Postoperative condition after the use of remifentanil with a small dose of piritramide compared with a fentanyl-based protocol in patients undergoing craniotomy

Background and objective: The use of remifentanil requires other analgesics for postoperative pain relief compared to fentanyl in patients undergoing craniotomy. This could possibly reduce the postoperative advantages of this short-acting opioid. Methods: We compared remifentanil and fentanyl-based anaesthesia in a randomized observer and patient blinded trial on patients, undergoing an elective craniotomy. Twenty patients received anaesthesia using remifentanil with a small dose of piritramide (0.1 mg kg^-1) after closure of the dura mater. Twenty patients underwent a fentanyl-based protocol. In both groups, anaesthesia was induced with thiopental and rocuronium, and maintained with 0.6-1 minimum alveolar concentration (MAC) isoflurane in a nitrous oxide/oxygen mixture 2:1 and rocuronium. Patients received 1 g of paracetamol rectally postoperatively. A visual analogue scale (VAS) for pain, the Glasgow Coma Score, a modified Aldrete Score, arterial carbon dioxide tension (PaCO₂) and piritramide consumption were evaluated every half an hour postoperatively. Results: No significant differences were found for pain, Aldrete or Glasgow Coma scores or for PaCO₂ between the groups when controlled for age, although the pain and Glasgow Coma Scores were consistently higher and PaCO₂ lower in the remifentanil group. Furthermore, 13 out of 20 patients in the remifentanil group requested extra piritramide as opposed to 7 out of 20 in the fentanyl group (P = 0.11). Conclusions: Despite the intraoperative use of piritramide in the remifentanil group, patients experienced more pain postoperatively. A significant influence of age on pain intensity was found. The use of remifentanil with a small dose of piritramide of 0.1 mg kg^-1 has no evident advantage over the use of fentanyl considering the postoperative conditions after craniotomy.