CRT has been shown to be influenced by ambient temperature, age, sex, and the anatomical testing and lighting conditions. The most reliable and applicable site for CRT testing is the finger pulp (not at the fingernail), and the cut-off value for the normal CRT should be 3 seconds, not 2 seconds.

What factors affect capillary refill time?

Its role in modern medicine has been questioned and several factors have been proven to impact the length of CRT. Among these factors are: temperature, gender, age, pressure time and pressure site as well as the observers interpretation of CRT.

What does a slow capillary refill mean?

A capillary refill time of three seconds or more should be considered abnormal. The results show that an abnormal CRT of 3 seconds or more increases the likelihood of a serious outcome including death and dehydration – however a normal CRT does not make a serious outcome less likely.