Pain Rating Scales

In the second half of the twentieth century, pain came to be understood as an experience which can be reported only by the sufferer. Although certain physiological responses or behaviors prompted by pain may be observed, modern medicine has produced no single parameter to represent our understanding of what we know to be pain. Pain has come to be viewed as a subjective phenomenon with many features, of which severity or intensity is, as Melzack comments, “the salient dimension of pain.” It is intensity which has been the subject of most methodological innovation in pain research.the underlying driver for a reliable, valid, and sensitive measure of pain intensity has, of course, been the need to establish the efficacy of analgesics and other

Pain is a multidimensional phenomenon. For example, pain has both a sensory dimension of intensity (how strong the pain sensation is) and affective (how upsetting the pain is). Consequently, a good measure should clearly identify and define which dimension is to be measured. The requirements for a pain measure in terms of reliability, sensitivity, and specificity will vary with the purpose of the measure Pain scales are reliable only to compare the intensity of one patient's pain at different times, thus allowing clinicians and patients to judge whether pain intensity is increasing or decreasing with time and treatment.

Pain rating scales:

Pain rating scales used in daily clinical practice generally deal with pain intensity that is how much a person hurts. Mainly there are two types of pain scales, the verbal scales and the nonverbal or observational scales. Verbal scales are used in patients who can self report pain and observational scales measure pain in patients cannot verbalize their pain. Pain rating scales used in daily clinical practice generally deal with pain intensity. Numerous scales for measuring pain intensity exist and have been referred to by different names.

Pain assessment in patients able to self report pain :.Self report is known to be the best method of assessing pain. Following are some of the tools that are used for patients who can self report

The patient is asked to rate pain from zero to ten with zero equalling no pain and ten equalling the worst possible pain.

In this study NRS is the scale selected to assess pain in verbal patients. The validity of the 0-10 NRS has been well established and is easy to score as well as easy for patients to remember. The NRS has been translated to many languages. In a study comparing the Visual Analogue Scale and the NRS, there was strong correlation supporting the validity of the verbally administered NRS. The NRS is found to be more reliable in less educated patients than other scales. [2]

• Visual Analogue Scale (VAS)

This is a horizontal (sometimes vertical) 10 cm line with word anchors at the extreme such as “no pain” on one end and “ worst pain imaginable” on the other end The patient is asked to make a mark along the line to represent pain intensity . Although it is to administer and has documented validity scoring is time consuming. A number is obtained by measuring in millimeters up to the point the patient has