Objective: Reliability of capillary refill time (CRT) has been questionable. The purpose of this study was to examine that a standardized method and clinical experience would improve the reliability of CRT.
Methods: This was a cross-sectional study in the emergency department (ED). Health care providers (HCPs) performed CRT without instruments (method 1) to classify patients as having normal or abnormal (≤2/>2 s) CRT. An ED attending physician quantitatively measured CRT using a chronograph (standardized visual CRT, method 2). A video camera was mounted on top of the hand tool to obtain a digital recording. The videos were used to calculate CRT via image software (image CRT, method 3) as a criterion standard of methods. Additionally, 9 HCPs reviewed the videos in a separate setting in order to visually assess CRT (video CRT, method 4).
Results: We enrolled 30 patients in this study. Standardized visual CRT (method 2) identified 10 abnormal patients, while two patients were identified by CRT without instruments (method 1). There was no correlation (κ value, 0.00) between CRT without instruments (method 1) and image CRT (method 3), however the correlation between standardized visual CRT (method 2) and image CRT (method 3) was strong (r = 0.64, p < 0.01). Both intra-observer reliability and correlation coefficient with image CRT (method 3) was higher in video CRT (method 4) by more experienced clinicians.
Conclusions: Visual assessment is variable but a standardized method such as using a chronograph and/or clinical experience may aid clinicians to improve the reliability of visually assessed CRT.
Keywords: Capillary refill time; Image analysis; Peripheral blood perfusion; Reliability; Visual assessment.
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