The physiological, pathological and therapeutical effects of compressed air

CHAPTER I. History, i

CHAPTER n.

The New York Caisson, i8

CHAPTER HI.

Effects of Compressed Air, .28

CHAPTER IV.

Pathological Effects of High Atmospheric Pressure, 43

CHAPTER V.

The Cassion Disease, , 47

CHAPTER VI.

Illustrative Cases, 77

CHAPTER VII.

Suggestions, 93

CHAPTER VIII.

Therapeutic Uses of Compressed Air, 98

AUTHORITIB]S CONSULTED.

Hamel, Bibliotheque de Geneve, 1820.

B, Pol. and T. J. J. Watelle, " Memoire sur les Effets de la Compression de 1 'Air, etc.," Annales d 'Hygiene Publique de Med. Legale, 1884.

Francois, " Des Effets sur les Ouvries Travaillants daus les Caissons du Pont du Grand Rhin," Ibid, i860.

A. Jaminet, " Physical Effects of Compressed air," St. Louis,

1873.

Preface

In 1873 the writer published a report on " The Effects of High Atmospheric Pressure, Including the Caisson Disease " which embodied his experience as Surgeon to the East River Bridge Co. during the sinking of the caisson on the New York side, together with a resume of the literature on the subject up to that time. A new edition of this report being called for, a chapter has been added giving in a condensed form the therapeutic uses of compressed air. This chapter is confined to the consideration of the pneumatic chamber, in which the conditions are the same as those in the caisson, except that the pressure is less and the period of exposure not so prolonged. To have extended the discussion so as to include the inhalation of compressed air by the methods of Waldenburg and others and the cabinet of Dr. Williams would have made the volume exceed greatly its prescribed limits, besides opening a line of inquiry entirely different from that of the body of the work.

In the preparation of this chapter much use has been made of Prof. Oertel's exhaustive treatise, in Ziemssen's Handbuch der Allgemeinen Therapie, to which the reader is referred for an extended discussion of the subject in all its bearings.

22 East 42d Street, New York, July, 1886.

The Physiological, Pathological and

Therapeutical Effects of

Compressed Air.

CHAPTER I.

HISTORY.

The discoveries of Torricelli, in 1644, which led to his invention of the barometer, and the further elucidation by Pascal of the principles of atmospheric pressure, five years later, were followed by confused and contradictory speculations on every hand as to what would be the effect upon animal life if the barometric changes so eagerly observed assumed a wider range.

Dr. Henshaw, an English physician, published an essay in 1664, in which he proposed to treat diseases by varying the pressure of the atmosphere by which the patient was surrounded. His idea was to have a room (domicilium) constructed of masonry, and made air-tight, in which the sick person could remain in an atmosphere which was to be either rarefied or condensed by the action of an organ bellows.

He fancied that acute diseases would be benefited by an increased pressure, while chronic diseases, on the other hand, demanded a rarefied atmosphere. His views seem, however, to have been purely theoretrical, as there is no record of any serious attempt to reduce them to practice.

More than a century elapsed before the subject again awakened the attention of scientific men. In the year 1783, the Academy of Sciences of Haarlem offered a prize for a description of the best apparatus for experimenting upon the effects of compressed air, with a record of experiments made by means of it on animal life, the growth of plants, and the inflammability of the different gases. This prize, however, was not contended for until more than half a century later.

Diving-bells were brought into use as early as the beginning of the sixteenth century, but the condensation of the air within them does not seem to have attracted attention, at least as affecting the occupant. Indeed, whatever influence the increased pressure may have exerted was masked by the impurity of the air, which, in the machines first employed, was not renewed. It was found that the strongest man could not remain under VN^ater longer than an hour; but the ill effects experienced were attributed to the heat which accumulated in the bell, and which was supposed to affect respiration. Subsequently, when an apparatus was added for supplying fresh air, it was remarked that the workmen felt no inconvenience whatever.

