Patients undergoing hip replacement are at risk of harm from extended chronic opioid use, with younger patients and women at particular risk of being chronic opioid users even after surgery, researchers have found.
The retrospective cohort study published in the BMJ Open, found back pain, diabetes and preoperative use of hypnotics were strong risk factors for the persistent and new development of chronic opioid use.
Additional risk factors for persistent use included younger age and longer use of opioids prior to surgery, while for new chronic use these included being a woman, depression, migraine, gastric acid disease and taking medications for neuropathic pain.
“These indicators of chronic opioid use can be used by clinicians for risk stratification prior to THA surgery, and will help to target patient groups for suitable pain management interventions presurgery and postsurgery,” the authors wrote.
The researchers accessed the Australian Government Department of Veterans’ Affairs health claims database to study 9525 patients who had an elective unilateral THA between 2001 2012. Chronic opioid use was defined as 90 days of continuous opioid use or 120 days of non-continuous use.
Lead author, Dr Maria Inacio, an epidemiologist at the University of South Australia’s Medicine and Device Surveillance Centre of Research Excellence, said many patients undergoing THA had been in chronic pain for years, even decades, before getting access to joint replacement surgery.
“By the time they have surgery they’ve been exposed to significant opioid use,” she told the limbic. “Then after surgery they have a period of acute post-operative pain. A small number of patients are chronic users of opioids before and after surgery.”
The study identified 492 (5% of the total cohort) chronic opioid users after THA – 61 per cent of these were persistent chronic users and 39 per cent became chronic users after surgery.
“Patients do get some relief from their pain after surgery, but we know that some patients find they are still chronic users anyway,” Dr Inacio said. “It’s not recommended for people to be on opioids for a longer period.”
She said being aware of patient co-morbidities prior to surgery was becoming more and more important, with a growing body of evidence leading many clinicians away from opioid use, especially for this condition.
“I think there is a pretty good consensus that opioids are not the definitive answer to pain management in this type of patient,” he said. “I think the surgeons are very aware that this is a problem and they are looking for a solution.”
Managing patient expectations when it comes to pain management plays an important role in preventing them developing dependence on opioids.
The next step for Dr Inacio and her team is to develop a risk calculator specifically for THA patients that can be used to estimate a range of adverse outcomes post-surgery, including chronic opioid use, respiratory events, infections and readmissions.
“There are risk calculators but not made specifically for this patient group,” she said. “They can be used as a very specific and educational tool to help patients understand the potential risks.”