Analgesia Ch.8 Objectives. Flashcards
Define pain
Pain is a complex phenomenon that has been defined as an aversive sensory and emotional experience that elicits protective motor actions (such as a dog trying to bite when given an injection), results in learned avoidance (the same dog exhibits fear the next time it is taken to the clinic for vaccine boosters), and may modify species-specific behavior traits, including social behavior.
Define Nociception
The detection of potential or actual tissue injury by the nervous system
Define Neuropathic Pain
Neuropathic pain results from injury to the nervous system (for example, due to nerve damage).
Define Idiopathic Pain
Pain that is not identifiable.
Define Physiologic Pain
The protective sensation of pain that normally occurs when there is a possibility of or actual tissue injury
Define Pathologic Pain
Pain that is amplified and persistent. This type of pain is due to malfunction of or damage to the nervous system
Define Inflammatory Pain
Occurs at the site of tissue injury due to the release of chemical mediators such as prostaglandins and histamine
Define Visceral Pain
Pain originating from organs, (e.g., pleuritis or colic), or from the musculoskeletal system
Define Somatic Pain
Somatic pain (e.g., bone fracture, skin incision). Somatic pain can be divided into superficial (i.e., skin) and deep (i.e., joints, muscles, bones) pain.
Define Preemptive Analgesia
Analgesia administered prior to the painful event
Define Pain Scale
Canine Acute Pain Scale and the CSU Feline Acute Pain Scale are numeric rating scales. These scales have descriptors in each of three categories (psychologic and behavioral, response to palpation, and body tension) that are used as a guide to classify the degree of pain on a scale of 0 to 4. There are also several pain scales available on-line that are designed for assessment of chronic pain.
Define Multimodal Therapy.
Also known as combination or balanced analgesia, may be more successful than treatment with any single agent, because pain perception is affected at several points along the pain pathway and different mechanisms are targeted
List the main steps of the pain pathway.
Transduction, transmission, modulation, and perception.
-The first step is the transformation of noxious mechanical, thermal, or chemical stimuli into electrical signals called action potentials by nociceptors (pain receptors), and is called transduction. These sensory impulses are then conducted to the spinal cord via peripheral nerve fibers, a process known as transmission. In the spinal cord, where the fibers terminate, the impulses can be altered by other neurons, which can either amplify or suppress them. The general term to cover both possibilities is modulation. The final step is perception, in which the impulses are transmitted to the brain, where they are processed and recognized.
List the benefits of multimodal analgesia.
Significantly reduced opioid usage, minimized side effects from individual medications, improved pain control, faster recovery times, decreased risk of chronic pain development, potential for shorter hospital stays, and better patient satisfaction by addressing pain at multiple points along the pain pathway, allowing for lower overall medication doses
Explain how primary hyperalgesia (peripheral hypersensitivity) develops.
This peripheral hypersensitivity, referred to as primary hyperalgesia, manifests clinically as increased sensitivity to a painful stimulus.
For example, if you fracture your wrist and someone touches the damaged area, you may feel an exaggerated sense of pain from that touch that is worse that can be accounted for by the extent of the injury.
List the consequences of untreated pain.
Pain that goes untreated has undesirable consequences for the patient.
* Pain produces a catabolic state, which may lead to wasting.
* Pain suppresses the immune response, predisposing to infection and increasing hospitalization time and cost.* Pain promotes inflammation, which delays wound healing.
* Anesthetic risk is increased because higher doses of anesthetic drugs are required to maintain a stable plane of anesthesia.
* Pain causes patient suffering, which is also stressful for owners and caregivers
Explain how secondary hyperalgesia (central hypersensitivity) develops.
This central nervous system hypersensitivity, referred to as secondary hyperalgesia, is also referred to as “windup.” Clinically this may manifest as allodynia, a phenomenon in which an area close to the site of tissue injury is painful if stimulated with a normally non-noxious stimulus.
List common surgical and medical conditions that are considered to be painful.
-Painful Medical Conditions:
Arthritis
Cancer
Cystitis
Pancreatitis
Peritonitis
Pleuritis
-Painful Surgical Conditions:
Spinal surgery
Fracture repair
Total hip replacement
Joint surgery
Ear surgery
Dental extractions
Rhinotomy or sinus surgery
Trauma
Eye surgery
Thoracotomy
Gastric dilatation–volvulus, colon torsion
Pyometra
Describe how to recognize and assess pain-associated behaviors in animals.
Different species often respond differently when they are in pain; cats tend to hide, dogs tend to seek attention from their owners, and herd or flock animals tend to separate from the other animals.
Changes in gait and level of activity such as lameness, limping, stiffness, and reluctance to move are all indicators of limb or joint pain. Vocalization is frequently associated with pain.
Compare and contrast major types of pain assessment tools and describe how to use each.
Evaluate the pain through careful observation, examination, and/or interaction with the patient. These assessment tools include verbal rating scales, simple descriptive scales, visual analogue scales, numeric rating scales, categorical numeric rating scales, and comprehensive scales.
List the routes by which analgesic drugs are commonly administered.
Intravenous, Intramuscular, Subcutaneous, Oral.
List the uses for and adverse effects of opioid analgesics.
Opioid analgesics such as morphine, oxymorphone, hydromorphone, methadone, and fentanyl are opioid receptor agonists and are the most effective drugs for treating acute pain. Opioids are commonly included in injectable premedications, often in combination with a tranquilizer such as acepromazine or dexmedetomidine. Adverse effects: Sedation (dogs), excitement (cats), respiratory depression, and nausea are therefore rare, although urinary retention and pruritus may be seen.
Explain the mechanism of action of non-steroidal anti-inflammatory drugs.
NSAIDs, also called nonsteroidal antiinflammatory analgesics or NSAAs, are a large group of agents that have been used for many years to control minor pain. Mechanism of Action: All NSAIDs appear to be effective analgesics for somatic (musculoskeletal) pain. Many NSAIDs have potent anti-inflammatory properties. Some NSAIDs are antipyretic (reduce fevers).
Describe the uses for and procedure for application of fentanyl transdermal patch.
Transdermal patches containing fentanyl are another convenient option for long-term opioid administration. Fentanyl patches have been used for several years in the treatment of severe pain. The patch is applied to the clipped skin of the animal and is left in place for several days.
List the uses for and adverse effects of non-steroidal anti-inflammatory drugs.
Many of the adverse effects of NSAIDs are attributable to the fact that they reduce not only the production of the prostaglandins that mediate pain, inflammation, and fever, but also those that are beneficial. Meloxicam, carprofen, and etodolac have less ulcerogenic activity in dogs and are preferred for long-term use, as in dogs with osteoarthritis. Gastrointestinal issues.
Define multimodal therapy and list two examples of multimodal therapy.
Multimodal therapy (also known as combination or balanced analgesia) may be more successful than treatment with any single agent, because pain perception is affected at several points along the pain pathway and different mechanisms are targeted. Ex: piroxicam (an NSAID) and buprenorphine (an opioid). acetaminophen and codeine
Describe nursing care that relieves discomfort in hospitalized patients.
Providing conscientious nursing care, including keeping the animal and its cage or stall clean and dry, affording ample opportunity for defecation and urination (including bladder expression or catheterization if necessary), providing comfortable bedding and quiet surroundings, and gently reassuring the patient. Also, treatments and monitoring should be scheduled so that the patient is not disturbed unnecessarily. Application/Administration of ointments and medications can assist in comfort.
