Stead S W, Stirt J A
Int J Clin Monit Comput. 1985;2(1):29-34. doi: 10.1007/BF02915870.
Collateral circulation of the hand and digits was evaluated in 20 healthy male volunteers using a modified Allen's test and photoelectric plethysmography. A borderline (7-14 sec) Allen's test was present in 12.5% and 2.5% required more than 15 seconds for thenar flush. Photoplethysmography was then used to compare the relative contributions of ulnar artery flow to total arterial flow into the hand. This ratio, (ulnar/total) was termed the flow index (FI). Average FI for the first digit (thumb) was 0.59, and for the second digit (index) was 0.64. The FI difference between the first digit and that of the third, fourth and fifth digits was statistically significant (p less than 0.01). The FI difference between the second digit and the third, fourth and fifth digits was also statistically significant (p less than 0.05). These results imply that Allen's test may be misleading, indicating adequate collateral circulation when in fact collateral blood flow to the digits may be poor or nonexistent.
使用改良的艾伦试验和光电体积描记法对20名健康男性志愿者手部和手指的侧支循环进行了评估。12.5%的人艾伦试验结果处于临界值（7 - 14秒），2.5%的人小鱼际充血需要超过15秒。然后使用光电容积描记法比较尺动脉血流对手部总动脉血流的相对贡献。这个比率（尺动脉/总动脉）被称为血流指数（FI）。拇指（第一指）的平均FI为0.59，示指（第二指）为0.64。第一指与第三、第四和第五指的FI差异具有统计学意义（p小于0.01）。第二指与第三、第四和第五指的FI差异也具有统计学意义（p小于0.05）。这些结果表明，艾伦试验可能会产生误导，即当实际上手指的侧支血流可能很差或不存在时，却显示侧支循环充足。
