Capillary refill time. Is it time to fill the gaps?

Abstract

Capillary refill time (CRT) is defined as “time required for return of color after application of blanching pressure to a distal capillary bed”.1 Pediatricians including neonatologists routinely check CRT as part of clinical assessment of sick children to look for possible hypovolemia and sepsis. CRT was introduced by Beecher et al. in 1947, and was defined as “normal”, “definite slowing” and “very sluggish”, correlating with no, slight/moderate and severe shock, respectively. No numerical values were placed on the definitions.2 There is limited data on the actual method to do CRT and there is no consensus on the correct practice. It is highly subjective and observer dependent, and it may vary with ambient or skin temperature, age, site of measurement, duration and amount of pressure, none of which have been standardized. Here we attempt to look at the various methods/standard references described in literature (Table 1). Table 1 Methods described for CRT. Assessment of CRT is almost universally done by pediatricians particularly in emergency room, neonatal ICU and pediatric ICU setting. There seems little agreement on the methods described for carrying out this simple assessment amongst the practitioners who follow various references as depicted in the table. In a multidisciplinary survey on CRT in Canada, no consistent response was found in how the health care providers in acute care setting performed and interpreted CRT.3 In another recent review on utility of CRT in assessment of hemodynamic status in neonates, the reviewer found a variety of methods used to assess CRT and concluded that central CRT has a wide variability while peripheral CRT was not useful.4Though we seldom use CRT alone as an indicator of hemodynamic status, it would be appropriate in this era of evidence based medicine to adopt uniform clinical methods which will then enable us to carry out studies to ascertain its validity. In the mean time, it seems best to follow the “Pediatric Advanced Life Support Providers manual 2011” guidelines for eliciting CRT in children and “The facility based IMNCI participants manual-2009” guidelines for eliciting CRT in young infants.