Every year in Ireland, at least 370,000 surgical operations are performed, of which 130,000-140,000 are inpatient operations. With the advent of minimally invasive surgical techniques and improved postoperative analgesia (the inability to feel pain) many individuals can be discharged with 24 hours.
Unfortunately, one in every five individuals can end up having to cope with daily pain that limits their quality of life, impairs their sleep and erodes their mental wellbeing.
Pain that persists beyond the normal healing time is referred to as persistent post-surgical pain (PPSP) and can be as high as 60 per cent following some surgical procedures. When the pain is described as “burning” or “electric” in nature with increased sensitivity in the surgical region it is referred to as neuropathic pain. In 2017, the International Association for the Study of Pain recognised the extent of the issue and made postsurgical pain the focus of a year-long awareness campaign.
Why is the incidence of post-surgical pain so high?
It appears that, irrespective of the nature of surgery, every individual who undergoes a surgical operation is at a risk of developing PPSP. While there are no specific predictive markers, it is recognised that those at greater risk are individuals who have chronic pain before surgery. The specific nature of the surgical operation is also a key consideration. For example, 10-12 per cent of inguinal hernia surgery cases, 20 per cent of lumbar discectomy and up to 60 per cent of individuals who have a thoracotomy can develop PPSP as late as three months after surgery.
Healthcare professionals are alert to the possibility of individuals developing PPSP and an enormous effort is made to use suitable analgesic regimes and surgical techniques aimed at reducing the occurrence and severity of acute postoperative pain.
Why is it difficult to provide post-operative pain relief?
Pain after surgery is a very specific entity. After surgery, the healing process relies on the activation of a complex biochemical process that can continue for six weeks. This same healing process can also lead to an increased sensation of pain. The combination of an increased inflammatory process and localised injury to nerves in the surgical field can contribute to the development of PPSP.
This results in increased hypersensitivity of the nerve fibres. Researchers have also considered the possibility that there may be a genetic predisposition to the development of PPSP but this has not been as fruitful as expected.
The intensity of PPSP can range between mild to moderate to severe over the course of a day. The unpredictable nature of the pain – not knowing when it might strike, if it will respond to painkillers or even if getting a few hours’ sleep is possible means that individuals with PPSP remain on “high alert”. This is termed central sensitisation, where the pain centre in the brain simply cannot “switch off”. It seems that the brain is constantly scanning the body for pain signals.
Too often, individuals do not speak up and tell their doctors that they continue to suffer pain. It is well reported that individuals are so “grateful” to have had surgery, that in some cases may have been life-saving, they “accept” the pain as an inevitable outcome.
What are the treatment options?
The complexity of post-surgical pain implies management is more than simply prescribing opioids as required. It is, therefore, not surprising that there is more than one way to manage PPSP. A paper published by the Australian and New Zealand College of Anaesthetists and its Faculty of Pain Medicine recommends that individuals who continue to suffer PPSP should speak with their doctor and seek the opinion of a pain specialist.
Three key questions should be:
1. Where is the pain and what is the nature of the pain?
Sometimes an individual may be “self-diagnosing” and in fact are wrongly attributing their pain to the surgical event. There may be a separate issue that requires a specific intervention or investigation. Discussing the location, possible source and the nature of the pain with your GP can help ensure the correct treatment is planned.
2. What can be achieved by using oral analgesics?
It is accepted that most individuals do not like the option of taking “tablets” on a regular basis. They are fearful of becoming “addicted” to the medication or that they may “hurt themselves even more” because they might not “feel the pain”. Pain medication can be very useful to gain control over the pain and provide a level of relief that can be maintained over time.
3. Is there a role of specific pain interventions?
In situations where analgesic multimodal planning does not provide the level of relief needed (>50 per cent relief) in a timely fashion then consideration should be given to referring the individual back to the surgical team or request a pain physician to review the case.
A skilled interventional pain physician may consider a suitable localised injection or treatment that may help relief the symptoms. For example, steroid injections, or advanced techniques such as denervation to destroy the painful nerves could be offered. Combined with physical rehabilitation this can be very helpful. With the wide range of modern pain management options available, individuals should no longer have to suffer the debilitating effects of PPSP.
– Dr Dominic Hegarty is a consultant in pain management and neuromodulation at the Mater Private Hospital, Cork and clinical director of Pain Relief Ireland
