The Effect of Interscalene Peripheral Nerve Block With 0.25% Bupivacaine vs 0.125% Bupivacaine on Lung Function

Utah System of Higher Education (USHE)

Status: Completed

Conditions: Diaphragm Paralysis

Treatments: Drug: interscalene block with 0.125% bupivacaine; Drug: interscalene nerve block with 0.25% bupivacaine

Study type: Interventional

Funder types: Other

Identifiers

NCT01429584

00026846

Details and patient eligibility

About

Peripheral nerve blocks are used to provide post-operative pain relief. Nerve blocks in the neck, in the interscalene area, provide pain relief after shoulder surgery but can cause temporary weakness or paralysis of the diaphragm. The investigators hypothesized that a lower concentration of bupivacaine would cause less weakness of the diaphragm but still provide good pain relief. Lung function and pain control was studied after interscalene peripheral nerve block with 20 milliliters of 0.25% bupivacaine or 0.125% bupivacaine.

Full description

Prior to placement of interscalene brachial plexus peripheral nerve block (ISPNB), diaphragm function was assessed using ultrasound as normal, no movement, or paradoxical. Room air pulse oximetry (SpO2) was recorded. Patients were randomized to receive either 0.25% bupivacaine or 0.125% bupivacaine. ISPNB was performed using a coded syringe of the study drug, so that the anesthesiologists performing the nerve block, the patient, and the nurses assessing the patient were blinded as to the concentration. Patients were given a general endotracheal anesthesia for rotator cuff repair, and opioids were administered at the discretion of the attending anesthesiologist. When patients met criteria for PACU discharge, diaphragm function was again assessed using ultrasound and room air SpO2 was recorded.

Enrollment: 30 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• patients presenting for outpatient rotator cuff repair
• adults
• English as the primary language

Exclusion criteria

• evidence of peripheral nerve damage on affected side
• refusal of peripheral nerve block
• pregnant women
• lung disease, including obstructive sleep apnea
• chronic opioid use
• mental handicap

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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30 participants in 2 patient groups

0.25% bupivacaine

Active Comparator group

Description:

interscalene nerve block with 0.25% bupivacaine

Treatment:

Drug: interscalene block with 0.125% bupivacaine

0.125% bupivacaine

Active Comparator group

Description:

interscalene nerve block with 0.125% bupivacaine

Treatment:

Drug: interscalene nerve block with 0.25% bupivacaine