Assessing Pain with the Visual Analog Scale
By Joan Whetzel
The perception of pain is subjective. It may be difficult for a patient to explain exactly what their pain feels like, still, they know their pain better than anyone else does. And because of this, medical personnel need a tool to help them determine just how much pain each patient is experiencing at any one time. They have a number of tools at their disposal to rate and compare the pain a patient is feeling. The Visual Analog Scale (VAS) is just such a tool.
What is the Visual Analog Scale (VAS)?
The Visual Analog Scale (VAS) is made up of a card or a slip of paper, on which is drawn a line, 10cm in length (3.9 inches). One end of the line is labeled "No Pain" and the other labeled "Worst Possible Pain." The nurse or doctor asks the patient where their pain falls along that line while they are at rest, while being active, and after they've moved around. When their pain is not attached to a specific word (sharp, dull) or number (scale of 1 to 10), they are free to choose their exact pain level and to express their pain using their own words. Once the pain level has been determined and marked on the line with pencil or pen, it can be measured in centimeters to give it a numerical rating for the patient's record. Example: the paramedic measures an 8.5cm level (measuring starting from zero) while the patient is in the ambulance. Later the patient's pain measures 2.5cm in the ER after having been given pain medication. In this example the second reading shows the effect of the pain medication.
Other Pain Scales
Some of the pain scales that have been around for a while contain up to 101 different pain levels, but most people can't truthfully discriminate between them all. However, use of another tool in conjunction with the VAS - a tool such as the McGill Pain questionnaire - can provide health care givers a clearer picture of the pain that the patient is suffering.
Using the VAS
Using the VAS scale with young children may be a bit tricky. It must be determined if the child can count to ten and if that child understands the concept of one number being higher (more pain) or lower (less pain) than another number. The VAS can be used for rating other things besides pain, things like confidence and skill level.
Benefits of Using the VAS
Benefits of this system is that medical personnel can more easily determine each patient's exact pain level at any given moment. making it easier to prescribe pain medications at the correct dosage. Which in turn prevents overdosing the patient and avoids keeping them on higher doses for longer periods of time than necessary.
Drawbacks to the VAS
While the VAS is quite helpful in determining the pain levels for individual patients, it cannot be used to compare pain levels between groups of patients, because it is so subjective. Also, unless the pain level along the line is marked and measured, it cannot be accurately recorded on the patient's chart. So the pain level must be marked and measured in order to be recorded, and an objective scale must be used in conjunction with the VAS in order to compare the pain levels between patients.
Rasch: Visual Analog Scales Downloaded 2/2012.
Journal for Clinical Epidemiology: Visual Analog Scale for Pain Reporting was Standardized Downloaded 2/2012.
Cincinnati Children's Organization: Visual Analog Scale Downloaded 2/2012.
Partners Against Pain: Visual Analog Scale (VAS) Downloaded 2/2012.
Free Printable Medical Forms: Visual Analog Scale Form Downloaded 2/2012.
Aetna Inteliheathl. Rating Your Pain. Downloaded 2/2012.
National Institute for Health. Adaptive Visual Analog Scales (AVAS): A Modifiable Software Program for the Creation, Administration, and Scoring of Visual Analog Scales.
Trauma Care Foundation. Visual Analog Scale. Downloaded. 2/2012.