This prospective, randomized, patient- and assessor-blinded, single-center non-inferiority trial will compare the analgesic efficacy of the Shoulder Posterior Pericapsular Nerve Group (SPENG) block with combined posterior suprascapular and axillary nerve blocks in adults undergoing elective shoulder arthroscopy under general anesthesia. Both groups will receive the same total volume and concentration of local anesthetic. The primary outcome will be the highest resting Numeric Rating Scale pain score recorded during the first 24 postoperative hours. Secondary outcomes will include block performance time, sensory block success in suprascapular and axillary nerve territories, opioid consumption, time to rescue analgesia, motor function, diaphragmatic function, postoperative recovery quality, patient satisfaction, and block-related complications.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
60
An ultrasound-guided single-injection posterior pericapsular block. With the participant in the lateral decubitus position and the operative shoulder uppermost, a high-frequency linear ultrasound transducer will be placed transversely immediately inferior to the posterior acromion. After identification of the humeral head, articular cartilage, infraspinatus muscle, and posterior glenoid rim, a block needle will be advanced in-plane in a medial-to-lateral direction. The needle tip will be positioned between the posterior glenoid rim and the deep surface of the infraspinatus muscle, and 20 mL of 0.25% bupivacaine with epinephrine 1:200,000 will be injected.
wo ultrasound-guided nerve blocks will be performed. For the posterior suprascapular nerve block, the suprascapular nerve will be identified in the suprascapular notch region beneath the supraspinatus muscle, and 10 mL of 0.25% bupivacaine with epinephrine 1:200,000 will be administered. For the axillary nerve block, the posterior humeral circumflex artery will be identified using color Doppler in the quadrilateral space, and 10 mL of 0.25% bupivacaine with epinephrine 1:200,000 will be administered adjacent to the axillary nerve.
Highest Resting Numeric Rating Scale Pain Score During the First 24 Postoperative Hours
Resting postoperative pain intensity will be assessed using an 11-point Numeric Rating Scale (NRS), ranging from 0 (no pain) to 10 (worst imaginable pain). For each participant, the highest resting NRS score recorded during the first 24 postoperative hours will be used as the primary outcome. Scheduled assessments will be performed on arrival in the post-anesthesia care unit and at 4, 8, 12, and 24 hours after surgery. Resting NRS scores obtained immediately before rescue analgesic administration outside these scheduled assessments will also be included when determining the highest value.
Time frame: From arrival in the post-anesthesia care unit through 24 hours after surgery
Block Performance Time
Time required to perform the allocated regional anesthesia technique, measured in seconds from the first contact of the ultrasound transducer with the skin until removal of the block needle after completion of local anesthetic injection.
Time frame: Periprocedural
Proportion of Participants With Complete Dual-Target Sensory Block Success
Cold sensation will be assessed over the posterior shoulder (suprascapular nerve territory) and lateral deltoid region (axillary nerve territory) using a 3-point scale: 0 = absent sensation, 1 = reduced sensation, and 2 = normal sensation. Suprascapular sensory component success will be defined as a reduction of at least one grade from baseline in the posterior shoulder region. Axillary sensory component success will be defined as a reduction of at least one grade from baseline in the lateral deltoid region. Complete dual-target sensory block success will require successful sensory blockade in both territories in the same participant.
Time frame: 30 minutes after block completion
Cumulative Opioid Consumption During the First 24 Postoperative Hours
All rescue opioid analgesics administered during the first 24 postoperative hours will be recorded and converted to intravenous morphine-equivalent dose for comparison between groups.
Time frame: From arrival in the post-anesthesia care unit through 24 hours after surgery
Time to First Rescue Analgesic
Time from completion of the study block to the first administration of rescue analgesic medication for postoperative pain.
Time frame: From block completion through 24 hours after surgery
Resting Numeric Rating Scale Pain Scores
Resting pain intensity will be assessed using an 11-point Numeric Rating Scale from 0 (no pain) to 10 (worst imaginable pain).
Time frame: On arrival in the post-anesthesia care unit and at 4, 8, 12, and 24 hours after surgery
Numeric Rating Scale Pain Scores With Movement
Pain intensity during standardized shoulder-related movement will be assessed using an 11-point Numeric Rating Scale from 0 (no pain) to 10 (worst imaginable pain), when clinically feasible.
Time frame: On arrival in the post-anesthesia care unit and at 4, 8, 12, and 24 hours after surgery
Anterior Shoulder Numeric Rating Scale Pain Score
Pain localized predominantly to the anterior shoulder will be rated separately using an 11-point Numeric Rating Scale ranging from 0 to 10.
Time frame: At 8, 12, and 24 hours after surgery
Posterior Shoulder Numeric Rating Scale Pain Score
Pain localized predominantly to the posterior shoulder will be rated separately using an 11-point Numeric Rating Scale ranging from 0 to 10.
Time frame: At 8, 12, and 24 hours after surgery
Proportion of Participants With Hemidiaphragmatic Paresis
Diaphragmatic excursion will be assessed using M-mode ultrasonography. Hemidiaphragmatic paresis will be defined as diaphragmatic excursion 30 minutes after block completion falling to less than 25% of the participant's baseline excursion.
Time frame: 30 minutes after block completion
Change in Diaphragmatic Excursion From Baseline
Diaphragmatic excursion will be measured using M-mode ultrasonography as the difference in diaphragm position between resting expiration and deep inspiration. Three measurements will be obtained and averaged. Change from baseline will be evaluated after the block.
Time frame: Baseline and 30 minutes after block completion
Shoulder Abduction Motor Strength
Shoulder abduction strength will be evaluated using the Medical Research Council (MRC) scale ranging from 0 to 5, with higher scores indicating greater muscle strength.
Time frame: Baseline, 30 minutes after block completion, and 24 hours after surgery
Proportion of Participants With Rebound Pain
Rebound pain will be defined as an increase from an NRS pain score of 3 or lower at the preceding assessment to an NRS score of 7 or higher at the subsequent assessment.
Time frame: During the first 24 postoperative hours
Quality of Recovery-15 Score
Postoperative quality of recovery will be assessed using the 15-item Quality of Recovery questionnaire (QoR-15). The total score ranges from 0 to 150, with higher scores indicating better quality of recovery.
Time frame: 24 hours after surgery
Patient Satisfaction With Perioperative Analgesia
Overall satisfaction with perioperative analgesia will be rated on an 11-point scale from 0 (completely dissatisfied) to 10 (completely satisfied).
Time frame: 24 hours after surgery
Number of Participants With Block-Related Complications
Participants will be assessed for block-related adverse events including hematoma, infection, persistent paresthesia, persistent weakness, and other clinically suspected complications.
Time frame: From block performance through postoperative day 7
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