Local Anesthetic Concentration and Rebound Pain

Not Applicable

Recruiting

• Conditions: Rebound Pain
• Interventions: Other: Usual concentration of local anesthetic (ropivacaine); Other: Reduced concentration of local anesthetic (ropivacaine)

• Registration Number: NCT04457557
• Lead Sponsor: Ajou University School of Medicine

Brief Summary

The rebound pain after nerve block could interfere with patient's recovery and rehabilitation. It is not known how local anesthetic concentrations affect rebound pain. The aim of this study is evaluation of the effect of local anesthetic concentration on rebound pain after interscalene block for shoulder surgery.

Detailed Description

Shoulder surgery is related to more than moderate pain after surgery. Interscalene nerve block could reduce the postoperative pain effectively. When the effect of nerve block ends, however, rebound pain could appear. The rebound pain could interfere with patient's recovery and rehabilitation.

The mechanism of rebound pain is not well known. One of possible mechanism is that the pain stimulus that was blocked suddenly comes out, and it is perceived as more severe pain. The strength of the block may vary depending on the concentration of the local anesthetic. Therefore, the concentration of local anesthetics could affect rebound pain. The aim of this study is evaluation of the effect of local anesthetic concentration on rebound pain after interscalene block for shoulder surgery.

Study Timeline

• Study First Submitted: 2020-06-30
• Study First Submitted QC: 2020-07-02
• Study First Posted: 2020-07-07
• Study Start: 2020-07-10
• Status Verified: 2022-09
• Last Update Submitted: 2022-09-28
• Last Update Posted: 2022-09-30
• Primary Completion: 2023-06-30
• Study Completion: 2023-07-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

• Elective shoulder surgery under general anesthesia and interscalene block for postoperative pain

Exclusion Criteria

• Contraindication of interscalene block: pulmonary disease, lung resection history, brachial nerve injury
• Diabetic neuropathy
• Adverse drug reaction history to ropivacaine, fentanyl
• Impaired coagulation

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Usual concentration	Usual concentration of local anesthetic (ropivacaine)	Interscalene block with 0.5% ropivacaine 15 ml
Low concentration	Reduced concentration of local anesthetic (ropivacaine)	Interscalene block with 0.15% ropivacaine 15 ml

Primary Outcome Measures

Name	Time	Method
Rebound pain score	48 hours after surgery	It is calculated by subtracting the visual analogue scale (VAS) of pain at the last time when the nerve block was effective from the highest VAS for 12 hours from the time when the nerve block effect disappeared.; VAS of pain: 0=no pain \~ 10=very severe pain

Secondary Outcome Measures

Name	Time	Method
fentanyl bolus injection time	48 hours after surgery	Number of bolus injection times using patient controlled analgesia (PCA)
total postoperative fentanyl dose	48 hours after surgery	Total dose of fentanyl injected (mcg) through patient controlled analgesia (PCA) for 48 hours after surgery
Subjective satisfaction	48 hours after surgery	Patient's subjective satisfaction 48 hours after surgery Use visual analogue scale (0=very unsatisfied, 10= very satisfied)

Trial Locations

Locations (1)

Ajou university school of medicine; 🇰🇷 Suwon, Gyeonggi-do, Korea, Republic of