Comparison of Remifentanil-induced Postoperative Hyperalgesia Between Patients From Plain Area and Plateau Area

Tianjin Medical University General Hospital160 enrolled

Overview

Purpose: 1. To compare the incidence of postoperative hyperalgesia induced by remifentanil in patients undergoing gynecological laparoscopic surgery in plateau and plain areas 2. To compare the peri-operative analgesic requirements of patients in plain and plateau areas

Our research group has been committed to the research of remifentanil-induced hyperalgesia for a long time. In the previous study, it was found that intraoperative infusion of remifentanil (0.3ug/kg•min) \>1h can lead to remifentanil-induced hyperalgesia and the incidence rate is relative high in the plain area. Due to the long-term low pressure and hypoxia of people living in plateau areas, a series of changes will occur in the respiratory and circulatory systems, and their anesthesia management needs to be adjusted accordingly. However, there is no relevant research on whether or not hyperalgesia occurs in people in plateau areas (altitude level \>3000 meters). Therefore, this study hopes to compare the incidence and degree of remifentanil-induced hyperalgesia after gynecological laparoscopic surgery in plain areas and plateau areas.

Study Type

OBSERVATIONAL

Enrollment

160

Conditions

Pain, Postoperative Anesthesia

Interventions

Sufentanil injectionDRUG

Sufentanil 0.3 μg/kg is intravenously administrated to maintain intraoperative analgesia

Remifentanil HydrochlorideDRUG

Remifentanil 0.3ug/kg/min is intravenously administrated to maintain intraoperative analgesia

plain areasOTHER

Patients should be long staying residents in plain areas (altitude level below 1,000 meters above sea level)

Eligibility

Sex: FEMALEMin age: 20 YearsMax age: 60 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Subject is scheduled to undergo gynecological laparoscopic surgery under a short general anesthesia of less than 2 hours 2. Subject's American Society of Anesthesiologists physical status is I-II. 3. The subject's parent/legally authorized guardian has given written informed consent to participate. 4. Patients in plateau areas are long staying residents in above 3000 meters above sea level for enrollment, while patients in plain areas are long staying residents below 1000 meters above sea level. Exclusion Criteria: 1. Subject has a diagnosis of renal or liver failure. 2. Subject has a diagnosis of Insulin dependent diabetes. 3. Subject is allergy and contraindication to any drugs used during general anesthesia. 4. Subject has a history of chronic pain, a history of alcohol or opioid abuse, pre-existing therapy with opioids, intake of any analgesic drug within 48 hours before surgery. 5. Subject has any contraindication for the use of patient-controlled analgesia (PCA). 6. Subject is pregnant or breast-feeding. 7. Subject is obese (body mass index \>30kg/m2).

Locations (2)

Gannan Tibetan Autonomous Prefecture People's Hospital

Hezuo, Gansu, China

Tianjin Medical University General Hospital

Tianjin, China

Outcomes

Primary Outcomes

Mechanical Hyperalgesia Threshold on the Dominant Inner Forearm

The mechanical hyperalgesia threshold was defined as the lowest force (g) necessary to bend a Von Frey filament, which was perceived to be painful by the patient and measured by Von Frey filament after surgery

Time frame: 48 hours after surgery

Secondary Outcomes

Pain Score (NRS)

The pain score at rest or after movement was evaluated by pain 11-point numerical rating scale (NRS): 0 = no pain, 10= greatest imaginable pain.

Time frame: 48 hours after surgery

Normalized Area of Hyperalgesia Around the Incision

The skin around the incision is stimulated in steps of 5 mm at intervals of 1 s starting outside of the hyperalgesic area in the direction of the incision. The distance from the incision to the first point where a'painful', 'sore' or 'sharper' feeling occurred is measured and noted. This measurement is repeated at predefined radial lines around the incision. To eliminate the variable length of incision, this length is subtracted from the longer diameter leaving four radial distances from the end and from the middle of the incision. The normalized area of hyperalgesia is calculated by summing up the areas of the remaining four triangles measured by and Von Frey filament.

Time frame: 48 hours after surgery

Mechanical hyperalgesia threshold around the incision

The mechanical hyperalgesia threshold was defined as the lowest force (g) necessary to bend a Von Frey filament, which was perceived to be painful by the patient and measured by Von Frey filament.

Time frame: 48 hours after surgery

Time of First Postoperative Analgesic Requirement

First postoperative pain (NRS≥5) is initially controlled by titration of Hydromorphone.

Time frame: 1 hour after surgery

Central Contacts

Guolin Wang, MD

CONTACT

+8618604755166 wangguolinghad@hotmail.com

Data from ClinicalTrials.gov

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