lower 90-day mortality (OR: 0.54, 95% CI: 0.34-0.86, P = .010), while severe hyperoxemia showed no significant effect (OR: 0.60, 95% CI: 0.30-1.20, P = .147). Kaplan-Meier curves demonstrated significantly improved long-term survival for mild hyperoxemia patients. Mild hyperoxemia in postsurgical sepsis patients is associated with reduced 90-day mortality, suggesting a potential optimal oxygenation range for better outcomes.