Pain

Nota:

• - Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. - The sensation is physical, while the response to it is psychological

1. The psychological apects

   Nota:

   • - Pain is invisible - The brain is actively involved in the experience - The body's defense mechanisms warn the brain that its tissues may be harmed, in danger, etc. - It involves, sensory, behavioral, emotional, and cultural components

Nota:

• - It necessary in that although a health problem, it makes people seek medical attention - It helps survival as it notifies us that something is not right in our bodies

1. Acute pain

   Nota:

   • - Extreme pain that comes on quick, but only lasts for a brief period (6 months maximum) - Warns of tissue damage or disease - Higher levels of anxiety can be caused by tissue damages, but distress eventually subsides as the conditions improve - The cause can be reversed
2. Chronic pain

   Nota:

   • - Lasts longer than acute pain (6 months) - If after tissue damage, the pain will continue regardless of the recovery of the damaged tissues - High levels of anxiety may continue and develop into feelings of hopelessness (ex. depression) - Pain interferes with daily activities and sleep - Medication is the most common treatment
3. Psychogenic pain

   Nota:

   • - Discomfort seems to result from psychological processes - There is no organic basis for this pain
   1. Neuralgia

      Nota:

      • - A sharp pain along a nerve pathway that occurs after the end of a nerve damaging disease (ex. herpes)
   2. Causalgia

      Nota:

      • - A burning pain that can develop after a severe would is healed
   3. Phantom Limbs

      Nota:

      • - A sensation of pain from a limb that has been lost or from a limb that no longer sends signals.

1. Evaluation

   Nota:

   • - Accurate when applied to certain types of pain and injuries - Mechanistic view that assumes surgery or medication can eliminate cause. This isn't the case for chronic pain - Phantom limbs aren't explained as there is no on-going tissue damage - The psychological side of pain isn't considered
2. Comparison

   Nota:

   • - Gate theory includes biological and psychological factors in the pain experience while the specificity theory does not - Gate theory is supported by the gate closing by nerve stimulation and phantom limb while the specificity theory isn't as the sensors are wired to the "pain center" - Pain can be shut off in the gate theory. It can't be in the specificity theory with emotions simply being reactions to the stimuli - Gate control theory is more holistic while the specificity is reductionist

Nota:

• - No separate system for pain. Receptors are shared - Different stimulation types create unique patterns of neural activity. Pain, is felt with the intense stimulation.

Nota:

• - Developed by Melzack & Wall in 1965 - The spinal cord contains a neurological 'gate' that can block signals from the brain - The gate can differentiate between different pain signals - Pain signals in small nerve fibers are allowed to pass while those in large nerve fibers are not - Small fibers carry messages quickly with intense pain - Larger fibers carry the throbbing pains and chronic

1. Factors

   Nota:

   • 1. Strong harmful stimuli in small fibers tend to open the gate 2. Activity in large nerve fibers can close the gate and inhibit pain (ex. touching, rubbing, scratching, etc.) 3. Neurons in the brain stem and cortex respond to emotional states such as anxiety and excitement by opening and closing the gate.
2. The psychological aspects

   Nota:

   • - Thoughts and emotions influence pain perception - Stimulating neurons by rubbing or shaking can close the gate, hence reducing pain - Pain is a perception - Pain is an interaction between the mind and body

Nota:

• Sensory - intensity, duration, tolerance, location Neurophysiological - brainwave activity, heart rate Emotional and motivational - anxiety, anger, depression, resentment Behavioral - avoidance of exercise, pain complaints Impact on lifestyle - marital distress, changes in sexual behavior Information processing - problem solving skills, coping styles, health beliefs

Nota:

• - As pain is a subjective internal experience, it is fitting that self-report is the most used method in assessing pain

1. Interviews

   Nota:

   • Dimensions of pain that are touched: - Site of pain - Type of pain (what it feels like) - Frequency of pain - Aggravating or relieving factors - Disability (how it effects daily life) - Duration of pain - Response to current and previous treatments  - Emotional and cognitive effect of the pain
   1. Evaluation

      Nota:

      • Reliability - consistency isn't guaranteed  as errors can occur as people aren't always reliable sources Validity - pain scales are used. are they valid?

