Another bedside assessment of volume status. This can be carried out through the “nail blanch test.” Place the patient’s hand at the same level as the heart, and then compress the distal phalanx of the middle finger for 5 seconds until it blanches.
Release pressure, and measure how long it takes for the nail bed to regain its normal color. At room temperature (21°C), the upper limits of this capillary refill time (CRT) are 2 seconds for children and adult men, 3 seconds for adult women, and 4.5 seconds for the elderly. At colder temperatures, the normal upper limit may even be higher, raising questions regarding the reliability of the test in the prehospital setting.
Release pressure, and measure how long it takes for the nail bed to regain its normal color. At room temperature (21°C), the upper limits of this capillary refill time (CRT) are 2 seconds for children and adult men, 3 seconds for adult women, and 4.5 seconds for the elderly. At colder temperatures, the normal upper limit may even be higher, raising questions regarding the reliability of the test in the prehospital setting.