Compensation

COMPENSATION (from Latin compensare - to replace, to reward), equilibration. This term conventionally denotes adaptations developed in the organism (or in an organ) which contribute to the equalization of functions impaired by a pathological process. A classical case of compensation, which is encountered comparatively rarely, however, is the regeneration of tissue after a loss of substance and the restoration of the working capacity of the affected organ at the expense of newly formed elements. Another path of compensation is the hypertrophy of a completely preserved part of the organ. An example of this can be vicarious emphysema of the lungs when a significant part of them is excluded by a pathological process. Most often, however, compensation is spoken of in relation to the heart, especially in disorders of its valvular apparatus, if the circulation occurs without a noticeable deviation from the norm, if there are no phenomena of blood stasis in one or another circulatory loop, which coincides with heart performance bordering on normal. As an example of full compensation of a disturbance of the valvular apparatus of the heart, one can cite athletes with heart defects who won prizes at international competitions. A decompensated defect or a heart in a state of decompensation is spoken of when there are signs of circulatory disturbance. Depending on the degree of heart failure, they speak of a complete disorder of compensation (decompensation) or only a partial one (subcompensation). The disorder of compensation of cardiac defects can occur immediately after the formation of defects in the valvular apparatus, and then it would be more correct to speak of unrealized compensation rather than its disorder. Most often, however, decompensation is revealed after a very long period of time (a number of years), and in a number of cases it is impossible to note the direct cause that caused the weakening of cardiac activity. The occasion for the onset of decompensation is sometimes a mental shock, and theoretically one can assume a threefold path of the latter's effect on the heart: 1) an increase in the frequency of heartbeats, 2) fluctuations in blood pressure, and 3) the influence through the nervous apparatus on the function of conductivity and contractility. A pathological process accompanied by moments purely mechanically affecting the work of the heart can also be the cause of decompensation; as an example of this, one can cite exudative pleurisy, leading to decompensation both by direct compression and displacement of the heart, and by cough jolts that fluctuate blood pressure (Botkin). Finally, a large physical exertion can serve as an occasion for decompensation. Recently, to explain certain phenomena in decompensation, the consideration of peripheral circulation factors, in particular the mass of circulating blood, has been put forward. These views, resting on new facts of the pathological physiology of blood circulation and showing with certainty that the mechanisms that are set in motion during various perturbations in the cardiovascular apparatus are very complex, somewhat shift the direction of research from the center (heart) to the periphery (vascular network, state of tissues). (See also Blood circulation - pathology.) - Lately, they began to conventionally speak of compensated (not depriving of working capacity) and decompensated pulmonary tuberculosis.