The Effect of Ultrasound-guided Erector Spinae Block on Postoperative in Patients Undergoing Nephrectomy.

Inclusion Criteria: 1. To undergo partial or total nephrectomy surgery 2. To be in ASA I-II classification 3. To be between the ages of 18-65. 4. Not having problems that prevent erector spinae block application such as local anesthetic drug allergy, infection at the injection site, and structural anomaly. 5. Being in good mental and psychological health 6. To accept to participate in the study. Exclusion Criteria: 1. Being in ASA III or IV class with a high risk of anesthesia 2. Being outside the age range of 18-65 3. Having problems such as local anesthetic drug allergy, infection at the injection site, and structural anomaly prevents block application. 4. Not being mentally and psychologically healthy 5. Those who are allergic to the active substance, patients using antiepileptic drugs 6. Those with severe hepatic and renal failure 7. Those who have long-term use of nonsteroidal anti-inflammatory and opioid analgesic, 8. Those with diabetes and other neuropathic diseases 9. Patients who cannot use patient-controlled analgesia (PCA) device