Abstract
Background: Arthroscopic shoulder surgery involves dynamic and severe postoperative pain. Interscalene brachial plexus block provides adequate analgesia, but the spread of local anaesthetics administered causes a phrenic nerve block that entrains a nonnegligible incidence of hemidiaphragmatic paralysis acute.The main objective of this trial is to compare the hemidiaphragmatic paralysis after interscalene brachial plexus block in arthroscopic shoulder surgery, between a standard volume (20 ml) and a low volume (10 ml) of 0.25% levobupivacaine.Methods: This is a comparative, prospective, single-center, double-blind, two-arm randomized controlled trial. Forty-eight patients will be included. The primary end-point is to determine the hemidiaphragmatic paralysis incidence diagnosed by the diaphragmatic thickness ratio in ultrasound. The secondary endpoints are as follows: (1) hemidiaphragmatic paralysis incidence diagnosed by forced vital capacity and (2) forced expiratory volume at 1 second decrease in spirometry; (3) hemidiaphragmatic paralysis incidence diagnosed by using diaphragmatic excursion decrease in ultrasound; (4) postoperative pain regarding 24-hour morphine intravenous total consumption and (5) time to first analgesic consumption of patient-controlled analgesia pump; and (6) postoperative harm between the two trial arms.Discussion: This trial would demonstrate that low-volume interscalene brachial plexus block decreases hemidiaphragmatic paralysis in arthroscopic shoulder surgery by using spirometry and ultrasound and would not provide inferior postoperative analgesia according to opioid requirements of postoperative patient-controlled analgesia in comparison to the standard volume used in current practice.Trial registration: EudraCT and Spanish Trial Register (REec) registration number: 2019-003855-12 (Registered on 07 January 2020). ClinicalTrials.gov identification number: NCT04385966 (Retrospectively registered on 08 May 2020). Ethics Committee approval: EC19/093 (18 Dic 2019).
The Effect of Ultrasound-Guided Interscalen Brachial Plexus Block Plus General Anesthesia for Postoperative Pain in Arthroscopıc Shoulder Surgery