Pain Measurement

Image by Wonderlane via Flickr

Pain Measurement

Pain is an unpleasant sensation that can affect the individual behaviour and can occur in various degrees, usually appearing as a result of an injury, a disease, or an emotional disorder. Pain can appear in any part of the body. To have a better understanding of pain intensity and to treat pain as accurately as possible, psychologists use a variety of techniques such as Biomedical and Bio psychosocial approaches. 

Biomedical approach is only involved in the fields of genetics; anatomy and physiology. In this approach the patients complaints are assumed to result from a specific disease manifested by a biologic disorder and tests will target only disease systems. Biomedical approach consists of various methods to understand pain intensity. This methods are self-report, visual analogue scale, box scale, verbal rating scale, EMG, EEG and autonomic activity. Self-report is a very simply and direct way of access pain as all patients have to do his rate some aspect of their discomfort on a scale (shapman et al 1985). This approach is used very often to measure how strong the pain is and there are three different types of scale. Visual analogue scale, box scale and verbal rating scale. On visual analogue scale the patient put a dot on a line at what point they think their pain is, judging from high to low intensity.The box scale is where the patients ring the number of how intense the pain is, judging from one to ten. On the verbal rating scale the patients describe their pain by choosing a word or phrase that best describes their pain. These are Self-report measurements, and may be very unreliable as the patient can lie or exaggerate about his pain. Other pain measurements are EMG. EMG stands for ElectroMyoGraphy” and detects the muscle signals when there are tension associated with pain. EEG; EEG is an ElectroEncephaloGram, and is used to record the electrical potentials generated by nerve cells in the brain. EMG and EEG are objective methods to measure pain, however this methods can be very expensive and not all the patients have access to them. This methods can be not very accurate as the levels of stress of the patient can be higher or lower at the moment of the test and can have influence in the pain senility of the patient. Furthermore, there is Autonomic activity measuremnet, which is done by measuring the pulse rate, skin temperature and skin conductance. It is possible using this rating method to measure physiological activity caused by pain.

Bio psychosocial approach, on the other hand,  is a way of looking at the mind and the body of a patient. This approach also treats the physical and social issues as systems of the illness incorporating as well biological factors. Bio psychosocial approach consists of various methods to understand pain, this methods are the Interview of patients, Mc Gill pain questionnaire, Behaviour assessment approach, Pain diary and Karoly’s six key pain elements. Interviews give an up to date evolution of the patients pain. Medical records and behavioural observations are looked at. With the interviews is also easier to focus on the history of the pain problem and its emotional adjustment. Interviews are a great method to assess pain, however, it can be ineffective if the patient for some reason is lying. Mc Gill pain questionnaires are questionnaires involving pain and Melzacks study consists of thee parts included in the pain experience; Affective – (emotional – motivational); Sensory (describing the physical properties); Evaluative (impact the pain has on the lifestyle). Here, patients are asked to tick words which best describe their pain and scores are given to each class of answer. It is an excellent method as it has visual examples with diagrams, however, it requires a good understanding of the question asked, so it will be difficult to be done in young children. Behaviour assessment approach. In the behaviour assessment approach a patient with intense pain is more likely to have worse symptoms. In this approach patients are asked to perform several activities and the medical staff rates each of ten behaviours, such as mobility, use of medication, etc. This is rated on a scale of “none”, “occasional” and “frequent”. this rates must be taken clearly and frequently during certain times of the day. A commonly used example of an observation tool for the behaviour assessment approach is the UAB used by nurses during different daily routines. Behaviour assessment is quite unreliable as the medical staff can be analysing a family member and because he is involved he might diagnose him wrong, or been worrying about the patient so much that he don’t take notice of the symptoms. Pain diaries. Pain diaries deal with the major problem of pain fluctuations over a period of time. The patient has to record this fluctuations of pain in his natural environment. This may provide important clues about situations which may have influence in the degree of the pain and help to determine the treatment. The patient have to complete the diary regularly, so unreliability of the records is avoided. One advantage of this method is that the measurement of the pain can be done while the patient is away from the medical environment and is done by the patient himself, however, as it was said before this can also be unreliable as self-report measures can be exaggerated by the patient. Karoly’s six key pain elements. Karoly’s (1985) suggested six elements, which should be considerate when trying to measure a patient’s experience of pain. The key elements are constituted by: Sensory (the intensity, duration, location, tolerance of the pain, etc.), Neuropsychological (heart rate and brain wave activity.), Emotional and motivational (resentment, anxiety, depression and anger, etc.), Behavioural (pain complaints and avoidances of exercise, etc.), Impact on lifestyle (changes in sexual behaviour and marital distress, etc.), Information processing (health beliefs, problem solving skills and coping styles, etc.). Probably this is the most accurate method used to assess pain as includes biomedical and bio psychosocial approach all together, looking at all the possible problems of the patient.

Tconclude, pain measurement is not easy to accomplish and not always is accurate as there are various factors which may interfere with the above methods, however, is always very important to use this methods as they are the closest techniques that the psychologists have to understand the intensity of the pain, which will help the patients and medical staff to deal with the same.

Bibliography

Pain measurement sheets

Psychology in practice