IV Acetaminophen vs Opioids: Updated Data

Co-author Joseph Bosco, M.D., professor in the Department of Orthopaedic Surgery and director of Quality and Patient Safety at the NYU Langone Orthopedic Hospital, also vice chair for Clinical Affairs in the Department of Orthopaedic Medicine, has been at the forefront of improved pain management for a long time and explained the genesis of this study (“Evolution of an Opioid Sparse Pain Management Program for TKA with the Addition of Intravenous Acetaminophen” published in the August issue of The Journal of Arthroplasty) to OTW. “Our patients’ pain levels temporarily spiked immediately after their spinal anesthetic wore off and before the peri-articular block with liposomal bupivacaine began to take effect. This usually occurred in our post-operative Care Unit. The use of IV acetaminophen addressed this issue.”

To put some numbers behind the anecdotal evidence, Bosco and his team organized a study which compared two multi-modal analgesia protocols in patients who underwent primary, unilateral total knee arthroplasty (TKA). The team collected data from 698 patients who received oral acetaminophen (OA) preoperatively, and on an as-needed basis. They also collected data from 318 patients who’d received two doses of IV acetaminophen (IA)—one intraoperative and one six hours postoperatively (no oral acetaminophen).

The researchers found that patients who’d received IV acetaminophen group demonstrated less narcotic usage on POD0 (OA: 13.3 mme; IA: 6.2 mme) and overall usage (OA: 66.1 mme; IA: 48.5 mme). They also documented that the patient’s pain scores were statistically and clinically lower in the immediate postoperative (the first 8 hours) for the IA group (OA: PRPS of 4.0; IA: PRPS of 2.0).

Finally, Bosco and his team report that both patient groups completed their physical therapy similarly for each postoperative day and length of stay and percent discharge home were slightly improved in the IA group although the difference did not reach a level which was statistically significant.

Dr. Bosco summarized his findings for OTW, “At NYU Langone Orthopedics we routinely spend time counseling our patients regarding post-operative pain. Our patients find this to be quite valuable. We tell them to expect a certain amount of pain in the post-operative period and let them know that we have ways of addressing this pain. We warn them that when the short acting spinal anesthetic wears off, they may experience discomfort before the peri-articular injection starts to work. That is why we are using the IV acetaminophen.”

“As a result of our experience with Medicare total joint bundled payment program, we transformed NYU Langone Orthopedics into a leader in value-based care. As is demonstrated in our study, the additional cost of IV acetaminophen is more than made up for by the pain relief and enhanced functional recovery it provides. It is another step in our constantly evolving multi-modal post-operative pain pathways.”