The aim of the study is to evaluate the effect of erector spina plane (ESP) block on pulmonary functions and postoperative analgesic consumption in patients undergoing bariatric surgery.

Optimal pain management is very important in obese patients. In the postoperative period, narcotic analgesics are often used to pain management. However, the use of narcotic analgesics in the postoperative period causes many undesirable adverse effects, especially sedation, dizziness, constipation, nausea, vomiting, muscle rigidity, tolerance, and respiratory depression.

The morbidly obese patients treated with narcotic analgesics increased risk for adverse effects such as atelectasis, hypoxemia, and postoperative ileus. Consequently, these are caused postoperative pulmonary complications, hypoxemia and longer lenght of hospital stay. Multimodal analgesia including local and regional anesthesia is recommended for morbidly obese patients.

In recent years, the ultrasound (USG) guided ESP block has been frequently used to eliminate postoperative pain and reduce narcotic analgesic use. In the literature, it has been shown that bilateral USG guided ESP block provides effective analgesia and decrease the analgesia requirements after laparoscopic cholecystectomy. Some case series and case reports has also been reported that ESP block provides effective analgesia after abdominal and bariatric surgeries.

The aim of the study is to evaluate the effect of erector spina plane (ESP) block on pulmonary functions and postoperative analgesic consumption in patients undergoing bariatric surgery. For this purpose, ASA II-III, patients over 18 years of age, BMI 40-60 kg/m2 and elective bariatric surgery planned patients will be included in the study.

Inclusion Criteria:

• American Society of Anesthesiology (ASA) II-III
• 18-65 years
• body mass index (BMI) 40-60 kg/m2
• elective bariatric surgery

Exclusion Criteria:

• ASA ≥4
• under 18 years of age or over 65 years of age
• declining to give written informed consent
• have neurological and/or psychiatric disorders
• cooperation cannot be established
• accompanying laparoscopic cholecystectomy or paraumbilical hernia repair
• history of bariatric surgery
• the block cannot be applied due to bleeding disorders or localized skin infection at the injection site
• with hepatic, neuromuscular, cardiac and/or renal failure
• history of allergy to the local anesthetics
• patients undergoing open surgery
• patients with severe obstructive or restrictive lung disease