ansc 3060 - pain and pain management

Problem

our pets can't talk and tell us they hurt, but animals suffer from pain just like we do

•Acute pain

- is obvious, distressing

- ex; after a spay/neuter, short lived, acute pain can be subjective

Chronic pain

- can be subtle, masked as "getting old" or "slowing down"

- tied to inflammation

- aging is not a disease but pain is

•Treatment options:

•Pharmaceuticals and nutraceuticals

•physical rehabilitation

•Acupuncture

•Laser therapy

•Therapeutic massage

pain

emotional, mental, physical suffering due to illness

pain can be

protective

•Alerts animal to tissue damage, may lead to protective behaviors

•Challenges in veterinary medicine

1.No "gold standard" to assess pain

2.Most veterinary pain scales involve recognizing behavioral changes which can vary with each interpreter

• Over or underestimated

3.Physiologic parameters(TPR)

not new about pain

•Pain is clinically relevant(not new)

new about pain

•Understanding of the complexity of pain (relatively new)

•Emphasis on ethical and medical obligations to treat pain in animals(relatively new)

what must become a part of PE

•Assessment, prevention, and treatment of pain must become an integral part of every PE and treatment plan!

•Animals and people have similar neural pathways

•Development

•Conduction

•Modulation of pain

•Expression of acute and chronic pain comparable

•Like us, dogs and cats develop myopathies and neuropathies = pain, discomfort!!

Clinical signs of pain

•Changes in posture

•Temperament changes

•Negative reactions to palpation, petting

•Vocalization (rare...most animals will not cry out)

•Reluctance to move- musculoskeletal

•Appetite(increases or decreases??)

•Grooming(increases or decreases??)

cat pain signs

•Cats generally more stoic

•Old School

•Pain Management SECONDARY to control of disease in human and animal medicine L

•the mindset of most veterinarians was reactive not proactive in regards to pain

•Historically only treated when it could no longer be ignored

Today pain is...

"The Fourth Vital Sign"

examining pain

•Every veterinarian in practice should be examining every pet for signs of pain!!

•observation, palpation, and thorough history

•considered the gold standard for the veterinary examination

Anticipation =

•early diagnosis and early treatment of pain is humane

•Prevents future suffering

•Actually alter the course of the disease

Why is pain bad??

•Inflammation is a main component of pain!!

•It hurts, remember??

•Veterinarians have...

an ethical obligation to recognize and treat pain

5 "freedoms"

•Freedom from Hunger and Thirst

•ready access to fresh water, good diet

•Freedom from Discomfort

•Environment includes shelter ,comfortable resting area

•Freedom from Pain, Injury, or Disease

•prevention or rapid diagnosis,treatment

•Freedom to Express Normal Behavior

•provide sufficient space, proper facilities, and company of the animal's own kind

•Freedom from Fear and Distress

•ensuring conditions and treatment that avoid mental suffering

Adverse clinical consequences of pain

•Distress

•Delayed healing

•Poor quality of life

•Sleep disturbance

•Poor appetite

•Depression

•Altered social interaction

•Progression to more serious levels of pain

•More difficult to treat

Types of pain

acute

chronic

cancer

neuropathic

1.Acute

symptom of disease

2.Chronic

•Is a disease in and of itself - altered neuroprocessing

•Does not serve a biological function

•Results in severe detrimental stresses

3.Cancer: related to disease or the treatment

•Result of primary tumor growth(inflammation)

•Metastatic disease

•Toxic effects of chemo, radiation

•Acute, chronic, or intermittent

4. Neuropathic

• Severe injury of the peripheral or central nervous systems

• trauma(amputation, crushing injury)

•Vascular injury

•thromboembolic disease

• Endocrinopathy

•eg, diabetes mellitus

•Infection

•Nociceptive information sent to higher centers in CNS

•Integration

•Modulation

•Interpretation into the conscious perception of pain

• Noxious stimuli include:

•Activate free sensory nerve endings known as nociceptors

•Fibers transmit sensory information from nociceptors to the dorsal horn of the spinal cord

•Directs, modulates input from periphery and higher centers

•may activate motor neurons responsible for the reflex response to noxious stimuli (withdrawal reflex)

conscious perception

•Fibers in S.C. bring info to relay centers in the brain - they send info to cerebral cortex= conscious perception

pain perception

•Thalamus

•Reticular formation (responsible for level of arousal- what reaches the cerebrum for conscious perception)

•Limbic system (responsible for emotions)

•"Pain - suppressing system"

•antinociceptive systems (originate in the brain stem)

•inhibit the transmission of nociceptive information in the spinal cord, brain

•Antinociceptive neurotransmitters:

•Ex: endorphin, serotonin, and norepinephrine

"Wind- up" pain

•Result in heightened or exaggerated pain states

•Often do not respond to conventional analgesic therapy

•Clinical pain management becomes more complicated

•Pain= activation of endocrine system:

•Result in negative changes at tissue level:

reduction in blood flow to area (micro level)

Analgesia

drugs to alleviate pain

Alleviation of pain - Combination of

•Nursing care

•Non-pharmacologic methods:

•Pharmacologic methods

•Pharmacolgy based on degree of tissue trauma, acute vs. chronic, systems involved etc..

•Many different classes of drugs - opiods, NSAIDS,

•Multimodal analgesia

pain management strategy that combines multiple methods

Surgery

•Local/regional anesthetic

•General anesthetic

•Preemtive analgesia(perioperative approach!)

•Intraoperative analgesia

•Post operatively(protocol depends on procedure, level of pain)

•Recovery period of surgery:

•Proper housing conditions

•Nutritional support

•+/- Interaction with other animals and/or people

Osteoarthritic pain

•Chronic, similar in people

•Pharmacologic (multimodal)

•Surgical

•Non pharmacologic:

•weight control, PT, controlled exercise, chondroprotectants, stem cell therapy, acupuncture

Cancer pain

•Related to disease or treatment(colitis secondary to chemo, stomatitis secondary to radiation)

•Tumorigenic (tumor-related products)

•Inflammatory

•Neuropathic

•Similar to all chronic pain

•Often doesn't respond to common therapies

•Requires frequent reassessment

•+/- adjustments in therapy

Weight control for Pain Management

•Adipose tissue secretes a mixture of cytokines

•Contribute to the pathology of many diseases(DJD)

•A lean body condition score is central to the treatment of chronic pain

Pain Management requires

•Requires a continuum of care

•Based on a well-thought-out plan

•includes anticipation, early intervention, and evaluation of response on an individual-patient basis

•Response to therapy is a legitimate pain assessment tool

•"PLATTER" - continuum of care loop

•PLan, Anticipate, TreaT, Evaluate, and Return

if pain persists

•Hospice care

•Humane euthanasia