The Rational Influence of Hot Applications.
In some recent experiments made by Schuller, it was determined that whenever the body of a rabbit, upon which he was experimenting, was immersed in hot water, all the blood vessels of the meninges of the brain contracted, showing that the amount of blood within the cranium was markedly diminished.
On the other hand, whenever the body was immersed in cold water, the meningeal vessels became engorged. Further experiments show that where cold was applied to produce local anemia, the condition was immediately followed by a secondary hyperemia in which the vessels greatly exceeded their normal size in distension with arterial blood.
This simple demonstration is a strong argument in favor of heat and should be borne in mind in the application of cold to any area during high temperature to overcome the acute congestion which precedes or acts as an initial factor in local acute inflammatory action. The effect of cold in driving the blood out of the part is only temporary, and the secondary result is that there is a greater determination there than before the cold was applied.
Furthermore, as there is no stimulating influence from cold, the morbific products present in the tissues and capillaries of the part, remain there and become one of the active factors which induce the engorgement, clogging up the capillaries and preventing elimination. Disintegration soon takes place and the excretory products of the inflammatory processes are immediately deposited and structural change becomes pronounced.
Let heat be applied instead of cold. There is thus no violent reaction taking place; the stimulating effect of heat is at once apparent. The capillaries are at once dilated, the blood is moved rapidly, and with this rapid movement the morbific products are carried off. At the same time the restorative processes are encouraged by the action of heat, and cell and capillary disintegration takes place to a very much larger degree.
These arguments can be demonstrated plainly by an investigator who is not prejudiced by deep-seated, long standing traditions. I have recently observed a case of meningitis in which ice packs were applied to the head almost from the first. The body and limbs were cold and almost blue, and from the first, the heat in the head increased.
If heat had been early applied to the body and extremities in place of applying ice to the head, the derivative influence of this powerful measure would have produced an active anemia of the brain, and the usual result of the inflammation, especially the exudation, would have been retarded or prevented entirely.
I know of an old physician who has successfully treated acute meningitis for many years by putting the patient in a very hot mustard bath and keeping this up during the first few days of the disease as often as is permissible.
I am aware that I am prejudiced against the application of cold in local inflammation; but I think I have most excellent reasons for arguing in favor of heat, and heat only, except, perhaps, in rare cases.