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Exciting times in veterinary analgesia
Veterinary Anaesthesia and Analgesia, 2003, 30, 1^2
E D I TO RIA L
Exciting times in veterinary analgesia The last few months have seen some exciting developments for pain management in animals. Over the last two years, we have gone from having no recent textbooks on this subject to having seven, with the recent publication of ‘Handbook of Veterinary Pain Management’ (Gaynor & Muir 2002). Earlier this year, theVeterinary Clinics of North America: Equine Practice (Mama & Hendricks 2002) focused on analgesia and pain management and in the last two years, three texts (Flecknell & Waterman-Pearson 2001; Hellebrekers 2000; Tranquilli et al. 2001) and two Veterinary Clinics of North America (Mathews 2001; Heard 2001) were published. We now have some excellent resources for small, large, and exotic animal practitioners. The texts provide a wide range of views on the topic: from philosophical discussions about approaches to animal pain, to very practical descriptions of local anesthetic techniques, to excellent reviews of the pharmacology and application of drug therapy. Several of these texts also include material on complementary therapies for animal pain management. These texts also point out the gaps in our knowledge about pain in animals: from our sparse abilities to assess pain in animals to our lack of data on the pharmacokinetics and pharmacodynamics of analgesic drugs in most of the species we handle. At the International Association for the Study of Pain meeting in San Diego in August 2002, the attending scientists presented a huge volume of information as reviews of current understanding and as cutting edge discoveries (approximately 1500 abstracts presented as posters over ¢ve days). New tools and techniques are allowing us to delve deeper into the mysteries of the nociceptive system and gain greater understanding of the mechanisms underlying various types of pain. Bone cancer pain is partly due to the acidic environment produced around osteoclasts, which activates the small C ¢bers present in bone. The activation of the osteoclasts has, in turn, been shown to be mediated by prostaglandins, and the new COX-2 selective drugs may reduce this activity (Mantyh 2002). Knockout mice allow researchers to investigate further the relative importance of individual receptors and provide greater insights into the interactions between various pain-modulating
systems (Kie¡er et al. 2002). At this meeting, the importance of glial cells in neuropathic pain was demonstrated. The release of fractalkine from primary a¡erent neurons activates the glial cells to release interleukin-1 (IL1), IL6 and tumor necrosis factor (TNF). In a fascinating development in the area, researchers demonstrated that IL10 would inhibit this activity and could switch o¡ the central sensitization that occurs with this form of pain (Watkins 2002). Novel formulations of drugs were reported and of interest to practising veterinarians is that Endo Laboratories is working on a slow-release form of oxymorphone (Matsumoto et al. 2002; Ahdieh et al. 2002). Although still under development, it will hopefully provide us with another familiar drug which can be used for the management of cancer or severe osteoarthritic pain. The conference also had a few posters showing analgesic e¡ects of complementary methods such as acupuncture and magnetic ¢eld oscillations. The IASP holds its World Congress on Pain every three years and special interest groups (SIGs) also get together at this congress. An SIG is a group of at least 30 individuals who want to advance knowledge and understanding of their subject. There are currently SIGs covering a diversity of subjects from childhood pain to pain and movement. A number of individuals are now trying to organize an SIG for those interested in animal pain with the hope that we can have our ¢rst meeting at the World Congress on Pain in Sydney in 2005. If you are interested in being part of this group, contact Dr Duncan Lascelles ([email protected]) or Dr Peter Pascoe ([email protected]). Membership in IASP is a requirement for being part of an IASP SIG, so join now (http://www.iasp-pain.org) and start planning for a visit to the lovely city of Sydney in 2005. A further development is the formation of another group ^ an academy which will focus on animal pain management. This academy hopes to bring together veterinarians and nonveterinarians who have an interest in this subject. The purpose of the academy will be to enhance communication in the discipline, foster the development of new knowledge, and advance the clinical management of pain in animals. The academy is still at a £edgling stage, but for 1
Exciting times in veterinary analgesia
further information contact Dr P Hellyer at [email protected]. Last, but not least, a group recently met to talk about the issues facing us in the recognition and management of pain in animals. The organizers of this meeting (Drs J Ludders and J Paul-Murphy) assembled an international team of scientists with a wide variety of interests and expertise. The meeting, funded by the Mayday fund, took place at the Airlie Conference Center in Virginia from 19th 22nd September. Thirty participants with research publications involving everything from ¢sh to frogs to fowl to elephants grappled with the current state of our knowledge (or lack of it) in this subject. The outcome should be a paper, published early this year that reviews where we are and gives directions to future research and development. It is clear from all of these exciting developments that we are in a new era of interest and pioneering in animal pain. The task ahead is daunting because of its complexity and diversity, but we are assembling groups of talented and dedicated people to push back the frontiers and improve our ability to successfully manage animal pain in all its forms.
