A treatise on the principles and practice of medicine : designed for the use of practitioners and students of medicine / by Austin Flint.
- Austin Flint I
- Date:
- 1884
Licence: Public Domain Mark
Credit: A treatise on the principles and practice of medicine : designed for the use of practitioners and students of medicine / by Austin Flint. Source: Wellcome Collection.
Provider: This material has been provided by the University of Massachusetts Medical School, Lamar Soutter Library, through the Medical Heritage Library. The original may be consulted at the Lamar Soutter Library at the University of Massachusetts Medical School.
80/1212 page 70
![immediately endangering life. Morphine, atropine, and especially ergot, were found useful in relieving the pain. The main reliance, when the sym])toms are urgent, and especially when life is endangered soon after removal of the pressure, is return to compressed air. Bert has proposed the inhalation of oxygen to displace the free nitrogen from the blood by diifusion. Air compressed not more than from one to five atmosplieres has been em- ployed as a therapeutical agent, chiefly in certain pulmonary disorders. The influence of moderately compressed air is to diminish the mmiber of pulsa- tions of the heart, and to increase the capacity of the lungs by compression of the intestinal gases. According to Bert, the maximum of oxidation takes place under a pressure of three atmospheres. A condition attributed to excess of oxygen in the blood is a temporary cessation of the respiratory acts, which is observed to follow violent and full inspirations, and which has been studied chiefly by physiologists on animals, the condition being induced by vigorous artificial respiration. To the cessation of breathing as thus produced, the term a[)ncea is limited by some German writers; but this term, as usually applied, embraces the various conditions which occasion dyspnea. In the latter comprehensive sense, inclusive of serious disturbances of hiematosis, wdiether accomjianied or not by a sense of the want of breath or dyspnoea, the term will be used in this work. Accord- ing to Hoppe-Seyler,^ apnoea, in the limited sense above mentioned, is to be attributed, not to an excess of oxygen in the blood, but to fatigue of the respiratory muscles. Deficiercy of oxygen in the blood is of much greater pathological import- ance than its increase. If the quantity of oxygen in the blood be greatly diminished, there follows a group of symjjtoms to which the names suffo- cation, asphyxia, cyanosis are applied. Causes which reduce the amount of oxygen in the blood sufficiently to produce suffocative symptoms are, 1, diminution in the supply of oxygen to the pulmonary capillaries, as from breathing in rarefied air and in small closed spaces, also from obstruction or compression of the air-passages as in croup; from diseases Avhich lessen the respiratory surface of the lungs or interfere with their function, as pneumonia, phthisis, pneumothorax, asthma, oedema; from interference with the respira- tory centre, as in certain affections of the central nervous system, and in nar- cotic poisoning; 2, obstruction to the circulation in the lungs, as from embolism of the pulmonary artery and in valvular lesions of the heart; 3, diminution in the amount of hemoglobin in the blood such as results from profuse hemor- rhages ; 4, displacement of oxygen from its combination with haemoglobin by other gases which enter into a firmer combination, as carbonic oxide from which many intentional and accidental cases of poisoning have resulted (nitric oxide also displaces the oxygen, but being irrespirable need not here be considered); 5, rapid reduction of oxyha^moglobin by gases which seize the oxygen, such as sulphuretted hydrogen, and, probably also phosphuretted, arseniuretted, and antiraoniuretted hydrogen, which further decompose the blood. Mention here should also be made of the asphyxia of new-born children, asphyxia neonatorum, which is due to separation of the placenta or to closure of the umbilical vessels before birth. After death from rapidly produced sufibcation, the blood is of a dark color, and usually, although not always, fluid or imperfectly coagulated, the riglit cavities of the heart are, as a rule, distended with blood, the mucous membrane of the larynx and trachea con- gested, ecchymoses are frequently present beneath the pleura and pericardium. In consequence of the fluid condition of the blood, there is hypostatic conges- tion of most organs, and livid spots (livores mortis) on the most dependent * Hoppe-Seyler, Zeitschrift fiir physiologische Chemie, iii. p. 105, 1879.](https://iiif.wellcomecollection.org/image/b21198135_0080.jp2/full/800%2C/0/default.jpg)
