Extracted from the 
TRANSACTIONS OF THE COLLEGE OF PHYSICIANS OF 
PHILADELPHIA, 
THIRD SERIES, VOLUME 11. ON THE 
THERAPEUTIC USES OF COMPRESSED AND 
RAREFIED AIR 
(being a, report of remarks made to the college of 
PHYSICIANS ON THE OCCASION OF A DEMONSTRATION 
OF WALDENBUEG’S APPARATUS BY DR, JAMES 
TYSON FOR DR. WILLIAM P£PFEr). 
I 
J. SOLIS COHEN, M.D., 
LECTURER ON LARYNGOSCOPY AND DISEASES OF THE THROAT AND CHEST IN 
JEFFERSON MEDICAL COLLEGE ; ONE OF THE ATTENDING PHYSICIANS 
TO THE GERMAN HOSPITAL OP PHILADELPHIA, ETC^,---—1-^---^^ 
[Communicated Feb. 2, 1876.] 
I haye one of Waldenburg’s 
my office, and should he very glad to have heard 
the results of Dr. Pepper’s experiments as far as they 
have gone. For my own part I should require a much 
longer experience in the use of this appliance before 
committing myself as to its utility, although the repu- 
tation of Waldcnhurg, who is likewise the author of 
one of the best works on tuberculosis, is such as to 
command the most respectful consideration; and Wal- 
denburg has, in his recent work on the pneumatic treat- 
ment of diseases of the respiratory and circulatory 
organs, advanced sufficient proof of the great value of 
this mechanical treatment in remedying certain phy- 
sical defects unattended with organic change. In my 
own opinion emphysematous dilatation of the pneu- 
monic vesicles from asthma and chronic bronchitis 106 
COHEN, 
would be the condition which would he most benefited 
by this method of treatment; and chiefly by forced 
expiration into rarefied air. The only instance in which 
I have as yet had a fair opportunity to test the value 
of the apparatus, apart from all other treatment, has 
been a case of emphysema with asthma, in a young 
lady who has suffered from asthma from her earliest 
recollection, and in whom the relief to respiration has 
been marked after each use of the apparatus, and in 
whom the vital capacity has increased from 1400 cubic 
centimetres to more than 1600 cubic centimetres in the 
course of one month. The use of compressed air is 
also indicated in cases of deficient expansion of the 
air-cells. 
Inspiration of compressed air increases the intra- 
thoracic pressure, including of course that upon the 
heart and vessels; and the arterial walls are thus dis- 
tended, so that the pulse becomes diminished in fre- 
quency, and full and hard at the same time. The 
treatment is indicated in dyspnoea from inefficient 
inspiration, whether cardiac or pulmonic, bnt it must 
not be pushed, lest it rupture the air-vesicles in deli- 
cate subjects. 
Expiration into compressed air diminishes the quan- 
tity of air leaving the lungs, impedes the interchange 
of gases, and, if pushed, will produce apnoea. It is 
indicated in deficiency of normal expiratory power, to 
strengthen the auxiliary muscles. 
Inspiration of rarefied air diminishes the amount of 
air inspired, diminishes the intra-thoracic pressure, and 
augments the external pressure on the chest. It en- 
feebles the action of the heart, and the pulse becomes 
soft, compressible, and more frequent. Pushed to COMPRESSED AND RAREFIED AIR. 
107 
excess, inspiration becomes difficult; and apnoea may 
result, and even haemoptysis. 
Expiration into rarefied air increases the amount of 
air expelled from the lungs, and causes the chest walls 
to contract to a much greater degree than is possible 
by the most powerful voluntary expiratory effort. 
A greater amount of carbonic acid is expelled, and 
the succeeding inspiration is deeper and more refresh- 
ing. It thus increases the respiratory power, augments 
the vital capacity, and, in patients the walls of whose 
chests are still to some degree movable, tends to 
diminish the volume of emphysematous lungs and 
facilitate the restoration of the elastic contractility of 
the over-distended air-cells. The intra-thoracic pres- 
sure being diminished, blood accumulates in the intra- 
thoracic organs, and is withdrawn from the periphery 
of the body. The treatment is indicated in chronic 
bronchitis and in emphysema. 
Thus from a study of the mechanical influences of 
augmented or diminished pressure upon the interior of 
the air-cells, and upon the intra-thoracic organs gene- 
rally, we can judge of the propriety or impropriety of 
the practice in any given instance. Considerable 
caution is necessary in the use of such a powerful 
agent as compressed air, especially when inspiration is 
not supported by an equal amount of pressure on the 
exterior of the body as is the case in the compressed 
air-chambers, therapeutic apartments which appara- 
tuses like that before us are intended to supersede. 
Where the pressure in the arterial system is already 
great, where there is congestion, or a disposition to 
congestion in important peripheral organs, as in 108 
COHEN, 
patients with internal hemorrhoids, menorrhagia, dis- 
position to apoplexy, etc., the use of compressed air 
is strongly contra-indicated, no matter what may be 
the direct physical result desired in the intra-thoracic 
cavity. In converse manner, rarefied air, which draws 
the blood from the periphery to the central organs, is 
contra-indicated in all cases in which increased afflux 
of blood to the lungs is to be avoided, and in cases of 
insufficient pressure upon the arterial system already 
present, as in disposition to haemoptysis, active con- 
gestion of portions of the lung-tissue, weak heart, and 
so on. 
