Early postoperative pain after arthroscopic shoulder surgery is a major problem for patients and orthopedic surgeons. Adequate pain control is vital for all aspects of patient recovery; including mental state, nutrition, cost of care period, rehabilitation, patient satisfaction, and overall post-surgery outcomes. (1) Single analgesic regimens are not always effective in controlling moderate to severe postoperative pain. Therefore, multimodal pain management is preferred and is currently recommended for early postoperative pain control.(2) Regional techniques form an integral part of multimodal analgesia of most of the enhanced recovery protocols and aid in minimizing the requirements of opioids to control acute postoperative pain which results in better, faster recovery and better satisfaction. Also, it is well known that sufficient management of acute pain is essential to prevent its transition to chronic pain.(3) The use of ultrasound guidance and its incorporation into the practice of regional anesthesia has dramatically improved the safety and success of perioperative care.(4) Ultrasound guided regional anesthesia is preferred in shoulder surgery as an effective way to provide anesthesia and postoperative analgesia. To ensure adequate postoperative pain control, nerve supply to the synovium, capsule, joint surfaces, ligaments, periosteum and shoulder muscles must be blocked.

Interscalene brachial plexus (ISB) block is considered the analgesic technique of choice for shoulder surgery. However, the hemi-diaphragmatic paresis that may occur after the block has led to the search for an alternative to the ISB block. (5) Pericapsular nerve group block (PENG) is a new block that provides a pericapsular distribution with local anesthetic infiltration around the glenohumeral joint and provides analgesia by reaching the sensory nerve branches of the glenohumeral joint. The block of this area did not cause motor block or pulmonary complications, nor result in muscle laxity, blocking only the shoulder and the upper third of the humerus. It was demonstrated that the PENG block may be safely applied for both partial anesthesia and analgesia.(6)

Inclusion Criteria:

• ASA physical status class I - II
• patient who will be scheduled for an elective unilateral arthroscopic shoulder surgery

Exclusion Criteria:

• Patients with respiratory disease, renal or hepatic insufficiency,
• infection of the skin in the puncture area,
• coagulopathy,
• allergy against any of the drugs to be used (bupivacaine),
• neuromuscular disease,
• obesity (body mass index, BMI >30),
• previous analgesic medication, chronic pain, and previously known neurological pathologies or central nervous system disorders