Capillary refill--is it a useful predictor of hypovolemic states?

To evaluate whether the capillary refill test can correctly differentiate between hypovolemic and euvolemic emergency department patients.

A prospective, nonrandomized, nonblinded time series.

The orthostatic and hypotensive patients were seen in a university hospital ED with 44,000 visits per year. Blood donors were studied in the hospital's blood donor center.

Thirty-two adult ED patients who presented with a history suggestive of hypovolemia and either abnormal orthostatic vital signs (19) or frank hypotension (13), and 47 volunteer blood donors who ranged in age from 19 to 83 participated.

Capillary refill was measured before rehydration in the ED subjects and, in the donor group, before and after a 450-mL blood donation.

Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated. Analyses were stratified by age, sex, and study group.

For the blood donor group, mean capillary refill time before donation was 1.4 seconds and after donation was 1.1 seconds. Mean capillary refill time for the orthostatic group was 1.9 seconds and for the hypotensive group was 2.8 seconds. When scored with age-sex specific upper limits of normal, the sensitivity of capillary refill in identifying hypovolemic patients was 6% for the 450-mL blood loss group, 26% for the orthostatic group, and 46% for the hypotensive group. The accuracy of capillary refill in a patient with a 50% prior probability of hypovolemia is 64%. Orthostatic vital signs were found to be more sensitive and specific than capillary refill in detecting the 450-mL blood loss.

Capillary refill does not appear to be a useful test for detecting mild-to-moderate hypovolemia in adults.