Video-based capillary refill measurement improves reproducibility in small critical care study

Capillary refill time (CRT) is a simple marker of peripheral perfusion, but visual assessment has limited reproducibility. A single-center observational study published in Critical Care compared trained clinicians’ assessments with semi-automated measurements using the YesReCan video-analysis platform. Researchers analyzed 126 standardized CRT videos from 34 critically ill patients, evaluating reproducibility, agreement, measurement precision, and discrimination for prolonged CRT (>3 seconds).

Intra-observer and inter-observer intraclass correlation coefficients were 0.945 (95% CI, 0.837–0.995) and 0.992 (0.985–0.997) for software-based assessment, compared with 0.640 (0.474–0.765) and 0.603 (0.428–0.736) for clinicians. The relative least significant change for single measurements was lower with software: 40.7% versus 74.7%. Agreement with clinician assessment was moderate, with a concordance correlation coefficient of 0.689 (95% CI, 0.533–0.772). Discrimination for prolonged CRT had an area under the curve of 0.885 (95% CI, 0.785–0.962).

The findings suggest that semi-automated video analysis could help standardize peripheral perfusion assessment. However, improved measurement reproducibility does not establish improved clinical outcomes. The small, single-center sample and use of standardized videos limit generalizability; external validation in larger multicenter cohorts is required before widespread implementation.