['This study aimed to examine the effects of sedative doses of morphine, fentanyl and sufentanil on intracranial pressure (ICP) in head-injured patients in whom changes in mean arterial pressure (MAP) were minimized.', 'Fifteen severely head-injured patients (GSC of < or = 8) were randomly assigned to receive either fentanyl, sufentanil or morphine, titrating the drug to a maximal 10% decrease in MAP. The patients were subsequently given an infusion of the same opioid. For four hours, ICP, MAP and heart rate were recorded.', 'In all groups, there were no increases in ICP. There was a decrease in MAP in the sufentanil group at 10 min (P < 0.05) and 45 min after the initial opioid bolus. These decreases in MAP were not associated with increases in ICP.'] Does opioid sedation alter intracranial pressure in head injured patients?