Persistent postoperative opioid use

In this step, Dr Jane Quinlan, Consultant in Anaesthesia and Pain Medicine at Oxford University Hospitals Trust and Honorary Senior Clinical Lecturer at the University of Oxford, explores the concept of persistent postoperative opioid use (PPOU), its definitions and incidence after different types of surgery.

Sam had an operation three months ago. Immediately after surgery his pain was severe, but it has improved since. In fact, it has now gone. The hospital gave him painkillers to take at home – a big bag of different tablets – and he still has lots left. He doesn’t know which ones he’s supposed to take but he likes the morphine tablets best. He’s been very stressed recently, and the morphine helps him feel more relaxed and helps him sleep at night. They help so much that he has started taking a few extra morphine doses at bedtime. He tried to stop the morphine, but he felt awful – he felt as though he had flu, had diarrhoea and his anxiety worsened – so he’s carried on taking it.

Persistent postoperative opioid use (PPOU) occurs in patients who were prescribed opioids for acute postoperative pain but are still taking them after the period of normal tissue healing. There is no standard definition of PPOU, but one frequently used in research is any opioid use for postoperative pain at more than 90 days (or three months) after surgery, as this aligns with the ICD-11 and IASP definitions of chronic pain and chronic post-surgical pain. For patients who were already on opioids before their surgery, PPOU a recommended definition is any increase in opioid use after 90 days post-surgery. You will look more closely at the relevance of different definitions of PPOU in Step 2.18.

Opioids do not improve chronic pain but often lead to a poorer quality of life in this setting.

Long-term opioid use also increases the risk of opioid-induced ventilatory impairment (OIVI), defined as type-2 respiratory failure associated with opioid administration. You will explore this in more detail in Weeks 2 and 3. OIVI is a more appropriate description than ‘respiratory depression’ as it is caused by a combination of adverse effects:

References

_{1. Kent ML, Hurley RW, Oderda GM, Gordon D, Sun E, Mythen M et al. American Society for Enhanced Recovery and Perioperative Quality Initiative-4 Joint Consensus Statement on Persistent Postoperative Opioid Use: Definition, Incidence, Risk Factors, and Health Care System Initiatives. Anes Analg 2019;129(2):543-552.}

_{2. Sitter T, Forget P. Persistent postoperative opioid use in Europe: a systematic review. Eur J Anaesthesiol 2021;38(5):505-511.}