The first observations of real value upon the effects of high atmospheric pressure were made at Howth, near Dublin, in the year 1820, by a distinguished Russian physician named Hamel. In the course of some engineering work in which diving-bells were employed, Dr. Hamel had the opportunity of studying the effects of compressed air, not only upon the workmen, but also upon himself. In describing his own experience, he states that at the depth of five or six feet severe pain was felt in the ears, which was relieved in a measure by swallowing. At fifteen or sixteen feet, there was a noise in the ears like an explosion, followed by entire relief from the pain. His respiration was perfectly easy.

The ascent was accomplished with much less inconvenience than the descent.

Hamel states that one of the workmen became so accustomed to the air of the bell as to be uncomfortable under the usual atmospheric pressure.

In 1826, Dr. Colladon published observations made at the same time and place as the above. In winter the hours of work in the bells were five daily; in summer, five and ten alternately. Toward the close of the work, each day the men became very much exhausted, and were given a little brandy and a bit of bread. Those newly employed suffered with pain in the head and ears, and were often affected with colic and diarrhoea, which last were attributed to cold and wet. Increase of appetite and augmentation of the

— 4 — urine were observed. In some cases, deafness was relieved, and one case of asthma was entirely cured.

In 1836, Junod published the results of extensive experiments upon compressed air as a remedial agent. This was the beginning of a series of memoirs upon this subject appearing in rapid succession in France and Germany. Institutes sprang up in various parts of the continent, designed to afford the most approved facilities for this mode of treatment, and the results obtained were, and continue to be, highly satisfactory. The "compressed air-baths" are especially useful in the treatment of pulmonary diseases and of dyspepsia.

But as the pressure employed in these baths is comparatively slight, usually not more than eight or ten pounds to the square inch, the effects observed differ widely from those produced by the high pressure employed for engineering purposes. It is probable, however, that the investigations in this direction of Junot, Tabarie, and Pravaz first suggested the employment of compressed air as a substitute for pumps in mining operations.

To M. Triger, a French engineer, belongs the credit of first conceiving and carrying out a plan by which atmospheric pressure was made to keep back the water flowing into a mining shaft. It had long been known that the valley of the Loire was underlaid by an extensive bed of coal, but, inasmuch as in order to reach the coal it was necessary to pass

— 5 — through twenty metres of quicksand in communication with the water of the river, the engineering difficulties had been considered, until the advent ofTriger, as insurmountable. To keep a shaft dry by pumping was equivalent to pumping out the Loire. To meet this difficulty, Triger conceived the idea of sinking an iron tube through the quicksand, the interior of the tube being kept free from water during the excavation by condensing the air in the tube to the point of counterbalancing the pressure of the water. After some preliminary experiments made by the aid of Tabarie's remedial bath, the work was begun in 1839, near Chalonnes. A tube of iron, seventy feet long by three and one-half feet in diameter, was provided, with a box or chamber at the top, such as we now call an air-lock, having a valve above opening inward, and and another below opening downward into the tube. These valves were of such a size as to permit the passage of the workmen, and the removal of the excavated material. The workmen having passed into the lock, the upper valve was closed, and a cock opened communicating with the main tube, where the air was compressed sufficiently to keep back the water, the compression being effected by means of condensers worked by steam. The pressure in the lock having become equal to that in the main tube, the lower valve was opened and the workmen descended into the tube. In going out, or in sending out material, the process was reversed. The tube was forced down into the earth in proportion as the workmen excavated at the bottom.

It will thus be seen that the first attempt at this mode of working embraced all the essential features of the method as now employed.

In his undertaking, Triger was completely successful. The quicksand was passed and the coal reached, and at the same time there was given to the world a new engineering resource of exceeding value.

It is much to be regretted that these operations were not carried on under the eye of a competent medical observer. The only report we have of them is by M. Triger himself, and it is natural that the engineering rather than the medical aspect of the question should principally engage his attention. His notice of the effects of the compressed air upon the workmen is extremely meagre, and is summed up in the following points:

" I, At the pressure of three atmospheres it is impossible to whistle, while a lower pressure does not produce this effect.

