Spine surgery is typically associated with severe postoperative pain. Although the number of spine surgeries has increased day by day, postoperative pain management have been limited. The recently described erector spinae plane block (ESPB) is obtained by applying the local anesthetic drug between the fascia of the erector spinae muscles and the transverse process of the vertebrae. Anatomical and radiological investigations in fresh cadavers suggest that the potential place of influence of ESPB is dorsal and ventral spinal nerve roots. A small number of publications showing the analgesic efficacy of ESP in spinal surgery have been reported in the literature. The erector spinae muscles are easily identified during spine surgery, and erector spinae plane blocks can be performed under direct vision rather than via ultrasound guidance or simply using anatomical landmarks. Therefore, the investigators aim to observe the efficacy of the under direct vision erector spinae plane block on pain scores after spinal surgery.

Approval from the university local ethics committee will be obtained. Participans will be informed about the potential benefits and complications after the study protocol has been fully and thoroughly explained. After premedication with 0.03 mg / kg iv midazolam, participans will be noninvasively monitored by taking into the operating room (heart rate, blood pressure, pulse oximetry). Anesthesia induction will delivered with fentanyl 1mcg / kg, propofol 2 mg / kg and rocuronium 0.6 mg / kg. The maintenance of anesthesia will be achieved by infusion of sevoflurane 2-3% in 50% O2/50% medical air and remifentanil infusion of 0.1-0.5 mcg / kg / min. Thirty minutes before end of the surgery, all patients were intravenously administered 1 mg/kg tramadol HCl and 1gr paracetamol.

Under direct vision ESPB technique: Erector spinae muscles and transverse processes will be identified by the surgeon. At the end of the surgery 20 ml bupivacaine 0.25%/lidocaine 1% mixture will be injected to the between of the erector spinae muscles and transverse processes bilaterally. In the sham comparator group, 20 ml of isotonic saline will be administered bilaterally by the surgeon as described above.

After the surgery, 1 g paracetamol was intravenously administered once every 8 h. A patient-controlled analgesia (PCA) device, which was prepared using morphine, was attached to the patients and was programmed to administer concentration 0.5mg / ml ( 2cc bolus 8 min lock time 2cc/h infusion). This administration continued for 24 h. Postoperative pain was assessed using visuel analog scale (VAS) (VAS 0 = no pain, VAS 10 = most severe pain ). Duration at postanesthesia care unit (PACU) was recorded right from 0 h. VAS scores at 0, 1, 6, 12 and 24 h were recorded. Postoperative nausea and vomiting (PONV) was evaluated using a numeric ranking scale (0 = no PONV, 1 = mild nausea, 2 = severe nausea or vomiting once attack, and 3 = vomiting more than once attack). If PONV score was >2, the antiemetic metoclopramide Hcl 10mg was intravenously administered.

Inclusion Criteria:

1. 20-75 years
2. ASA 1-2-3
3. Patients scheduled for elective surgery

Exclusion Criteria:

1. Patients with previous neurological disease symptoms (TIA, syncope, dementia, etc.)
2. Allergy to drugs
3. Major cardiac disease
4. Renal failure
5. Psychiatric disease
6. Patients who refuse to participate in the study
7. Chronic back and lower back pain
8. Body mass index <18.5 and >40