The Pathophysiology of Pain, Our Veterinary Patients, And you… What Can or Should Be Done? Andrew Claude DVM, Dipl ACVAA Michigan State University College of Veterinary Medicine
[email protected] Objectives • Definitions. • Process of Nociception. • What is pain? • AVMA/ACVAA regarding pain. • Patient – client considerations • Pain management in medicine • Clinical signs of pain in dogs/cats • Preemptive analgesia options • Pain scores in dogs and cats (if time) Definitions • Anesthesia = analgesia = analgesic? Clinician's Brief • General anesthesia: General vs. local and regional anesthesia • Analgesia: the inability to feel pain • Analgesic: any member or group of drugs used to achieve analgesia or relief from pain. • Analgesia →Nociception • Acute vs. Chronic pain, neuropathic pain Process of nociception • Transduction • Aβ, Aδ, c-Fibers, silent • Transmission • Dorsal horn, CNS • Primary Modulation • Segmental reflexes • Projection • Perception • Conscious Pain • Autonomic (SNS) • Memory • Emotions • Central/peripheral • Humans/animals What is pain? • Definition: “an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage.” • Sensory component (nociception) • Affective component (experience) • Considered the 5th clinical sign • HR • RR • Temp • BP • Pain assessment What is pain? • Requires conscious perception of a noxious event • Do unconscious patients perceive pain? • Nociception: “the neurophysiological process whereby noxious mechanical, chemical, or thermal stimuli are transduced into electrical signals (action potentials) by high-threshold nociceptors.” These action potentials follow a series of pathways that ultimately end in the brain • The conscious result is “pain” AVMA • Pain in Animals • Animal pain is a clinically important condition that adversely affects an animal's quality of life. Drugs, techniques, or husbandry methods should be used to prevent, minimize, and relieve pain in animals experiencing or expected to experience pain.