{{Short description|Medical term}} thumb|A person demonstrates how to assess capillary refill time (CRT) on a dummy<ref>{{Cite book|last1=Doyle|first1=Glynda Rees|last2=McCutcheon|first2=Jodie Anita|date=2015-11-23|chapter=2.7 Focused Assessments|url=https://opentextbc.ca/clinicalskills/chapter/2-5-focussed-respiratory-assessment/|title=Clinical Procedures for Safer Patient Care|language=en}}</ref> thumb|Capillary refill test on index finger pulp.<ref name=":2">{{Cite journal |last1=Monteerarat |first1=Yuwarat |last2=Limthongthang |first2=Roongsak |last3=Laohaprasitiporn |first3=Panai |last4=Vathana |first4=Torpon |date=April 2022 |title=Reliability of capillary refill time for evaluation of tissue perfusion in simulated vascular occluded limbs |url=https://link.springer.com/10.1007/s00068-020-01594-9 |journal=European Journal of Trauma and Emergency Surgery |language=en |volume=48 |issue=2 |pages=1231–1237 |doi=10.1007/s00068-020-01594-9 |pmid=33475776 |s2cid=231665460 |issn=1863-9933|url-access=subscription }}</ref> '''Capillary refill time''' ('''CRT''') is defined as the time taken for color to return to an external capillary bed after pressure is applied to cause blanching.<ref name="King 111–116">{{cite journal|last=King|first=D|author2=Morton, R |author3=Bevan, C |title=How to use capillary refill time|journal=Archives of Disease in Childhood: Education and Practice Edition|date=Nov 13, 2013|pmid=24227793|doi=10.1136/archdischild-2013-305198|volume=99|issue=3|pages=111–116|s2cid=12252412}}</ref> It can be measured by holding a hand higher than heart-level and pressing the soft pad of a finger or fingernail until it turns white, then taking note of the time needed for the color to return once pressure is released.<ref name="scripps">{{Cite web |url=http://www.scripps.org/articles/2748-capillary-nail-refill-test |title=Capillary nail refill test |access-date=2014-12-21 |archive-url=https://web.archive.org/web/20150924095548/http://www.scripps.org/articles/2748-capillary-nail-refill-test |archive-date=2015-09-24 |url-status=dead }}</ref> In humans, a CRT of more than three seconds indicates decreased peripheral perfusion and may indicate cardiovascular or respiratory dysfunction.<ref name=":0">{{Cite book|last1=Doyle|first1=Glynda Rees|last2=McCutcheon|first2=Jodie Anita|date=2015-11-23|chapter=Appendix 1: Glossary|title=Clinical Procedures for Safer Patient Care|url=https://opentextbc.ca/clinicalskills/back-matter/appendix/|language=en}}</ref>
==Assessment== === In adults === CRT can be measured by applying pressure to the pad of a finger or toe for 5–10 seconds.<ref name=":1">{{Cite journal|last=Cooke|first=R.|date=2014-07-01|title=The Lewis-Prusik test. Time to say goodbye to an old friend?|journal=Occupational Medicine|language=en|volume=64|issue=5|pages=312–313|doi=10.1093/occmed/kqu055|pmid=25005540 |issn=0962-7480|doi-access=free}}</ref> It became popularized in the 1980s when Champion et al. proposed a CRT of less than 2 seconds be deemed normal and included CRT in the Trauma Score.<ref>Champion HR, Sacco WJ, Hannan DS, Lepper RL, Atzinger ES, Copes WS, Prall RH. Assessment of injury severity: the triage index. Crit Care Med. 1980 Apr;8(4):201-8. doi: 10.1097/00003246-198004000-00001. PMID 7357873.</ref> The value of 2 seconds for a normal CRT that was proposed by Dr Champion had been arbitrarily chosen by his nurse, and no evidence supporting that value has subsequently been found.<ref>Baraff LJ. Capillary refill: is it a useful clinical sign? Pediatrics. 1993 Nov;92(5):723-4. PMID 8414865.</ref> CRT has been shown to be influenced by ambient temperature, age, sex, skin color, and the anatomical testing and lighting conditions.<ref>Schriger DL, Baraff L. Defining normal capillary refill: variation with age, sex, and temperature. Ann Emerg Med. 1988;17(9):932-5.</ref><ref>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.