Introduction. Hypoxia is one of the secondary insults and it worsens the outcome in patients with severe traumatic brain injury (TBI). On the other hand, there is some controversy about the impact of hyperoxia on the outcome in these patients. The aim of the study was to determine the impact of pre-hospital hypoxia, hyperoxia and pre-hospital ventilation status on outcome after isolated TBI.
Methods. We retrospectively reviewed charts from patients with isolated severe TBI who underwent pre-hospital endotracheal intubation. The population was sorted into groups based on PaO2 (hypoxic, PaO2 <100 mmHg; normoxic, PaO2 100-200 mmHg; hyperoxic, PaO2 > 200 mmHg) and initial Glasgow Coma Scale (GCS) level (3-5 and ≥ 6). Ventilation status was defined as: hypocarbic (PaCO2 < 35 mmHg), normocarbic (PaCO2 35-45 mmHg) and hypercarbic (PaCO2 > 45 mmHg).
Results. Oxygenation status had no significant impact on 24- and 48-hour survival, on the length of hospital stay or on neurological outcome (measured by the Glasgow Outcome Scale (GOS), Glasgow Pittsburgh Cerebral Performance Categories Scale (CPC), and GCS score at discharge) when all six groups were compared together. We were unable to prove a deleterious effect of hypoxia or hyperoxia compared to normoxia on rate of survival to hospital discharge (STHD) (0.38 (0.52) vs 0.50 (0.51) vs 0.65 (0.49), where 0 – no and 1 – yes; f = 1.246, p = 0.298). Ventilation status also failed to significantly affect survival and functional outcome in patients with isolated severe TBI.
Conclusion. Pre-hospital oxygenation and ventilation status have no significant impact on outcome in patients with isolated severe TBI.
Key words: hypoxia, pre-hospital, intubation, hyperventilation, traumatic brain injury