Editorial I: Acute pain management: scientific evidence revisited

Abstract

Acute Pain Management: Scientific Evidence1National Health and Medical Research Council. Acute Pain Management: Scientific Evidence. 1999. Available from http://www.nhmrc.health.gov.au/publications/_files/cp30.pdfGoogle Scholar was first published by the National Health and Medical Research Council (NHMRC) of Australia in 1999. An editorial2Smith G Power I Cousins MJ Acute pain—is there scientific evidence on which to base treatment?.Br J Anaesth. 1999; 82: 817-819Crossref PubMed Scopus (13) Google Scholar published the same year in the British Journal of Anaesthesia assessed the importance of this document along with Guidelines on the Use of NSAIDs in the Perioperative Period.3Royal College of Anaesthetists Guidelines for the Use of Non-steroidal Anti-inflammatory Drugs in the Perioperative Period. 1998Google Scholar It was noted that ‘there is still a need for properly conducted controlled clinical studies evaluating most areas of therapy in acute pain’ and that ‘guidelines can only remain valid for a relatively short period’ as the field of pain management is a rapidly evolving one.2Smith G Power I Cousins MJ Acute pain—is there scientific evidence on which to base treatment?.Br J Anaesth. 1999; 82: 817-819Crossref PubMed Scopus (13) Google Scholar Since then, there has indeed been an enormous increase in the number of peer-reviewed articles relating to the treatment of acute pain, as well as a marked improvement in the quality of evidence available for acute pain therapies. Over the same period, there has also been both an increase in the complexity of acute pain treatments and in the type of patient seen with acute pain. In addition, there has been increasing recognition that acute pain is just one end of the pain spectrum and that many patients do not fit neatly into either an acute pain or chronic pain category. No longer do the more comprehensive Acute Pain Services (APSs) see mainly postoperative, obstetric and trauma patients. Patient referrals now commonly include those with acute-on-chronic pain, acute cancer pain or acute pain from a multitude of medical conditions. There has also been a progressive increase in the percentage of patients who are opioid-tolerant, when, whatever the reason for the tolerance, effective management of acute pain can be more problematic. It is also now well understood that acute neuropathic pain can occur within a very short time (hours not days) of a nerve injury, for example, as a result of limb amputation or crush injury, and that patients undergoing particular types of surgery are at greater risk of developing persistent postoperative pain.4Perkins FM Kehlet H Chronic pain as an outcome of surgery—a review of predictive factors.Anesthesiology. 2000; 93: 1123-1133Crossref PubMed Scopus (1083) Google Scholar5Macrae WA Chronic pain after surgery.Br J Anaesth. 2001; 87: 88-98Crossref PubMed Scopus (529) Google Scholar Reinforcing this link between acute injury and persistent pain are reports that operations and injuries may contribute to a significant proportion of the burden of chronic pain.6International Association for the Study of Pain, European Federation of IASP Chapters. Fact Sheet: Unrelieved Pain is a Major Global Healthcare Problem. 2004. Available from http://www.painreliefhumanright.com/pdf/04a_global_day_fact_sheet.pdfGoogle Scholar Crombie and colleagues7Crombie IK Davies HTO Macrae WA Cut and thrust: antecedent surgery and trauma among patients attending a chronic pain clinic.Pain. 1998; 76: 167-172Abstract Full Text Full Text PDF PubMed Scopus (252) Google Scholar looked at the contribution of surgery and trauma to chronic pain in more than 5000 patients seen in pain clinics; surgery was said to contribute to the pain in 22.5% of patients and trauma was a cause of the pain in 17.5%. This has meant that treatment regimens now routinely used by many APS include those that, in the past, were largely the territory of chronic pain medicine (e.g. drug regimens including ketamine infusions, tricyclic antidepressants and anticonvulsants). However, advances in knowledge do not necessarily lead to the same degree of progress in patient care. Recent publications have shown that the management of acute pain may still be less than optimal in both surgical and medical patients8Apfelbaum JL Chen C Mehta SS et al.Postoperative pain experience: results from a national survey suggest postoperative pain continues to be under managed.Anesth Analg. 2003; 97: 534-540Crossref PubMed Scopus (1466) Google Scholar, 9Johnson L Regaard A Herrington N Pain in general medical patients: an audit.in: Dostrovsky JO Carr DB Koltzenburg Proceedings of the 10th World Congress of Pain. Progress in Pain Research and Management. Vol. 24. IASP Press, Seattle2003Google Scholar, 10Dix P Sandhar B Murdoch J et al.Pain on medical wards in a district general hospital.Br J Anaesth. 