208 AUG. 3, 1935 USE OF QUININE IN NORMAL LABOUR fEDrcALJOURNAL from the nurse or doctor, than when the uterus is-fully equal to its task, and the attendant is free to exert THE PHYSIOLOGY OF DEEP-SEA DIVING* restraining influence on the crowning head. BY (e) " After-pains" WILLIAM A. R. THOMSON, M.D. LATE SURGEON LIEUTENANT R.N. The frequency of these is not increased. In confirma- tion of this bald statement we can only say that the The term " deep diving " defines any diving operation matter has never been mentioned (except by ourselves) carried out at a depth exceedinig 200 feet. in any correspondence on the subject. The scientific study of diving may be said to date from 1878, when Paul Bert' published La Pression Baro- mdtrique. The following thirty years witnessed the Discussion accumulation of many new facts concerning diving and Such, then, is a short statement of more recent experi- caisson work, and in 1907 was published the " Report of ences in the use of quinine in normal labour, and we may a Committee appointed by the Lords Commissioners of well be asked to explain the limitations of the method. the Admiralty to consider and report upon the condi- tions of Deep Water Diving."''0 The recommendations of Claimed as a valuable aid to normal midwifery, the ante- this committee, for which Professor J. S. Haldane was natal use of quinine is also of undoubted value in certain mainly responsible, rapidly gained universal adoption, conditions outside normality. This region, however, is and were instrumental in reducing the morbidity attached vast and ill-explored, and it is wiser to admit at once to such work to almost infinitesimal figures. Progress, that in the realm of the abnormal each case must be however, was inevitable, and in 1930 the Admiralty considered on its own merits. There are definite contra- appointed a further Deep-diving Committee-the mem- indications to the use of quinine, such as the presence bers of which included Sir Leonard Hill-to investigate of albuminuria, flat pelvis, or, for that matter, any con- the possibilities of diving to greater depths than had dition in which, for the purpose of moulding, slow labour hitherto been considered possible." This subject can perhaps be best studied by a con- is desirable. sideration of the three major difficulties to be overcome When normal cases alone are under consideration it in deep diving. These consist of: (a) carbon dioxide may justly be claimed that the method solves many poisoning, (b) oxygen poisoning, (c) caisson disease, or, problems of obstetric routine. It is rarely necessary to as it may be more accurately termed, compressed air interfere or in any way to assist the patient during the illness. first stage. The relative freedom from pain during this Carbon Dioxide Poisoning period is so frequent and so striking that the patient Prior to the investigations of the 1907 Admiralty Com- is often seen for the first time when the cervix is fully mittee one of the major difficulties encountered at depths or nearly fully dilated. When the second stage isNreached exceeding 90 feet had been that the breathing of the both humanitarian and obstetrical principles are well diver became very laboured, and cases of loss of con- served by the use of short and simple hypnotics, sciousness were not uncommon. This, the committee analgesics, or anaesthetics, according to the taste and showed, was due to the pressure of carbon dioxide. experience of the individual practitioner. There is seldom Normally, respiration is so regulated as to maintain a time or opportunity for the more complicated methods constant percentage of carbon dioxide in the alveolar air " -that is, 5.6 per cent. At abnormal atmospheric pres. of twilight sleep," or the more drastic routine of sures, however, it is the absolute pressure, not the "tissue "-and dare we add " foetal "-poisoning. percentage, of carbon dioxide in the alveolar air that In conclusion, we should like to emphasize a point remains constant-that is, a diver at 297 feet, or 10 which we have repeatedly had to explain in discussions. atmospheres absolute pressure, will nieed ten times as Our method of using quinine as an ante-natal prophy- much air as he would at the surface. At this depth a lactic has little in common with the use of this drug in tension of 0.1 per cent. in the air breathed has the same much larger doses for the deliberate induction of labour, effect as breathing 1 per cent. of carbon dioxide at and we strongly deprecate the natural tendency to strive atmospheric pressure. When the 1930 Admiralty Com- for better results by giving larger doses. mittee" began its deliberations on diving at depths Such attempts, exceeding 200 feet, it was faced by the problem of as we know from experience, never do any