References Ahdieh H, Ma T, Babul N et al. (2002) Oxymorphone ER is e⁄cacious and well tolerated in patients with post-surgical pain following knee arthroplasty: results of a randomized, controlled trial. Abstracts from
2
the 10th World Congress on Pain, San Diego, CA, USA, pp. 428. Flecknell P,Waterman-Pearson A (2000) Pain Management in Animals.W. B. Saunders Co., London, UK. GaynorJS, MuirWW III (2002) Handbook of Veterinary Pain Management. Mosby, St Louis, MO, USA. Heard D (2001) Analgesia and anesthesia. Vet Clin North Am: Exotic Anima Pract 4. Hellebrekers LJ (2000) Animal Pain. A Practice-Oriented Approach to an E¡ective Pain Control in Animals. Van Der Wees, Utrecht, the Netherlands. Kie¡er BL, Evans C, Beaudet A (2002) Opioid receptors and diversity of opioid responses. Abstracts from the 10th World Congress on Pain, San Diego, CA, USA, pp.352. Mama KR, Hendrickson DA (2002) Pain management and anesthesia.Vet Clin North Am: Equine Pract18. Mantyh PW (2002) A mechanism-based understanding of cancer pain. Abstracts from the 10th World Congress on Pain, San Diego, CA, USA, pp.362. Mathews KA (2000) Management of pain. Vet Clin North Am: Small Anim Pract 30. Matsumoto A, Ma T, Babul N et al. (2002) Oxymorphone ER (20 mg and 40 mg) provides superior e⁄cacy compared with placebo and oxycontin1 (20 mg) in pain associated with osteoarthritis: results of a randomized, controlled trial. Abstracts from the 10th World Congress on Pain, San Diego, CA, USA, pp. 428. Tranquilli WJ, Grimm KA, Lamont LA (2002) Pain Management for the Small Animal Practitioner. Teton Newsmedia, Jackson,WY, USA. Watkins LR (2002) Glial activation as a mediator of pathological pain: Implications for clinical pain control. Abstracts from the 10th World Congress on Pain, San Diego, CA, USA, pp.123.
Veterinary Anaesthesia and Analgesia, 2003, 30, 1^2
E D I TO RIA L
Exciting times in veterinary analgesia The last few months have seen some exciting developments for pain management in animals. Over the last two years, we have gone from having no recent textbooks on this subject to having seven, with the recent publication of ‘Handbook of Veterinary Pain Management’ (Gaynor & Muir 2002). Earlier this year, theVeterinary Clinics of North America: Equine Practice (Mama & Hendricks 2002) focused on analgesia and pain management and in the last two years, three texts (Flecknell & Waterman-Pearson 2001; Hellebrekers 2000; Tranquilli et al. 2001) and two Veterinary Clinics of North America (Mathews 2001; Heard 2001) were published. We now have some excellent resources for small, large, and exotic animal practitioners. The texts provide a wide range of views on the topic: from philosophical discussions about approaches to animal pain, to very practical descriptions of local anesthetic techniques, to excellent reviews of the pharmacology and application of drug therapy. Several of these texts also include material on complementary therapies for animal pain management. These texts also point out the gaps in our knowledge about pain in animals: from our sparse abilities to assess pain in animals to our lack of data on the pharmacokinetics and pharmacodynamics of analgesic drugs in most of the species we handle. At the International Association for the Study of Pain meeting in San Diego in August 2002, the attending scientists presented a huge volume of information as reviews of current understanding and as cutting edge discoveries (approximately 1500 abstracts presented as posters over ¢ve days). New tools and techniques are allowing us to delve deeper into the mysteries of the nociceptive system and gain greater understanding of the mechanisms underlying various types of pain. Bone cancer pain is partly due to the acidic environment produced around osteoclasts, which activates the small C ¢bers present in bone. The activation of the osteoclasts has, in turn, been shown to be mediated by prostaglandins, and the new COX-2 selective drugs may reduce this activity (Mantyh 2002). Knockout mice allow researchers to investigate further the relative importance of individual receptors and provide greater insights into the interactions between various pain-modulating
