Postoperative Pain Trajectories in Chronic Pain Patients Undergoing Surgery  

SLR - September 2013 - Trevor E. Black

Reference: The Effects of Chronic Opioid Pharmacotherapy on Acute Pain The Journal of Pain, Vol 12, No 12 (December), 2011: pp1240-1246

Scientific Literature Review
 

Reviewed by: Trevor E. Black, DPM
Residency Program:  Grant Medical Center

Podiatric Relevance: Podiatric physicians and surgeons regularly prescribe opioids for patients as a means to alleviate postoperative pain. However, patients that suffer from chronic pain who use opioids regularly often receive inadequate perioperative pain control. The following observational review conducted out of the University of Utah examined postoperative pain in chronic pain patients and chronic pain patients receiving chronic opioid therapy. The authors evaluated the increased levels of pain in opioid-tolerant and opioid-naïve patients in the postoperative setting and highlighted the need for more aggressive pain management in these patients following surgical intervention.
 

Methods: The study observed 55 patients with chronic pain undergoing elective surgery at the University of Utah. Inclusion criteria were age greater than 18, elective surgery, and a preoperative medically managed chronic pain condition. Patients were considered to have chronic pain if they received medical attention for ongoing pain three months or greater.  Sample populations included chronic pain patients that were not using opioid therapy for pain relief and those that were using opioid therapy for relief. Seven patients recorded having one area of chronic pain, 34 reported two separate foci of chronic pain, 12 reported three foci, and one patient reported four foci. Median number of chronic pain foci was two.  Participant age range was 19-85 with mean 55.3 years. Forty-seven patients were white, five Hispanic, one polynesian, and two unknown race. Thirty patients were not receiving opioid therapy, 25 were treated with opioid therapy. Opioid medications included hydrocodone, fentanyl, oxycodone, morphine, and tramadol. Eighteen patients used only one medication, nine used two, and three used three medications. In the patients that were not using opioids, 12 reported using acetaminophen or NSAIDS for pain, six used gabapentinoid with an NSAID, and seven did not receive pain medication.

Results: Patients with chronic pain on opioid therapy were found to have initial average pains 2.27 points and 2.81 points higher than chronic pain patients not receiving opioid therapy both with movement and at rest. Pain at rest and pain with movement did not vary significantly with surgical site. Chronic pain patients who did not receive opioid therapy were found to have a mean intercept of 5.6 with a mean slope of 0.20 which indicated a slower resolution to postoperative pain of 0.2 units per day. Chronic pain patients who received opioid therapy had a mean intercept of 7.68 which indicated a much higher level of initial pain. These values indicate that patients suffering from chronic pain who underwent surgery had the same initial level of postoperative pain as normal surgical patients. However, the postoperative pain resolved much more slowly compared to the normal patient. These patients report more pain than normal as postoperative time increases. Chronic pain patients receiving opioid therapy have higher initial levels of pain postoperatively and the postoperative pain resolves at the same slow rate as the opioid-naïve patients.
 

Conclusions: Patients with chronic pain, both opioid-naïve and opioid-tolerant, present unique challenges in the postoperative setting. These patients may have higher initial levels of postoperative pain and longer trajectory to pain resolution. Patients suffering from chronic pain that undergo surgical intervention require aggressive postoperative pain management and further research into innovative postoperative pain management protocols is indicated.