good, and supplying sufficient air to the diver to prevent any can only bring the method into disrepute. accumulation of carbon dioxide, as a very large amount Nowadays the claim is made neither by pharmacolo- of air would be required to provide the necessary venti- gist nor clinician that quinine is a reliable, or even lation to an ordinary diving helmet when a diver is in effective, initiator of uterine contractions. Rather should deep water. The committee finally adopted a special it be regarded as a true tonic-that is, an agent which deep-diving dress in which the diver carries a canister increases the basic tone of the uterine muscle fibres, and containing a carbon dioxide absorbent instead of the back thus reinforces contractions which are excited by other weight-designed and produced by Messrs. Siebe Gorman endogenous means. This tonic action is developed by a and Co., of London. Air is supplied to the diver from a small high-pressure air system through reducer valves which relatively dose, and lar,ger doses can even produce reduce the pressure from 2,500 to 180 lb. per square inch. a state of inertia and increasing paralysis of the uterinie That this system is completely successful is shown by muscle. For the purpose here discussed our combined the figures for analysis of air in the diver's helmet at expenence shows that the dose of quinine should not depths from 168 to 287 feet. The average figure for exceed 1 to 2 grains given thrice daily for two to three twernty-three dives was 0.13 per cent. of carbon dioxide. weeks before labour is expected. Further simplification From the practical point of view it is equally successful, of the method, such as the use of a single daily dose of as by means of it very rapid descents are possible, one five grains, spells failure. diver having descended to 290 feet in under two minutes without any inconvenience. REFERENCES l Mitchell, D. A.: British Medical Journal, 1930, i, 144. Oxygen Poisoning 2 Green-Anrinytage, V. B.: Ibid., 1933, ii, 397. 'Johnston, D. J. Gair: Ibid, 1933, ii, 265. The toxic effect of oxygen may be divided into two 4Luker, S. Gordon: Ibid., 1933, ii, 58. groups: (a) that resulting from short exposures to high Buddee, F. W.: Ibid., 1934, ;, 1159. pressures, and (b) that resulting from prolonged exposure 6 Ganner, P.: Paper read before the M\idland Obstetrical and to low pressures. The forrner takes the form of con- -Gynaecological Society, May 20tL, 1935. Hewetson, W. M.: British Medical Journal, 1928, i, 156. * The substance of a lecture delivered to the Naval Medical * Rees, W. A.: Ibid., 1933, i, 587. O)fficers, Royal Naval Hospital, Haslar, December 6th, 1934. THE BRITISH 91Q AUG. 3., I 935 PHYSIOLOGY OF DEEP DIVING MEDICAL JOUVtAL 2V -W vulsions, passing into unconsciousness, and even death, utilized, and being carried to the various parts of the while the latter is seen in congestion of the lungs and body these gradually become saturated. If the pressure sometimes pneumonia. Paul Bert' found that at an abso- be now suddenly reduced to normal a state of super- lute pressure exceeding about 3 atmospheres of oxygen saturation exists throughout the body, and the nitrogen (corresponding to 15 atmospheres of air, or a depth of about tends to liberate itself in the form of bubbles. These 460 feet of se, water) animals went into convulsions and bubbles may result in the onset of paralysis, asphyxia, or soon died, while with an exposure of several hours a merely excruciating pain, depending upon their localization. pressure of even 2 atmospheres (300 feet of sea water) These findings of Bert have been confirmed both ex- proved dangerous. Lorrain Smith12 showed that fatal perimentally and at necropsies, and perhaps the most pneumonia may be produced after four days' exposure to beautiful demonstration has been that of Leonard Hill,9 an oxygen pressure of 75 per cent. of an atmosphere who was able to show through a microscope the bubbles (corresponding to a depth of 84 feet), while at about forming in the capillaries of a frog's web when the pres- 2.8 atmospheres of oxygen (420 feet of sea water) marked sure was suddenily lowered, and disappearing again when symptoms were observed in about fhree hours, and death the animal was recompressed. As a result of his work in nine hours. Hill and Macleod9 obtained similar results. Bert' recommended that the pressure should be lowered Bornstein2 at the Elbe tunnel in 1909-10 breathed slowly in order to prevent the onset of compressed air oxygen at 3 atmospheres absolute for forty-eight minutes illness, and the rate of decompression he recommended without ill effects, but considered that this was near the was twelve minutes per atmosphere of pressure. In 1906 limit. Leonard Hill"' exposed baboons, goats, and smaller Hill