" 2. In the compressed air, every one speaks through the nose, and that is more noticeable the higher the pressure.

" 3. All the laborers remarked that in ascending the ladders they were much less out of breath {inoins essoiiffles) than when mounting to a similar height in the open air.

, ''4. A laborer who had been deaf since the seige of Antwerp (1832), always heard more distinctly in the compressed air than any of his comrades.

" No illness was occasioned among the laborers except that two of them, after seven hours of labor in the tube, experienced severe pains in the arms and knees, coming on about half an hour after ascending into the open air." These are the first recorded cases of what I have named the Caisson Disease.

About the year 1850 compressed air was employed in the sinking of piers. A railway bridge was constructed over the Medway, between Rochester and Chatham, the piers of which rested on a basis composed of hollow iron piles, forty-two inches in diameter, each of which was sunk in precisely the same manner as the tube of Triger. I have not been able to find any record of the effects of the compressed air upon the men employed, though some accidents due to this cause are stated to have occurred.

The results obtained by Triger led, in 1845, to the application of the same principle to the working of the mine at Douchy, Department du Nord. The laborers in this case were under the supervision of MM. B. Pol and T. J, J. Watelle, who published an extremely interesting memoir upon the subject.

The entire personnel comprised sixty-four men, who were employed at two different epochs, under different pressures. They were divided into gangs of six or seven each, laboring alternately four hours twice a day. At first, the time allowed for locking out was one-fourth of an hour, but as the pressure increased it was extended to half an hour. The maximum pressure was three and one-half atmospheres.

After each shift the men bathed and put on dryclothes, when a cup of bouillon and a glass of Bordeaux were served to each man.

As the number of cases of illness increased, a sort of ambulance, or temporary hospital, was established on the spot.

At a pressure of two and three-quarter atmospheres. Pol experienced in his own person the pain in the ears while locking in, and the ease with which a ladder is ascended in the compressed air, confirming in this latter particular the observation of Triger, The soot from the candles with which the air in the shaft was loaded, produced a troublesome cough, attended with black expectoration. The mucous membrane of the nose and throat became stained with it, and even the faeces were blackened.

While locking out there was experienced by all the men a feeling of suffocation. Pol was the first to perceive that the real danger was in passing from the condensed into the normal atmosphere, instead of in passing in the reverse direction. On emerging into the open air, he found that his pulse, which had fallen while in the caisson from seventy, its normal standard, to fifty-five, rose suddenly to eighty-five. When the pressure had increased to three and one-half atmospheres, he again entered the caisson. The unpleasant sensations already referred to were found to be intensified. In blowing his nose he accidently discovered that this operation gave him more perfect relief to the ears than the act of swallowing. In speaking he found that the tongue moved stiffly and with difficulty. Sounds were not heard with their usual intensity. The secretion of urine was decidedly increased. After reaching home he was seized with severe pain in one arm and shoulder, and in the walls of the chest. Afterward, there were chills, followed by vomiting. Rest in the horizontal position, and the use of sudorifics, restored him to his usual health by the following day.

Of the sixty-four men employed, thirty-nine continued until the work was completed, and twenty-five were compelled to give up their places, not being able to support the effects of the compressed air.

The most usual affection was muscular pains, occurring either alone or ushering in other symptoms. Pulmonary congestion occurred in several cases, but it may well be questioned whether the excessive impurity of the air, as evinced by the amount of soot it contained, may not have had much to do with the the production of this otherwise unusual result. Other symptoms which he describes, such as great hebitude, incoherence of speech, tottering gait, etc., indicate the effects of carbonic acid, and as no mention is made of any provision for removing the products of combuslO

tion and respiration, this gas must have been present in considerable quantity.

The conclusions arrived at by Pol are as follows:

1. A pressure of four and one-quarter atmospheres is not in itself dangerous, but the return into the open air may cause serious accidents, and even sudden death. The danger is in proportion to the previous pressure.

