Pain Flashcards
What is Pain?
- Pain is an unpleasant sensory and emotional experience associated with actual/potential tissue damage acting as a signal.
- Pain also works by making us less likely to repeat the damaging behaviour again
Types of pain
- Acute pain-is intense or time limited pain that is generally the result of tissue damage or disease such as a broken bone, a cut/bruise and the labor of childbirth.(Meichenbaum 1983). This type of pain typically disappears over time as the injury heals and lasts less than 6 months.
- Chronic pain- Begins as acute pain in response to injury or disease but doesn’t go away after 6 months for e.g: arthritis, back pain, stab wounds, cancer, phantom limbs.
- Phantom limb pain- ongoing painful sensations that seem to be coming from the part of the limb that is no longer there.
* Mirror Treatment(Ramachadran and Rogers-Ramachdran) works by placing the remaining arm into a box with a mirror down the middle so that when it is viewed at a slight angle, it looks to the patient as if they have two intact arms.
* Patients then take part in a range of arm movement exercises which eventually leads to some people experiencing a reduction in phantom pain.
MacLachlan et al.
Aim- To investigate the efficacy of mirror treatment on treating lower limb pain.
Sample: 32 year old man, Alan, who had life-saving surgery to remove his leg at the hip.
Procedure: Presenting complaints
* Pain at the point of amputation
* Toes crossing
* Pins and needles
* The phantom limb being shorter than the other
Previous treatments:
-Pain relivers(analgesics)
-TENS(Transcutaneous electrical nerve stimulation)
Current treatment(Mirror treatment)- which involved ten repetitions each of ten different exercises such as straightening and bending the leg, pointing the foot up and down, clenching and unclenching toes and moving the foot in circles.
* Straightening with a physiotherapist and homework exercise. A rating scale was used to judge the level of phantom pain and stump pain.
* After a few days Alan could carry out the exercises alone and eventually without a mirror. At this stage exercises were carried out four times a day
Results: At the start, the phantom pain would range from 5-9 which decreased to 0 at the end of the treatment.
For the stump pain the range was 0-2 which reduced to 1.
Conclusion: Mirror treatment can be effective for treating phantom limb pain
Theories of pain
- Specifity
- Gate control
- Pattern theory of pain
Specificity Theory
-Proposes that specialised pain receptors respond to pain via nerve impulses, send signals to the brain. The brain then processes the signal as a sensation of pain, and quickly responds with a motor response to try to stop the pain.
Gate control theory
- Proposes that the spinal cord contains a ‘gate’ that either prevents pain signals from entering the brain or allows them to continue.
- This theory can explain why our emotional state or our expectations affect how much something hurts.
- The gating mechanism occurs in the dorsal horn of the spinal cord, where both small nerve fibres(pain fibres) and large nerve fibres (fibres for touch, pressure and other skin sensations) carry information to.
- When there is more large nerve fibre activity compared to small fibre activity people experience less pain (the pain gates are closed). When there’s more small fibre activity, pain signals can be sent to the brain so that the pain can be perceived(the pain gates are open). This explains why we rub injuries after they happen.
Measuring pain(Subjective measures)
Clinical interview:
-Involves asking a patient a range of open questions and will focus on getting an understanding of the patient’s experience of their pain.
-Evaluates a range of factors such as behavioural and psychological that influence the patient’s experience and reporting of pain.
-ACT UP(Activites, Coping, Think, Upset, People)
-Gathers factual info
-Doctor observes the patient’s behaviour, thoughts & feelings about their pain, adherance to treatment and their expectation and goals.
Strength: Collects qualitative data with lots of rich detail to get a deep and thorough understanding of the patient and their experience of pain.
Weakness: Relies solely on the patient giving their opinion and interpretation of things which may be inaccurate as some may downplay (in order to not make a fuss) or overexaggerate (to be taken seriously) their symptoms
Psychometric measures(McGill Pain questionnaire)
McGill Pain Questionnaire:
-Designed to assess the quality and intensity of subjective pain and can be used in patients with conditions such as cancer and muscular pain.
-Composed of 78 words- of which the patient chooses the words that best describe their pain.
-These words are assigned a value based on their severity and the patient is given a score from 0(no pain) to 78(severe pain)
-MPQ covers several categories:
* Pain descriptors-e.g. flickering, sharp, searing
* Affective-e.g. tiring, sickening
* Evaluation of pain-e.g. annoying, troublesome
* Miscellaneous-e.g. numb, squeezing
-MPQ asks which out of the lists of items, increase or decrease the pain:
* Eating, Heat, Cold, Weather changes, movement, Rest
-MPQ asks a range of questions to measure the strength of the pain, how it’s best describe atm, when it’s at it’s worst and when it’s at it’s least painful with the following responses:
* Mild, Discomforting, Distressing, Horrible, Excrutiating
Strength: - Can be used to assess changes over time and the effectiveness of pain management treatment.
-Gathers quantitative data which allow for statistical analyses to be carried out and for comparisons to be easily made.
-Relatively quick and easy to administer
Weakness:- Closed questions force a patient to choose an answer that doesn’t fully represent what they feel. Lack of open questions means that qualitative data can’t be collected which means lack of detailed info about the patient and their experience.
Visual Analogue Scale(VAS)
-Instrument used to measure pain on a continuum from no pain to an extreme amount of pain
-Presented as a horizontal line (100mm long) with ends defined in their extreme limits.
-Patient marks where along the line best represents their current pain and this is transferred to numerical value by measuring the distance from the end point to the patients mark giving a score between 0-100.
