Reliability of capillary refill time for evaluation of tissue perfusion in simulated vascular occluded limbs



No standardized execution or evidence demonstrates the area of the digit giving the most accurate capillary refill time (CRT). This study investigated the reliability and validity of CRT, and the relative merits of areas where the test could be performed.


In all, 127 healthy volunteers were assessed for normal CRT at the fingernail, lateral paronychia, and proximal and distal pulps of the index finger. The predictive validity of the CRT for the diagnosis of compromised vascular perfusion was also investigated on 24 subjects, using an inflated tourniquet. Three raters assessed interobserver reliability.


The mean fingernail, lateral paronychia, proximal pulp, and distal pulp CRTs were 1.93, 1.78, 1.70, and 1.57 s, respectively. The tourniquet and non-tourniquet results demonstrated significant mean differences; however, the fingernail showed a subtle difference (1.22 s) compared with the proximal pulp (4.46 s). The CRT interobserver reliability was fair at the fingernail (intraclass correlation coefficient [ICC] = 0.51), but very poor in occluded limbs (ICC = 0.13). At the lateral paronychia and finger pulp, the interobserver reliability was reasonable (ICC = 0.75–0.81 [non-tourniquet] vs 0.62–0.68 [tourniquet]). In a receiver-operating characteristic curve analysis, the proximal pulp demonstrated better discrimination (area under the curve = 0.93, 95% CI 0.89–0.97, p  < 0.0001); the best cutoff point was calculated to be 3 s at the proximal pulp.


CRT use at appropriate areas is reliable. The most dependable site is the finger pulp, and the proposed cutoff is 3 s.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Availability of data and material

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.


  1. 1.

    Beecher HK, Simeone FA, et al. The internal state of the severely wounded man on entry to the most forward hospital. Surgery. 1947;22(4):672–711.

    CAS  PubMed  Google Scholar 

  2. 2.

    Champion HR, Sacco WJ, Hannan DS, Lepper RL, Atzinger ES, Copes WS, et al. Assessment of injury severity: the triage index. Crit Care Med. 1980;8(4):201–8.

    CAS  Article  Google Scholar 

  3. 3.

    Halvorson JJ, Anz A, Langfitt M, Deonanan JK, Scott A, Teasdall RD, et al. Vascular injury associated with extremity trauma: initial diagnosis and management. J Am Acad Orthop Surg. 2011;19(8):495–504.

    Article  Google Scholar 

  4. 4.

    Mavrogenis AF, Panagopoulos GN, Kokkalis ZT, Koulouvaris P, Megaloikonomos PD, Igoumenou V, et al. Vascular Injury in Orthopedic Trauma. Orthopedics. 2016;39(4):249–59.

    Article  Google Scholar 

  5. 5.

    Wegmann H, Eberl R, Kraus T, Till H, Eder C, Singer G. The impact of arterial vessel injuries associated with pediatric supracondylar humeral fractures. J Trauma Acute Care Surg. 2014;77(2):381–5.

    Article  Google Scholar 

  6. 6.

    Anderson B, Kelly AM, Kerr D, Clooney M, Jolley D. Impact of patient and environmental factors on capillary refill time in adults. Am J Emerg Med. 2008;26(1):62–5.

    Article  Google Scholar 

  7. 7.

    Schriger DL, Baraff L. Defining normal capillary refill: variation with age, sex, and temperature. Ann Emerg Med. 1988;17(9):932–5.

    CAS  Article  Google Scholar 

  8. 8.

    Arifin WN. A Web-based Sample Size Calculator for Reliability Studies. 2018;10:67–76.

    Google Scholar 

  9. 9.

    Brabrand M, Hosbond S, Folkestad L. Capillary refill time: a study of interobserver reliability among nurses and nurse assistants. Eur J Emerg Med. 2011;18(1):46–9.

    Article  Google Scholar 

  10. 10.

    Youden WJ. Index for rating diagnostic tests. Cancer. 1950;3(1):32–5.

    CAS  Article  Google Scholar 

  11. 11.

    Fluss R, Faraggi D, Reiser B. Estimation of the Youden Index and its associated cutoff point. Biom J. 2005;47(4):458–72.

    Article  Google Scholar 

  12. 12.

    Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977;33(1):159–74.

    CAS  Article  Google Scholar 

  13. 13.

    Watson A, Kelly AM. Measuring capillary refill time is useless. Emergency Medicine. 1993;5(2):90–3.

    Article  Google Scholar 

  14. 14.

    El Nahid MS, El Ashmaui A. The skin microcirculatory changes in the normal and hypertensive elderly. European Geriatric Medicine. 2015;6(1):7–10.

    Article  Google Scholar 

  15. 15.

    Lima A, Jansen TC, van Bommel J, Ince C, Bakker J. The prognostic value of the subjective assessment of peripheral perfusion in critically ill patients. Crit Care Med. 2009;37(3):934–8.

    Article  Google Scholar 

  16. 16.

    Lima A, Bakker J. Clinical assessment of peripheral circulation. Curr Opin Crit Care. 2015;21(3):226–31.

    Article  Google Scholar 

  17. 17.

    Sheridan DC, Baker SD, Kayser SA, Jones D, Hansen ML. Variability of Capillary Refill Time among Physician Measurements. J Emerg Med. 2017;53(5):e51–7.

    Article  Google Scholar 

  18. 18.

    Alsma J, van Saase J, Nanayakkara PWB, Schouten W, Baten A, Bauer MP, et al. The Power of Flash Mob Research: Conducting a Nationwide Observational Clinical Study on Capillary Refill Time in a Single Day. Chest. 2017;151(5):1106–13.

    Article  Google Scholar 

  19. 19.

    Espinoza ED, Welsh S, Dubin A. Lack of agreement between different observers and methods in the measurement of capillary refill time in healthy volunteers: an observational study. Rev Bras Ter Intensiva. 2014;26(3):269–76.

    Article  Google Scholar 

  20. 20.

    Nicholas B. Vedder DPH. The Mangled Upper Extremity. In: Scott W. Wolfe RNH, William C. Pederson, Scott H. Kozin, editors. Green’s Operative Hand Surgery, 6th ed. Philadelphia: Churchill Livingstone; 2011. pp. 1603–1644.

Download references


The authors did not receive support from any organization for the submitted work.

Author information




All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Yuwarat Monteerarat and Torpon Vathana. The first draft of the manuscript was written by Yuwarat Monteerarat and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Torpon Vathana.

Ethics declarations

Conflict of interest

The authors have no relevant financial or non-financial interests to disclose.

Ethics approval

This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of the Faculty of Medicine Siriraj Hospital, Mahidol University (Date August 14, 2014 /No Si480/2014).

Consent to participate

Inform consent was obtained from all individual participants included in the study.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Monteerarat, Y., Limthongthang, R., Laohaprasitiporn, P. et al. Reliability of capillary refill time for evaluation of tissue perfusion in simulated vascular occluded limbs. Eur J Trauma Emerg Surg (2021).

Download citation


  • Capillary refill time
  • Cutoff point
  • Reliability
  • Finger pulp
  • Arterial occlusion