and Greenwood8 published the results of their in- animals in air to pressures equivalent to 330 feet of sea vestigations, in the course of which the latter had actually water (corresponding to a little over 2 atmospheres of gone to a pressure of 92 lb. (206 feet of sea water) and oxygen) for durations up to half an hour, and even to been decompressed at a rate of twenty minutes per pressures equivalent to 400 feet of sea water for shorter atmosphere. periods, without any signs of oxygen poisoning. Sub- This method was known as the "uniform " system of sequently twelve divers were subjected to 2 atmospheres decompression, in contrast to the " stage " system which (absolute) of pure oxygen for one hour, and four divers was recommended by the Admiralty Committee of 1907, to 3 atmospheres (absolute) of pure oxygen for half an and was based on the following findings: hour without any ill effects being noticed. Further (a) The progress of saturation follows a logarithmic curve, animal experiments suggested that with animals there but proceeds at different rates in different parts of the body, is a critical point somewhere between 4 and 5 atmo- so that while some parts are fully saturated in a few minutes spheres (absolute), beyond which the onset of convulsions others take as long as five hours. becomes much more rapid. (b) Desaturation after a given change of pressure down- In 1933 two research workers on this subject-both war.ls proceeds along the same curve and at the same rate naval officers-found, experimenting on themselves, that as would saturation after the same change of pressure upwards. (c) In starting a decompression from any pressure up to breathing oxygen at 45 lb. pressure, corresponding to at least 6 atmospheres, it is safe to reduce the absolute 4 atmospheres absolute, brought on convulsive symptoms pressure quickly to one-half. Decompression ceases to be in sixteen and thirteen minutes respectively. In the first safe when the absolute pressure becomes less than half that case violent twitching of the face was experienced, but of the dissolved nitrogen in any part of the body. was immediately relieved by reverting to air breathing. In the second case tremor of the lips was noticed at the Recent work by Campbell and Hill6 suggests that the end of thirteen minutes and, in spite. of reversion to air average rate of saturation with nitrogen is much slower breathing, this passed into clonic convulsions with than that upon which these propositions are based. They unconsciousness. found that the goat's solid tissues-liver, brain, and bone The pathology of oxygen poisoning is not known, but marrow-are only about 50 per cent. saturated with recent work has thrown light on one aspect of the problem gaseous nitrogen in about three to five hours during which is of particular interest from the point of view exposures to +3, +4, and +5 atmospheres pressure, of diving. It is now recognized that the power of the whereas Boycott, Damant, and Haldane,3 upon whose blood to combine with carbon dioxide in the tissues and work the 1907 Admiralty Committee's findings are based, carry it to the lungs depends on the giving up of oxygen were of the opinion that goats' tissues were fully saturated to the tissues by oxyhaemoglobin. Argyll Campbell4 5 in three hours. Should these findings be confirmed it is showed that the carbon dioxide tension in the tissues possible that some modification may be indicated in the increased to a dangerous level when animals were ex- present decompression tables. posed to oxygen at, sufficient pressures to keep the After reviewing the whole situation and carrying out oxyhaemoglobin unreduced, and he suggested that oxygen a very extensive series of experiments on goats and many convulsions are due to this high tension of carbon dioxide. actual diving trials over a period of three years, the 1930 This was finally proved by Leonard Hill.7 Admiralty Committee drew up a series of decompression The bearing of this problem on deep diving is two- tables, and came to the conclusion that, by means of fold-namely: (1) the depth which divers can attain these tables, " diving can be carried out with safety without risk of oxygen poisoning, (2) the use of oxygen in a rubber dress at depths down to 300 feet. Divers in decompression. thus dressed have actually descended to depths in excess of this figure, but it is considered that for the present Compressed Air Illness it should not be exceeded in this form of diving "" (p. 9). Ever since diving has been extensively practised, one OXYGEN DECOMPRESSION of its greatest handicaps has been the occurrence of that The tables referred to above are based upon the use group of illnesses, common to both it and caisson work, of oxygen during decompression, a procedure which had