Severe pain after arthroscopic surgery is a common experience for the patients . Different regional anesthetic technique has been applicated for postoperative pain relief . The main goal of regional anesthesia regarding postoperative pain relief is to reduce opioid requirements. The most commonly used approach is Interscalene brachial plexus block (ISB), since it provides effective postoperative analgesia upto 12 hours. Erector spinae plane block (ESPB) has been reported for a variety of indications such as thoracic and abdominal surgery. Recently, a novel description of a T2-3 erector spinae plane (ESP) as an alternative to a BP block for an upper extremity surgical procedure. Following these studies, direct cervical ESP block has been recently performed successfully as both clinical and cadaveric study. The investigators hypothesized that cervical ESP block is as effective as (non-inferior) interscalene brachial plexus block in terms of postoperative analgesia of shoulder surgery. To evaluate the effectiveness of the cervical ESP block, the investigators have designed a randomized study. Primary aim is to evaluate the postoperative opioid consumption. Secondary aim is to evaluate postoperative pain scores by Numeric Rating Scale (0 to 10 point scale).

This study has been designed as a prospective, randomized and single-blind trial. Local ethics committee of Ataturk University has approved the study (B.30.2.ATA.0.01.00/142). After obtaining the patients' written informed consents, we will include a total number of 94 patients (47 patients for each group). The inclusion criteria of the study was considered as age between 18-80, American Society of Anesthesiologists (ASA) status I-III, eligible for regional anesthesia, and unilateral shoulder surgery. The patients who have clotting disorder, contra-indication for regional anesthesia, infection on the injection site, chronic opioid usage, previous same side shoulder surgery, severe Chronic obstructive pulmonary disease (COPD) , diaphragmatic paralysis, BMI 35 or over will be excluded. A computer-generated randomization program will be used to allocate the patient into two groups. Interscalene brachial plexus block group will be named as Group ISB (n=47) and cervical ESP block group will be named as Group cESP (n=47). The assessor of the outcomes will be blinded to the study groups of the patients. Both ISB block and cervical ESP block will be performed under ultrasound guidance in the block room preoperatively.

Inclusion Criteria:

1. Age between 18-80
2. ASA I-III
3. Eligible for regional anesthesia
4. Unilateral shoulder surgery

Exclusion Criteria:

1. The patients who have clotting disorder
2. Contra-endication for regional anesthesia
3. Infection on the injection site
4. Chronic opioid usage
5. Previous same side shoulder surgery
6. Severe COPD
7. Diaphragmatic paralysis
8. BMI 35 or over

Undecided