2. The pathological changes consist m visceral congestions, among which congestion of the lungs and brain take the foremost rank.

3. The tendency to these congestions increases with the age, at least between eighteen and fifty-five.

4. Not the period of greatest strength, which is between thirty and forty, but that between eighteen and twenty-six is that which is exposed to the least danger.

5. Experience teaches that the ill effects are in proportion to the rapidity with which the transition is made from compressed air to the normal atmosphere.

6. Unimportant troubles, such as cough, gastric symptoms, etc., may be due to the smoke from the lamps.

7. The treatment is not different from that which is usual when like symptoms arise from other causes. The first indication is to bring about a reaction, which is in turn to be combatted when it exceeds physiological limits.

8. One case seems to indicate that the quickest

— ^11 —

and safest means of restoration is an immediate return into the compressed air.

9. Cold to the surface is the best means for restoring the function of the skin.

About the year 1856 this method of excavation was employed in the coal mines of Eischweiler, near Aix-le-Chapelle. No phenomena were observed differering from those already described, except that bleeding from the nose occurred in several cases on emerging into the open air.

About 1858-9 excavation by the aid of compressed air was extensively employed in laying the foundations of piers for bridges. Among the first of these were the Quarantine Bridge at Lyons, the bridge at Magon, and the chain bridge over the Thiess. A report upon the latter is contained in the Annales des Fonts et des Chausses, for 1859. Ringing and pain in the ears was complained of by the laborers, as also pain in the teeth, and in the muscles generally. The sound of the voice was observed to be changed, and the breathing to be quickened. The return to the open air was often followed by bleeding at the nose. Men of several different nationalities were employed, and it was observed that the Hungarians and the French suffered the least, while the Italians, Germans, and Sclavonians were most affected.

In 1859, the mines at Eischweiler were re-opened, compressed air being again employed. The pressure did not exceed two and one-half atmospheres. The

• 12

duration of the shifts was six hours. Excessive sweating was observed, followed by thirst after leaving the mine. There was generally impairment of appetite.

At the same time work was being carried on by similar means in the coal mines at Liittich. According to the statement of the superintendent, the men became so emaciated that after a few months they could no longer be prevailed upon to continue the work, notwithstanding large wages were offered and the most nourishing food provided.

Perhaps the most extensive work undertaken in Europe by the aid of compressed air was the bridge over the Rhine, at Strasburg. An account of this is given by Dr. Frangois, who had medical charge of the workmen.

The caissons were fourteen in number, each seven metres long by five and eight-tenths wide and three and five-tenths high. The locks were two metres in diameter and four metres in height.

Frangois refers to the progressive impairment of hearing as the pressure increased in the lock; to the increase of temperature from the compression of the air; and to the accumulation of soot in the air-passages, which had been before obf^erved by other writers. On going out of the caissons, intense pain in the ears sometimes occurred, together with muscular and articular pains. A very annoying itching of the skin was sometimes felt. Cerebral congestions, hoemoptysis, and bleeding of the nose, were also not uncommon. Sometimes these various affections occurred immediately upon leaving the caisson, while in other cases they were deferred for several hours. In two or three instances the men were able to walk home, and afterwards fell " as if struck by lightning." The attacks usually pass off quickly. Only one death occurred, and that resulted from breaking the rule as to the length of time to be occupied in locking out.

The rule established was to allow from four to five minutes in locking out when the pressure was one-quarter to one-half an atmosphere; six to seven minutes for one atmosphere; ten for one and one-half atmospheres; twelve for two atmospheres. A woolen vest was provided for each man to be put on when leaving the caisson, in order to guard against the effect of the sudden reduction of temperature which resulted from the expansion of the air in the lock. It was observed that the foremen suffered much less than the laborers, since their superior intelligence enabled them to realize the necessity for observing the rules.

Some other points observed by this writer will be referred to hereafter in their proper connection.

