Participants who have a surgical procedure called Posterior Cervical (neck) Spine Surgery will normally need pain medication to relieve post operative pain. This usually includes opioid medications. In this study, the consented participant may receive a nerve block procedure, in addition to the pain relieving medication. There is a fifty-fifty chance to receive the nerve block. The goal is to see if the nerve block group needs less opioid medication, has lower pain scores and is discharged from the hospital sooner.

The purpose of this research study is to evaluate the opioid-sparing effect of the use of an Inter-semispinalis plane (ISP) block after posterior cervical spine surgery.

Posterior cervical fusion (PCF) is a painful procedure that often requires the use of high doses of opioids to minimize postoperative pain. Uncontrolled pain can result in a delay in recovery and discharge. Additionally, high doses of opioids carry the risk of opioid dependence, and other side effects, include nausea, vomiting, sedation, and, in rare cases, respiratory depression. For all of the above reasons, reducing the use of opioids is of utmost importance.

Nerve blocks are one alternative to opioid use. The ISP block is a procedure described in 2017; it is a relatively simple procedure that entails injecting local anesthetic between two muscles in the back of the neck, bilaterally, to block the nerves that run in this plane. It is done under ultrasound guidance and, although a limited number of studies have shown promise, more data on its safety and efficacy are needed. The addition of Dexamethasone to local anesthetics, in nerve blocks, resulted in significant prolongation of the analgesia.

Inclusion Criteria:

• Having Posterior Cervical Spine Surgery from C2 - C7, which may extend to the upper thoracic vertebrae, inclusive to T3.
• Capacity to provide informed consent

Exclusion Criteria:

• Fusion and decompression due to trauma
• Emergent procedures
• Patient is on a medication-assisted treatment, e.g., buprenorphine, naltrexone or methadone.
• There is an infection near or in the area of neck where the block will be placed.
• The patient is having a complicated surgery or a revision surgery
• Female patient with a positive pregnancy test on the day of surgery (hospital standard-of-care).
• Patient has Diabetes
• Patients who have had a prior adverse reaction to bupivacaine or dexamethasone
• Patients with Glucose-6-phosphate dehydrogenase deficiency or congenital or idiopathic methemoglobinemia

Participants will be randomized using REDCap software. If the participant is randomized to the ISP Block group, it will be completed after the participant has been administered General Anesthesia and prior to surgery start.