Kapillarrefill

Kapillarrefill, or capillary refill time (CRT), is a quick clinical test used to assess peripheral perfusion and circulatory status. It evaluates how long it takes for color to return to a blanched capillary bed after brief pressure, most commonly on the nail bed of a finger or the pad of a toe.

Methodically, the examiner applies gentle, firm pressure to blanch the skin for about 5 seconds and then releases. The time until normal coloration returns is measured in seconds. A CRT of less than 2 seconds is generally considered normal, although the exact threshold can vary with age and environmental conditions.

CRT is used in the initial assessment of dehydration, hypovolemia, shock, and other conditions that affect peripheral perfusion. It is commonly employed in pediatrics and emergency medicine as part of a broader evaluation.

Interpretation and limitations: A prolonged CRT suggests reduced peripheral perfusion or vasoconstriction, but it is not a standalone test for shock or circulatory failure. A normal CRT does not exclude serious illness. Factors that can affect accuracy include ambient temperature, lighting, skin pigmentation, nail polish or thick nails, edema, local trauma, and drugs that cause vasoconstriction. In difficult cases or when hands are unsuitable, alternative sites such as the sternum, forehead, or chest can be used.

Overall, capillary refill is a rapid, low-cost bedside measure that complements vital signs and other perfusion assessments.