MCW Researcher Highlights a Potentially Novel Therapy for Treating Postoperative Pain
The opioid epidemic touches the lives of most Americans. Opioid-related overdoses took the lives of more than 47,000 people in 2017, and 36 percent of those deaths were contributable to prescription opioids.  Current statistics show that approximately 80 percent of surgical patients experience acute postoperative pain, and of these patients, 74 percent of them will continue to experience extreme pain after discharge. [2,3]
Many of these opioid prescriptions are given to patients to ease their pain after undergoing surgery or other operations involving incisions. Postoperative pain has both inflammatory and neuropathic qualities and this in part is why postoperative pain is difficult to treat.
Preliminary research conducted by Dr. Ashley Cowie during her PhD candidacy at the Medical College of Wisconsin demonstrated that a protein complex of the innate immune system, the NLRP3 inflammasome, drives the development and maintenance of postoperative pain in a sex-dependent manner. The study was highlighted as the Editor’s Choice article in the research journal PAIN and is accompanied by a video abstract of the findings. It explained that among the 9 known inflammasomes, the NLRP3 inflammasome is ideally positioned to drive postoperative pain through interleukin-1β production, an inflammatory cytokine of the innate immune system, because NLRP3 can be activated by factors that are released by incision. While conducting her study, she found that the deletion of NLRP3 decreased the intensity and duration of postoperative pain in male, but not female, mice. The study concludes by stating that this is the first evidence of a key role for NLRP3 in postoperative pain and reveals immune-mediated sex differences in postoperative pain.
This study highlights a potentially novel therapy to further explore and possibly, one day, holds the key to treating postoperative pain without the use of prescription opioids.
Ashley Cowie, PhD
 Scholl L, Seth P, Karisa M, Wilson N, Baldwin G. Drug and Opioid-Involved Overdose Deaths – United States, 2013-2017. (https://www.cdc.gov/mmwr/volumes/67/wr/mm675152e1.htm?s_cid=mm675152e1_w).
 Chapman CR, Vierck CJ. The Transition of Acute Postoperative Pain to Chronic Pain: An Integrative Overview of Research on Mechanisms. (https://www.ncbi.nlm.nih.gov/pubmed/27908839)
 Gan TJ, Habib AS, Miller TE, White W, Apfelbaum JL. Incidence, patient satisfaction, and perceptions of post-surgical pain: results from a US national survey. (https://www.ncbi.nlm.nih.gov/pubmed/24237004)