Spinal fusion is a painful surgery, and control of postoperative pain is difficult. Several studies have indicated that appropriate pain treatment protocols reduce postoperative morbidity, improve the results of the surgery, and decrease hospital costs

Forty four patients were randomly allocated into two groups of equal size to receive either lidocaine infusion (Lidocaine group) or 0.9% sodium chloride infusion (Control group).

Randomization: was performed using Lidocaine group and Control group registers, which was placed in sealed envelopes prior to study initiation and opened prior to anesthesia by a physician who prepared the intravenous solution and identified it with the patient number, according to the envelope drawn. The solution was handed to another physician, blind to the prepared solutions' content, who was responsible for the anesthesia. The solution volume was equal. The responsible investigator was remained blind to the chosen group until the end of the study.

Inclusion Criteria:

Age > 18 years American Society of Anesthesiologists 1-3 status Patients undergoing spinal fusion or fixation

Exclusion Criteria:

1. Previous spinal fusion surgery.
2. Morbid obesity (BMI > 40)
3. Diagnosis of spinal metastatic cancer
4. Allergy to an amide local anesthetic or morphine sulfate
5. History of renal dysfunction, liver dysfunction or congestive heart failure
6. History of substance abuse disorder.
7. Chronic opioid use.

Double Blind