Postoperative Pain Management: Reducing the Evidence – Practice Gap

‘Less than a generation ago the prevalent attitude towards acute pain was widespread acceptance as inevitable, and frequent indifference to its suboptimal management. Now, proper pain management is understood to be a fundamental human right and integral to the ethical, patient-centred and cost-effective practice of modern medicine.’
(Cousins & Carr in Acute Pain Management: Scientific Evidence. 3^rd ed., 2010 p.iii)

As a natural response to actual or potential injury, pain serves a biological function. It signals injury within the body. Acute pain and injury are inevitably interrelated and activate a complex of neurological, hormonal and immune responses. However, if severe and prolonged, the acute pain response to injury becomes counterproductive. It is known today that untreated acute pain may have damaging immediate and long term consequences.

Postoperative pain is distinguished by its onset following surgery. It is typically characterised by constant aching pain near the surgical site with exacerbation during activities such as coughing, getting out of bed, physiotherapy and dressing changes. Often it is a self limiting condition with a progressive and fairly rapid improvement.

A clear aim of postoperative pain treatment is to keep the patient comfortable and to ease breathing, coughing and movement. This in turn facilitates restoration of physical function. Effective acute pain management is now also known to have substantial benefits well beyond the immediate comfort of the patient. In the acute setting, the risk of medical complications, prospective length of stay and total rehabilitation time may all be markedly reduced.

Effective acute pain control can also have significant physical and psychological health benefits for the patient long after their return to the community. For some patients, debilitating chronic pain can be averted by minimisation of acute pain postoperatively. Effective postoperative pain management, while clearly an ethical priority, is now also being recognised as fundamental in efforts to minimise the total cost of hospital care and rehabilitation.

Acute pain management is a specialist area of clinical practice, backed by substantive scientific evidence. The International Association for the Study of Pain and their journal Pain facilitates pain management research, education and practice worldwide. As advanced acute pain management techniques have principally developed within the field of anaesthesia, most professional anaesthesia organisations have policy statements or guidelines on pain management.

Acute Pain Management: Scientific Evidence is published by the Australian and New Zealand College of Anaesthetists (ANZCA) and is recognised as the leading English language acute pain reference. Now in its third edition, it has been endorsed by anaesthetic colleges and pain societies throughout the English speaking world. The editorial working group is an international collaboration that has been chaired successively by Australian leaders in the field. Beyond providing a succinct account of the current scientific evidence, this reference provides a clear framework for managing acute pain and an outcomes-based rationale for doing so. Notwithstanding their detailed attention to the scientific evidence, the authors caution that individualised treatment of patients is needed for the evidence to be applied effectively.

At a local level, many major hospitals have implemented Acute Pain Services to provide around-the-clock pain care. These institutions provide staff and facilities specifically to optimise perioperative pain management. Clinical activities may be augmented by responsibility for the definition and effective implementation of policies, protocols and guidelines.

In the Acute Postoperative Pain Management Project (APOP) conducted by Australia’s National Prescribing Service in 2007, it was found that institutional barriers continue to limit the uptake of best practice approaches to postoperative pain management. The project was conducted in Australian public and private hospitals in relation to orthopaedic, abdominal, obstetric and gynaecological surgery. Self described as ‘moderately successful’, the APOP team promoted specific practice changes to improve pain assessment, analgesic prescribing and communication at the point of discharge.

It may initially appear that notions of ‘best practice’ provide a rationale for restricting patients’ access to the more complex postoperative pain management options. However current scientific evidence clearly portrays individual differences in patient response to particular analgesic techniques and agents. This is a consequence of the complexity in the pain response and genetic differences in metabolism of various analgesic drugs. Perhaps with growing awareness of these issues and the benefits of effective postoperative pain management, the implementation of flexible and patient centred practices will have greater impetus.

The widely referenced Australian Therapeutic Guidelines provide an account of the current state of postoperative pain management in Australia. Although not referencing the latest ANZCA scientific evidence, the guidelines do accord with established principles which are evidence based. While consistency might be expected, the guidelines are a purposefully different document, emphasising matters which require consideration when choosing analgesia techniques and agents for a particular patient. The guidelines do not attempt consideration of the differences in pain management requirements following specific surgical interventions.

These guidelines are explored in the 7^th HPS Pharmacies in-service education session for 2012, titled Postoperative Pain Management. The underlying principles of pre-emptive analgesia; multimodal analgesia; pain assessment using the patient’s self-report; regular ‘time contingent’ dosing; utilisation of local anaesthetics; and continual patient monitoring and assessment will be discussed. An update on the currently available analgesic agents will also be provided with consideration of the effect that patients genetic differences have on drug choice.

Directed at professional nursing staff, the session is also of value to others with an interest in optimising patient care and reducing hospital costs.