Pain
Conditions
Keywords
acute pain, postoperative, surgery
Brief summary
High-dose remifentanil infused intraoperative ironically results in postoperative hyperalgesia. Ultra-low dose nalxone is demonstrated to prevent these opioid-induced hyperalgesia in animal model. In this clinical trial in patients undergoing general anesthesia with remifentanil, we evaluate the effects of ultra-low-dose naloxone on remifentanil-induced hyperalgesia
Detailed description
We enrolled adult patients undergoing thyroidectomy under general anesthesia with desflurane and remifentanil. Remifentanil was administered via target-controlled infusion and anesthetic depth was maintained keeping the BIS between 40 and 60. Patients were randomized into one of three groups depending on intraoperative doses of remifentanil and naloxone: effect-site concentrations of remifentanil 1 ng/ml (control group), 4 ng/ml (remifentanil group), and 4 ng/ml combined with infusion rate 0.8 ng/kg/min of naloxone (remifentanil and naloxone group). Postoperative mechanical pain thresholds, pain intensity, and analgesic consumption were examined during 48 h of postoperative period. The primary outcome was mechanical pain threshold measured on the peri-incisional area 24 h after surgery.
Interventions
remifentanil infusion at 4ng/ml of Ce
DRUGNaloxone
naloxone infusion
remifentanil infusion at 1ng/ml of Ce
DRUGNormal Saline
normal saline infusion
Sponsors
Seoul National University Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
20 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* patients who are scheduled to undergo elective thyroidectomy
Exclusion criteria
* consent refusal, obesity, pregnancy, hx. of thyroid surgery, neurological disorders, psychiatric disorders, hx. of drug abuse or chronic use of opioids or sedative drugs, intake of any analgesic drug within 12h before surgery.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mechanical pain thresholds | 24hr after surgery | Mechanical pain thresholds were assessed by von Frey filaments. The patients were asked to close their eyes during the test, and an investigator made the filament pressing the skin perpendicularly against the skin until bowing and being maintained for 1.5 seconds. The filament size was started from 0.4 g and was increased to the point until the patient perceives a clear change in sensation. |
Secondary
| Measure | Time frame |
|---|---|
| Mechanical pain thresholds | 48hr after surgery |
| pain score | verbal numerical rating scale at 24 hr after surgery |
Countries
South Korea
Outcome results
None listed