Recommended cutoff points:
* No pain-0-4mm
* Mild pain-5-44mm
* Moderate pain- 45-74mm
* Severe pain- 75-100mm
Strength: -Easy and quick to administer
-effective method of detecting change in pain over time and is more sensitive to small changes
-Collection of quantitative data allows for statistcal analysis to be made as well as comparisons.
Weakness: VAS doesn’t collect detailed qualitative data and doesn’t gather a range of items, it is limited.
Key Study: Brudvik et al.
Aims:
-To investigate the level of agreement of pain intensity when measured by the children, parents and physicians.
-To estimate the influence of children’s age, medical condition and severity of pain on the difference in pain assessment given by children, parents and physicians.
-To see how the pain assessments affected the physicians administration of belief
Design:
Sample: 243 children, 53% male, aged 3-15 years, attended a Norwegian emergency department over a 17-day period. 51 different physicians (57% were men. 51% had children of their own, Half of them had 5+ years of medical experience and 30% of them had a specialty in family medicine)
Procedure:
* The patients, their parents and the physicians all completed a questionnaire.
* Different measures were used to assess pain in order to ensure the measures were age appropriate.
* Children aged 3-8 years completed the Face Pain Rating Scale-Revised (FPS-R) which had 6 faces showing increasing levels of pain.
* Children aged 9-15 years used VAS and Coloured Analogue Scale(CAS) where they marked on a line where their pain was from no pain(green) to the worst thinkable pain(red).
* Parents and physicians completed the Numeric Rating Scale(NRS) to estimate the child’s level of pain from 0-10. Parents completed their score before the children completed theirs, but they were not completely blind, however parents and children were instructed not to tell the physician of their ratings.
* As well as pain assessments, the parents’ questionnaires gathered demographic information .
* Physician’s questionnaires gathered information about their medical experience, specialty and if they had their own children.
* The child’s diagnosis was classified as either: infections, fractures, wound injuries/soft tissue or ligament/muscle injuries. Most children had soft tissues, ligament or muscle injuries (51%), followed by fractures, infections and wound injuries.
** Results:**
-The children’s pain ratings were higher than those of the doctor and the parents
-There was little agreement in pain assessment between parents, physicians and children
-Agreement ratings between parents and children were higher at 40%
-The higher the pain ratings, the higher the percentage of pain killers administered by the physicians
Strengths: High ecological validity, High face validity, Usefulness-educating doctors.
Weaknesses: Self-reports, Cultural bias
University of Alabama(UAB) pain behaviour scale
- Scale consisting of 10 target behaviours and the person observing the patient(sum1 who lives with patient) records detail about each of the target behaviours over a period of time.
- For each of the target behaviours the observer reports on the severity, frequency or intensity of each behaviour every day.
- Each behaviour is assigned either 0, 1/2 or 1 mark and a total score is calculated out of a total of 10 , with a high score reflecting a more marked pain associated behaviour and a greater level of impairment.
Strength: Useful as it gathers information on outward signs of pain which can be observed by someone else.
Weakness:-Relies on the interpretation of the person completing the scale and the observer may not
witness the true extent of the behaviours being shown or may misinterpret them
-Scores on the UAB pain behaviour scale do not correlate well with the MPQ, suggesting that outward displays of pain-related behaviours are not closely related to subjective experience of pain.(Person could be conditioned into displaying pain in a certain way that isn’t congruent with the pain their experiencing/ or it could be that someone is experiencing large amounts of pain but doesn’t express it outwardly as a way of coping)
Varm & Thompson Pain questionnaire(& Wong-baker scale)
- Words (simplified) that describes the pain, almost similar to the McGill Pain questionnaire
- Visual Analogue Scale
- Smiley faces to detonate the intensity of pain.
- Diagram for the patient to indicate the pain site and whether it’s internal or external
- Participant is provided with crayons/pencils of different colours to state where the pain is and the intensity with dark colours denoting severe pain and light shades mild foam?
- Strength- Triangulation
- Weakness- subjective (elaborate)
Wong Baker scale
-Has the visual analogue scale and the smiley faces but not the colours
Biological Treatments
Analgesics (medicines used to relieve pain often referred to as pain killers) They differ in terms of how they work and their potency. Two types of analgesics that work differently to each other:
1. Nonsteroidal anti-inflammatory drugs(NSAIDS)e.g. Burufen- reduce the production of hormone-like substances that cause pain prostaglandins can be bought over the counter, are available in stronger forms of prescription. Side effects are: indigestion, headaches, drowsiness
2. Opioids e.g. Phentanyl- work by entering the bloodstream and attaching opiod receptors in your brain. These cells then release signals that reduce your perception of pain and increase your feelings of pleasure. They tend to be used for acute pain and are very effective. Risk of side effects such as drowsiness, slowed heart rate and addiction.
Psychological Treatments (Attention Diversion)
- Attention diversion- shifting attention away from the pain and onto something different.
- Involves competition for attention between the pain and a consciously directed focus on some form of cognitive event e.g. counting. Practice is important so that the skill is learnt over time e.g. doing puzzles.
- Effective for mild and moderate pain rather than severe.
- No negative side effects and can be learned relativley easy and can be practised and used without professional help.
Psychological treatment(Non-pain Imagery)
- Involves the person thinking about a calm and relaxing situation/scene and focusing on this rather than the pain.
- Individual is likely able to slow their breathing, heart rate and blood pressure which help to feel a sense of calm and relaxation which in turn helps to manage the pain.
- Can be achieved through use of auditory recording, to talk the individual through the relaxing scene as well as breathing relaxation techniques to tap into imagination.
- Has shown to be effective for mild and moderate pain and less effective for severe pain.
- No negative side effects and can be learned relativley easy and can be practised and used without professional help.
