Capillary Refill Time

What Is Capillary Refill Time?

Capillary refill time (CRT) is the duration required for color to return to a peripheral capillary bed after applying pressure to induce blanching. This assessment is typically performed on the nail bed or skin and is indicative of peripheral perfusion. Not to be confused with pulse oximetry, CRT is a rapid evaluation tool utilized in triage situations, such as during START assessments, to gauge circulatory status and potential shock in patients. In EMS contexts, it is commonly framed alongside structured communication and triage concepts such as START (Simple Triage and Rapid Treatment) or SALT (Sort, Assess, Lifesaving interventions, Treatment/Transport) as shared terminology.

Why Capillary Refill Time Matters on the Fireground

CRT serves as a critical, non-invasive measure of peripheral perfusion, aiding EMS personnel in the early identification of shock or dehydration. Timely assessment of CRT can influence treatment decisions and prioritization in emergency medical scenarios. Clear definitions improve handoffs, documentation clarity, and team alignment when multiple providers must prioritize tasks under time pressure.