ObjectiveThe capillary refill test (CR test) is often used in emergency care, and the capillary refill time (CR time) is used to assess a patient's circulatory condition. The objective of this study was to investigate if repeated CR tests affect CR time.MethodsThirteen healthy volunteers had repeated CR tests performed on the sternum, forehead, and fingers. The tests were filmed using polarized reflectance spectroscopy and dedicated software for objective quantification of the CR time.ResultsThere were no statistical differences between the first CR test in a series and the following. However, there were statistically significant differences in CR time between the different anatomical sites.ConclusionRepeated CR tests, separated by a minimum of 2 min, do not affect CR time in healthy volunteers. The site where the test is performed is of importance for CR time. Repeated capillary refill tests were performed on the skin of the study subjects and filmed with polarized reflectance spectroscopi and analyzed with a software program where the concentration of hemoglobin in the skin, representing erythema, was measured. From that capillary refill time was calculated.image

BackgroundThe capillary refill test is widely used in pediatric emergency medicine and critical care although its validity and reliability are debated. Naked eye estimation is the recommended method for capillary refill time (CR time) assessment. The goal of this study was to compare naked eye estimations of the CR time in pediatric patients to quantified capillary refill time (qCR time) using polarized reflectance imaging as an objective reference, and to investigate interobserver and intra-observer consistency of naked eye assessments of CR time.MethodA film sequence comprising videos of capillary refill tests from 15 emergency pediatric patients was shown under standardized conditions to 62 observers (pediatricians, nurses, assistant nurses, and medical secretaries). The observers' estimations of CR time in seconds and in descriptive categorizations were compared to objectively derived qCR time. Three tests were shown twice without the observers' knowledge.ResultsThere was poor interobserver agreement in all professions, with limits of agreement ranging from 1.17 s (assistant nurses) to 2.00 s (secretaries). Intra-observer agreement for estimations of both time and descriptive categorizations was limited. The correlation between naked eye assessments and qCR time was weak.ConclusionThis study shows that naked eye assessment of CR time in children is highly subjective with poor reproducibility in pediatric nurses and pediatricians, as well as in comparison to a quantitative method. Based on the lack of both inter- and intra-observer consistency in the assessments, these findings suggest that CR time assessed by naked eye should be questioned as a routine test in pediatric emergencies.

BackgroundThis study aimed to investigate whether changes in capillary refill (CR) time precede macrovascular signs of deterioration in a human model of blood loss shock. The study was conducted at the Department of Emergency Medicine in Link & ouml;ping, Sweden, and involved 42 healthy volunteers aged 18-45. Participants were randomized into two provocations of applied lower body negative pressure (LBNP): a stepwise escalation protocol and a direct application protocol, to simulate gradual and acute blood loss. The main outcome measure was CR time. Systolic, diastolic, and mean arterial pressures, heart rate, cardiac output, and systemic vascular resistance were measured continuously. CR time was assessed on the finger pulp using a standardized pressure and measured with a polarized reflectance imaging system.ResultsThe provocation elicited pre-syncope reactions and clear decrease in blood pressure for all participants, yet two-thirds of the participants in both protocols reacted with shorter CR times at maximum provocation, and the overall median CR time decreased by 0.2 s (Wilcoxon W = - 395.0, range: - 6.3 to 3.2, IQR - 1.3 to 0.1, P = 0.0070). Participants with shorter CR times exhibited comparatively greater increases in systemic vascular resistance and a more pronounced decrease in cardiac output.ConclusionsOur findings reveal that finger CR time paradoxically decreases in a majority of healthy volunteers in a lower body negative pressure model of blood loss, challenging traditional assumptions about the CR test's reliability as a shock indicator in its present interpretation.