Comprehensive Summary
This substudy of the TRAUMAOX2 randomized trial evaluated the occurrence and duration of hypoxemic episodes in trauma patients managed with restrictive versus liberal oxygen strategies. At two Danish trauma centers, 60 patients were continuously monitored with pulse oximetry for a median of 6.9 hours during the trial’s 8-hour intervention period. The primary outcome was at least one episode of oxygen saturation (SpO₂) <90% lasting five or more consecutive minutes. Three of sixty patients (5%; 95% CI 1-14%) met this criterion, with two in the restrictive group and one in the liberal group, showing no between-group difference. Hypoxemic episodes occurred during initial resuscitation or invasive procedures, rather than later routine care. The liberal group had slightly longer hypoxemic episodes (median +2 seconds; p=0.008), but this difference was considered clinically negligible.
Outcomes and Implications
These findings are notable given that supplemental oxygen is universally administered in trauma care, where clinicians must balance prevention of hypoxemia with avoidance of hyperoxemia. This analysis indicates that prolonged hypoxemia (SpO₂ <90% for ≥5 min) is uncommon, affecting only 5% of patients in the immediate post-trauma period, regardless of oxygen strategy. For clinicians, the results suggest that restrictive oxygen therapy does not substantially increase early desaturation risk, providing reassurance about its short-term safety compared with liberal oxygen delivery. Although limited by a small sample size and two-center design, the substudy underscores the need to refine oxygen targets in trauma care while offering reassurance that restrictive strategies do not compromise short-term safety.