Clinical Trial: Effect of Higher Doses of Remifentanil on Postoperative Pain in Patients Undergoing Thyroidectomy

Study Status: Completed
Recruit Status: Unknown status
Study Type: Interventional

Official Title: Comparison of Different Doses of Remifentanil on Postoperative Pain in Patients Undergoing Thyroidectomy: a Prospective, Double-blinded Randomized Control Trial

Brief Summary: Extensive clinical studies have shown that intraoperative infusion high dose of remifentanil (0.2ug/kg/min) induced postoperative hyperalgesia. Recent experimental study however suggests that higher dose of remifentanil may attenuate postoperative hyperalgesia. Thus, the present study is designed as a "proof of principle" study and hypothesizes that higher dose of remifentanil may reduce postoperative pain in patients.

Detailed Summary:

Remifentanil, an ultra-short acting opioid, is widely used in the patients undergoing surgery. However, extensive studies report that remifentanil,administered at 0.2ug/kg/min or 0.4ug/kg/min intraoperatively, can result in postoperative hyperalgesia and increase the consumption of analgesics when compared with low dose (0.05ug/kg/min). However, a recent experimental study shows that large dose of remifentanil can inhibit pain hypersensitivity through erasing the spinal sensitization of pain. The present study thus hypothesizes that higher dose of remifentanil (1.2ug/kg/min) may attenuate postoperative pain. The present study will compare the effect of two different dose of remifentanil (0.2ug/kg/min and 1.2ug/kg/min) on postoperative pain. Patients undergoing thyroidectomy will be recruited, and mechanical threshold will be measured in the remote region of surgical site preoperatively. The patients will be randomly divided by two groups, 0.2ug/kg/min (group I) and 1.2ug/kg/min (group II). After operation, mechanical threshold and visual analogue scale (VAS) will be measured as the indicators of postoperative pain. The consumption of morphine will also be compared between these two doses of remifentanil.

The present study may find optimized dose of opioid usage in the patients undergoing surgery to relieve the postoperative pain.


Sponsor: Central South University

Current Primary Outcome: Changes of sensory threshold from baseline to postoperative 24hours [ Time Frame: 24 hour ]

Quantitative sensory threshold in the remote uninjured site (here, the inner forearm) is commonly used to examine the occurrence of postoperative hyperalgesia. The present study will examine the mechanical threshold in two different doses of remifentanil to determine whether high dose of remifentanil induces hyperalgesia


Original Primary Outcome: Same as current

Current Secondary Outcome: visual analogue score (VAS) [ Time Frame: 24 hours ]

VAS is widely used to assess postoperative pain. It will be divided as 10 points. Zero refers to no pain and ten refers to extremely pain. Based on this way, we can know the difference of postoperative pain in these two different groups.


Original Secondary Outcome: Same as current

Information By: Central South University

Dates:
Date Received: December 30, 2012
Date Started: December 2012
Date Completion:
Last Updated: January 3, 2013
Last Verified: January 2013