1. Rating scales
   1. Visual analog scale

      Nota:

      • - Patients mark a continuum of severity from "No Pain" to "Very Severe Pain - Can track the pain experience as it changes - this could reveal patterns such as situations or times of the day when the pain is better or worse - May be used before, during, and following treatment to evaluate changes in the patient's perception of pain relative to treatment.
      1. Evaluation

         Nota:

         • - Reliable - Reductionistic since it is limited to a single dimension - Simple and quick and can be filled out repeatedly - Easy to understand - no complex words
2. Questionnaires
   1. McGill Pain Questionnaire (MPQ)

      Nota:

      • Melzack asked doctors and university graduates to classify 102 adjectives into groups describing different aspects of pain. As a result of this exercise, they identified three major psychological dimensions of pain: •    sensory: what the pain feels like physically —where it is located, how intense it is, its duration and its quality (for example, ‘burning’, ‘throbbing’)•    affective: what the pain feels like emotionally —whether it is frightening, worrying and so on•    evaluative: what the subjective overall intensity of the pain experience is (for example, ‘unbear­able’, ‘distressing’). - Then Melzack asked a sample of doctors, patients, and students to rate the words in each subclass for intensity.
      1. How it's used

         Nota:

         • - Patients are asked to tick the word in each sub-­class that best describes their pain. - Based on this, a pain rating index (PRI) is calculated: ( 1 for the adjective describing least intensity, 2 for the next one and so on). - Scores are given for each subclass and for the cumulative total - Body chart is used to indicate location - Present pain is a 6 point scale - Set of 3 verbal rating scales describing the pattern of the pain
      2. Limitations

         Nota:

         • - Patients need to have extensive understanding of English - Patient must be in normal cognitive scale (not while in a lot of pain!) - Difficult and time consuming

Nota:

• - People behave in certain ways when they are in pain; observing such behavior could provide a means of assessing pain. - Physicians can identify 'problem' behaviors that the patient may be reluctant to report - Physicians can monitor the progress of a course of treatment

1. Pain behaviors

   Nota:

   • •   Facial /audible expression of distress: grimac­ing and teeth clenching; moaning and sighing. •   Distorted ambulation or posture: limping or walking with a stoop; moving slowly or carefully to protect an injury; supporting, rubbing or hold­ing a painful spot; frequently shifting position. •   Negative affect: feeling irritable; asking for help in walking, or to be excused from activities; asking questions like ‘Why did this happen to me?’ •   Avoidance of activity: lying down frequently; avoiding physical activity; using a prosthetic device.
2. Everyday life observtions

   Nota:

   • - Assessments are made by family members or other key members in patient's life - Assessor compiles list of behaviors signaling pain - Assessor is trained to watch for behaviors, track the duration, and monitor how people react to behavior - Procedure helps determine the impact a patient's behavior has on his/her life and the social context that may maintain pain behaviors
3. Clinical observation

   Nota:

   • - Observing pin behaviors in a clinical setting - In most clinical situations, there will be different observers at different times; important tht they are consistent
   1. UAB Pain Behavior Scale

      Nota:

      • - Used by nurses on standard routines in clinical settings - Patient performs several activities and nurse rates 10 behaviors on a 3-point scale - Each clinical session has patients perform standard activities - Trained assessors rate performance for pain behaviors, such as guarded movement, rubbing, grimacing, etc
      1. Evaluation

         Nota:

         • - Correlation between scores on the UAB and on the McGill Pain Questionnaire is low indicating that the relationship between observable pain behavior and the self-reports of the subjective experience of pain - Behavioral relies on the observer’s interpretation of the patient’s pain behaviors      - this can be dealt with by using clearly defined checklists and carrying our inter rater reliability - Individual may be displaying a great deal of pain behaviour due to social reinforcement for  pain behavior (ex attention, sympathy and time off work)  

Nota:

• - Children have limited language abilities - Children have difficulty reporting location, intensity, quality, duration and pattern of pain  - Typically observe pain behavior for children under 5 - Older children can use visual analog scales and verbal rating scales ( :) to :'( ) - Some measures assess pain and psychosocioal effects (ex Pediatric Pain Questionnaire) - 

1. Pediatric Pain Questionnaire

   Nota:

   • Varni and Thompson (1976) assess factors though to influence pediatric pain perception - 23 families with a child that had juvenile rheumatoid arthritis - Developed an age-appropriate assessment tool to determine the effects of family environment, child psychological adjustment, and disease factors on child's pain perception - Children between ages 5 and 15 were found to be reliable judges of their pain intensity - Suggested that the assessment tools be used to examine pediatric chronic and recurrent pain
   1. Evaluation

      Nota:

      • Reliability: - patient can give different answers in tests- Examiner can interpret responses differently Subjective vs Objective measurements - Pain is subjective. But if measured reliably, the measurement is objective Kid friendly since the questions are open ended and not that suggestive Different dimensions of pain are measured

Nota:

• Reliability: - The patient may give a different response for each examination - The examiner may interpret responses differently for each examination Subjective andk Objective measurements -  Pain is subjective. But if measured reliably, the measurement is objective

Nota:

• 1. Surgery can be done to remove or disconnect portions of the peripheral nervous system (PNS) or spinal cord to prevent pain signals from reaching the brain - It is extreme, risky, and rarely provides long-term relief - Most appropriate when person is severely disabled and nonsurgical methods have failed 2. Surgery can be done without removing or disconnecting nerve fibers.- Synovectomy - surgeon removes inflamed membranes - Spinal fusion - joins two or more vertebrae to treat back pain

