title: Is the Allen test reliable enough?
abstract: OBJECTIVE
  The Allen test is a widely used screening method of hand circulation. Our aim was to study whether the Allen test alone gives sufficient information for harvesting the radial artery in coronary artery bypass grafting.
  
  
  METHODS
  One hundred and forty-five patients scheduled for coronary artery bypass grafting underwent the Allen test, upper arm Doppler ultrasonography and digital plethysmography. In ultrasonography both anatomical and circulatory measurements were performed. The Allen test was then compared with more objective tests and sensitivity; specificity and diagnostic accuracy were calculated.
  
  
  RESULTS
  Most of the patients had a negative Allen test, but 23% were positive (abnormal). Ultrasound scanning revealed anatomical anomalies in 10 patients and circulatory deficits in 17 patients. Thirteen patients had both circulatory and anatomical abnormalities. Sensitivity of the Allen test was 73.2% and specificity 97.1% based on our findings. There were no abnormalities in the recovery of the arms with harvested radial grafts.
  
  
  CONCLUSIONS
  The Allen test is a good and valid screening test for the circulation of the hand. If the Allen test is negative it is safe to harvest the radial artery. If it is positive further examinations are needed to ensure safe harvesting of the radial artery.
authors: Heart Center, Department of Clinical Physiology, Tampere University Hospital, Tampere, Finland. mika.kohonen@pshp.fi
authors: Mika
authors: M
authors: Kohonen
authors: Ossi
authors: O
authors: Teerenhovi
authors: Tiina
authors: T
authors: Terho
authors: Jari
authors: J
authors: Laurikka
authors: Matti
authors: M
authors: Tarkka
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003097:Collateral Circulation; D000075202:Contraindications; D001026:Coronary Artery Bypass / Q000379:methods*; D003935:Diagnostic Techniques, Cardiovascular; D005260:Female; D006225:Hand / Q000098:blood supply*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010167:Pallor; D010991:Plethysmography; D011300:Preoperative Care / Q000379:methods; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000502:physiology*; D012039:Regional Blood Flow; D012680:Sensitivity and Specificity; D020858:Tissue and Organ Harvesting / Q000379:methods*; D018608:Ultrasonography, Doppler