Local Anesthetic Concentration and Rebound Pain

Ajou University School of Medicine

Status: Enrolling

Conditions: Rebound Pain

Treatments: Other: Reduced concentration of local anesthetic (ropivacaine); Other: Usual concentration of local anesthetic (ropivacaine)

Study type: Interventional

Funder types: Other

Identifiers

NCT04457557

MED-INT-20-140

Details and patient eligibility

About

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.

Full 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.

Enrollment: 60 estimated patients

Sex: All

Ages: 19 to 70 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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60 participants in 2 patient groups

Low concentration

Experimental group

Description:

Interscalene block with 0.15% ropivacaine 15 ml

Treatment:

Other: Reduced concentration of local anesthetic (ropivacaine)

Usual concentration

Active Comparator group

Description:

Interscalene block with 0.5% ropivacaine 15 ml

Treatment:

Other: Usual concentration of local anesthetic (ropivacaine)