Open gastrectomy causes severe postoperative pain due to wide surgical incisions, retraction of the abdominal wall and direct manipulation of the visceral organs. It leads to delayed postoperative recovery, increased medical expenses and poor surgical outcomes. Epidural analgesia, intrathecal morphine and patient-controlled analgesia are frequently used in the postoperative pain management of abdominal surgeries. Intrathecal morphine is applied as a standard protocol in many centers due to its ease of application and effective pain control. However; it has undesirable effects such as postoperative nausea-vomiting, itching and most importantly respiratory depression. Regional interfascial plane blocks, such as erector spina plane block, have recently been popular in clinical practice to provide postoperative pain control. Erector spina plane block, when placed preoperatively, is expected to reduce opioid consumption and improve outcomes. The primary implication of this study is to compare postoperative pain scores and opioid consumption. It is also aimed to compare the effectiveness of Numeric Rating Scale and Clinically Aligned Pain Assessment Tool used in postoperative pain assesment.

Inclusion Criteria:

• Patients over 18 years old
• Patients undergoing open gastrectomy surgery

Exclusion Criteria:

• Patients with solid organ dysfunction
• Patients who receive opioid or corticosteroid medication prior to surgery
• Patients with bleeding diathesis
• Patients with psychiatric disorders
• Patients who can not be contacted after surgery

Patients over 18 years old undergoing open gastrectomy surgery in Marmara University Training and Research Hospital