Comparative Effects of Hypothermia, Barbiturate, and Osmotherapy for Cerebral Oxygen Metabolism, Intracranial Pressure, and Cerebral Perfusion Pressure in Patients with Severe Head Injury

Abstract

In order to select the optimal neurointensive treatment for patients with severe head injury and intracranial hypertension, the effects of hypothermia (HT), barbiturates (BT), and osmotic agents (OT) on focal and diffuse cerebral oxygen metabolism were evaluated by means of continuous monitoring of bifrontal regional oxygen saturation (rSO2), jugular bulb oxygen saturation (SjO2), jugular bulb temperature (Tjh), intracranial pressure (ICP), and cerebral perfusion pressure (CPP). Patients and Methods: Cerebral oxygen metabolism in SjO2 and rSO2, ICP, CPP, and Tjb were continuously monitored in severe head injury patients with Glasgow Coma Scale <8, ages 10-62: 13 with focal and 10 with diffuse injuries. The effects of BT (n = 6), HT (n = 9), and OT (n = 8) on these parameters (ICP/CPP, SjO2, and rSO2) were compared. Evaluations were performed in terms of: a) Percentage of abnormal values based on normal control values; ICP < 20mmHg, CPP > 60mmHg, SjO2 55-75%. and rSO2 60-80% were calculated. b) Effects of pentobarhital dose (mg/kg/ h) for the parameters compared among <1.0, 1.1-2.0, 2.1-3.0, and >3.1. c) Effects of Tjb (°C) on parameters compared among hyperthermia (>38°C), normothermia (36-37.9°C), mild hypothermia (34-35.9°C) and moderate hypothermia (<33.9°C). Results: a) Abnormal data differed significantly among the three treatment groups. rSO2 showing ischemia on the affected side was more marked in BT than in HT or OT. b) ICP decreases and CPP increases correlated significantly with the pentobarbital dose. c) ICP decreases and CPP increases correlated significantly with decreased Tjb. Conclusion: The therapeutic effects of hypothermia, barbiturates, and osmotherapy on cerebral oxygen metabolism and ICP/CPP are different according to the underlying pathological lesions of patients with severe head injury.