The efficient use of the apparatus before us, and all 
of the same kind, requires from fifteen minutes to half 
an hour each time that it is employed. It is evident, 
then, that it will not come into use in general practice, 
but is more applicable to hospital practice provided 
there are attendants who can devote a proper amount of 
time to superintend its use. For the reasons mentioned, 
it is hardly a safe apparatus to place in the hands of 
patients, for fear of the injurious results that may 
arise from its over-use. In the compressed air-cham- 
bers employed on the Continent of Europe for some 
thirty or forty years, the entire surface of the body is 
exposed to the same pressure, and thus a much greater 
amount of compression or rarefaction can be resorted 
to than in the use of an apparatus which limits the 
action to the respiratory surfaces. In the compressed 
air-chambers they use from three-sevenths to two- 
thirds of an atmosphere compression; with this 
apparatus we dare use but from one-eightieth to one- 
thirtieth of an atmosphere; and this is to be exceeded 
only with great circumspection. Still the portable COMPRESSED AND RAREFIED AIR. 
109 
apparatus is to be preferred to the air-chamber because 
the remedial agent can thns be brought within the 
reach of the patient at his own home. 
Some ten years ago, when engaged upon the first 
edition of my treatise on inhalation, I made some 
attempts to devise an apparatus for administering 
compressed air, and thns superseding the air-chambers. 
I first employed a kitchen bellows, then a condensing 
syringe and capacious reservoir, and subsequently a 
large acoustic bellows, but was unable to secure uni- 
formity of compression, and this, with the lack of 
clinical material to work upon, led me to abandon the 
attempt; I was, however, very glad when I saw that 
others had succeeded, and in the edition of the work 
referred to which has just issued from the press, I 
have presented a succinct account of the subject, with 
illustrations of several forms of apparatus, including 
the one before the College. I would state, before con- 
cluding, that an apparatus in the form of an accordeon 
has been devised by Frsenkel for the home use of the 
patient. The month being applied with the accordeon 
closed, the patient breathes into rarefied air as he 
expands the instrument; and, the accordeon being 
distended, he breathes compressed air as he closes the 
instrument. This I regard as very ingenious, but 
rather tiresome for patients; and I think that an 
apparatus to be worked with a treadle could easily be 
contrived to subserve the same purpose. 
Finally, I would say, that there are some simple 
methods of increasing or diminishing the intra-thoracic 
pressure at will, without the aid of any apparatus at 
all, and which may be resorted to with advantage 
under appropriate circumstances. These are: (1) 110 
COHEN, COMPRESSED AND RAREFIED AIR. 
Valsalva’s method. A forcible movement of expira- 
tion, with mouth and nostrils closed, increases the 
intra-thoracic pressure, and has the same physical 
effect as the inspiration of compressed air; and the 
effect can be increased by external compression of the 
chest and abdomen; (2) Deep and prolonged inspira- 
tions with mouth and nose closed, will expand the 
chest and rarefy the air in the lungs, and the effect is 
the same as that of the inspiration of rarefied air; (3) 
Expiration aided by external compression of the chest 
and abdomen has an effect similar to that of expiration 
into rarefied air. 
These movements may be occasionally substituted 
for the gymnastic exercises of the pneumatic apparatus, 
in cases in which the muscular efforts to produce them 
would not be injurious; but as a matter of course less 
effort would be required with the use of the apparatus, 
which will also fulfill indications for which the substi- 
tutes are incompetent. PACKARD, COHEN, COMPRESSED AND RAREFIED AIR. 11l 
[ln connection with Dr. Cohen’s remarks, Dr. John H. 
Packard reported the following case ;—] 
A boy four years of age was the subject of a very insidious attack 
of pleurisy of the left side, in February, 1875. The effusion into 
the pleural cavity was such as to produce the most threatening 
symptoms, and about four weeks after the beginning of the dis- 
ease, with the consent of Dr. J. F. Meigs, who saw the patient with 
me, I drew off eighteen fluidounces of sero-purulent liquid by 
means of the aspirator. Great relief was immediately given, and 
there was no reaccumulation. The little fellow slowly recovered, 
but when the family went into the country, in May, the left thorax 
was still very much contracted, and the breathing on that side 
very imperfectly accomplished. 
His father procured him a horn, and encouraged him to blow 
it, by way of salute to vessels passing on the river. The exercise 
thus afforded the muscles of the chest-walls was highly beneficial, 
and on the return of the family to town, in November, I found the 
thorax in excellent condition, the respiration on the left side being 
fully restored. The child’s general health was perfect, and his 
appearance that of robust health. 
[Dr. Cohen said:—] 
The effect is similar to that recorded by Laennec, who saw 
good results sometimes in asthma, from making his patients count 
aloud as fast and as long as they could. This exhausted the 
residual air of the lungs, and was like breathing into rarefied air, 
and the subsequent inspiration was therefore more vigorous and 
effectual, and sometimes sufficiently effective to overcome the 
spasm.