EFFECTS OF HYPOXIA IN HEAD INJURY

Kim, Gab Teug; Lee, Jong An

Abstract

To evaluate the effects of hypoxia to the outcome of patients with head injury, we analyzed 223 patients prospectively. We divided patients into two groups; without hypoxia and with hypoxia. Hypoxia was defined as PaO2<60mmHg at room air. And clinical parameters such as patient's age, causes of injury, time interval from injury until arrival at the emergency medical center, Glasgow Coma Scale(GCS) on admission, types of brain lesion, and presence of hypotension were compared. Hypoxia was seen in 37 patients with head injury(16.6%). Hypoxia was noted in 32 patients among 162 traffic accidents(19.8%), in 28 patients among 150 cases with mass lesions(18.6%), and in 18 patients among 56 cases with obliterated basal cisterns in CT scan(32.1%). Hypoxia was more commonly seen in patients with severe head injury(GCS< or =8)(26.3%) compared to patients with mild to moderate head injury(GCS>9)(8.9%). Hypoxic insult to the already-injured brain was closely associated with increased mortality and morbidity. Of the 37 patients with hypoxic insult, 23(62.2%) showed poor outcome (vegetative state & dead); only 48 patients(25.8%) without hypoxia showed poor outcome(p<0.001). Among hypoxic group, the incidence of poor outcome was especially high in patients injured in vehicular accidents(55.6%), in low consciousness level(GCS<8) on admission(80.7%), and in intracranial mass lesions(67.9%). Care for the patient with head injuries should start at the scene of injury. 100% oxygen should be administered via a suitable airway during transportation to the hospital, and early positive-pressure ventilation may be necessary.