Improving clinical outcomes from acute subdural hematomas with the emergency preoperative administration of high doses of mannitol: a randomized trial.

Objective: To evaluate clinical outcomes and postoperative physiological findings for comatose patients with acute subdural hematomas who received preoperative high-dose mannitol (HDM) versus conventional-dose mannitol treatment.

Methods: One hundred seventy-eight adult patients with non-missile, traumatic, acute, subdural hematomas were prospectively and randomly assigned to receive emergency, preoperative, intravenous HDM treatment (91 patients), compared with a control group treated with a lower preoperative mannitol dose (87 patients).

Results: Preoperative improvement of abnormal pupillary widening was significantly more frequent in the study group than in the control group of patients (P < 0.0001). Preoperative HDM treatment was also associated with significantly better clinical outcomes at 6-month follow-up evaluations (P < 0.01). Postoperative physiological findings revealed statistically significant between-group differences, with higher intracranial pressure and lower cerebral extraction of oxygen (relative cerebral hyperperfusion) in the control group, compared with the HDM group. Postoperative global brain ischemia (abnormally low arteriojugular lactate difference values) was rare and was detected in 2.2 and 3.4% of the patients in the study and control groups, respectively.

Conclusion: Emergency preoperative HDM administration was associated with improved clinical outcomes for patients with acute subdural hematomas. Preoperative improvement of abnormal pupillary widening and better postoperative control of intracranial hypertension and associated relative cerebral hyperperfusion seemed to be relevant factors associated with improved outcomes.