Opioids no better for post-surgical pain

Opioids can increase adverse events after minor or moderate surgery and fail to reduce pain intensity.

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Opioids prescribed on discharge after minor or moderate elective surgery don’t reduce the intensity of pain, but they do increase adverse events, say Canadian researchers, suggesting opioid-free analgesics are a viable option.  

The meta-analysis looked at 47 multidose randomised controlled trials in 6607 patients aged 15 years or older, who had undergone minor or moderate procedures. 

These including dental surgery, orthopaedic procedures like cruciate ligament, rotator cuff and meniscus and extremity fracture and carpel tunnel repair, and general surgery such as cholecystectomy and hernia repair, mastectomy, lumpectomy, haemorrhoidectomy, phlebectomy, knee repair, sinus surgery, thyroidectomy and rhinoplasty.  

Researchers focused on self-reported pain intensity on the first day after discharge and vomiting in up to 30 days. 

At one day after discharge, opioids did not reduce pain any more than non-opioids. And the relative risk of vomiting in the 30 days post discharge was 4.5 times higher for those on opioids than those who used opioid-free analgesia (pharmacological, non-pharmacological, or combined). Adverse events significantly associated with opioid use included nausea, constipation, dizziness and drowsiness.  

Even without an opioid crisis, there are better ways

The Canadian research was carried out in the context of a North American opioid crisis.  

“Surgeons are responsible for the second-highest rate of opioid prescribing among all medical specialties, and thus, are considered to be important contributors to the opioid crisis,” the authors noted. 

“Although the prescription of opioids after surgery stems from well-intended efforts to reduce the postoperative pain and discomfort of patients, studies have shown that even minor surgeries can serve as an initial event for patients who are opioid naive to become persistent opioid users. Patients who do not become persistent users might also contribute to the opioid crisis by diverting unused tablets for non-medical use by others.”  

Australia is not experiencing an opioid crisis, but pharmaceutical opioids are still responsible for more deaths than illegal opioids like heroin. 

“As the paper points out, anxiety, depression and catastrophising are known to affect opioid consumption and prolonged use. They’re the same sort of factors which increase the risk of ongoing pain after surgery.”

DR GAVIN CHIN

Figures released by the TGA reveal three people die every day and 14 require hospital ED admissions from prescription opioid use. 

Australian pain management experts told The Medical Republic that there were other good options for pain management, and taking a holistic view was the way to go. 

Dr Gavin Chin runs the public pain service in Darwin as well as his own private practice. 

“I see the whole range of pain related referrals, from people who are misusing medication to those that are very elderly, have severe arthritis or are post-cancer,” he said. 

“You need to understand the whole person. That’s the main push with pain management these days – you need to look at what else is going on in the person’s life, and not just think this person should be fine after this surgery. 

“As the paper points out, anxiety, depression and catastrophising are known to affect opioid consumption and prolonged use. They’re the same sort of factors which increase the risk of someone having ongoing pain after surgery.”

In his work, Dr Chin mainly deals with people who have had major surgery.  

“The aim is to try and discharge them on the least amount of opioid analgesia and also give them a plan,” he said. 

“But there are patients who are discharged fairly soon after major surgery, or they don’t necessarily get to see someone who advises them on how to wean off their medication. So then it’s up to the GP to work out what to do.” 

Useful in these circumstances were longer acting paracetamol, which has a slightly lower dose than the standard tablets, and slow-release anti-inflammatories in combination with paracetamol to provide immediate release for fluctuations in pain, Dr Chin advised. 

“And then good advice about how to get back into normal activities. It’s a bit like how we have changed our approach to managing acute back pain,” he said. 

“Before I was practicing medicine, the standard advice would be to go home and rest. But these days, we advise people that is not a good idea and they need to actually continue to be active and gradually get back into usual activity. 

“And that’ll be the same with post-op advice and management after any minor surgery, especially an arthroscopy of the knee or abdominal laparoscopy.” 

Acknowledging all aspects of pain

In Australia, the goal is to manage chronic, non-cancer pain with multimodal analgesia and the biopsychosocial assessment of pain, said Tasmanian pain specialist Dr Marcus Gurgius. 

Finding the right treatment requires an acknowledgement of all the aspects of pain – biological, social or psychological, he said.  

“Not everything will be fixed with medications – even a combination. There is no one magic pill that will fix pain. So sometimes you need to resort to other people, psychologists, physiotherapists, nurses, dieticians – whoever is needed. 

“A multidisciplinary approach to pain works well, provided that people are communicating with each other and are all on the same page, with the same treatment goal and approach.” 

For patients who have been living with pain for some time, the need to manage additional pain, for example post-operatively, can be a good opportunity to review the whole analgesic regime and start afresh. 

“When it comes to chronic, non-cancer pain, you always lose the battle with opioids. Eventually either the patient will become tolerant, or it will contribute to the pain, or they will become addicted or have other side effects.”

DR MARCUS GURGIUS

Opioids can in some circumstances contribute to pain, Dr Gurgius said.  

“It’s not uncommon. We see it in roughly 10% of patients on long-term opioids. There are theories about why that is. It causes microinflammation around the nervous system.” 

Other analgesic options are available, including co-analgesics like anti-depressants, which work particularly well for neuropathic pain or pain with a psychological aspect. 

“The patient needs to be made aware that, unlike opioids, it will take some time to kick in, or they might think it’s not working,” he said. 

Gabapentinoids like Lyrica or gabapentin, anti-seizure drugs often used for nerve pain, are also an option although these drugs do have side effects, can interact with other medications and are potentially addictive, Dr Gurgius said. 

“Whether they are right for your patient is all about the context,” he said. “It depends whether addiction is an issue, the age of the patient, what type of pain they’re dealing with. Pain management has to be tailored to individual requirements.” 

Opioids still do have a place in pain management, he said.  

“If it’s short term, and there is no contraindication to use opioid for some patients, it’s definitely the best painkiller we have so far. Sometimes common sense and clinical context applies.” 

For example, there is no need to discontinue opioids for an elderly patient with osteoarthritis who is on a low dose and is functioning well, said Dr Gurgius. Tolerance to opioids slows down after the age of 60, and addiction is less of an issue in this age group than it is for younger patients, he said. 

“There’s no point in stopping opioids for this patient and making them suffer just because the guidelines recommend no more opioids for chronic non-cancer pain. It comes down to the context and the whole picture,” he said. 

“But when it comes to chronic, non-cancer pain, you always lose the battle with opioids. Eventually either the patient will become tolerant, or it will contribute to the pain, or they will become addicted or have other side effects.” 

The Lancet 2022, online 18 June