In this study, the efficacy of melatonin and gabapentin in evaluating the anxiety and postoperative pain in lumbar spine surgery in patients referred to Golestan Hospital General Operative Room. A total of 90 patients were selected randomly in 3 groups of melatonin, gabapentin and placebo. 120 min before induction, melatononin, gabapentine and palacebo groups received 60 mg melatonin, 600 mg gabapentine and 5 ml distilled water, respectively. After transferring patients to surgical room, all will be taken care of under standard monitoring including electrocardiogram, pulse oximetry, non-aggressive blood pressure and heart rate. Meanwhile anxiety level in patients before surgery would be measured with a VAS. After prescription of 10 ml/kg isotonic liquids and preoxygenation for 3 min, all patients with a same procedure, 3 mg/kg midazolam, 2 mg/kg phentanyl, 4 mg/kg STP and 5 mg/kg atracurarium will be anesthesized. After intubation and fixation of tube, the vital symptoms including BP, HR and SpO2 will be measured. Anesthesizing process with 75% oxygen and isoflurane 8%is managed. At the end of the surgery and extubing the patient, the following parameters will be studied.
-Need for remedy 1, 2, 6, 12 and 24 h after surgery
-Pain intensity using VAS 1, 2, 6, 12 and 24 h after surgery
-Satisfaction level of patients of analgesia with a quality score (perfect, good, average and poor) 1, 2, 6, 12 and 24 h after surgery
All data will be recorded by a non-informed third person of the study.