Assessing Pain By Orest Kornetsky

The Fifth Vital Sign Pain: an unpleasant sensory and emotional experience associated with actual or potential tissue damage (International Association for the Study of Pain). Not only a sensory experience resulting from activation of pain receptors, but also the pt’s emotional and cognitive response. Pain is personal and subjective

Physiology of Pain Pain is the result of 2 opposing pathways Pain impulses are carried to the brain, generating sensation of pain Activation of pain receptors by mechanical (pressure), thermal, or chemical (histamine, serotonin, bradykinin) stimuli. Prostaglandins or substance P can enhance the sensitivity of pain receptors to activation. Periphery  Spinal Cord  Thalamus  Cerebral Cortex Pain impulses are suppressed by the brain, diminishing pain sensation Done by endogenous opioids, especially endorphins and enkephalins. Released at both spinal cord and cerebral cortex The opioids we give activate the same receptors as these endogenous opioids

2 Types of Pain Nociceptive Neuropathic Results from injury to tissues Carried to CNS by 2 types of fibers, Aδ and C fibers 2 types Somatic Results from injury to somatic tissues (bones, joints, muscles) Described as localized and sharp Visceral Results from injury to visceral organs (intestine). Described as vaguely localized and achy Both forms of nociceptive pain respond well to opioid analgesics (morphine) and may respond to nonopioids (ibuprofen) Neuropathic Results from injury to peripheral nerves Described as burning, shooting, jabbing, tearing, numb, dead, cold. Responds poorly to opioid analgesics Responds well to adjuvant analgesics (antidepressants, anticonvulsants, local anesthetics such as lidocaine) One example of neuropathic pain is called phantom limb syndrome. This occurs when an arm or a leg has been removed because of illness or injury, but the brain still gets pain messages from the nerves that originally carried impulses from the missing limb. These nerves now misfire and cause pain. Phantom limb syndrome. Neuropathic pain which occurs when an arm or a leg has been removed because of illness or injury. But the brain still gets pain messages from the nerves that originally carried impulses from the missing limb. These nerves now misfire and cause pain.

What kind of pain is caused by cancer? May be caused by cancer or by therapeutic interventions Direct invasion or metastatic invasion of other sites Neuropathic pain may be caused through infiltration of nerves Visceral pain may be caused through infiltration, obstruction, and compression of organs

Types of Pain (by duration) Acute pain Short term Following injury, surgery, trauma Dissipates after injury heals Chronic pain Pain longer than 6 months Malignant or nonmalignant Malignant pain due to invasion of surrounding tissues (nerves, organs, bone) or interventions such as chemotherapy (causing neuropathy) Nonmalignant pain often has no protective purpose and is due to abnormal processing of pain from peripheral and central sites Cancer pain - Often by necrosis or stretching of organ

Assessing Pain Location – Where is your pain? Do you feel pain in more than one place? Can you point to the location of pain? Onset and temporal pattern – When did it begin? How often does it occur? Has the intensity increased, decreased or remained constant? Quality – What does your pain feel like? Is it sharp or dull? Does it ache? Is it burning or tingling? Intensity Modulating factors – What makes your pain better? What makes it worse? Previous treatments – What have you previously tried to relieve your pain? Was it effective? Function – Does your pain affect your ability to function and how? Does it interfere with work, eating, sleeping, etc?

Assessing Pain Numeric – “Can you rate your pain on a scale of 0 to 10 with 0 being no pain and 10 being the worst pain you can imagine.” Descriptive – for older adults. List words to describe intensity of pain. Wong-Baker FACES Scale -

Assessing Pain – Nonverbal Cues Acute Pain Grimacing, moaning, agitation, diaphoresis Change in vital signs (tachycardia, increased BP, hypoventilation) Other physiological changes (N&V, decreased immunity, muscle spasms, depression) Chronic Bracing, rubbing, diminished activity, sighing, appetite change

Developmental Considerations Infants Lack inhibitory neurotransmitters until 38 weeks gestation  more sensitive if preterm It’s now believed to be a myth that infants don’t feel pain Aging adults Don’t assume pain is normal

Question 1 During your physical exam, your patient is diaphoretic, pale, and complains of pain directly over the LUP of the abdomen. This would be categorized as: Cutaneous pain Somatic pain Visceral pain Psychogenic pain

Question 2 While caring for an infant, you are aware that: Inhibitory neurotransmitters are in sufficient supply by 15 weeks’ gestation The fetus has less capacity to feel pain Repetitive blood draws have minimal long-term consequences The preterm infant is more sensitive to painful stimuli

Question 3 The most reliable indicator of pain the in the adult is: Degree of physical functioning Nonverbal behaviors MRI findings The client’s self report

Question 4 While examining a broken arm of a 4-year old boy, select the appropriate assessment tool to evaluate his pain status 0-10 numeric rating scale Wong-Baker scale Simple descriptor scale 0-5 numeric rating scale

Question 5 The CRIES is an appropriate pain assessment tool for: Cognitively impaired elderly Children ages 2-8 Infants Preterm and term neonates