The development of experimental pneumonia under direct observation of the lungs in the living animal

Abstract

Experimental pneumonia produced by intra-bronchial insufflation of virulent pneumococci may develop quite rapidly. Thus in the experiments of Lamar and Meltzer it was observed that in one instance seven hours after the injection, nearly complete consolidation affecting the greater part of one lobe was already present. We therefore now made several experiments in which the lungs were under direct observation continuously for several hours after the insufflation of the culture. The procedure has been as follows. The dog was anesthetized by the cone method, and a tube introduced into a bronchus as deep as it could be pushed; the pneumococcus culture was then injected. Immediately after, the tube was withdrawn, so that its lower end was just above the bifurcation, and the arrangement made for continuous intratracheal insufflation. The dog received about “half ether” and was continually under complete anesthesia, The thorax was now widely opened transversely and about two thirds of three or four of the lower ribs on the right side removed; the right lower lobe, which is usually the seat of the inflammation, was now exposed to full view. We shall not enter here upon details. It may suffice to state that we were able to watch the successive stages from the earliest signs of engorgement to complete hepatization. We were also able to establish changes in the auscultation phenomena in the consolidated parts, in some instances even clearly suggesting tubular breathing. We intended to demonstrate such experiments, and we prepared several animals for this purpose. The experiments were successful indeed, but we did not take the lateness of the hour of the meeting sufficiently into account. We prepared the experiments too early and all the animals died before the meeting began. The acute infection, the great loss of heat, the severe operation, and the long-lasting anesthesia are severe factors to contend with.