The data on the performance of capillary refill time (CRT) in adults is quite limited and what’s available does not suggest that the commonly cited 2 seconds cutoff is useful in assessing peripheral perfusion in critically ill adults1,2.
For example, a large study involving 1000 healthy adults reported that 45% of participants had a CRT > 2 seconds3. Age also affects CRT with its 95 percentile upper limits reaching 4.5 seconds among healthy adults >60 y old3.
Among patients with septic shock, a baseline median CRT of 5 seconds has been reported. Values <5.0 seconds within 6 hours of treatment of septic shock has also been highly associated with successful resuscitation even before normalization of lactate levels4.
For these reasons, if CRT is used as a measure of peripheral perfusion in critically ill adults, a cut off of 5 seconds, not 2 seconds, may be more appropriate. But just like many other diagnostic tests, CRT should never be interpreted in isolation from other clinical parameters.
- Lima A, Bakker J. Clinical Assessment of peripheral circulation. Critical Care 2015:21: 226-31. https://www.ncbi.nlm.nih.gov/pubmed/25827585
- Lewin J, Maconochie I. Capillary refill time in adults. Emerg Med J 2008;25:325-6. https://www.ncbi.nlm.nih.gov/pubmed/18499809
- Anderson B, Kelly AM, Kerr D, et al. Impact of patient and environmental factors on capillary refill time in adults. Am J Emerg Med 2008;26:62-65. https://www.ncbi.nlm.nih.gov/pubmed/18082783
- Hernandez G, Pedreros C, Veas E, et al. Evolution of peripheral vs metabolic perfusion parameters during septic shock resuscitation. A clinical-physiologic study. J Crit Care 2012;27:283-288. https://www.ncbi.nlm.nih.gov/pubmed/21798706