An experimental study of the resistance to compression of the arterial wall

The object of this study was to determine whether the resistance to compression of the arterial wall introduces an error of any importance in the clinical measurement of systolic blood pressure by methods employing circular compression of the arm. No previous studies are free from serious criticism on the ground of inaccuracy of the methods employed. Some direct on post-mortem vessels (v. Basch, Martin, Herringham and Womack), and some indirect (Oliver, Hill, Williamson, Russell). In consequence of the discordant results, opinion has been divided. Some hold the resistance to compression of the arterial wall to be negligible; others that it might be extreme. The present study has been carried on by a method giving graphic records of the pressure within the artery, the pressure in the external compressing medium, and of the changes in the outflow from the artery by a Hürthle membrane manometer. Ringer's solution was used in all the experiments. The point of first collapse of the artery, of complete obliteration of its lumen, and of resumption of the flow on lowering the external pressure after obliteration were recorded in each experiment. The latter proved by far the most constant index and most analogous to the ordinary criterion of the return of the pulse in clinical work.