PERIPHERAL VASCULAR DISEASES 



12 19 



such as recent use of tobacco, alcohol, or certain 

 drugs should be controlled. 



Because of the great number of variables in disease 

 and because of the wide range of normal variation, 

 the clinician must take advantage of "built-in" 

 controls. To this end, he should carefully and con- 

 tinually examine and compare symmetrical parts 

 of the body. 



DETERMINATION OF THE ADEQUACY OF THE CUTANEOUS 



circulation. The presence and location of cutane- 

 ous ulcerations should be noted. In arterial disease 

 these tend to be at the tips of the digits and over 

 pressure areas, whereas in venous disease they tend 

 to be located over the medial lower one-third of the 

 leg. The skin should be examined for texture and 

 consistency. The skin tends to be thin and shiny in 

 arterial disease and thick and brawny in long- 

 standing venous and lymphatic disease. Tissue 

 swelling and edema tend to be absent in arterial 

 disease, unless there has been considerable capillary- 

 injury, but they are frequent findings in venous and 

 lymphatic insufficiency. Changes in the growth rate 

 and appearance of the nails may be clues to impaired 

 cutaneous circulation. The nails tend to be thickened, 

 ridged, deformed, brittle, and pigmented. In vaso- 

 spastic states there may be thinning of the proximal 

 nail fold with merging into the cuticle (pterygium). 

 Hair growth may be impaired. The degree of sweating 

 is important. Absence of sweating may indicate 



complete ischemic destruction of sympathetic nerve 

 fibers or ischemic impairment of sweat gland func- 

 tion. Excessive sweating, in the absence of a demand 

 of this function for thermal regulation, usually 

 indicates increased sympathetic activity with intact 

 nerves, frequently due to psychogenic disturbances. 

 Other vascular manifestations of increased sympathe- 

 tic activity with respect to temperature and color of 

 the skin are usually present. 



Temperature and color changes are of such 

 importance in the evaluation of the cutaneous 

 circulation that they demand special comment. The 

 observations of Lewis (49) are still authoritative. 

 Under standardized conditions, the amount of heat 

 brought to the skin may be considered a gross reflec- 

 tion of the rate of local blood flow. It should be noted 

 that the temperature of a part cannot decline more 

 than 1 C to 2 C below room temperature and then 

 only if the part is moist and the circulation com- 

 pletely arrested. The temperature rarely decreases 

 below 20 C in a cool room and rarely exceeds 34 C 

 in a warm room. Temperature differences of sym- 

 metric areas, similarly exposed, should arouse sus- 

 picion of circulatory disorder. When exposed to 

 cold, the part with the better circulation will remain 

 warm longer and on rewarming its temperature will 

 increase faster. 



Except for modification by skin pigments, the 

 color of the skin is due mostly to blood in the venules 

 of the subpapillary venous plexus and to a lesser 



34 



24. 



_^.^_ REFLEX VASODILATATION 

 (BODY HEATED) 



POSTERIOR TIBIAL 

 NERVE BLOCK 



MINUTES 



"I I I I I I I I I T" 



5 10 



"~ 1 1 I I I I I I I I I I I I I 1 1 I I 1 1 1 1 1 1 1 r~ 

 15 20 25 30 35 40 



45 



fig. I. Thermocouple recording of thermal change in the right big toe demonstrating the effects 

 of reflex vasodilatation and posterior tibial nerve block. 



