The effect of cerebrospinal fluid drainage on cerebral perfusion in traumatic brain injured adults

Cerebrospinal fluid drainage is a first line treatment used to manage sever ely elevated intracranial pressure (greater than or equal to 20 mm Pig) and improve outcomes in patients with acute head injury. There is no consensus regarding the optimal method of cerebrospinal fluid removal. The purpose o f this investigation was to determine whether cerebrospinal fluid drainage decreases intracranial pressure and improves cerebral perfusion and to iden tify factors that impact treatment effectiveness. This study involved 31 se verely head injured patients. Intracranial pressure and other indices of ce rebral perfusion (cerebral perfusion pressure, cerebral blood now velocity, and regional cerebral oximetry) were measured before, during, and after ce rebrospinal fluid drainage. Arterial and jugular venous oxygen content was measured before and after cerebrospinal fluid drainage. Patients underwent three randomly ordered cerebrospinal fluid drainage protocols that varied i n the volume of cerebrospinal fluid removed (1 mL, 2 mL, and 3 mL) for a to tal of 6 mL of cerebrospinal fluid removed. There was a significant change in the intracranial pressure from a mean at baseline of 26.1 mm Pig (SD = 4 .4) to 22.1 mm Pig immediately after drainage. One third of patients experi enced a decrease in the intracranial pressure below 20 mm Pig; in two patie nts the intracranial pressure dropped less than 1 mm Pig. The following fac tors predicted 61.5% of the variance in the responsiveness of intracranial pressure to drainage: vecuronium hypothermia, baseline cerebral perfusion p ressure and acuity of illness. Cerebrospinal fluid drainage provides a tran sient decrease in intracranial pressure without a measurable improvement in other indices of cerebral perfusion.