Homeostasis: a physiologic and psychologic function in man.

Abstract

HOMEOSTASIS: A PHYSIOLOGIC AND PSYCHOLOGIC FUNCTION IN MAN ALVAN L. BARACH, M.D., F.A.C.P.* The application of homeostasis to psychologic as well as physiologic functions was suggested by the broad interpretation of this principle in man presented by Norbert Wiener: "The process by which we living beings resist the general stream of corruption and decay is known as homeostasis. We can continue to live in the very special environment which we carry forward with us until we begin to decay more quickly than we can reconstitute ourselves [1, p. 12]. In his development of cybernetics as the varied means of communication between organisms and the environment, Wiener postulates that certain limited areas of the universe, which he calls "local enclaves," manifest an opposing direction to the general tendency of the universe to deteriorate toward chaos. The aim of this communication is to describe, first, a local physiological realm in which the breathless patient with chronic obstructive lung disease illustrates a remarkable capacity to reconstitute himself, and, second, a psychologic realm in which man may adapt himself to the hazard of evil in such a way as to preserve his life and well-being. Although medicine is generally concerned with overt assaults on disease, adaptive responses of the human organism to injury appear to have a therapeutic potential of some magnitude. Cannon coined the term "homeostasis" to define the compensatory physiological responses to impairment of the body's function [2]. Prior to his unique animal experiments in this field, Claude Bernard had emphasized nature's attempt to maintain a constancy in the internal environment of the body when threatened by adverse influences [3, p. viri]. The use of carbon dioxide to illustrate the evolution of a homeostatic mechanism seems especially appropriate, since it is the waste material *Consultant in medicine, Presbyterian Hospital, New York. Address: 72 East 91st Street, New York, New York 10028. This paper was composed to celebrate and commemorate the eightieth birthday of Henry A. Murray, M.D., who has served as vice president and president of the American Goethe Society (unincorporated). 522 I Alvan L. Barach · Homeostasis in Man rejected by the lungs during the expiratory cycle, in contrast to oxygen, which is the manifestly life-preserving principle inspired into the lungs; oxygen and CO2 represent a dualism in nature, as do inhale and exhale, light and darkness, good and evil, anabolism and catabolism. In the course of studies on oxygen therapy in 1920, I reported that inhalation of60-80 percent oxygen in two dyspneic patients with shallow breathing resulted in a fatal respiratory acidosis in a matter of several hours [4]. The volume of breathing was so markedly diminished that carbon dioxide was swiftly retained until the pH of the arterial blood shifted markedly to the acid side. Compensatory measures did not evolve in time to prevent coma and death. Later on, having observed the onset of coma in some patients with chronic obstructive lung disease treated with continuous inhalation of 50 percent oxygen, I proposed a regime oflow-flow oxygen therapy, that is, 1 liter ofoxygen per minute through a nasal catheter, increasing 1 liter/min per day as indicated for 3-5 days [5]. This program resulted in a gradual increase in arterial blood carbon dioxide with gradual decrease of the volume of breathing, relief of dyspnea , without coma or other adverse side effects. Nature had thus been provided with the opportunity of developing a physiological homeostasis . The progressive accumulation of CO2 in the blood was balanced by elimination of CO2 in high concentrations in the alveolar air, approximating the high arterial carbon dioxide tension, a reaction that permitted the decrease in minute ventilation originally engineered by oxygen. Base bicarbonate was slowly but progressively conserved by the kidneys to offset the increased carbonic acid. The acid base equilibrium remained within the normal range, the patients felt well, breathlessness was relieved, and the body's hypoxia was remedied. Unfortunately, the increased CO2 found in the arterial blood of patients with chronic obstructive lung disease is still regarded as an unmitigated evil, and mechanical hyperventilation is recommended to lower the elevated carbon dioxide tension by clinicians who have not understood the function of...