known as caisson disease, Dr, more accurately, compressed already been tested by many workers. One of the great air illness. Bert' showed that these illnesses were due handicaps of deep diving is the prolonged time necessary to a supersaturation of the tissues with nitrogen during for decompression, in order to prevent the onset of com- diving, which, -on the diver coming to the surface, pressed air illness. This time can be materially reduced resulted in the liberation of bubbles of nitrogen through- if oxygen is breathed instead of air. If pure oxygen, is out the body. When a diver is exposed to compressed breathed it may be assumed that the partial pressure of air the blood passing through the lungs takes up an nitrogen entering the lungs is zero, so that the " nitrogen increased proportion of oxygen and nitrogen in simple extracting stress " (upon which depends the length of solution, in accordance with Dalton's law. The oxygen time which must be spent at any stage during decom- and carbon dioxide in the air cause little inconvenience, pression) will be the same as the partial pressure of as the former can be largely utilized by the tissues, and dissolved nitrogen in the body, instead of the partial the latter, unless the air breathed is very foul, is kept pressure of dissolved nitrogen in the body less that of_ at a constant pressure in the lungs by means of altera- the nitrogen in the alveolar air at whatever depth the tions in the rate and depth of respiration. The increased diver may be. That the saving of time thus obtained is proportion of nitrogen in the blood cannot, however, be considerable is shown by the fact that an " air decom- 210 AUG. 3, 1935 PHYSIOLOGY OF DEEP DIVING MEDIOURNA1 pression " is practically two and a half times as long as deep diving is the strongly built athletic type of even an " oxygen decompression." temperamnent "11 (p. 10). Two successive sets of diving The factors upon which these decompression tables were trials have confirmed these recommendations, in that finally based were as follows: their adoption has been followed by a disappearance of (a) When the exposure was such that the average satura- such a state of affairs. tion of the goat's tissues (taking those which are considered to half saturate in five, ten, twenty, and forty minutes REFERENCES respectively) was below 210 feet the original method was Bert, P.: La Pression Baromdtrique. Reclerchies de Physiologie used-that is, that the ratio between the absolute pressure Experimenttale, Paris, 1878. and that of the dissolved nitrogen in any part of the body 2 Bornstein, A.: Deut. med. Woch., 1912, xxxviii, 1495. should not exceed 2: 1. 3 Boycott, A. E., Damant, G. C. L., and Haldane, J. S.: journ. of Hygiene, 1908, viii, 342. (b) WVhen the average saturation as above exceeded 210 feet ' Campbell, J. Argyll: journ. of Physiol., 1927, lxii, 211; lxiii, the same method of calculation was used, but with the ratio 325. reduced to 1.75: 1. Idem: Ibid., 1929, lxviii, Proc. Physiol. Soc., VII. (c) In all cases where the pressure of the exposure exceeded Campbell, J. Argyll, and Hill, Leonard: Quart. Journ. Exper. 270 feet, a supplement of about 15 per cent. was added to the Physiol., 1933, xxiii, 219. length of the oxygen part of the decompression" (p. 56). Hill, Leonard: Ibid., 1933, xxiii, 49. 'Hill, Leonard, and Greenwood, M.: Proc. Roy. Soc., B, 1907, As a result of subsequent trials a further addition of lxxix, 21. 25 per cent. wa-s made to the length of the oxygen part Hill, Leonard, and Macleod, J. J. R.: Jouirni. of Hygiene, 1903, of the decompression in drawing up the final tables. iii, 401. 1Report of a Committee appointed by the Lords Commissioners of the Admiralty to consider and report upon the conditions of THE DAVIS SUBMERGED DECOMPRESSION CHAMBER Deep Water Diving, London, 1907. The administration of oxygen to the diver during de- Report of a Committee appointed by the Lords Commissioners of compression is dependent upon the use of the Davis the Admiralty to consider and report upon the Equipment and Material required for the provision- of Deep Diving and submerged decompression chamber, designed by Sir Ordinary Diving in H.M. Service, London, 1933. Robert Davis. This is a cylindrical steel chamber, large 1Smith, Lorrain: journ. of Physiol., 1899, xxiv, 19. enough to hold two men comfortably, and tested to an internal pressure of 100 lb. to the square inch. This chamber is lowered to a depth of 60 feet-the first stage at which the diver breathes oxygen. The diver, having Clinical Memoranda made his first few " stops " on the " shot rope," enters the chamber, at 60 'feet, and at once begins breathing oxygen. Subsequent " stops" are made by lowering the A Second (Fatal) Attack of Scarlet Fever with pressure in the