Primarily, This study aims to compare between interscalene block alone versus combined with superior truncus block in producing diaphragmatic paralysis and Secondarily aims to evaluate 1. Effect on the pulmonary function. 2. Duration of the sensory and motor block. 3. Postoperative analgesic consumption. 4. Any complications or side effects during shoulder surgery.
Regional anesthesia is central to modern shoulder surgery because it provides excellent perioperative analgesia, reduces opioid consumption, and facilitates early rehabilitation. The interscalene brachial plexus block (ISB) has long been considered the gold-standard single-shot regional technique for shoulder procedures due to its reliable analgesia and surgical anesthesia. However, ISB commonly causes ipsilateral hemidiaphragmatic paresis (HDP) from unintended phrenic nerve blockade, which can produce clinically important declines in pulmonary function and may be poorly tolerated in patients with limited respiratory reserve. To minimize phrenic involvement while preserving analgesic effectiveness, more selective approaches have been proposed. The superior trunk block (STB) - performed at the level where C5-C6 fibers form the superior trunk - aims to anesthetize the shoulder innervation more distally and thus reduce spread to the phrenic nerve. A landmark randomized trial and subsequent studies reported that STB provides analgesia comparable to ISB while greatly lowering the incidence of HDP (for example, ISB 71% vs STB 5% in one trial). Systematic reviews and meta-analyses since then have reinforced STB as an effective phrenic-sparing alternative for many shoulder procedures. Despite encouraging data for STB, the literature is not entirely uniform. Some randomized trials and observational reports have found either reduced anesthetic quality with STB or smaller-than-expected reductions in phrenic involvement, particularly when block technique, local anesthetic volume, or patient anatomy differ. Moreover, combining blocks (for example, ISB with selective superior-trunk targeting or other modifications) has been proposed as a strategy to balance surgical anesthesia and respiratory safety, but comparative prospective data examining the effect of ISB alone versus ISB combined with STB on diaphragmatic function are limited. This uncertainty is important because even partial diaphragmatic paresis can degrade postoperative pulmonary mechanics and increase complications in vulnerable patients.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
DIAGNOSTIC
Masking
TRIPLE
Enrollment
60
Comparison of the interscalene block alone versus combined with superior truncus block during shoulder surgery in diaphragmatic function
Comparison between interscalene block alone versus combined with superior truncus block inproducing diaphragmatic paralysis
Assessment of diaphragmatic function by diaphragm excursion (DE) and diaphragm thickening fraction (TF) will be measured both before and 30 minutes post-block. To measure DE, patients will be placed in a supine position, a convex transducer (3.5 \~ 5 MHz) will be used to scan while the right diaphragm through the hepatic window and the left diaphragm through the splenic window, which located near the anterior-axillary line. The craniocaudal movement of the diaphragm will be documented during deep inspiration using M-mode. * Complete diaphragmatic paralysis was defined as a 75% \~ 100% reduction in DE, including the occurrence of paradoxical movement. * Partial diaphragmatic paralysis was defined as a 25% \~ 75% reduction in DE. * No diaphragmatic paralysis was indicated by a DE reduction of less than 25%. To measure TF, patients will be placed in the same position with the head of the bed at 45°degree
Time frame: Assessment of diaphragmatic function by diaphragm excursion (DE) and diaphragm thickening fraction (TF) will be measured both before and 30 minutes post-block.
Evaluation of the interscalene block alone versus combined with superior truncus block during shoulder surgery on the pulmonary function
Assessment of pulmonary function by a handheld spirometer to measure forced vital capacity (FVC), forced expiratory volume ( FEV1, FEV2) with patients in an upright-seated position pre-block and 30 minutes post-block as well as 2-hours post-surgery. Spirometry will be performed three times, with the best effort recorded.
Time frame: Assessment of pulmonary function by a handheld spirometer to measure forced vital capacity (FVC), forced expiratory volume ( FEV1, FEV2) with patients in an upright-seated position pre-block and 30 minutes post-block as well as 2-hours post-surgery
Duration of the sensory and motor block onset, duration of the interscalene block alone versus combined with superior truncus block during shoulder surgery
Sensory block onset time will be assessed at the time from local anesthetics injection by pinprick test which will be preformed with 22-gauge short beveled needle every minute. Sensory block recovery time will be noted every hour in 1st 6 hours, every 2 hours in 2nd 6 hours till recovery of all pain sensation in all dermatomes performed by pinprick test. Motor block onset time will be assessed at the time from local anesthetics injection until complete motor block which will be assessed by absence of voluntary movement on asking the patient to elevate his arm every minute. Motor block recovery time will be noted as the time of return of voluntary movement in the arm every hour in 1st 6 hours, every 2 hours in 2nd 6 hours.
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Time frame: Sensory, motor block onset time every minute. Sensory, Motor block duration every hour in 1st 6 hours , every 2 hours in 2nd 6 hours
Evaluation of postoperative analgesic consumption
Pain will be evaluated Postoperative immediately every hour in 1st 6 hours, every 2 hours in 2nd 6 hours by Visual Analogue Scale ( VAS) by instructing the patient to point to the position on the line to indicate how much pain they are currently feeling(10). * VAS (zero) indicates no pain. * VAS ( 1, 2, 3) indicates mild pain. * VAS ( 4, 5, 6) indicates moderate pain. * VAS ( 7, 8, 9, 10) : indicates severe pain.
Time frame: 12 hours
Evaluation of any complications or side effects during shoulder surgery
Any local or systemic complications or side effects will be recorded every 2 hours post operative for 24 hours such as local anesthetic systemic toxicity (LAST), Horner's syndrome, hypoxia, dyspnea, pneumothorax and post-operative nausea and vomiting (PONV).
Time frame: 24 hours