systems (Kie¡er et al. 2002). At this meeting, the importance of glial cells in neuropathic pain was demonstrated. The release of fractalkine from primary a¡erent neurons activates the glial cells to release interleukin-1 (IL1), IL6 and tumor necrosis factor (TNF). In a fascinating development in the area, researchers demonstrated that IL10 would inhibit this activity and could switch o¡ the central sensitization that occurs with this form of pain (Watkins 2002). Novel formulations of drugs were reported and of interest to practising veterinarians is that Endo Laboratories is working on a slow-release form of oxymorphone (Matsumoto et al. 2002; Ahdieh et al. 2002). Although still under development, it will hopefully provide us with another familiar drug which can be used for the management of cancer or severe osteoarthritic pain. The conference also had a few posters showing analgesic e¡ects of complementary methods such as acupuncture and magnetic ¢eld oscillations. The IASP holds its World Congress on Pain every three years and special interest groups (SIGs) also get together at this congress. An SIG is a group of at least 30 individuals who want to advance knowledge and understanding of their subject. There are currently SIGs covering a diversity of subjects from childhood pain to pain and movement. A number of individuals are now trying to organize an SIG for those interested in animal pain with the hope that we can have our ¢rst meeting at the World Congress on Pain in Sydney in 2005. If you are interested in being part of this group, contact Dr Duncan Lascelles ([email protected]) or Dr Peter Pascoe ([email protected]). Membership in IASP is a requirement for being part of an IASP SIG, so join now (http://www.iasp-pain.org) and start planning for a visit to the lovely city of Sydney in 2005. A further development is the formation of another group ^ an academy which will focus on animal pain management. This academy hopes to bring together veterinarians and nonveterinarians who have an interest in this subject. The purpose of the academy will be to enhance communication in the discipline, foster the development of new knowledge, and advance the clinical management of pain in animals. The academy is still at a £edgling stage, but for 1
Exciting times in veterinary analgesia
further information contact Dr P Hellyer at [email protected]. Last, but not least, a group recently met to talk about the issues facing us in the recognition and management of pain in animals. The organizers of this meeting (Drs J Ludders and J Paul-Murphy) assembled an international team of scientists with a wide variety of interests and expertise. The meeting, funded by the Mayday fund, took place at the Airlie Conference Center in Virginia from 19th 22nd September. Thirty participants with research publications involving everything from ¢sh to frogs to fowl to elephants grappled with the current state of our knowledge (or lack of it) in this subject. The outcome should be a paper, published early this year that reviews where we are and gives directions to future research and development. It is clear from all of these exciting developments that we are in a new era of interest and pioneering in animal pain. The task ahead is daunting because of its complexity and diversity, but we are assembling groups of talented and dedicated people to push back the frontiers and improve our ability to successfully manage animal pain in all its forms.
References Ahdieh H, Ma T, Babul N et al. (2002) Oxymorphone ER is e⁄cacious and well tolerated in patients with post-surgical pain following knee arthroplasty: results of a randomized, controlled trial. Abstracts from
2
the 10th World Congress on Pain, San Diego, CA, USA, pp. 428. Flecknell P,Waterman-Pearson A (2000) Pain Management in Animals.W. B. Saunders Co., London, UK. GaynorJS, MuirWW III (2002) Handbook of Veterinary Pain Management. Mosby, St Louis, MO, USA. Heard D (2001) Analgesia and anesthesia. Vet Clin North Am: Exotic Anima Pract 4. Hellebrekers LJ (2000) Animal Pain. A Practice-Oriented Approach to an E¡ective Pain Control in Animals. Van Der Wees, Utrecht, the Netherlands. Kie¡er BL, Evans C, Beaudet A (2002) Opioid receptors and diversity of opioid responses. Abstracts from the 10th World Congress on Pain, San Diego, CA, USA, pp.352. Mama KR, Hendrickson DA (2002) Pain management and anesthesia.Vet Clin North Am: Equine Pract18. Mantyh PW (2002) A mechanism-based understanding of cancer pain. Abstracts from the 10th World Congress on Pain, San Diego, CA, USA, pp.362. Mathews KA (2000) Management of pain. Vet Clin North Am: Small Anim Pract 30. Matsumoto A, Ma T, Babul N et al. (2002) Oxymorphone ER (20 mg and 40 mg) provides superior e⁄cacy compared with placebo and oxycontin1 (20 mg) in pain associated with osteoarthritis: results of a randomized, controlled trial. Abstracts from the 10th World Congress on Pain, San Diego, CA, USA, pp. 428. Tranquilli WJ, Grimm KA, Lamont LA (2002) Pain Management for the Small Animal Practitioner. Teton Newsmedia, Jackson,WY, USA. Watkins LR (2002) Glial activation as a mediator of pathological pain: Implications for clinical pain control. Abstracts from the 10th World Congress on Pain, San Diego, CA, USA, pp.123.
Veterinary Anaesthesia and Analgesia, 2003, 30, 1^2