</ref><ref>{{Cite journal |last=Nickel |first=Amanda |last2=Jiang |first2=Shen |last3=Napolitano |first3=Natalie |last4=Saeki |first4=Kota |last5=Hirahara |first5=Hideaki |last6=Nadkarni |first6=Vinay |last7=Nishisaki |first7=Akira |date=2018-11-06 |title=Abstract 276: Impact of Skin Color on Accuracy of Capillary Refill Time Measurement by Pulse Oximeter |url=https://www.ahajournals.org/doi/10.1161/circ.138.suppl_2.276 |journal=Circulation |language=en |volume=138 |issue=Suppl_2 |doi=10.1161/circ.138.suppl_2.276 |issn=0009-7322|url-access=subscription }}</ref> The most reliable and applicable site for CRT testing is the finger pulp (not at the fingernail), and the cut-off value for the normal CRT should be 3 seconds, not 2 seconds.<ref name=":2" />
To assess shock, central CRT, which is done by assessing capillary refill time at the sternum, rather than finger CRT, is more useful.<ref name=":1"/>
=== In infants === In newborn infants, capillary refill time can be measured by pressing on the sternum for five seconds with a finger or thumb, and noting the time needed for the color to return once the pressure is released (central CRT). The upper normal limit for capillary refill in newborns is 3 seconds.<ref>{{cite journal |author1=Krzysztof S Strozik |author2=Clarissa H Pieper |author3=Jacques Roller |title=Capillary refilling time in newborn babies: normal values |issue=3 | date=1997-01-13 | doi=10.1136/fn.76.3.F193 | url= | volume=76 | journal=Archives of Disease in Childhood: Fetal and Neonatal Edition | pages=F193–F196|pmc=1720653 | pmid=9175951}}</ref> A prolonged capillary refill time may be a sign of shock and can also indicate dehydration and may be a sign of dengue hemorrhagic fever and decreased peripheral perfusion.<ref>{{ cite web| url=https://www.medlineplus.gov/ency/article/003394.htm| author= David C. Dugdale, III, MD| title=Capillary nail refill test|date=2009-05-07 |access-date=2010-11-27}}</ref> Prolonged capillary refill time may also suggest peripheral artery disease.<ref name="scripps" /> It is generally accepted that the test is affected by many different external factors and therefore should not be relied upon as a universal diagnostic measure.<ref name="King 111–116"/>
=== In animals === Capillary refill time is also used in veterinary medicine. An animal should have a capillary refill time of less than 1 to 1 3/4 of a second. Because animals have fur, the gums are typically used to test capillary refill time.<ref>{{Cite journal|last=Stephen J. Hernandez-Divers|first=BVetMed|date=2015-03-30|title=World Small Animal Veterinary Association World Congress Proceedings, 2005|url=http://www.vin.com/doc/?id=6694579|website=VIN.com}}</ref>
== Use == Capillary refill time is a quick and cheap way to indicate decreased peripheral perfusion and may indicate cardiovascular or respiratory dysfunction.<ref name=":0" /> It has also been used to assess or diagnose diseases of the peripheral circulatory system such as Raynaud's syndrome and hand–arm vibration syndrome.<ref name=":1"/> Poor finger or toe capillary refill time is a contraindication for the use of compressive techniques to treat peripheral oedema. Capillary refill time is also traditionally used as a clinical indicator of tissue vascularity either after limb injury or after revascularization.<ref>{{Cite web |last=Monteerarat |first=Yuwarat |title=Is Capillary Refill Time Still A Reliable And Useful Test For Evaluating Tissue Perfusion In Injured Limb |url=https://meeting.handsurgery.org/abstracts/2016/P44.cgi |access-date=June 25, 2023 |website=meeting.handsurgery.org/}}</ref>
