Pain Perception & Pain Scales - CANCER

Pain Perception & Pain Scales

December 5, 2011, 12:50 pm

Pain scales and what kind of information they provide. That is the question I have to answer every day.  Over the years my pain became my everyday companion. Balancing my medication with my pain-level developed into my daily struggle.

I have therefore decided to summarize my experiences and reflections on the subject of pain. In the process I have also gathered information about the methods used for establishing pain levels. There is also an official site about cancer pain, called www.cancer-pain.org, which I found interesting and useful during my search.

Over the years with surgeries and treatments (see Veronica’s story) I was often asked to describe my pain by setting a number between 0 and 10. I was told that 0 means no pain at all and 10 the worst possible pain. I never questioned the method and just told a number to make everyone happy. I knew that I should use a number above 5 to get painkillers, but I never asked and never questioned the method. Until one day when my husband asked the question about how was I able to set the number? He was aware of the fact that I had pain within different areas of my body. Some of it caused by radiation, some of it by scars after the surgeries, some of it by existing tumours, and many others. He also understood that my pain differed from one area to the other. Some felt like heat, some was pounding. Some pain disappeared after an exercise, some pain got worse when I was freezing. And I explained to him about the scale. He responded with other questions.

(1) What does “the worst possible pain” mean?

The questions have one meaning to me and another to others for example my husband. I have experienced such high levels of pain that I honestly considered taking my life. That became my reference point defining “10”. But what’s for example my husband’s reference point. He haven’t even broken any bone nor spent a night at a hospital.

(2) Does the person asking know what your reference point is?

Probably not. The number on the pain scale would be meaningful if the person who asks would know my whole background. I often wondered if my answers were adjusted in the minds of those who asked. I also wondered which of the areas of pain in my body I should use to set the number. And only a few times I was asked about the quality of my pain. Cancer patients have been trough amputations, extensive chemotherapy treatments, or have other reasons to suffer of high pain-levels and I soon understood how a wrong understanding could easily result in a wrong treatment. Since the day my husband asked me about my pain I started to describe my reference point as well as the areas of pain whenever asked. When I started my information gathering about pain it became clear to me that pain assessment is an extremely complex process.

Below is a summary of some methods that seem to be in use. Most of them focus on the intensity of pain. Only McGill Questionnaire (MPQ) questions the quality of pain by using adjectives to describe it. This was the first time I came across this method and I do not know how often it is used in reality. The questionnaire is very extensive. I also found a short version of the McGill questionnaire, so called SF-MPQ. Even here I do not know about the use.

However, I thought that the adjectives used in both McGill versions could be useful to study in order to be more precise when describing pain.

NRS, Numeric Rating Scale, requires the patient to give a value on the 0 to 10 scale, to indicate the degree of pain. With 0 indicating “no pain” and 10 indicating “the worst possible pain”.

VAS, Visual Analogue Scale, requires patients to mark a point on a 10 cm horizontal or vertical line to indicate their pain intensity, with 0 indicating “no pain” and 10 indicating “the worst possible pain”. This scale is very similar to the one used for the NRS.

Wong-Baker Faces Pain Intensity Scale

The Original MPQ

The McGill Pain Questionnaire was developed at by Dr. Melzack at McGill University in Montreal Canada and has been translated into several languages. It uses 78 adjectives divided into 20 groups to describe pain. The idea is that by choosing some of the adjectives the patient or the doctor should be able to establish both quality and intensity of the patient’s pain. Below, please, find some examples of groups and the adjectives used in the questionnaire:

What Does Your Pain Feel Like?

  • Group 1 (temporal): Flickering (1), Quivering (2), Pulsing (3), Throbbing (4), Beating (5), Pounding (6)
  • Group 6 (traction pressure): Tugging (1), Pulling (2), Wrenching (3)
  • Group 7 (thermal): Hot (1), Burning (2), Scalding (3), Searing (4)

How strong is the pain? (PPI)

No Pain (0), Mild (1), Discomforting (2), Distressing (3), Horrible (4), Excruciating (5)

How does the pain change with time?

  • Group 1: Continuous, Steady, Constant;
  • Group 2: Rhythmic, Periodic, Intermittent;
  • Group 3: Brief, Momentary, Transient.

You can find the whole questionnaire at the end of this article.

SF-MPQ

The short version of the MPQ, the SF-MPQ by C. S. Burckhardt and A. Bjelle uses only 15 adjectives to describe pain (throbbing, shooting, stabbing, sharp, cramping, gnawing, burning, aching, heavy, tender, splitting, exhausting, sickening, fearful, punishing-cruel). The adjectives are combined with an intensity scale ranging from 0, meaning “no pain” to 3, “severe”.

The McGill Pain Questionnaire