The determination and evaluation of capillary resistance--a review of methodology.

By JENO KRAMA.R SINCE the diagnostic significance of “fragile capillaries” was first recognized,”2#{176} much productive work has been accomplished to improve the methods for determination of capillary resistance and to elucidate the variables concerned. Strangely enough, these studies have led to little practical application. Tile current clinical routine for measuring capillary resistance continues with the same shortcomings as of old: ( 1 ) There is still no firm agreement as to tile most suitable method; ( 2 ) the procedure is not standardized, hence findings of various investigators are difficult to compare; ( 3 ) pitfalls incidental to tile testing are not generally appreciated; ( 4 ) interpretation of findings is not uniform and frequently erroneous. This is all the more deplorable because these tests still constitute useful tools for experimental studies of hemorrhagic disorders as well as for the clinical approach to the question of whether a vascular abnormality may be present. In addition, recent observations suggesting that increased capillary resistance may also represent abnormal conditions broaden the field of application of capillary resistance measurement beyond that of clinical and experimental hemorrhagic disorders. The purpose of the present paper, which is the result of ten years’ clinical and experimental studies, is to draw practical conclusions and to suggest how the present unsatisfactory situation can be improved. References are limited to data directly pertinent to the topics discussed and, since excellent review articles are available,20’24’29 no attempt is made to review the extensive literature.