Major clinical and physiological benefits of early high doses of mannitol for intraparenchymal temporal lobe hemorrhages with abnormal pupillary widening: A randomized trial

OBJECTIVE: We evaluated long-term clinical outcomes and postoperative physiological findings in acutely comatose patients with nonmissile surgical intraparenchymal temporal lobe hemorrhages and abnormal pupillary widening who received early preoperative high-dose mannitol (HDM) versus conventional dose mannitol treatment in the emergency room. METHODS: One hundred forty-one adult patients with traumatic, nonmissile, acute, intraparenchymal temporal lobe hemorrhages associated with early abnormal pupillary widening were prospectively and randomly assigned to receive emergency preoperative intravenous HDM treatment (approximately 1.4 g/kg; 72 patients) and were compared with a control group that was treated with a lower preoperative mannitol dose (approximately 0.7 g/kg; 69 patients). RESULTS: Early preoperative improvement of abnormal bilateral pupillary widening was significantly more frequent in the study group than in the control group (P < 0.03). The same was true for abnormal unilateral pupillary widening (P < 0.01). Early HDM treatment in the emergency room was also associated with significantly better 6-month clinical outcomes (P < 0.005). The two groups of patients were well matched with respect to diameter of the temporal lobe hemorrhages (approximately 4 cm) as well as timing of clot removal (approximately 2.5 hours after injury). Postoperative physiological findings revealed statistically significant between-group differences, with higher intracranial pressure and lower cerebral extraction of oxygen (global relative cerebral hyperperfusion) in the control group than in the HDM group. Postoperative global brain ischemia (abnormally low arteriojugular lactate difference values) was rare and was found for less than 3% of the patients in both groups. CONCLUSION: Early preoperative HDM administration in the emergency room was associated with improved clinical outcomes for adult comatose patients with acute, nonmissile, intraparenchymal temporal lobe hemorrhages and associated abnormal pupillary widening. Early improvement of bilateral or unilateral pupillary abnormalities and better postoperative control of intracranial hypertension and associated global relative cerebral hyperperfusion seemed to be relevant factors that were related to improved outcomes.