Related Experiment Videos
Defining normal capillary refill: variation with age, sex, and temperature
1Emergency Medicine Center, UCLA Center for the Health Sciences 90024-1744.
Annals of Emergency Medicine
|September 1, 1988
Summary
Capillary refill time, used to assess shock, varies significantly with age and temperature. The standard two-second limit is unreliable, leading to high false-positive rates in diverse populations.
Area of Science:
- Physiology
- Medical Diagnostics
Background:
- Capillary refill time (CRT) is a clinical indicator for assessing perfusion status, particularly in critically ill patients.
- A widely recommended upper limit of normal for CRT is two seconds, though supporting evidence is lacking.
Purpose of the Study:
- To evaluate the validity of the two-second upper limit for CRT.
- To investigate the influence of age and temperature on CRT.
Main Methods:
- CRT was measured in 100 children, 104 adults, and 100 elderly volunteers.
- CRT was also assessed in 20 adults before and after cold water immersion (14°C).
Main Results:
- Median CRT varied significantly by age and sex, with younger individuals and males exhibiting shorter times.
- Cold exposure markedly increased CRT (median 1.3s pre-immersion vs. 2.9s post-immersion, P < .01).
- Applying a two-second limit yielded high false-positive rates: 4.0% (pediatric/adult males), 13.7% (adult females), and 29.0% (elderly).
Conclusions:
- Capillary refill time is demonstrably dependent on both age and body temperature.
- Revised upper limits for normal CRT are proposed: 2.9 seconds for adult women and 4.5 seconds for the elderly.
- The temperature dependency questions the reliability of CRT in prehospital settings.