2004; 92: 235-237Crossref PubMed Scopus (45) Google Scholar indicating that there remains significant room for improvement. These disappointing results are not only important in terms of patient suffering. It has been suggested that unrelieved severe postoperative pain may also lead to complications, such as myocardial ischaemia or infarction and pneumonia, with the associated costs of extended length of hospital stay and readmissions.6International Association for the Study of Pain, European Federation of IASP Chapters. Fact Sheet: Unrelieved Pain is a Major Global Healthcare Problem. 2004. Available from http://www.painreliefhumanright.com/pdf/04a_global_day_fact_sheet.pdfGoogle Scholar Data on the risks associated with the undertreatment of severe acute pain are not available per se, but it has been shown that improved pain relief may reduce the incidence of such complications. Epidural analgesia significantly decreases the risks of postoperative pulmonary complications11Ballantyne JC Carr DB deFerranti S et al.The comparative effects of postoperative analgesic therapies on pulmonary outcome: cumulative meta-analyses of randomized, controlled trials.Anesth Analg. 1998; 86: 598-612Crossref PubMed Google Scholar12Liu SS Block BM Wu CL Effects of perioperative central neuraxial analgesia on outcome after coronary artery bypass surgery: a meta-analysis.Anesthesiology. 2004; 101: 153-161Crossref PubMed Scopus (256) Google Scholar and myocardial infarction,13Beattie WS Badner NH Choi P Epidural analgesia reduces postoperative myocardial infarction: a meta-analysis.Anesth Analg. 2001; 93: 853-858Crossref PubMed Scopus (432) Google Scholar the incidence of pneumonia and the number of ventilator days in patients with multiple rib fractures,14Bulger EM Edwards T Klotz P et al.Epidural analgesia improves outcome after multiple rib fractures.Surgery. 2004; 136: 426-430Abstract Full Text Full Text PDF PubMed Scopus (202) Google Scholar and dysrhythmias and time to extubation in patients after coronary artery bypass surgery.12Liu SS Block BM Wu CL Effects of perioperative central neuraxial analgesia on outcome after coronary artery bypass surgery: a meta-analysis.Anesthesiology. 2004; 101: 153-161Crossref PubMed Scopus (256) Google Scholar It became clear that the evidence available for the management of acute pain needed to be updated and disseminated in a concise form to all healthcare practitioners. The NHMRC now encourages development or revision of clinical practice guidelines by external bodies, although such guidelines are still subject to the same rigorous processes and reviews before they can be endorsed by the NHMRC. Therefore, the Australian and New Zealand College of Anaesthetists (ANZCA) and the Faculty of Pain Medicine (FPM) agreed to undertake the revision of Acute Pain Management: Scientific Evidence. The practice of acute pain medicine appears to be very similar in Australia and the UK. As the Royal College of Anaesthetists (RCoA) was interested in promoting the revised document to its Fellows, a representative from the RCoA was appointed as a consultant to the ANZCA/FPM working party established to coordinate the revision. A panel of contributors was selected to draft sections of the document and a large multidisciplinary consultative committee (including medical, nursing, allied health and complementary medicine clinicians in addition to consumers) was appointed to review the early drafts of the document and contribute more broadly as required in order to ensure general applicability and inclusiveness. Recent evidence-based guidelines already existed for the management of cancer pain15Scottish Intercollegiate Guidelines Network. Control of Pain in Patients with Cancer. 2000. SIGN Publication Number 44. Edinburgh. Available from http://www.sign.ac.uk/pdf/sign44.pdfGoogle Scholar and acute musculoskeletal pain16Australian Acute Musculoskeletal Pain Guidelines Group. Evidence-based Management of Acute Musculoskeletal Pain. Brisbane: NHMRC Australian Academic Press, 2003. Available from http://www.health.gov.au/nhmrc/publications/pdf/cp94.pdfGoogle Scholar and were the sources of recommendations relevant to the management of acute pain in these areas. Evidence was annotated according to the levels recommended by the NHMRC17National Health and Medical Research Council. A guide to the development, implementation and dissemination of clinical practice guidelines. 1999. Available from http://www7.health.gov.au/nhmrc/publications/_files/cp57.pdfGoogle Scholar where (I) Evidence obtained from a systematic review of all relevant randomized controlled trials.