Ultrasound-guided Shoulder Block Versus Pericapsular Nerve Group Block (PENG) for Postoperative Analgesia in Arthroscopic Shoulder Surgery: a Randomized Controlled Trial

Effective analgesia in arthroscopic shoulder surgery is a major concern and is essential for all aspects of the patient's recovery. Multimodal pain management is recommended for early postoperative pain control. Regional anesthesia is preferred in shoulder surgery as an effective means of providing anesthesia and postoperative analgesia. Commonly used techniques for shoulder surgery include interscalene brachial plexus (ISB) blocks, continuous ISB (CISB) blocks, suprascapular nerve blocks (SSB), supraclavicular nerve blocks (SCB), local infiltration (LI), and ISB with adjuvants.Interscalene brachial plexus (ISB) block is considered the analgesic technique of choice for shoulder surgery. Shoulder block which is combination of suprascapular nerve block and axillary nerve block has been recently proposed as an alternative anesthetic and postoperative analgesic modality in this patient population. These two nerve blocks cause the loss of the sensory innervation of the shoulder. Shoulder block is advantageous to the interscalene brachial plexus block since it does not lead to respiratory dysfunction due to phrenic nerve palsy or other serious complications.The pericapsular nerve group (PENG) block may be safely applied for both partial anesthesia and analgesia in selected shoulder surgery cases. It did not cause motor block or pulmonary complications, nor result in muscle laxity, blocking only the shoulder and the upper third of the humerus. PENG block has been studied extensively in hip surgeries but its place in shoulder surgeries is not yet clear. Therefore, this study will be conducted to compare efficacy of ultrasound guided shoulder block with PENG block for postoperative analgesia in patients undergoing arthroscopic shoulder surgeries.

The aim of this study:

assess the quality of pain relief in patients who will undergo arthroscopic shoulder surgeries receiving either shoulder block versus PENG block comparing and evaluating the differences between the two techniques.

Sample Size Calculation:

Sample size was calculated using Power Analysis and Sample Size software program (PASS) version 11.0.4 for windows (2011) with time to first analgesic request as the primary outcome. Using the results published by Pani et al 2019 with the mean time to first analgesic request in shoulder block group was (5.9 ± 1.2 hours) Using a two-sided two-sample unequal-variance t-test, sample size of 40 patients is needed to achieve 90% power to detect 20 % difference in time to first analgesic request. Using a two-sided hypothesis test with a significance level of 0.05. A 10% drop out is considered, so a total of 46 patients will be enrolled (23 in each group) in this study.