Comparison of peripheral and central capillary refill time in febrile children presenting to a paediatric emergency department and its utility in identifying children with serious bacterial infection

What is already known on this topic? Abnormal capillary refill time (CRT) is considered a warning sign for serious infection in febrile children.

CRT differs by body site, peripheral (fingertip) CRT differs from central (sternum) CRT.

Studies on the association between abnormal CRT and serious infection in febrile children are conflicting.

What this study adds? Dichotomised peripheral (fingertip) and central (sternum) capillary refill times (CRTs) differ, as assessed with chance-corrected agreement and this difference is not significantly associated with categorised age and body temperature.

Only a small part of febrile children at risk for serious infections at the emergency department (ED) show abnormal CRT values.

Both abnormal peripheral CRT or central CRT (defined as >2 s) have low diagnostic value for serious infections in febrile children at the ED.

Introduction

Assessing febrile children presenting to a paediatric emergency department (ED) is challenging. Primarily, we aim to establish the risk of having a serious bacterial infection (SBI) with a potential lethal outcome or serious sequelae. 1 2 Several clinical determinants that could serve as warning signs for SBI have been identified. Capillary refill time (CRT) has been shown to be associated with an increased risk of SBI. 1 3 4 It has also been included in National Institute for Health and Care Excellence (NICE) guidelines as a marker of severe infection and of dehydration in gastroenteritis. 5-7 The NICE guideline on the evaluation of feverish illness in young children includes CRT assessment at initial evaluation, but labels prolonged CRT an amber (not red) warning sign in the 'traffic light system', reflecting some ambiguity regarding the predictive value for SBI. 5 This may be supported by studies including children within broader age ranges, which showed a modest predictive value of CRT for serious infection. 3 8

From a pathophysiological perspective CRT is considered to indicate peripheral skin perfusion. 9 In states of reduced effective circulating volume, for example, shock or dehydration, the CRT is presumed to be prolonged as a result of a vasoconstrictive response in peripheral vascular beds. 10 This mechanism aims at retaining circulating volume for vital organs (eg, central nervous system) while reducing flow to non-vital tissues (eg, gastrointestinal tract and extremities). 9 Different distances to the heart could lead to a discrepancy between...