Landmark Lancet series reveals poor management of surgery pain key contributor to global opioid crisis

A landmark series in The Lancet, led by Monash University Professor Paul Myles, reveals that a major contributor to the global opioid epidemic is inappropriately managed post-surgery pain that becomes chronic and long-lasting.

Globally up to 75% of surgery patients are prescribed opioids at hospital discharge with no plan to monitor their use or to wean the patients off the painkillers – and the study shows that the risk of misuse increases by 44% for every week and for repeat prescription after discharge.

The three papers making up the series are from researchers from Australia, the US and Scotland reveals that 10% of patients who have surgery have ongoing wound pain that can last months or even years, with half of those affected rating the pain as severe.

According to Professor Myles, it is possible to detect those patients whose pain is “transitioning” from acute to chronic so that their pain can be better managed, however the majority are simply prescribed more potent painkillers, often leading to long term addiction. The transitioning phase is distinctive from the post-surgical pain and can include sensations like burning, hyper-sensitivity to pain, and itching, all symptoms that can be used as hallmarks for early intervention.

Worldwide, use of prescription opioids more than doubled between 2001-2013 – from 3 billion to 7.3 billion daily doses per year – and doctors in many countries give medication in excess of what is needed for pain control, increasing the risks of misuse or diversion.

The Lancet papers, which includes an editorial, brings together global evidence detailing the role of surgery in the opioids crisis.

Chronic post-surgical pain is a growing problem as the population ages and more surgeries are done. It can occur after any type of surgery but is particularly common after lung, hernia and breast surgery. Each year there are 320 million people having surgery around the world, including more than 2 million in Australia, and chronic pain occurs in 10% of cases.

It typically begins as acute postoperative pain that is difficult to control, and develops into a persistent pain condition with features that are unresponsive to opioids. In response to this pain, clinicians often prescribe higher levels of opioids, but this can lead to tolerance and opioid-induced hyperalgesia (a counterintuitive increase in pain in line with increased opioid consumption), creating a cycle of increased pain and increased opioid use where pain remains poorly managed.

“Providing opioids for surgical patients presents a particularly challenging problem requiring clinicians to balance managing acute pain, and minimising the risks of persistent opioid use after surgery,” says Series lead Professor Myles Head of Monash University’s Department of Anaesthesia and Perioperative Medicine.

“Over the past decade there has been an increasing reliance on strong opioids to treat acute and chronic pain, which has been associated with a rising epidemic of prescription opioid misuse, abuse, and overdose-related deaths.”

The authors argue that - to reduce the increased risk of opioid misuse for surgery patients there need to be a comprehensive and urgent approach to:

  • reducing opioid prescriptions
  • increasing the use of alternative medications
  • reducing leftover opioids in the home and educating patients and clinicians about the risks and benefits of opioids

Professor Myles in particular called on better training for medical students in the management of postoperative pain. “Too often GPs and specialists either dismiss long term pain following surgery or simply provide the patients with more painkillers, with no plan to ween the patient off opioids,” he said. This year, under Professor Myles’ direction, a lecture to all final year medical students that “takes them through their basic pharmacology that they learnt in their first year through to issues like opioid tolerance and addiction.” The course is aims to teach medical students specifically about pain management and the correct use of opioids like fentanyl.

One of the papers in The Lancet, Professor Lesley Colvin from the University of Dundee, reveals that high doses of opioids after surgery can actually produce what is known as opioid induced hyperalgesia, whereby the pain pathways become hyper-sensitive to pain medication, so that the pain increases in response to pain-killers – leading to taking further pain killers, continuing the cycle.

Professor Myles, who was commissioned to write this series by The Lancet 18 months ago, is planning to conduct a clinical trial of 4000 Australian women who have surgery for breast cancer. This group has a particularly high rate of post-surgical pain becoming chronic. He is hoping to study the transitioning phase from acute post-surgical to chronic pain, with a view to reducing opioid use.