On the respiratory changes of the intrathoracic pressure : measured in the mediastinum posterior / By Dr. S.J. Meltzer.

  • Samuel James Meltzer
Date:
[1892]
Catalogue details

Licence: Public Domain Mark

Credit: On the respiratory changes of the intrathoracic pressure : measured in the mediastinum posterior / By Dr. S.J. Meltzer. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    of this locality were, as we just pointed out, the effects resulting from the thickness of the oesophagus wall and its muscular tissue. Now if we could determine the pressure alongside of the ossophagus, but outside of it, i.e. in the mediastinum posterior, there will be, we should expect, no more objections to the conclusions drawn from the results obtained in this locality as to the real state of the pressure in the pleural cavity, as the thin layer of tissue separating the mediastinum from the pleural cavity could not amount to much. The same consideration gave me at the same time an idea how to gain access to the mediastinum: along- side the oesophagus which is surrounded on its entire way by loose connective tissue; this is a convenient path, unfortunately very often preferred by the pus of retropharyngeal abscesses—why should we meet with ditficulty by pushing a katheter down the same way ? It is this method and some results I obtained by it I intend to report here. With a single exception my experiments were made on rabbits, the results therefore are so far restricted to this class of animals only. The single experiment I made on a young dog, however, convinced me that the method will be practicable in these animals also, and that the results will probably not differ materially. All the animals have been narcotized with chloral. This offers the advantage that the breathing continues regularly and is less frequent. I wish to emphasize, however, that the introduction of the katheter into the mediastinum does not alter the respiration even in the absence of narcosis. The procedure is simple, though I lost many an experiment before settling it. The rabbit being placed on its back, the skin of the neck was cut lengthwise on the larynx, and opposite the crico-thyroideal ligament, a path was bored with a blunt instrument on the left sterno-hyoideal muscle to its outer margin, and here a narrow entrance was bored behind the lower part of the pharynx. Into this opening a katheter was introduced and pushed downward parallel and behind the oesophagus. Three centimeters, counted from the mentioned ligament, may be pushed down at once, as at this distance the blind end of the katheter is even in small rabbits still above the aperture of the chest. All further pushing has to be done carefully, groping, and in small distances, about five millimeters each. The direction should be towards the middle of the aperture, the katheter can be felt through the skin behind the trachea, and it is advisable, while pushing the katheter with one hand, to control the lower end with two fingers just above the aperture in order to keep in the right direction, and at the same time to press the
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