Infraclavicular and supraclavicular approaches to brachial plexus for ambulatory elbow surgery: A randomized controlled observer-blinded trial

Abstract

Study objective: To compare the effectiveness of supraclavicular and infraclavicular approaches to brachial plexus block for elbow surgery.

Design: Prospective, parallel arm, observer-blinded, randomized controlled trial.

Setting: This study occurred in a designated block room at St. Joseph's hospital, a large academic tertiary hospital in London, Canada.

Patients: 150 adult ASA class I-III patients undergoing elective ambulatory elbow surgery.

Interventions: Patients were randomized to receive either an ultrasound-guided infraclavicular or a supraclavicular block with ropivacaine.

Measurements: Both groups were assessed for performance and sensory block onset times. Motor block, effective surgical anesthesia, procedure-related pain, axillary nerve block and ulnar nerve sparing were additional outcomes. We analyzed continuous and non-continuous variables with the independent t-test and chi-square test respectively and considered statistical significance when type 1 error was under 0.05.

Main results: We observed similar mean block procedure times at 285 (±128) seconds in infra and 307 (±138) seconds in supra group (p = 0.3). The mean time of sensory block onset in both groups was similar: Infra 20.4 (±7.9) and supra 18.9 (±7.1) min (p = 0.4). Conversion to general anesthesia (4.2 vs 5.5%; p = 0.73) and the need for local anesthetic supplement (4.2 vs 4.1%; p = 0.98) was similar in both groups. We observed an increased incidence of paresthesia in the supra group (8.3 vs 23.2%; p = 0.014).

Conclusion: We found that both blocks were equally effective for elbow surgery with similar procedure and block onset times and failure rates. Lower incidence of paresthesia was associated with the infraclavicular block with no change in other complications compared to the supraclavicular technique.

Keywords: Elbow surgery; Infraclavicular nerve block; Supraclavicular nerve block; Ultrasound.