Use of erector spina plane (ESP) block for postoperative analgesia is continuously increasing. However, few studies have investigated intraoperative effects of ESP block. The investigators aim to study the effects of ESP block in terms of cost-effectiveness, consumption of inhalation agents and opioids in perioperative and postoperative period.

Erector spina plane (ESP) block has analgesic efficiency and its popularity is growing steadily. ESP block forms a sensorial block by local anesthetic infiltration between the musculus erector spina and facia. ESP block given to participants undergoing laparoscopic cholecystectomy for postoperative opioid analgesia resulted in a decrease of postoperative pain scores in the first 24 h. Due to increases in health expenditure, cost control is becoming more and more important. Cost-effective studies are important in healthcare economics. Inhaled anesthetics used in anesthesia departments account for about 20% of total anesthetic agents. Local anesthetic agents decrease the minimum alveolar concentration (MAC) value of inhaled agents. And also in perioperative and post operative period, the anesthetic management often need to be supported with opioid drugs. The investigators think that ESP block has analgesic effects and decreases the consumption of inhalation agents. The investigators aim to investigate the cost-effectiveness of ESP block in anesthetic applications in laparoscopic procedures.

Inclusion Criteria:

1. American Society of Anesthesiologist (ASA) physical status I-II,
2. ages 18-75 years,
3. undergoing laparoscopic cholecystectomy

Exclusion Criteria:

1. Patients with cardiac, endocrinological, neurological diseases,
2. patients with coagulation disorders
3. allergy to local anesthetics
4. Operations that started as laparoscopy but transitioned to open surgery for a surgical reason