Safety and feasibility of continuous infusion of remifentanil in the neurosurgical intensive care unit.

Abstract

Remifentanil is a selective mu-opioid agonist with a context-sensitive half-time of 3 to 5 minutes, independent of dose or administration duration. Other desirable effects include decreased cerebral metabolism and intracranial pressure (ICP) with minimal cerebral perfusion pressure changes. We present six cases illustrating indications for the use of remifentanil in the neurosurgical intensive care unit. Patients received bolus doses of remifentanil of 0.05 to 1.0 microg/kg, followed by continuous infusions of 0.03 to 0.26 microg/kg/min, titrated to effect. When infusions were discontinued for neurological examinations, another bolus dose preceded infusion reinstitution. Indications for the use of remifentanil included mean arterial pressure and cerebral perfusion pressure decreases with the use of other agents (e.g., codeine or propofol) for ICP control, elevated ICP that was refractory to propofol/mannitol treatment, agitation that was unresponsive to standard therapies, and coughing that caused ICP increases after subarachnoid hemorrhage. Three patients experienced spontaneous intracranial bleeding (two cases of subarachnoid hemorrhage and one case of intraventricular hemorrhage), and three patients exhibited severe traumatic subdural hemorrhage. All patients recovered from the effects of remifentanil within 3 minutes after discontinuation of infusion, which allowed frequent rapid neurological assessments. Procedures for pulmonary toilet (i.e., endotracheal suctioning, postural drainage, and bronchoscopy) were performed without deleterious ICP increases or mean arterial pressure or cerebral perfusion pressure decreases during remifentanil infusions. The ultrashort duration of action of remifentanil allowed easy performance of frequent neurological examinations in the neurosurgical intensive care unit. No patient experienced deleterious hemodynamic or neurological effects as a result of remifentanil use.