Diaphragmatic Effects of Combined Infraclavicular Brachial Plexus Block and Suprascapular Nerve Block

This prospective observational study was conducted to evaluate the effects of combined infraclavicular brachial plexus block and anterior suprascapular nerve block on diaphragmatic excursion in patients undergoing elective arthroscopic shoulder surgery.

Patients scheduled for arthroscopic shoulder surgery under regional anesthesia were enrolled in the study. Prior to block administration, baseline diaphragmatic excursion was assessed using ultrasonography during both normal and deep breathing. Each measurement was repeated three times, and the mean value was recorded. The same measurements were repeated 30 minutes after completion of the block procedures using an identical protocol.

The percentage change in diaphragmatic excursion between baseline and post-block measurements was calculated for both normal and deep breathing. Hemidiaphragmatic paralysis was categorized according to the degree of reduction in diaphragmatic excursion as absent (≤25% reduction), partial (25.1-74.9% reduction), or complete (≥75% reduction).

All nerve blocks were performed under ultrasound guidance by anesthesiologists experienced in regional anesthesia techniques. The infraclavicular brachial plexus block was performed using 15 mL of 0.5% bupivacaine deposited around the posterior cord and 8 mL of 0.5% bupivacaine around the lateral cord. The anterior suprascapular nerve block was performed with 7 mL of 0.5% bupivacaine. In addition, arthroscopic portal sites were infiltrated with 10 mL of 0.2% bupivacaine to provide supplementary analgesia.

All patients received intravenous midazolam (2 mg) and paracetamol (1 g) during the intraoperative period. Additional analgesic or sedative medication was administered when required according to clinical conditions and surgical needs. Block performance time, requirement for supplemental analgesia or sedation, and any block-related adverse events were recorded.

The primary outcome measure was the change in diaphragmatic excursion measured by ultrasonography 30 minutes after block administration. Secondary outcome measures included the incidence and severity of hemidiaphragmatic paralysis, block performance time, duration of postoperative analgesia, need for additional intraoperative analgesia or sedation, time to first analgesic requirement, patient and surgeon satisfaction, block-related complications, and conversion to general anesthesia.

The study was designed to investigate whether the combination of infraclavicular brachial plexus block and anterior suprascapular nerve block could provide effective anesthesia and analgesia for arthroscopic shoulder surgery while minimizing impairment of diaphragmatic function and reducing the incidence of clinically significant hemidiaphragmatic paralysis.

Inclusion criteria

• Patients aged 18-80 years.
• ASA physical status I-III.
• Scheduled for elective arthroscopic shoulder surgery.
• Ability to provide written informed consent

Exclusion criteria

• Refusal to undergo peripheral nerve block.
• Pre-existing peripheral neuropathy.
• Known pulmonary, hepatic, or renal disease.
• Allergy to local anesthetics.
• Infection at the block site.
• Pre-existing neurological deficit.
• Body mass index (BMI) > 40 kg/m².
• Coagulopathy.
• Sepsis.
• Previous surgery at the planned block site.

• Major psychiatric disorders.
• Inability to complete diaphragmatic ultrasonographic assessment.