Capillary refill time (CRT)

In children over 7 days of age, the upper limit of normal CRT is approximately 2 s when measured on a finger, and 4 s when measured on the chest or foot, irrespective of whether the child is feverish or not. Longer pressing times and ambient temperature outside 20°C–25°C are associated with longer CRT.

Evidence suggests that the use of stopwatches reduces variability between observers.

Recommend following standardised CRT method: press on the finger for 5 s using moderate pressure at an ambient temperature of 20°C–25°C. A capillary refill time of 3 s or more should be considered abnormal.  Other timings apply to other sites.

[Systematic review – 21 studies on 1915 children.  Arch Dis Child doi:10.1136/archdischild-2014-307079]