Capillary refill

[3] It can be measured by holding a hand higher than heart-level and pressing the soft pad of a finger or fingernail until it turns white, then taking note of the time needed for the color to return once pressure is released.

[7] The value of 2 seconds for a normal CRT that was proposed by Dr Champion had been arbitrarily chosen by his nurse, and no evidence supporting that value has subsequently been found.

[8] CRT has been shown to be influenced by ambient temperature, age, sex, and the anatomical testing and lighting conditions.

[4] It is generally accepted that the test is affected by many different external factors and therefore should not be relied upon as a universal diagnostic measure.

[14][6] Poor finger or toe capillary refill time is a contraindication for the use of compressive techniques to treat peripheral oedema.