In the year 1863, Dr. Antoine Ed. Foley published a monograph comprising his observations upon the effects of condensed air as demonstrated during the sinking of the piers for a bridge at Argenteuil. The original work not being accessible, I avail myself of the resume contained in the treatise of Vivenot, of which I give a somewhat condensed translation from the German.

Foley observes that during the time that the pressure was increasing, the organs of hearing were always, without exception, affected. Occasionally neuralgic pains were felt dartiwg through the forehead, the nasal cavities, and the jaws; the voice acquired a metallic sound; whistling became impossible; in a few cases stammering was induced. Taste, smell, and the sense of touch lost their acuteness. There was experienced a sense of warmth in the skin, as if one were in a drying-room. The pulse become small and thready, sometimes imperceptible to the touch. The venous blood had a bright red hue.

The lungs seemed to increase in development, while the motion of the ribs was less. Shortness of breath was not often observed. Increase of appetite was soon experienced, but never thirst.

While the pressure remained stationary, all subjective phenomena disappeared, to return again during the locking out. Ringing of the ears and bulging of the ear drums were observed; taste and smell returned; a prickling sense of warmth was felt in the nostrils, which was sometimes followed by bleeding at the nose. At the same time the rapid decline of the temperature from the expansion of the air caused extreme chilliness.

At first the laborers remained in the compressed air four hours at a time, twice a day, with an interval of rest. But as the pressure increased it was found necessary to diminish the hours of labor.

The ill effects upon the workmen were almost entirely confined to a distressing itching of the skin and painful congestive swelling of the muscles. They observed that the appetite was increased, while thirst was diminished. The flow of urine was also greater than usual.

A remarkable case is mentioned, in which a man, far advanced in consumption, with an enormous cavity in one lung, and suffering from hectic, persisted in working in the caisson, contrary to the advice of Foley, and at the end .of two months had gained very much in flesh, was looking well, and feeling in the best of health.

I shall have occasion hereafter, when treating of the Caisson disease, to refer more in detail to some of the experiences of this writer.

In the year 1868 there was begun at St. Louis a work which involved the application of compressed air on a scale far exceeding anything before attempted. This was the sinking of two piers and two abutments for a bridge across the Mississippi. The magnitude of the work consisted in the great depth to which it was necessary to sink the caissons, in order to obtain a solid foundation. One of them, at the moment when it touched the rock, was no feet below the surface of the water. This implied a pressure within the caisson of 50 lbs. to the square inch. The dimensions of the caissons, too, far exceeded those of any before constructed, the average superficial area being about 3,700 square feet.

A large number of workmen were employed, and an opportunity was presented for studying the effects of compressed air upon the human body on a scale which dwarfed all former experiences into comparative insignificance.

The physician in charge was Dr. A. Jaminet, whose report is extremely interesting. It describes a number of valuable experiments upon the boiling point of water at various pressures, electrical phenomena, etc., and proceeds to detail the physiological action of high atmosperic pressure as demonstrated upon himself and others. The writer then gives his own experience in an attack of paralysis resulting from a prolonged sojourn in the caisson — a paralysis from which he fortunately recovered by the following day.

He next discusses the mode in which the pressure acts to bring about the morbid phenomena observed, and arrives at the conclusion, which the facts do not seem to me to warrant, that the ill effects are simply the result of exhaustion from too rapid tissue-change, caused by the absorption of an excess of oxygen. Following out this idea, he lays down a plan of treatment which consists simply of rest in a recumbent position, with the feet elevated, and the administration of stimulants and nourishment.

He describes, more or less in detail, seventy-seven cases, in eight of which death took place. The post-mortem appearances in these are described. They were all characterized by congestion of the brain and cord, and of most of the abdominal viscera.

Dr. Jaminet's observations are exceedingly valuable; but some of his conclusions seem to have been arrived at without sufficient thought. It is especially to be regretted that his theory of exhaustion, framed at the outset, prevented the trial of remedial plans other than the routine administration of stimulants and beef-tea.

