Detection of rapid loss of intravascular volume due to haemorrhage or fluids can be a time-sensitive data point in critical situations. Clinical evaluation can be difficult and prior research has shown inaccuracies leading to increased morbidity and mortality.1 One way to measure this is through the assessment of capillary refill time (CRT), which has been shown to significantly vary between physicians.2 However, goal-directed fluid management often uses manual CRT measurements as a guiding metric. The goal of this study was to evaluate technology (PeriFRL by ProMedix Inc) to objectively measure CRT before and after healthy subjects donated blood. The hypothesis was that the CRT would become prolonged after donation.

All adult subjects over 17 years gave consent. All subjects over three separate 1-day periods who signed up to …