charmber. Two further advantages of the Haematemesis chamber are: (1) if any signs of compressed air illness haemor- develop, the diver can be immedia-tely recompressed; This case is an example of the now rarely seen (2) should adverse weather conditions develop, the rhagic type of scarlet fever, with the unusual complication chamber can be hoisted on to the deck of the diving of haematemesis. Permission for post-mortem examina- ship and the remaining decompression carried out in tion was not obtainable, but it is fair to assume that the safety. haematemesis was the result of bleeding from petechiae Should a case of compressed air illness develop, the in the gastric mucosa. Incontinence prevented a com- treatment consists of immediate and adequate re- plete analysis of urine, but one specimen examined showed compression-either in a recompression chamber or by only albuminuria and no blood. sending the diver down again. The second unusual feature is the occurrence of two The Psychotogy-of Deep Diving attacks of scarlet fever in the same child within four months; the first, a mild infection easily resisted; the One of the problems which confronted the 1930 second, a severe infection with almost no response from Admiralty Committee was the occurrence in divers of a example either of great sensation variously described, as dizziness, faintness, or the patient. This is a curious semi-loss of consciousness. These sensations oc,curred at variation in immunity or of alteration in the virulence of depths beyond 200 feet, and one of the disconcerting the infection. No other case of similar type was en- features of them was that the diver continued to answer countered during the same epidemic period. signals and even speak on the telephone, yet when he reached the submerged decompression chamber he could CASE HISTORY recall nothing of what had happened in deep water. At A female, aged 7 years, was admitted to Stockport Isolation this time the divers were in complete darkness at depths Hospital late in the course of scarlet fever. The onset had of over 200 feet, and as balance is largely a matter of been sudden with headache, vomiting, fever, and sore throat, co-operation between the eyes and semicircular canals, and the rash appeared after the first twenty-four hours, an it was decided to lower a light to assist the diver. For intense generalized punctate erythema with petechiae. A this purpose a 3,000 candle-power lamp was used, and thick, rapidly forming exudate soon covered the fauces, and did improve matters, but a few cases still occurred. was so membranous in character that swabs were taken to Carbon dioxide and oxygen poisoning having been ex- eliminate the possibility of an infection with Klebs-Loeffler cluded as causal agents, and the fact that some men bacilli. These were negative. were more prone to be affected than others suggested There had been a previous attack of scarlet fever four that the condition was more- psychological than physical, months previously, and this, though of a milder type, was a speculation which was supported by the fact that certain quite definite-headache, vomiting, sore throat, and rash. divers showed a steady improvement as the diving trials A twin sister to the patient was infected at the same time proceeded. and both desquamated. Some of the affected divers were examined by Professor The condition of the child on admission to hospital on the Millais Culpin, who considered that during these periods seventeenth day of the 'disease closely resembled the typhoidal of bemiconsciousness they were actually in a state of state-emaciation and pallor with oedematous lips, stupor, fugue. During the interview the so-called periods of hot dry skin, and double incontinence; temperature 104.20, semiconsciousness were reconstructed by the divers them- pulse 144, the heart sounds feeble, but no bruits. A few selves, suggesting that in actual fact there was no loss moist rales were heard at the lung bases, and the edges of of consciousness at all, and that the state was a form the liver and spleen were palpable through the thin abdominal of terror which caused the memory of events during the wall. These were the general signs associated with a scar- period to be suppressed. As a result of these findings the latinal infection of very severe type. The trunk was covered committee recommended that " tendencies to phobias with a coarse cyanotic rash, with punctate, petechial, and should be treated with suspicion, and. any sign of blotchy macular elements confused, and with desquamation claustrophobia should debar a man from deep diving "i' present in parts, chiefly on the sides of the thorax and upper (p. 159). " The type of man likely to be suitable for arms. The fauces were injected, and there was evidence of