Graded oxygenation levels and clinical outcomes among patients with traumatic brain injury: a propensity...

The optimal arterial oxygen tension (PaO₂) target in patients with traumatic brain injury (TBI) remains controversial. While both hypoxemia and hyperoxemia may worsen outcomes, yet the prognostic impact of distinct PaO₂ ranges has not been fully clarified. This multicenter retrospective study enrolled 1531 TBI patients from six Chinese hospitals between January 2022 and July 2025. Patients were stratified by average PaO2 in the first 72 h into three groups: 60-80 mmHg, 80-120 mmHg, and > 120 mmHg. We performed 1:1:1 multinomial propensity score matching. The primary endpoint was 28-day all-cause mortality. Subgroup and restricted cubic spline analyses were conducted to verify results. After propensity score matching, 408 patients were included in the final analysis. Crude comparison showed that 28‑day mortality was similar between the 60-80 mmHg group and the 80-120 mmHg group, but was significantly higher in the > 120 mmHg group. In multivariable Cox regression adjusted for confounders, using the 60-80 mmHg group as reference, the hazard ratios for the 80-120 mmHg and > 120 mmHg groups were 1.12 (95% CI: 0.65-1.93) and 1.89 (95% CI: 1.14-3.13), respectively. The duration of mechanical ventilation was 50, 131, and 120 h in the 60-80, 80-120, and > 120 mmHg groups, respectively (P = 0.038), while no significant differences were found among the three groups in ICU stay, hospital stay, pulmonary infection rate, or tracheotomy rate. Subgroup analyses and restricted cubic spline analyses consistently confirmed the robustness of these results. In TBI patients, PaO₂ 80-120 mmHg conferred no survival advantage over 60-80 mmHg, while PaO₂ >120 mmHg significantly increased mortality risk. The 60-80 mmHg group had shorter mechanical ventilation. These data suggest that targeting higher oxygenation may not confer short‑term survival benefit and could potentially add to respiratory care burden, though further validation is required.