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Postoperative Pain Keeps Patients Awake, Extends Hospital Stays

October 31, 2014
New research explores how pain affects sleep and recovery after hip or knee replacement.

It has been shown that pain impacts a person’s quality of sleep—and poor sleep may affect pain perception. So imagine undergoing major knee or hip surgery and then having postoperative pain. Not surprisingly, researchers found that people who reported poor sleep following surgery also had more pain, especially in the first 24 hours after the operation. But what does this mean for recovery?

To study this phenomenon, researchers at Henry Ford Hospital in Detroit, Michigan, looked at 50 middle-aged patients who were recovering from hip and knee replacement surgeries. By fitting patients with Actigraph bracelets, researchers examined the duration and quality of the patients' sleep during the immediate post-operative period. They also examined medical records to assess use of pain medication and pain evaluation scores.

“Our results show that increased pain scores result in decreased sleep duration,” reported Anya Miller, MD, who practices at Henry Ford's Department of Otolaryngology-Head & Neck Surgery. “So better pain control could potentially improve sleep duration in these patients.”  Dr. Miller recently presented the results of the study at the 2014 American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) annual meeting held in Orlando, Florida. 

Postopertive Pain

>Knee and hip arthroplasty procedures can be highly invasive and many patients experience significant postoperative pain1,2 and disruption in their sleep.3-5 According to Dr. Miller, she and her team specifically chose to examine hip and knee arthroplasty patients because those patients' surgical and analgesic protocols are highly standardized at Henry Ford, reducing the implication of variability.

While the team found patients with sleep deficiency had worse pain, the researchers are still unsure as to how this inference may relate to post-operative complications.

"Whether [sleep deficiency] correlates to their actual surgical outcome, we can't say," Dr. Miller said, "but we also had only 50 patients in our study, so presumably with more patients we’ll be able to find the statistical correlation with poor sleep and complications."

Low Back Pain Following Hip Replacement

Another recent study found acute low back pain to be a complication among hip arthroplasty patients.  Researchers in Japan published research much like Dr. Miller’s group—they also used actigraphy technology, assessing sleep quality in a group of patients recovering from hip arthroplasty.6

Consistent  with other recent findings, these arthroplasty patients had adversely affected rapid eye-movement (REM) cycles because of frequent sleep disturbances, particularly from acute low back pain, which stemmed from recumbent bed rest. According to the researchers, this presents a new challenge in pain management for recovering arthroplasty patients.

"Continuous intravenous infusion and a dose of analgesics were sufficient to control postsurgical hip pain but not low back pain," the researchers wrote, noting that this may indicate "a need for other methods (e.g. positioning, massage) to ease low back pain."

"We found that care for back pain is as important as pain management,"  noted the researchers. Other studies have shown that "alleviation of the pain experienced by the patient after surgery minimizes energy consumption and is linked to early recovery."7,8

Would Sleep Rx Help?

insomnia, to fast-track hip and knee replacement patients.5 While the medication didn't significantly improve sleep quality compared to the placebo group, patients did report feeling less fatigue and having fewer postoperative arousals.

Some doctors may have reservations about using a sleep medication in recovering arthroplasty patients. David Ring, MD, a practitioner who serves on the patient safety committee for the American Academy of Orthopaedic Surgeons, told Practical Pain Management that "you got to remember that surgery hurts,"  noting that pain and subsequent loss of sleep after an arthroplasty procedure are natural and should be expected. "I'm a little concerned hearing about an emphasis on sleep and using medication [to manage] that."

Patients should be prepared to be in discomfort, Dr. Ring said, and having the right mindset, healthy coping strategies, and strong support from family members can make all the difference. "I think that's where the focus should be, not on sleep or medications."

Dr. Miller had similar conclusions about decreased sleep quality after an arthroplasty operation. "Apparently, there's the misconception that the hospital is a restful place; that it’s the time for recovery – when oftentimes there's still much going on that it's not that at all, and that has some real negative impact on patients," Dr. Miller said.

Co-authors of the Henry Ford study included Kathleen Yaremchuk, MD, senior author, along with Thomas Roehrs, PhD and Timothy Roth, PhD.

Last updated on: May 19, 2015