(II) Evidence obtained from at least one properly designed randomized controlled trial.(III-1) Evidence obtained from well-designed pseudo-randomized controlled trials (alternate allocation or some other method).(III-2) Evidence obtained from comparative studies with concurrent controls and allocation not randomized (cohort studies), case-controlled studies or interrupted time series with a control group.(III-3) Evidence obtained from comparative studies with historical control, 2 or more single-arm studies, or interrupted time series without a parallel control group.(IV) Evidence obtained from case series, either post-test or pre-test and post-test. In the previous edition, according to the levels of evidence used by the NHMRC at that time, level IV indicated ‘the opinions of respected authorities based on clinical experience, descriptive studies or reports of expert committees’.17National Health and Medical Research Council. A guide to the development, implementation and dissemination of clinical practice guidelines. 1999. Available from http://www7.health.gov.au/nhmrc/publications/_files/cp57.pdfGoogle Scholar As the working party believed that many practical recommendations existed for the treatment of aspects of acute pain for which there was no evidence that fitted any of the above categories (e.g. the need to use both antireflux and antisiphon valves with patient-controlled analgesia pumps comes mainly from case reports),18Australian and New Zealand College of Anaesthetists, Faculty of Pain Medicine. Acute Pain Management: Scientific Evidence, 2nd Edn. Melbourne: Australian and New Zealand College of Anaesthetists, 2005. Available from http://www.anzca.edu.au/publications/acutepain.htm http://www7.health.gov.au/nhmrc/publications/synopses/cp104syn.htmGoogle Scholar a system of ‘clinical practice points’ was introduced, each indicated by a tick box. In the first edition there are 34 statements made for which there was level I, II or III evidence. Such has been the increase in available evidence that the second edition now has 108 statements of level I evidence alone, in addition to many more statements at all other levels. Nevertheless, still more research is needed to expand our knowledge of acute pain management. The second edition of Acute Pain Management: Scientific Evidence was approved by the NHMRC in June 2005 and published in July 2005.18Australian and New Zealand College of Anaesthetists, Faculty of Pain Medicine. Acute Pain Management: Scientific Evidence, 2nd Edn. Melbourne: Australian and New Zealand College of Anaesthetists, 2005. Available from http://www.anzca.edu.au/publications/acutepain.htm http://www7.health.gov.au/nhmrc/publications/synopses/cp104syn.htmGoogle Scholar The aim of the document is, as with the first edition, to combine the best available evidence for acute pain management with current clinical and expert practice and to summarize the substantial amount of evidence currently available for the management of acute pain in a concise and easily readable form. Unlike the excellent evidence-based information for procedure-specific postoperative pain management being developed by the Prospect group,19Procedure Specific Postoperative Pain Management (PROSPECT). Available from www.postoppain.orgGoogle Scholar Acute Pain Management: Scientific Evidence covers acute pain in its broader context, including that associated with non-surgical conditions such as spinal cord injury, burns, cancer, acute zoster, neurological diseases, haematological disorders (e.g. sickle cell disease) and HIV/AIDS, as well as abdominal (e.g. renal and biliary colic), cardiac, musculoskeletal and orofacial pain and headache. In addition, the management of acute pain in some specific patient groups was addressed including the paediatric, obstetric, elderly and opioid-tolerant patient, patients with obstructive sleep apnoea, renal or hepatic impairment or a substance abuse disorder. While there is better evidence available for acute pain management in general since the first edition of the document was published, both in terms of quantity and quality, patients in groups such as these are often specifically excluded from randomized controlled trials of acute pain therapies. The lack of high quality evidence on which to base acute pain management in these patients highlights just some of the specific areas in which further research is needed. The second edition of Acute Pain Management: Scientific Evidence has been formally endorsed by the RCoA, the International Association for the Study of Pain (IASP), the Australian Pain Society and the other component Colleges and Faculty that, with ANZCA, comprise the FPM (the Royal Australasian College of Physicians, Royal Australasian College of Surgeons, Royal Australian and New Zealand College of Psychiatrists and the Australasian Faculty of Rehabilitation Medicine). The American Academy of Pain Medicine is also promoting the document to its members via a link from its website.20American Academy of Pain Medicine. Available from http://www.painmed.org/productpuGoogle Scholar Effective dissemination and implementation must follow the production of any evidence-based clinical guidelines.17National Health and Medical Research Council. A guide to the development, implementation and dissemination of clinical practice guidelines. 