1. Anti-inflammatory drugs

   Nota:

   • - Peripherally acting analgesics (ex aspirin, acetaminophen, and ibuprofen) inhibit the production of neurochemicals that cause inflammation and activate nociceptors - they can reduce pain, inflammation and fever
   1. Side effects

      Nota:

      • - Gastric irritation - Bleeding (aspirin) - Deafness
   2. Problem

      Nota:

      • - Hospitalized patients tend to demand medication too often Solution: - Allowing patients to self-administer medication has led to less use of medication - When patients feel in control, they can manage without the drug for longer
2. Narcotics (opiates)

   Nota:

   • - Centrally acting analgesics (ex morphine and heroin) can bind to opiate receptors in the CNS and inhibit nociceptor transmission or alter perception of pain stimuli - They are prescribed for chronic or persistent pain
   1. Side effects

      Nota:

      • - Drowsiness - Mood changes - Mental clouding - Tolerance - Withdrawal
3. Local anesthetics

   Nota:

   • - These act directly on the site applied where pain originates - Chemicals block nerve cells in the region from generating impulses ( ex Novocaine) - Not recommended for long term use since there are serious side effects such as muscle paralysis
4. Indirectly acting drugs

   Nota:

   • - Non-pain conditions such as emotions that contribute pain are effected - Sedatives are depressants that depress bodily functions - Antidepressants reduce psychological depression that accompanies chronic pain - Anticonvulsants inhibit random nerve impulses, which will control some types of pain

1. Behavioral strategies
   1. Operant conditioning

      Nota:

      • - Uses social reinforcement to gradually increase activity levels - Gradually decrease the use of medication - Training carers not to reinforce pain behaviors by being sympathetic
      1. Children with burns

         Nota:

         • - Ignore pain behaviors - Provide rewards for compliant behavior - Give praise if the child helps in putting on splints, etc.
      2. Reducing medication

         Nota:

         • - Use a fixed schedule rather than giving meds on request - Medication is mixed with flavored syrup to mask its taste - Dosage is gradually reduced, but the patient does not detect this
      3. Evaluation

         Nota:

         • - Useful if patient has developed an inappropriate response to pain (ex reliant on medication) - Study has no control group - i is difficult to know whether the operant methods changed the behavior or some other factor did - Not suitable for chronic progressive pain (ex cancer) - Patients that are unwilling to participate or those that receive disability compensation are not likely to benefit from this technique
2. Cognitive techniques
   1. Distraction

      Nota:

      • - Focusing on a non-painful stimulus in the immediate environment in order to divert attention from discomfort - More effective if the pain is mild or moderate than if it is strong
   2. Non-pain imagery

      Nota:

      • - Person tries to alleviate discomfort by conjuring up a mental scene that is unrelated to or incompatible with the pain - Therapists encourage the patient to include all of the senses - It is similar to distraction, except that it is based on imagination
      1. Evaluation

         Nota:

         • - Patients can have multiple scenes that work reliably and conjure them when necessary - Some patients are less adept at imagining scenes that other
   3. Cognitive redefinition

      Nota:

      • - Patient substitutes constructive or realistic thoughts about the pain experience for thoughts that arouse feelings of threat or harm - Therapists can help by providing information about the sensations to expect in medical procedures
      1. Coping statements

         Nota:

         • - Emphasize the person's ability to tolerate pain by saying "it hurts, but you're in control" or, "be brave. you can take it."
      2. Reinterpretative statements

         Nota:

         • - Designed to negate unpleasant aspects of the pain, as when people think "it's not so bad", "it's not the worst thing that could happen", or "it hurts, but think of the benefits of this experience"
   4. Evaluation

      Nota:

      • - Cognitive strategies are effective in reducing acute pain -Distraction and imagery are particularly useful with mild or moderate pain - Redefinition appears to be more effective with strong pain

1. Acupuncture

   Nota:

   • - Fine metal needles are inserted under skin at special locations and are twisted or electrically charged to create stimulation - Placement of needles is based on charts showing points associated with specific parts of the body
   1. Evaluation

      Nota:

      • - Useful for chronic pain - Evidence for effectiveness is problematic as it lacks controlled trials which can compare to a placebo group.
2. Transcutaneous Electrical Nerve Stimulation (TENS)

   Nota:

   • - Place electrodes on skin near where the pain is felt to stimulate the area with a mild electric current - Stimulates large diameter nerve fibers to close the gate - Used for post-operative pain, arthritis, cancer, etc.
   1. Evaluation

      Nota:

      • - There are still doubts as to the effectiveness of electrotherapy as it is not fully understood