What is the acceptable capillary refill time (CRT) in seconds?

Acceptable Capillary Refill Time in Seconds

A capillary refill time of less than 2 seconds is considered normal and acceptable in most clinical scenarios, while a time of 2 seconds or more indicates delayed refill and potential circulatory compromise. 1

Normal Values by Age Group

Capillary refill time (CRT) varies by age and clinical context:

• Children and Adults: Less than 2 seconds is normal 1
• Elderly Adults: Up to 4.5 seconds may be normal (higher threshold due to age-related changes) 2
• Adult Women: Up to 2.9 seconds may be normal 2
• Neonates: Normal values can range up to 3 seconds 3

Clinical Significance and Assessment

Proper Measurement Technique

1. Apply moderate pressure to blanch the skin (commonly at nail beds, sternum, or extremities)
2. Release pressure
3. Count seconds until normal color returns
4. Perform in a warm environment (temperature affects results)

Interpretation in Shock States

• CRT ≥ 2 seconds is considered a sign of compensated shock in pediatric patients 1
• In septic shock, CRT strongly correlates with skin blood flow and microvascular reactivity 4
• Prolonged CRT (≥ 2 seconds) is a reasonable prognostic indicator, especially in children with decreased consciousness 1

Factors Affecting CRT Measurement

• Temperature: Cold environments significantly prolong CRT 2, 5
• Measurement site: Values may differ between hand, foot, and sternum 5, 6
• Pressure duration: Longer pressure application results in longer CRT 6
• Ambient conditions: Phototherapy and radiant warmers can shorten CRT in neonates 3

Clinical Applications

As Resuscitation Endpoint

CRT < 2 seconds is an initial therapeutic endpoint in the resuscitation of septic shock 1, along with:

• Normal blood pressure for age
• Normal pulses with no differential between peripheral and central pulses
• Warm extremities
• Adequate urine output
• Normal mental status

In Pediatric Resuscitation

In pediatric resuscitation algorithms, restoration of CRT ≤ 2 seconds is a first-hour goal in management of septic shock 1. This is used alongside:

• Heart rate within normal range
• Normal blood pressure
• Appropriate oxygenation and ventilation

Pitfalls and Caveats

1. Inter-observer variability: CRT assessment can be subjective; standardized measurement techniques are essential
2. Unreliability in neonates: Some research suggests CRT may be an unreliable indicator of cardiovascular status in term neonates during the first few hours after birth 6
3. Temperature dependence: Always consider environmental and skin temperature when interpreting CRT
4. Age considerations: Using the standard 2-second cutoff for elderly patients may result in high false-positive rates (up to 29%) 2
5. Not a standalone measure: CRT should be evaluated alongside other clinical parameters such as blood pressure, heart rate, and mental status for a comprehensive assessment of perfusion

CRT remains a valuable, non-invasive tool for rapid assessment of peripheral perfusion, but its limitations must be recognized when making clinical decisions about a patient's circulatory status.