1999. Available from http://www7.health.gov.au/nhmrc/publications/_files/cp57.pdfGoogle Scholar This process will be helped if there is seen to be international and national recognition of the importance of pain management, an acknowledgement that relief of acute pain should indeed be a ‘basic human right’21Cousins MJ Relief of acute pain: a basic human right.Med J Aust. 2000; 172: 3-4PubMed Google Scholar and that ‘the failure to treat pain appropriately is substandard medicine’ and unethical.22Cousins MJ Brennan F Carr DB Pain relief: a basic human right.Pain. 2004; 112: 1-4Abstract Full Text Full Text PDF PubMed Scopus (133) Google Scholar The recognition is growing. At an international level, the IASP, the European Federation of IASP Chapters and the World Health Organization co-sponsored the launch of the Global Day Against Pain on 11 October 2004, in support of the declaration applying to acute, chronic non-cancer and cancer pain, that ‘The Relief of Pain should be a Human Right’.6International Association for the Study of Pain, European Federation of IASP Chapters. Fact Sheet: Unrelieved Pain is a Major Global Healthcare Problem. 2004. Available from http://www.painreliefhumanright.com/pdf/04a_global_day_fact_sheet.pdfGoogle Scholar At national levels there has also been increasing recognition of the right of the patient to more effective pain relief—for example, ANZCA and the FPM published a document entitled ‘Patients’ Rights to Pain Management’ in 2001.23Australian and New Zealand College of Anaesthetists, Faculty of Pain Medicine. Patients’ Rights to Pain Management. ANZCA Professional Document PS45. Australian and New Zealand College of Anaesthetists and Faculty of Pain Medicine, 2001. Available from http://www.anzca.edu.au/publications/profdocs/profstandards/ps45_2001.htmGoogle Scholar There has also been a growing recognition of the need to improve pain management, and that acute pain medicine forms an important part of the role of an anaesthetist. The ANZCA states that ‘education and practical experience in acute pain management are essential components of training programs’24Australian and New Zealand College of Anaesthetists. Guidelines on Acute Pain Management. 2001. Available from http://www.anzca.edu.au/pdfdocs/PS41_2000.pdfGoogle Scholar and anaesthetist-based APS are standard in hospitals involved in the training program. The FPM, established as an intercollegiate faculty in 1999 by ANZCA and the Colleges and Faculty listed above, requires pain medicine training programs to have ‘access to an APS’ and that this service must have at least one specialist anaesthetist session and one nursing session allocated every weekday.25Faculty of Pain Medicine. Guidelines for Programs Offering Training in Multidisciplinary Pain Medicine. 2003. Available from http://www.fpm.anzca.edu.au/documents/profdocs/pm2_2003.htmGoogle Scholar Pain medicine is also regarded as an important branch of anaesthesia by the RCoA and pain management is provided and assessed at all levels of the training program. The RCoA has also recently established a FPM.26Justins D A new pathway for pain.Bulletin of the Royal College of Anaesthetists. July 2005; 32: 1590-1593Google Scholar One of the conclusions from the Global Day Against Pain was that improvements in the management of pain, including acute pain, require ‘global education of health professionals, patients and their families’.6International Association for the Study of Pain, European Federation of IASP Chapters. Fact Sheet: Unrelieved Pain is a Major Global Healthcare Problem. 2004. Available from http://www.painreliefhumanright.com/pdf/04a_global_day_fact_sheet.pdfGoogle Scholar The considerable amount of knowledge now available in the field of acute pain medicine means that it can be difficult to keep up to date. It is hoped that this updated version of Acute Pain Management: Scientific Evidence will assist those caring for patients to approach the treatment of acute pain more effectively and safely. A consumer version of the document is under production. The members of the ANZCA and FPM working party were the authors and Dr David Scott, Dr Eric Visser and Dr Doug Justins (RCoA representative).