Abstract / Summary
Abstract Jugular venous oxygen saturation (SjvO₂) is used in multimodal monitoring to assess cerebral oxygen delivery–consumption balance after acute brain injury (ABI). We evaluated whether arterial oxygen tension (PaO₂) influences SjvO₂ and may mask elevated cerebral oxygen extraction (CEO₂). In this retrospective study, paired arterial and jugular venous blood gases obtained within 30 minutes were analyzed in patients with ABI undergoing multimodal monitoring between 2015 and 2023. SjvO₂ was categorized as low (< 60%), normal (60–75%), or high (> 75%), and CEO₂ ≥40% was considered elevated. Critical perfusion despite reassuring SjvO₂ was defined as SjvO₂ ≥60% with elevated CEO₂. Overall, 138 patients contributed 3,090 paired measurements. SjvO₂ increased nonlinearly with PaO₂. Compared with PaO₂ <100 mmHg, the odds of preserved SjvO₂ increased progressively across higher PaO₂ categories, whereas PaO₂ was not significantly associated with preserved CEO₂. Among 3,042 measurements, 29 met criteria for critical perfusion despite reassuring SjvO₂ and had higher PaO₂ values (174 [153–291] vs. 118 [95–174] mmHg). PaO₂ identified these measurements with an AUC of 0.78 (95% CI, 0.73–0.83); 129 mmHg provided 100% sensitivity and 59% specificity. Elevated PaO₂ may therefore produce falsely reassuring SjvO₂ values and should be considered when interpreting cerebral oxygenation in ABI.