II. Epidemiology
- Inadequate collateral flow in 3% hospitalized patients
III. Causes of Inadequate Ulnar Circulation
- Normal anatomic variant
- Hypothenar Hammer Syndrome
IV. Indications
- Test wrist collateral Blood Flow
- Arterial Puncture for Arterial Blood Gas
V. 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
VI. Normal Result
- Hand color flushes within 5 to 7 seconds
VII. Abnormal result: Inadequate collateral circulation
- Hand remains white until radial pressure released
- Risk of serious hand ischemia if radial vessel spasm
VIII. Alternative means for assessing collateral circulation
- Doppler Ultrasound
- Finger plethysmography