This study consisted of a randomized controlled trial designed to evaluate a Multimodal Analgesia (MMA) Protocol on patients undergoing Posterior Spinal Fusion. The purpose is to describe the narcotic requirements and usage during the perioperative period of posterior spinal fusion and instrumentation surgery with the implementation of multimodal anesthesia protocol. The study will consist of two parallel arms, with Group 1 receiving our MMA protocol and Group 2 receiving a traditional opioid-based regime. The primary outcome of this study will be the reported Visual Analog Scale (VAS) for pain at 12, 24, and 48 hours after surgery. We considered that our findings could contribute to the fight against the opioid crisis proving alternatives to opioids as feasible alternatives for pain management even in significant surgery, as is posterior spinal fusion with instrumentation.

After seeking Institutional Review Board (IRB) approval, a randomized clinical trial study will be conducted with a diagnosis of Lumbar stenosis between levels of L1-S1 who underwent operative posterior spinal fusion and instrumentation (PSF) and were admitted to Hospital Universitario de Adultos, San Juan, PR. A sample size of n=50 is considered for each study arm. Three surgeons with Spine orthopedic surgery fellowship will perform all the surgical procedures. Inclusion criteria for eligible patients are lumbar stenosis with levels between L1-S1, no prior surgical treatment of spinal deformity, 30 - 85-years of age, and atraumatic pathology. The patients were considered participants after providing written informed consent. Patients were excluded if they were younger than 30 years old or older than 85 years and had a prior history of chronic opioid abuse, corrective surgery, or traumatic pathology. Patients were divided into two randomly selected groups. A random numerator generator has chosen patients' analgesic protocol, creating two groups in an aleatory manner. Group 1 received a Multimodal Analgesia (MMA) Protocol. Group 2 experienced a traditional analgesia protocol (Narcotics/Opioids). As part of the preoperative care for all patients undergoing PSF, lab work includes complete blood count, complete metabolic panel, and coagulation panel. In addition, all patients were assessed by internal medicine for clearance before surgery. Group 1 received multimodal analgesia, including Toradol 60mg IV, Acetaminophen 1,000mg PO, Orphenadrine 100mg PO, and Gabapentin 800 mg PO prior to surgery. Group 2 will not be given oral analgesia preoperatively. As part of the intraoperative care, group 1 was given: Bupivacaine 30cc, Epinephrine 1c,c, and MPF Intramuscular Inj 0.5% (30cc of Saline Solution) in paraspinal and adjacent areas before surgical incision at the time of timeout. Both study arms received routine postoperative care and were followed daily while admitted to the hospital. Patients in group 1 were treated with a postoperative pain management protocol including Gabapentin 300mg PO Q6hrs, Toradol 30mg IV Q6hrs, Methylprednisolone 125mg Q8hrs, and orphenadrine 100mg PO twice daily. Group 2 received a traditional opioid-based pain management approach with Morphine 4mg Q4hrs. Patients were asked for daily pain levels using 1-10, and IV morphine use as needed will be measured daily. Data Collection will occur intra-hospital during the perioperative period. The study variables retrieved included sociodemographic Information, surgery Duration, surgical approach, levels of instrumentation, type of instrumentation, Surgery blood loss, Complications, Discharge Time, Length of Stay, Comorbidities, and Visual Analog Scale (VAS) for pain score preoperative and postoperative at 12, 24, and 48 hours.

Inclusion Criteria:

• lumbar stenosis affecting L1-S1
• Requiring Posterior Spinal Fusion Surgery
• Age 30-85 years

Exclusion Criteria:

• younger than 30 years old or older than 85 years
• Chronic Renal Disease
• Hypersensitivity to any medication
• history of chronic opioid abuse.

There is no plan to make individual participant data (IPD) available to other researchers. However, data could be shared upon individual researchers' reasonable request.