Regenerative medicine (stem cells) and other emerging chronic pain management techniques (Proceedings)

Apr 01, 2010

Accurate measurement of pain perception in individual non-human patients is impossible. However, management of pain requires objective measures of effectiveness of the applied treatment. This paradox of pain management underlies much of the frustration associated with clinical management of pain and creates the opportunity for ineffective treatments to be supported by "scientific" studies. As a veterinary care provider treating patients likely experiencing differing intensities of pain, it is important to understand the pros and cons of pain assessment methods and utilize a critical anthropomorphic evaluation and treatment of postoperative pain.

Critical anthropomorphic evaluation of pain

Animal behaviour differs between species, between individuals of the same species, and even within the same individual over time and with different environmental influences. Creating a rapid and simple method for evaluation of pain perception is unlikely. However many clinicians advocate the use of pain scoring to measure treatment effectiveness to prevent the unnecessary suffering of feline patients. The most useful approach to clinical treatment incorporates some of our own human experiences and feelings (anthropomorphic) but modifying those expected feelings based on knowledge of feline behaviour and physiology. While not scientifically rigorous, this critical anthropomorphic approach incorporates our knowledge of pain in humans with our understanding of how we expect animals to react to noxious stimulation to clinically guide our treatment of pain.

Pain physiology

An important conceptual breakthrough in understanding pain physiology is the recognition that pain following most types of noxious stimulation is usually protective and quite distinct from pain resulting from overt damage to tissues or nerves. It plays an integral adaptive role as part of the body's normal defense mechanisms, warning of contact with potentially damaging environmental insults and initiating behavioral and reflex avoidance strategies. It is also often referred to as nociceptive pain because it is only elicited when intense noxious stimuli threaten to injure tissue. It is characterized by a high stimulus threshold, is well localized and transient, and demonstrates a stimulus-response relationship similar to the other somatosensations. This protective mechanism is facilitated by a highly specialized network of nociceptors and primary sensory neurons which encode the intensity, duration and quality of noxious stimuli and, by virtue of their topographically organized projections to the spinal cord, its location.