http://www.fpnotebook.com/
Allen Test
Aka: Allen Test, Allen's Test, Wrist Collateral Circulation
- Epidemiology
- Inadequate collateral flow in 3% hospitalized patients
- Causes of Inadequate Ulnar Circulation
- Normal anatomic variant
- Hypothenar Hammer Syndrome
- Indications
- Test wrist collateral Blood Flow
- Arterial Puncture for Arterial Blood Gas
- Technique
- Patient elevates hand and makes a fist for 20 seconds
- Firm pressure held against radial and ulnar arteries
- Patient opens hand and should blanche white
- Examiner releases only ulnar compression
- Normal Result
- Hand color flushes within 5 to 7 seconds
- Abnormal result: Inadequate collateral circulation
- Hand remains white until radial pressure released
- Risk of serious hand ischemia if radial vessel spasm
- Alternative means for assessing collateral circulation
- Doppler Ultrasound
- Finger plethysmography
