Effect of remifentanil on intracranial pressure and cerebral blood flow velocity in patients with head trauma

Background: Remifentanil, an ultra-short-acting opioid, is used as an on-top analgesic in head trauma patients during transient painful procedures, e.g. endotracheal suctioning, physiotherapy, on the intensive care unit. However, previous studies have shown that opioids may increase intracranial pressure and decrease cerebral blood flow. Methods: The present study investigates the effect of remifentanil on mean arterial blood pressure, intracranial pressure measured with intraparenchymal or epidural probes, and on cerebral blood flow velocity assessed by transcranial Doppler flowmetry in 20 head trauma patients sedated with propofol and sufentanil. Ventilation was adjusted for a target PaCO₂ of 4.7-5.1 kPa. After baseline measurements a bolus of remifentanil (0.5 μg·kg^-1 i.v.) was administrated followed by a continuous infusion of remifentanil (0.25 μg·kg^-1·min^-1 i.v.) for 20 min. Results: There was no change in mean arterial blood pressure, intracranial pressure, and cerebral blood flow velocity in response to remifentanil infusion over time. Statistical analysis was performed using the Wilcoxon Signed Rank test. Conclusions: These data suggest that remifentanil can be used for on-top analgesia in head trauma patients without adverse effects on cerebrovascular haemodynamics, cerebral perfusion pressure or intracranial pressure.