This study will compare two regional anesthesia techniques for shoulder surgery and evaluate their effects on diaphragmatic function. The standard regional anesthesia technique for shoulder surgery is the interscalene brachial plexus block (ISB), which provides effective analgesia but is frequently associated with ipsilateral hemidiaphragmatic paresis due to phrenic nerve involvement. An alternative diaphragm-sparing strategy is the combination of a suprascapular nerve block (SSNB) and an infraclavicular brachial plexus block (ICB), which may reduce the risk of diaphragmatic dysfunction while maintaining effective analgesia for shoulder surgery. All participants will receive ultrasound-guided regional anesthesia prior to surgery and will be randomly assigned to one of two groups: Group 1: Interscalene brachial plexus block Group 2: Suprascapular nerve block combined with infraclavicular brachial plexus block The primary aim of this study is to determine whether the diaphragm-sparing technique reduces the incidence of hemidiaphragmatic paresis while providing analgesia comparable to the standard interscalene block. Diaphragmatic movement will be assessed using ultrasound before and after block placement. Secondary outcomes include postoperative pain intensity, opioid consumption, pulmonary function parameters, and block-related complications.
The interscalene brachial plexus block (ISB) is widely used for anesthesia and postoperative analgesia in shoulder surgery because of its reliable and effective pain control. However, ISB is commonly associated with ipsilateral hemidiaphragmatic paresis due to unintended phrenic nerve blockade, which may impair respiratory function, particularly in older patients and in those with pre-existing pulmonary disease. The combination of a suprascapular nerve block (SSNB) and an infraclavicular brachial plexus block (ICB) has been proposed as a diaphragm-sparing alternative for shoulder surgery. This approach may provide adequate surgical anesthesia and postoperative analgesia while minimizing the risk of diaphragmatic dysfunction. This randomized controlled trial will compare the interscalene brachial plexus block with the combined suprascapular and infraclavicular brachial plexus block in patients undergoing elective shoulder surgery. Diaphragmatic function will be evaluated using ultrasound imaging before block performance and after block placement. Additional outcomes will include postoperative pain intensity at rest and during movement, opioid consumption, pulmonary function parameters, block-related complications, length of hospital stay, and patient satisfaction.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
70
Participants in this arm will receive an ultrasound-guided interscalene brachial plexus block using 20 mL of 0.2% ropivacaine. The block will be performed as a single-shot injection prior to shoulder surgery. No suprascapular or infraclavicular block will be performed in this group
Participants in this arm will receive two ultrasound-guided peripheral nerve blocks as part of the diaphragm-sparing strategy: Infraclavicular brachial plexus block: 15 mL of 0.2% ropivacaine Suprascapular nerve block: 5 mL of 0.2% ropivacaine Both injections will be performed as single-shot blocks prior to surgery. No interscalene block will be performed in this arm
Poznan University of Medical Sciences
Poznan, Poland
Incidence of Hemidiaphragmatic Paresis
Incidence of hemidiaphragmatic paresis, defined as a \>75% reduction in diaphragmatic excursion or paradoxical movement on ultrasound M-mode compared with baseline.
Time frame: before block and 30-60 minutes after block.
Pain Scores at Rest (NRS 0-10)
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Pain scores will be recorded at 2, 6, 12, 24, and 48 hours after surgery and analyzed as repeated measures over time.
Time frame: 2 hours postoperatively
Pain Scores at Rest (NRS 0-10)
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Pain scores will be recorded at 2, 6, 12, 24, and 48 hours after surgery and analyzed as repeated measures over time.
Time frame: 6 hours postoperatively
Pain Scores at Rest (NRS 0-10)
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Pain scores will be recorded at 2, 6, 12, 24, and 48 hours after surgery and analyzed as repeated measures over time.
Time frame: 12 hours postoperatively
Pain Scores at Rest (NRS 0-10)
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Pain scores will be recorded at 2, 6, 12, 24, and 48 hours after surgery and analyzed as repeated measures over time.
Time frame: 24 hours postoperatively
Pain Scores at Rest (NRS 0-10)
Pain intensity at rest measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Pain scores will be recorded at 2, 6, 12, 24, and 48 hours after surgery and analyzed as repeated measures over time.
Time frame: 48 hours postoperatively
Pain Scores During Movement (NRS 0-10)
Pain intensity during passive or assisted shoulder movement measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Mean values at each time point will be compared between groups.
Time frame: 2 hours postoperatively
Pain Scores During Movement (NRS 0-10)
Pain intensity during passive or assisted shoulder movement measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Mean values at each time point will be compared between groups.
Time frame: 6 hours postoperatively
Pain Scores During Movement (NRS 0-10)
Pain intensity during passive or assisted shoulder movement measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Mean values at each time point will be compared between groups.
Time frame: 12 hours postoperatively
Pain Scores During Movement (NRS 0-10)
Pain intensity during passive or assisted shoulder movement measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Mean values at each time point will be compared between groups.
Time frame: 24 hours postoperatively
Pain Scores During Movement (NRS 0-10)
Pain intensity during passive or assisted shoulder movement measured using the 0-10 Numerical Rating Scale (0 = no pain, 10 = worst imaginable pain). Mean values at each time point will be compared between groups.
Time frame: 48 hours postoperatively
Total Opioid Consumption
Cumulative dose of opioid analgesics administered during the postoperative period, converted to oral morphine milligram equivalents (MME), will be recorded and compared between groups.
Time frame: Within 24 hours after surgery.
Block-Related Adverse Events
Incidence of complications related to the regional anesthesia technique, including local anesthetic systemic toxicity (LAST), prolonged sensory or motor deficit, hematoma, infection at the injection site, or nerve injury. Neurological assessment may be performed in the outpatient clinic if required.
Time frame: From block placement until 30 days after surgery.
Oxygen Saturation (SpO₂)
The lowest recorded peripheral oxygen saturation (SpO₂, %) during the first 24 hours after surgery will be compared between groups.
Time frame: From block performance until 24 hours after surgery.
Respiratory rate (breaths per minute).
The highest recorded respiratory rate during the first 24 hours after surgery will be compared between groups.
Time frame: From block performance until 24 hours after surgery.
Incidence of oxygen desaturation (SpO₂ < 92%)
Oxygen desaturation will be defined as the occurrence of at least one episode of peripheral oxygen saturation (SpO₂) \< 92%, measured by pulse oximetry, during the first 24 hours after surgery. The outcome will be analyzed as a binary variable (presence or absence of oxygen desaturation).
Time frame: From block performance until 24 hours after surgery
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.