Postoperative Opioid Use and Pain Scores in Patients Undergoing Transforaminal Lumbar Interbody Fusion

The purpose of this project is to study the effects of preoperative followed by scheduled
intravenous acetaminophen on pain control for 24 hours postoperatively after minimally
invasive 1 or 2 level transforaminal lumbar interbody fusion. The advantages of intravenous
acetaminophen are well known in the literature and its opioid-sparing effects have been
documented in multiple surgical studies.

Multimodal regimens are now being advocated in the literature to decrease opioid use (8, 23).
This is especially significant in spine surgery patients who often have chronic pain
requiring long-term use of these habit-forming drugs as well as in patients who may not be
able to tolerate opiods due to health status.

To our knowledge there are no studies done in the U.S. on the opioid sparing and pain
reducing effects of intravenous acetaminophen on patients undergoing elective minimally
invasive 1 or 2 level transforaminal lumbar interbody fusion. Investigating intravenous
acetaminophen, particularly its pain reducing and opioid sparing effects, may give surgeons
another medication for use in a multimodal approach to pain.

Inclusion Criteria:

- Age > 18 years old

- Being scheduled to have elective primary minimally invasive 1 or 2 level
transforaminal lumbar laminectomy interbody fusion

- ASA I, II, or III

- Informed consent form signed

Exclusion Criteria:

- Anyone weighing less than 50kg (as this would require a dosing change).

- Hypersensitivity or contraindication to intravenous acetaminophen or opioids

- Allergy to Methocarbamol; morphine sulfate, sevoflourane, or fentanyl

- Impairment of liver function-- defined as the inability to receive intravenous
acetaminophen without dose adjustment as determined by the investigator; or history of
chronic liver disease defined as history of hepatitis of any kind as recorded in the
patient's chart

- Mental retardation recorded as a diagnosis in the patient's chart

- History of chronic pain (defined as currently receiving treatment from a specialist
for pain)

- History of pain recalcitrant to intravenous morphine

- Impaired kidney function (defined as creatinine > 1.5)

- Anyone who is not a candidate for general anesthesia or any other portion of the
investigator's standard of