My Pulmonary Rotation
Guide to Clinical Experience at Ephraim McDowell Lung Center
Simple exercise oximetry has no parameters for the intensity or duration of physical activity. The 6-minute walk, however, does incorporate some additional measurement parameters as well as instructions to the patient which significantly increases the diagnostic yield of this procedure.
With a 6-minute walk the patient is placed on a level surface and given instructions to walk at a pace of their choosing. During the 6-minute timeframe the patient may stop and rest for as long as they feel is necessary.
The parameters measured during the study include the patient's pulse rate and saturation levels every minute as well as the total distance covered over the course of 6 minutes.
In addition to the information that can be gleaned with regards to the presence of exercise desaturation there are also prediction equations based on gender, height, age, and weight.
Male predicted in meters = (7.57 * height in cm) - (5.02 * age) - (1.76 * weight in kg) -309
Female predicted in meters = (2.11* height in cm) - (2.29 * weight in kg) - (5.78 * age) + 667
when performed as a serial measurement, a 45m change is considered clinically significant.
The test has been used in numerous conditions including:
In pulmonary conditions it has been shown to have a better predictive value for mortality than pulmonary functions studies.