title: Reliability of Allen's test in selection of patients for radial artery harvest.
abstract: BACKGROUND
  Allen's test is widely used to assess the ulnar collateral blood supply of the hand before radial artery harvest for coronary bypass surgery. This study was performed to determine the optimum cut-off point for a positive Allen's test and the clinical reliability of Allen's test in this role.
  
  
  METHODS
  Patients undergoing coronary artery bypass surgery were examined by independent observers using both Allen's test and a Doppler ultrasound test of the ulnar collateral circulation.
  
  
  RESULTS
  We examined 93 hands in 47 patients; mean age was 63.6 years. Receiver operating characteristic analysis found that at a conventional cut-off of 6 seconds on Allen's test had a sensitivity of 54.5%, specificity of 91.7%, and diagnostic accuracy of 78.5%. At a cut-off of 5 seconds diagnostic accuracy was maximal (79.6%), with sensitivity of 75.8% and specificity of 81.7%; 100% sensitivity occurred at a cut-off of 3 seconds, with specificity of 27% and diagnostic accuracy of 52%.
  
  
  CONCLUSIONS
  At no cut-off point does Allen's test perform satisfactorily as a discriminatory test. It should be replaced by more objective tests, such as Doppler ultrasound.
authors.affiliation: Department of Cardiothoracic Surgery, Glenfield Hospital, Leicester, United Kingdom. martin-sie@cabg-jarvis.freeserve.co.uk
authors.forename: M A
authors.initials: MA
authors.lastname: Jarvis
authors.forename: C L
authors.initials: CL
authors.lastname: Jarvis
authors.forename: P R
authors.initials: PR
authors.lastname: Jones
authors.forename: T J
authors.initials: TJ
authors.lastname: Spyt
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D003097:Collateral Circulation / Q000502:physiology; D001026:Coronary Artery Bypass / Q000379:methods*; D005260:Female; D006225:Hand / Q000098:blood supply*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011237:Predictive Value of Tests; D017534:Radial Artery / Q000637:transplantation*; D020858:Tissue and Organ Harvesting; D018608:Ultrasonography, Doppler