On the admission of air into the veins / by G.F. Lane.

  • Lane, George F. (George Frederick), 1828?-1856.
Date:
[1850]
Catalogue details

Licence: Public Domain Mark

Credit: On the admission of air into the veins / by G.F. Lane. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    air present a frothy appearance; yet in others, not to be distinguished from these by the previous symptoms, the air and blood are unmixed in the same cavity. Sometimes the blood is fluid in both auricles and ventri- cles, and at other times these cavities contain clots. The lungs are ob- served to be quite healthy. Iu a few cases a condition resembling emphy- sema was noted, which, according to Mr. Erichsen, may have been due to the large size of the air cells in dogs, or it may have pre-existed in some horses about to be lolled when unlit for other use. These are the more probable, since in the majority of cases reported no emphysema was present, even though air had been injected in many cases with as much force as possible. In all cases in which air has been found on the left side of the heart it has been present in much larger quantities on the right side. The experiments from which these facts are collected are those of Nysten, Amussat, Cormack, and Erichsen. Instances have been cited by some experimenters in which, on exposing the heart immediately after death, its riyht cavities were found contracted and flabby. Ur. J. Reid suggests that this probably resulted from wounding some large vein in the process, though not mentioned, as it is quite at variance with the numerous and well-conducted experiments of Nysten and Amussat. Our object will now be to ascertain, if possible, the proximate cause of death; for if we can accurately deter- mine this, we stand in the most favour- able position for the successful treat- ment of cases in winch the accident before alluded to has occurred. The opinions of various observers who have been, I may say, unfortunate enough to witness cases, differ widely. The irritation of air in the vessels of the brain,—the poisonous effects of car- bonic acid gas, supposed to be elicited from the venous blood,—the over-dis- tension of the right side of the heart,— obstruction in the pulmonary capillaries, —and a combination of three of these, —are opinions which have been respec- tively assigned by Bichat, Marchel de Calvi, Nysten, and Bouillaud. Piedag- nel believed that death arose from em- physema of the lungs, and Sir C. Bell, that the respiratory movements ceased from destruction of the functions of the medulla oblongata by air circulating in its vessels. A little consideration will show the incorrectness of the theory of Bichat and Sir C. Bell. Iu the first place, when Nysten injected quantities of air into the carotid artery, symptoms of apoplexy came on, and death did not occur till after the lapse of some hours. Dr. John Reid also blew air into the carotids in several experiments, and found that it produced convulsions and coma, which lasted some hours before death. In the second place, the air but seldom passes to the leftside of the heart. Hence, if it does not reach the brain, its presence in the cerebral vessels can- not be said to destroy the functions of this organ or the medulla. The same course of experiments affords a refutation of the theory that carbonic acid in the blood is the cause of death. Nysten injected this gas into the ves- sels, and found the same results follow as when atmospheric air was tin-own in, with this difference, that the gas could be found nowhere after death , but that when air was injected into the arterial system in large quantities, it was to be found throughout the vascular system as well as in the cavities of the heart. He ascertained that a small quantity of carbonic acid injected produces no visible effect. After performing numerous experi- ments, it is the opinion of Mr. Erichsen that the heart is not capable of being so distended by air as to arrest its action, unless it be forcibly injected with a powerful instrument; and he questions whether this could of itself arrest the heart’s action. The distension of the heart has been compared to that of the urinary bladder; but the analogy will not hold, the conditions being quite different. The bladder becomes dis- tended gradually, audits walls rendered thereby incapable of contracting. The distension of the heart is supposed to be sudden. Furthermore, the effect of suddenly injecting large quantities of fluid into the bladder is to induce powerful contraction. I am disposed to think that the effect of a small quan- tity of air in the cavity of the heart is to induce at first increased action, whether owing to a spontaneous effort of the heart to get rid of the air, or to its me- chanical action on that organ; and this opinion is assumed from noting in Nysten’s experiments that the first oc-
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