Tropisetron on Postoperative Pain

The role of 5-HT3A receptors in nociceptive processing has been demonstrated in several animal models. However, studies in human volunteers have not been reported except for one recent study suggesting that ondansetron could alleviate propofol-induced nociception. Previous studies demonstrated that patients anaesthetized with sevoflurane have more pain than those anaesthetized with propofol. And we further posit that the difference is due to the nociceptive processing induced by the action of 5-HT3A receptors. In this prospective, randomized, double-blind, placebo-controlled study, we assessed the analgesic action of a 5-HT3A receptor antagonist (tropisetron) in women after gynaecological laparoscopy under general anaesthesia maintained with either sevoflurane or propofol.

General anaesthetics, gynaecological laparoscopy, anaesthetic i.v., propofol, anaesthetic volatile, evoflurane, antiemetics, reopisetron, postoperative pain

In this arm, anaesthesia was maintained with propofol and remifentanil (0.1 μg kg-1 min-1), and primary anaesthetic namely propofol was titrated to maintain intraoperative BIS values between 45 and 55. If the patient did not respond to increases in the level of primary anaesthetic, additional doses of remifentanil up to 0.2 μg kg-1 min-1 were permitted to provide a more cardio-stable anaesthesia. Patients in this arms received saline placebo i.v. after the induction of anaesthesia.

In this arm, anaesthesia was maintained with propofol and remifentanil (0.1 μg kg-1 min-1), and primary anaesthetic namely propofol was titrated to maintain intraoperative BIS values between 45 and 55. If the patient did not respond to increases in the level of primary anaesthetic, additional doses of remifentanil up to 0.2 μg kg-1 min-1 were permitted to provide a more cardio-stable anaesthesia. Patients in this arms received tropisetron 2 mg i.v. after the induction of anaesthesia.

In this arm, anesthesia was maintained by sevoflurane and remifentanil (0.1 μg kg-1 min-1), and primary anaesthetic namely sevoflurane was titrated to maintain intraoperative BIS values between 45 and 55. If the patient did not respond to increases in the level of primary anaesthetic, additional doses of remifentanil up to 0.2 μg kg-1 min-1 were permitted to provide a more cardio-stable anaesthesia. Patients in this arms received saline placebo i.v. after the induction of anaesthesia.

In this arm, anesthesia was maintained by sevoflurane and remifentanil (0.1 μg kg-1 min-1), and primary anaesthetic namely sevoflurane was titrated to maintain intraoperative BIS values between 45 and 55. If the patient did not respond to increases in the level of primary anaesthetic, additional doses of remifentanil up to 0.2 μg kg-1 min-1 were permitted to provide a more cardio-stable anaesthesia. Patients in this arms received tropisetron 2 mg i.v. after the induction of anaesthesia.

The primary outcome was the postoperative pain at rest assessed by numeric analog score (NAS, where 0 indicates no pain, and 10 indicates the most severe pain) immediately after awaking.

The patients were instructed to give the number that represented the pain level at rest soon after awakening, the first 30 min postoperatively, and every 2 hours within the first 24 postoperative hours.

Heart rate and mean arterial pressure (MAP) every 5 min within 30 min after induction and 30 min before last suture

Inclusion Criteria: female patients American Society of Anaesthesiologists Physical Status (ASA-PS) I or II undergoing selective gynaecological laparoscopies for infertilities Exclusion Criteria: aged under 18 years old body mass index (BMI) > 30 history of cardiovascular disease history of respiratory disease history of neurologic disease history of chronic antidepressants history of anxiolytics history of chronic analgesics intake participating in other studies

Department of Anaesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China

Department of Anaesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China