The facts observed by Dr. Jaminet will be frequently referred to in the following pages, care being taken to give him credit for all that had not been anticipated by others.

Chapter II. The New York Caisson

Before the St. Louis bridge was projected, a much more gigantic work had been inaugurated at New York, and plans and specifications had been adopted which anticipated the leading features of the work at St. Louis. To cross a stream i,6oo feet in width with a single span was an idea never before entertained. But the difficulties were immensely increased by the fact that the towers to support this immense structure had to be erected under circumstances that rendered the usual methods for sinking piers impracticable. It was, therefore, determined to employ the method by compressed air, and caissons were constructed having the horizontal dimensions of the proposed piers, which, on the New York side, were 102 by 172 feet. Each caisson was in effect a wooden box turned bottom upward, the interior space being 9 feet high. The roof of the New York caisson (bottom of the box) was 22 feet thick, of solid timber bolted together, and was supported by frames running from side to side, which frames, together with the edges of the box, were to sustain the vast superincumbent weight, aided by the upward pressure of the condensed air within the caisson. The area of the structure was equal to seven building lots of 25x100 feet each.

The caissons having been built on ways, were launched in the same manner as a ship, and were towed to the points where the piers were to be located. Courses of granite blocks were then laid upon the top of the caisson, by which it was sunk until it rested upon the bed of the river. Air was then forced into the chambers beneath by means of engines upon the shore, until the water was entirely displaced, and the river-bed left dry. The pressure was maintained at this point, the engines working day and night. The workmen obtained access to the chamber by means of two shafts, which extended above the surface of the water. At the bottom of each shaft were two air-locks, which were simply ante-chambers constructed of iron, into which the men entered from the shaft, and, closing an air-tight door behind them, admitted the compressed air from the caisson b/ means of a cock, until the pressure in the lock reached the same degree as that in the caisson, when a communicating door was opened, and the men passed into the chamber below. In going out the process was reversed, the compressed air in the lock being allowed to blow off through a cock into the open shaft. The control of these cocks was intrusted to men detailed exclusively for that work, and upon their proper management depended the comfort, if not the life, of every one in the lock.

By a very ingenious arrangement, which it is not necessary to describe here, the earth excavated from beneath the caisson was carried up to the surface without affording opportunity for the air to escape. In this way the earth was being constantly removed from underneath the caisson, and the vast mass settled day by day down through the gravel and quicksand, which formed the bed of the river, until at a depth of 78 feet on the New York side, a solid foundation was reached. In proportion as the caisson settled the masonry upon it was built up, so that the top of the stone-work was always above water. When a solid foundation was reached, the interior of the caisson was filled with concrete, and the 400,000 cubic feet of timber was left buried nearly 80 feet below the surface, where, practically indestructible, it remains as the foundation of the tower.

Of course the pressure of air required to keep the water out of the caisson increased in exact proportion to the depth. Thus, at the beginning of the work, the caisson being covered by forty feet of water, the pressure was about eighteen pounds to the square inch, while at the close of the work it stood at thirtysix pounds.

The air-locks were connected with the surface of the pier by means of a spiral stairway within the shaft. Ascending this was found to be exceedingly fatiguing as the depth increased, and the stair in one of the shafts was finally replaced by a steam elevator.

Looking upon it merely from a sanitary point of view^ I regard it as a serious mistake to have placed the air-locks at the bottom instead of at the top of shafts, as by that arrangement the men were compelled to make a fatiguing ascent at the moment when the circulation was embarrassed and the system unstrung by the sudden removal of the pressure. All testimony is agreed upon the ease, on the one hand, with which exertion is supported while in the compressed air, and upon the unfitness of the system, on the other hand, to bear even the slightest fatigue during the period immediately following the change to the normal atmosphere. These conditions should render the rule invariable that the air-lock is to be placed at the top of the shaft, unless an elevator is employed. In this view I am sustained by all the engineers connected with the work.