There is disagreement as to whether the test is useful, however, and it is poorly standardised.<ref>{{Cite journal |last1=Pickard |first1=Amelia |last2=Karlen |first2=Walter |last3=Ansermino |first3=J. Mark |date=July 2011 |title=Capillary refill time: is it still a useful clinical sign? |journal=Anesthesia and Analgesia |volume=113 |issue=1 |pages=120–123 |doi=10.1213/ANE.0b013e31821569f9 |issn=1526-7598 |pmid=21519051 |s2cid=32622801 |doi-access=free}}</ref><ref name=":1" /> Inter-rater reliability is often poor, caused by different lighting conditions and variable pressure that substantially change CRT results from person to person.<ref>{{Cite journal |last=Brown |first=Lawrence H. |last2=Prasad |first2=N. Heramba |last3=Whitley |first3=Theodore W. |date=1994-01-01 |title=Adverse lighting condition effects on the assessment of capillary refill |url=https://www.sciencedirect.com/science/article/pii/0735675794901961 |journal=The American Journal of Emergency Medicine |volume=12 |issue=1 |pages=46–47 |doi=10.1016/0735-6757(94)90196-1 |issn=0735-6757|url-access=subscription }}</ref><ref>{{Cite journal |last=Kawaguchi |first=Rui |last2=Nakada |first2=Taka-aki |last3=Oshima |first3=Taku |last4=Shinozaki |first4=Masayoshi |last5=Nakaguchi |first5=Toshiya |last6=Haneishi |first6=Hideaki |last7=Oda |first7=Shigeto |date=2019-01-08 |title=Optimal pressing strength and time for capillary refilling time |url=https://doi.org/10.1186/s13054-018-2295-3 |journal=Critical Care |language=en |volume=23 |issue=1 |pages=4 |doi=10.1186/s13054-018-2295-3 |doi-access=free|issn=1364-8535 |pmc=6323707 |pmid=30621748}}</ref>
However, CRT can still be a useful test, especially for conditions of septic shock, where markers such as serum lactate levels take time to analyze.<ref>{{Cite journal |last=Hariri |first=Geoffroy |last2=Joffre |first2=Jérémie |last3=Leblanc |first3=Guillaume |last4=Bonsey |first4=Michael |last5=Lavillegrand |first5=Jean-Remi |last6=Urbina |first6=Tomas |last7=Guidet |first7=Bertrand |last8=Maury |first8=Eric |last9=Bakker |first9=Jan |last10=Ait-Oufella |first10=Hafid |date=2019-03-13 |title=Narrative review: clinical assessment of peripheral tissue perfusion in septic shock |url=https://doi.org/10.1186/s13613-019-0511-1 |journal=Annals of Intensive Care |language=en |volume=9 |issue=1 |pages=37 |doi=10.1186/s13613-019-0511-1 |doi-access=free|issn=2110-5820 |pmc=6419794 |pmid=30868286}}</ref> The ANDROMEDA-SHOCK-2 trial saw better patient outcomes by using CRT as a target for septic shock resuscitation compared to the usual standard of care.<ref>{{Cite journal |last=The ANDROMEDA-SHOCK-2 Investigators for the ANDROMEDA Research Network, Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), and Latin American Intensive Care Network (LIVEN) |last2=Pálizas |first2=Fernando |last3=Lattanzio |first3=Bernardo |last4=Durandal |first4=Natalia |last5=Alonso |first5=Maria Eugenia |last6=Duque |first6=Julio |last7=Falcon |first7=Nicolas |last8=Mesa |first8=Ruben |last9=Hunter |first9=Martin |last10=Pozo |first10=Mario |last11=Gutierrez |first11=Facundo |last12=Sac |first12=Santiago |last13=Goette |first13=Nicole |last14=Consalvo |first14=Sebastián |last15=Zamudio |first15=Pilar |date=2025-12-09 |title=Personalized Hemodynamic Resuscitation Targeting Capillary Refill Time in Early Septic Shock: The ANDROMEDA-SHOCK-2 Randomized Clinical Trial |url=https://jamanetwork.com/journals/jama/fullarticle/2840823 |journal=JAMA |language=en |volume=334 |issue=22 |pages=1988 |doi=10.1001/jama.2025.20402 |issn=0098-7484 |pmc=12573117 |pmid=41159835}}</ref>
In veterinary medicine, poor gum CRT may be an contraindication for use of anaesthesia, as the likelihood of anaesthesia being fatal is higher if there is an underlying heart or lung problem. Gum CRT may also be used to monitor health during anaesthesia.<ref>{{Cite journal|last1=Warne|first1=L. N.|last2=Bauquier|first2=S. H.|last3=Pengelly|first3=J.|last4=Neck|first4=D.|last5=Swinney|first5=G.|date=2018|title=STANDARDS OF CARE Anaesthesia guidelines for dogs and cats|journal=Australian Veterinary Journal|language=en|volume=96|issue=11|pages=413–427|doi=10.1111/avj.12762|pmid=30370594 |s2cid=53097101 |issn=1751-0813|doi-access=free|hdl=11343/284701|hdl-access=free}}</ref>
==See also== * Peripheral vascular examination * Skin turgor
==References== {{reflist}}
{{DEFAULTSORT:Capillary Refill}} Category:Cardiovascular physiology