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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    (currence observed by him was accelera- l tion of the pulse and burned respiration. ' With regard to emphysema, it scarcely i needs alluding to. Are we to consider i that this can be the cause of death, ■ when it has only been observed in one i or two experiments, and these in doubt- ful cases, and since death occurs with i equal rapidity when the lungs are quite healthy ? That some obstruction exists in the lungs, we are warranted in concluding from the fact that in almost all tho cases recorded there was fulness of the right side of the heart, and comparative emptiness of the left side ; also from the constant presence of air in the right cavities where any was found, and its very rare occurrence in the left. Mr. Erichsen states that arrest to the passage of blood takes place in the capillaries of the lungs in consequence of their be- coming obstructed by bubbles of air; the right auricle and ventricle becoming filled with a spumous fluid which they can neither propel forward nor drive back to any material extent, but which, oscillating in the large veins about the heart, acts as a mechanical obstacle to the passage of the blood tlu-ough them; and that the animal dies as though a ligature were tied around the two cavffi; and we accordingly find after death the same congestion of blood in the venous, and absence of blood in the arterial system, that would result from such an operation. Whether the impaired action of the heart, when it exists, is primary, and in- duced by the air in its cavities, or se- condary, through disorder of the pul- monary circulation, I must leave for others to determine. An argument in favour of the distended condition of its cavities having some immediate influ- ence in the production of death may be foimd in the fact that in many cases decided benefit has followed the free escape of blood horn the wounded vessel, whether it be mixed with air or not: an experiment of Nysten’s, related in the former part of this paper, is a re- markable instance, and other cases might be mentioned. As the circulation in the lungs be- comes more and more impeded, the quantity of blood which reaches the left side of the heart must be diminished; the heart itself is deprived of the ne- cessary amount of blood through the coronary arteries; the nervous centres do not receive sufficient oxygenated blood to maintain their functions, and the respiratory movements cease from an absence of those impressions of sensation which are necessary for the act of respiration. Mr. Erichsen, Dr. John Keid, and, as far as I am able to ascertain, all the others who have written upon this subject, have omitted mentioning an important class of cases in which the symptoms of asphyxia and coma have been most prominently marked by great lividity of the head and face approaching to blackness, convulsive movements; the respiration deep, la- boured, and stertorous, and the pulse slow : two cases of this kind are reported by Dr. Warren ;* another occurred to Dr. Willis, the full particulars of which I have been unable to find; and a similar case is related by Dr. Connack. But the presence of air-bubbles in the capillaries of the lungs, Mr. Erichsen demonstrates by experiment. He took the lungs of a dog recently killed, and found nearly double the propulsive power, ascertained by adjusting a hsema- dynamometer, to drive blood through the lungs from the pulmonary artery, when air had been previously blown into the artery, than when the blood was unmixed with air. An experiment, also, of Cormack’s, on a similar- organ, the liver, shows the effect of air-bubbles in considerable quantities in the ca- pillaries of that organ. After injecting air into the mesenteric vein of an ani- mal, he found the liver in a condition of almost complete anaemia. I must, then, infer, that obstruction to the blood in thepulmonary capillaries in the majority of instances is the im- mediate cause of death, and that such obstruction is occasioned by the unna- tural admixture of air rvith the blood ; but that in a few instances, where the amount of pidmonary obstruction ap- peal’s to be inadequate to the produc- tion of asphyxia, the symptoms of apo- plexy which present themselves lead clearly to the inference that the tem- porary obstruction about the heart has induced fatal cerebral congestion. As regards the remedial measures to be adopted in cases in which air has already entered a vein ; without waiting for the supervention of symptoms, an immediate indication is to prevent its * American Cyclopedia of Practical Medicine and Surgery.