Analgesic Efficacy of Repeated Doses of Intravenous (IV) Acetaminophen in Post-operative Pediatric Spine Fusion Patients

This is a prospective, randomized, double-blinded, placebo controlled trial Potential subjects will be identified from the Pre-Surgical Anesthesia Clinic visit. Parents/legal guardians will be approached about study participation at the Anesthesia outpatient pre-visit. Attending Anesthesiologist will receive e-mail notification about potential subject participation the day before the scheduled surgery. Study lab (hepatic function panel) will be collected as soon as possible after anesthesia induction by anesthesia. Results will be reviewed by study team member and study drug will be ordered by study team if patient does not meet exclusion criteria. Study drug (IV acetaminophen or placebo) will be administered at the time of skin closure by anesthesia on completion of the surgical procedure (after randomization). Study drug will be administered every 6 hours for 2 days. Subjects will continue to receive standard of care with patient controlled analgesia (PCA) opiate therapy (morphine or hydromorphone) for analgesia as per the Pain Management Service. Pain scores, opiate (morphine equivalent) administered, requirements for treatment of opiate related side effects (treatment for nausea and itching), and certain post-operative characteristics will be measured for up to 4 days post-operatively (time to mobilization, time to diet advancement, time to discharge).

An ideal drug as an opiate-sparing analgesic adjunct, acetaminophen, unlike some other drugs, is platelet function sparing, and thus particularly useful in the post-operative orthopedic patient population. In part because of its well established safety profile, as well as minimal drug interactions, acetaminophen is considered a cornerstone of a multimodal analgesic approach. Several studies have described the clinically significant beneficial effects of a multimodal drug approach to analgesia, citing improved pain control and a shorter recovery time. Reduced adverse events and improved pain control with multimodal analgesia drug approaches may result in shorter hospitalizations, improved recovery and function, and reduced health care costs. Opiate therapy, while effective analgesia, is associated with a variety of potential adverse side effects, including pruritus, nausea, emesis, ileus, respiratory depression, tolerance, addiction and sedation. These adverse effects may limit post-operative mobility, postpone return of bowel function, cause feeding intolerance, prolong hospitalization, and postpone post-operative recovery.

While oral acetaminophen is useful as an opiate-sparing therapy, the oral route of drug administration may not be feasible in the early post-operative period. Enteral drug absorption in the initial post-operative period may be erratic, with negative impacts on therapeutic effect. Intravenous acetaminophen may a particularly useful analgesic in these circumstances. At present, there are no pediatric studies in the United States examining the efficacy of multiple- dose IV acetaminophen in the post-operative surgical population. This study will compare analgesic efficacy, nausea and pruritus scores, time to recovery, and length of hospital stay in two subject groups who are status post spine fusion surgery: those who receive schedule IV acetaminophen and opiate for 48 hours, and those who are treated with standard opiate therapy without IV acetaminophen.

Eligibility Criteria:
Inclusion Criteria:

Subjects 10-18 years who are status post anterior or posterior spine fusion surgery

Exclusion Criteria:

1. All patients requiring mechanical ventilation post-operatively, continuous infusions of sedative, or continuous infusions of alternate opiates (i.e. fentanyl)
2. Patients with hepatic dysfunction
3. Patients with chronic opiate requirements
4. Pregnant or lactating females
5. Patients placed on opiates other than morphine or hydromorphone
6. Patients with opiate or acetaminophen allergies
7. Patients placed on alternate analgesic adjuncts (i.e. ketamine, etc)
8. Patients who receive intrathecal opiates