Effect of fever on capillary refill time

Abstract

Objective: To assess the effect of fever on capillary refill time in children. Design: Prospective cohort study. Setting: Tertiary care children's hospital emergency department (ED). Participants: Convenience sample of 234 children age one month to five years presenting to the ED with a complaint of vomiting, diarrhea, or poor oral fluid intake. Interventions: None. Measurements: Before any therapy, capillary refill was measured according to a standard protocol. Rectal temperature was measured in children less than three years old, oral temperature in older children. Fluid deficit was calculated as the percentage difference between initial weight and stable weight following treatment. Main results: Among the 80 children with dehydration, defined as a deficit of ≤5% of body weight, mean capillary refill was 2.0 ± 1.0 seconds. versus 1.3 ± 0.5 seconds in the well hydrated group (P < 0.001). Within each group, mean capillary refill time for febrile patients (temperature ≤38.3°C) was essentially the same as in those without fever. Using a two-second upper limit of normal, prolonged capillary refill had a sensitivity of 0.44 and specificity of 0.94 for diagnosing dehydration; the diagnostic performance did not differ when stratified by presence or absence of fever. Conclusions: Presence of fever does not have a clinically important effect on capillary refill time in children.