This article is taken from book by prof. George Abbott, published in 1914 in USA. We would like to present it to the bigger group of readers, especially when it is very difficult to be found anywhere. Therefore we took this opportunity to present an interesting matter as seen back in 1914. Still some parts of this article are valid, and hydrotherapy as presented here is being used in spa treatment.



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Prof. George Knapp Abbott

Published 1914

By reference to the observation recorded under reflex and hydrostatic effects, it will be seen that thermic applications to the surface exert two classes of effects- a reflex and a hydrostatic effect- which are directly opposite and, therefore, conflicting. Probably an application produces more or less of both, though one or the other usually predominates. Since they are opposite, one will neutralize or overshadow the other. Kellogg makes the following statement: “Doubtless both of these effects are always produced. When the application is general, the mechanical effect is dominant; when the area involved is limited, the reflex effect is prominent. In general applications, the primary reflex effect is quickly effaced by the succeeding mechanical effect, due (in case of cold) to the inrush of blood from the periphery. This diversion of blood from the surface vessels to the interior of the body is termed retrostasis. Marked retrostasis is produced only when the cold application is made simultaneously to a very large cutaneous area.” These are essentially the views of Schuller, who considered that, at the beginning of the application, the pial vessels were affected reflexly, which effect is soon overbalanced by the thermic effect upon the vessels of the skin.

“If the surface area to which the application is made is small, the reflex effect may be confined to the internal area in sympathetic relation therewith, and wil be greater and more prolonged for the reason that the reflex influence is concentrated upon a circumscribed area; while the mechanical effect is distributed over the rest of the body, so that it does not overshadow and wipe out the reflex effect on the smaller area involved.” Baruch’s comment upon this subject is as follows: “Baths and other procedures without mechanical excitation, when applied to large portions of the body, doubtless have a hydrostatic effect; while douches, which impinge on limited portions, and are combined with mechanical effects (irritation), act chiefly by reflex influence.”

Is it possible to determine which result will be greater in a given case, or which will be practically the only effect from a certain application? In reply to this very natural question, we may state that there are definite laws governing these opposing actions. By them, one may so time and regulate applications as to secure a desired and definite result.

Laws of Balance: The following are the laws; other things being equal, the results stated obtain:

Size of Area- 1) When an application covers a small area, the effect is chiefly reflex, and is concentrated upon the internal part in reflex relation with the surface treated; 2) When applications are made to a large area, the hydrostatic effect predominates, and the larger the area treated the greater the hydrostatic effect
Location of Area- 1) The chief effect of an application to certain areas (example, the head or the precordia) is a reflex effect; 2) The principal result of an application to certain other areas (example, the feet and legs) is hydrostatic

Duration and Intensity of Application: The duration and intensity of the effect, either reflex or hydrostatic, depend upon the duration and intensity of the application. The intensity of an application is gauged by the degree of heat or cold and by the form and pressure of douches, or the degree and amount of friction

Examples: The prolonged application of an ice bag (small application of intense cold) to the precordia (special area) produces a (reflex effect) prolonged slowing of the rate of the heart beat, and a decided increase in its force for the same length of time. There is no tendency to produce retrostasis of blood or engorgement of the heart (hydrostatic effect).

A hot trunk pack (large area) withdraws blood from the viscera (hydrostatic effect) rather than producing dilatation and engorgement of their vessels (reflex effect).

A hot and cold douche to the chest (small intense application) stimulates the heart and respiration (reflex effect) rather than having any decided hydrostatic effect upon the blood current of these organs. Applications to the head (special area), whether hot or cold, have a reflex effect almost entirely.

Many other examples might be given, but the principle involved in the above are the same as those which govern other applications. It will be seen that, although reflex and hydrostatic effects directly oppose each other, the reflex overshadows and obliterates the hydrostatic when certain areas are involved, and especially when these areas are small. The hydrostatic effect wipes out the reflex effect when the application is to certain other areas, and especially when those areas are very large.

We have so far discussed these two classes of effects as to their opposing results. Reflex and mechanical effects may be made to assist each other in securing depletion when diverse applications are made to different areas simultaneously. This will be discussed under the head of derivation.

Double Effects: In the case of hot applications applied over congested organs, certain phases of both the reflex and the hydrostatic effect may prevail. This is especially noticeable with large fomentations or hot packs over the liver or kidneys. These reflexly relax (and dilate) the blood vessels of the internal organ while hydrostatically they draw blood from the organ thus leaving the vessels of that organ relaxed but only partially filled with blood, i.e., partly collapsed. This double effect from a single application is of great importance in acute congestions of the kidneys and liver as in eclampsia where vascular tension is high but the organ functionally inactive. The tension being relieved by relaxation of the muscular coat (reflexly) and the congestion depleted (hydrostatically), the blood again circulates more rapidly and functional activity begins almost at once.