Hypoxemia and arterial hypotension at the accident scene in head injury.

To quantify the occurrence of arterial hypotension and arterial oxygen desaturation in a series of patients with head trauma rescued by helicopter. Prospective, observational study. Arterial HbO2 was measured before tracheal intubation at the accident scene in 49 consecutive patients with head injuries. Arterial pressure was measured using a sphygmomanometer. Mean arterial saturation was 81% (SD 24.24); mean arterial systolic pressure was 112 mm Hg (SD 37.25). Airway obstruction was detected in 22 cases. Twenty-seven patients showed an arterial saturation lower than 90% on the scene, and 12 had a systolic arterial pressure of less than 100 mm Hg. The outcome was significantly worse in cases of hypotension, desaturation, or both. Hypoxemia and shock are frequent findings on patients at the accident scene. Hypoxemia is more frequently detected and promptly corrected, white arterial hypotension is more difficult to control. Both insults may have a significant impact on outcome.