sodium bicarbonate in diabetic coma

of 2 /2
521 Prof. Parsons ends his book with a brief tour of St. Thomas’s today, and in passing College House he reminds us that the residents’ photographs include notorious as well as famous characters. All old St. Thomas’s men should read thit little book, and there is much in it to interest those who grew up in less venerable institutions. CARCINOGENESIS IN THE LUNG How far the results of animal experiments on cancer can be interpreted as applying to man is a question raised again in a paper by Valade.1 The suggestion has been made by more than one observer that the apparent increase of pulmonary cancer in recent years is attributable to the inhalation of tar-laden dust from the modern roads, and experi- ments on animals have been cited as supporting this. It has been shown for example that application of tar to the skin of mice is often followed by cancer of the lungs, and Argyll Campbell has succeeded in demonstrating that in mice exposed to an atmosphere contaminated with road dust there is a high incidence of these tumours. Campbell suggests that his experi- mental results can be applied to man, or in other words that they indicate tar as the probable causative factor in cancer of the human lung ; but Valade questions this. He points out that mice are especially prone to spontaneous pulmonary cancers, and that their lung tissues are susceptible to carcinogenic agents. Other animals do not necessarily have a similar susceptibility ; in the rat, for instance, he found that intratracheal injections of methylcholan- threne in oil has no carcinogenic effect on the lungs. Out of 50 rats which he subjected to this procedure 14 developed connective-tissue tumours about the trachea and oesophagus, but none developed epithelial tumours of the bronchi or lungs, notwithstanding the fact that after the rats were killed crystals of methyl- cholanthrene could be demonstrated lying in direct contact with their lung tissues. Valade argues that if an agent so strongly carcinogenic as methylcholan- threne fails to produce pulmonary cancers in rats there must be great variations in the susceptibility of different animals, and we cannot assume that what is true for a mouse will also be true for a man. INFANT FEEDING IN CHINA IN an inquiry into Chinese methods of infant feeding carried out for the Henry Lester Institute at Shanghai, Platt and Gin 3 found that the great majority of the 400 babies investigated were breast- fed. Wet-nurses were employed in 36 cases, in 6 imported milk powder was used and one mother claimed that she had brought up her child on a food based on rice-starch powder, entirely without milk. The usual procedure in the breast-fed baby is to give a solution containing some cathartic substance of native manufacture immediately after birth and again a few hours later. This is intended to drive out of the body all the " heating " substances. Breast- feeding is begun on the second day. A thin sweetened paste of rice flour or starch cake (if the family can afford it) is given once or twice daily. In a few days’ time if the supply of milk is adequate the child may refuse to take any additional food ; but most children continue to take small amounts of rice flour. Breast- feeding when established is irregular, the frequency of feeds being determined by the baby’s cry. The infant is fed less often during the night, and some 1. Valade, M. P., Bull. Acad. Méd. Paris, 1939, 121, 115. 2. Campbell, J. A., J. industr. Hyg. 1937, 19, 449. 3. Platt, B. S., and Gin, S. Y., Arch. Dis. Childh. 1938, 13, 343. 8-10 feeds are usually given in the course of twenty- four hours. There is no accepted time for the duration of a feed, which is usually continued until the baby falls asleep. Mixed feeding begins at about five months with some preparation of soft rice, and vegetable soup is added after six months. At about eight months a greater variety of soups are introduced together with egg, biscuit and oranges. The importance of feeding the mother or wet-nurse adequately is thoroughly appreciated by the Chinese. There are recognised rules as to the special foods required, and the mother is expected to consume a definite number of eggs as well as chicken, fish, soup and so forth shortly after delivery. Even with the very poor every effort is made to fulfil the require- ments of tradition. Emphasis is laid on a sufficient supply of fluid, and when milk secretion is poor drinks of many kinds are prescribed. A large number of substances have a reputation as lactagogues, such as mashed lean pork, a mixture of pork fat and cream beans, cuttle-fish in the form of soup, shrimps cooked with red wine, and cooked sea-slugs. When an infant’s requirements cannot be wholly met by the mother wet-nursing is often resorted to, and in most big cities there is a subdivision of a general servants’ agency which provides wet-nurses. Apart from wet-nursing the commonest way of supplementing breast-milk is to give rice flour or starch-cake powder two or three times a day. In nearly a third of the babies breast-feeding was discontinued by the end of the first year, but about half were still breast-fed during their second year, and the commonest reason given for weaning was a fresh pregnancy. From the European standpoint perhaps the most surprising finding of this inquiry was that in the 300 cases in which the indications for weaning were investigated " doctor’s advice " was recorded in only one. SODIUM BICARBONATE IN DIABETIC COMA ALTHOUGH during the last year or two surprisingly little has been written about the treatment of diabetic coma, it would be rash to infer that the last word has been said on the subject. It is of course true that inmost cases the response to insulin leaves nothing to be desired. Yet from time to time the clinician still meets with patients who give him grave anxiety. While delay in starting treatment is often responsible it is well to admit that other factors, at present unknown, may be concerned and to search widely for methods of reducing the mortality. When the treatment of a disease is revolutionised in the way that the treatment of diabetes has been revolu- tionised by the discovery of insulin there is always a tendency to discard prematurely the older thera- peutic weapons. In the early days of insulin treat- ment, for instance, little attention was paid to the extreme dehydration that attends diabetic coma, and it was several years before the importance of saline was recollected. Elsewhere in this issue Dr. Kirk suggests reviving another old remedy-namely, parenteral sodium bicarbonate-which was widely used in pre-insulin days in the belief that the symptoms of coma were due to acidosis. Although nowadays it is agreed that it is ketosis rather than acidosis that is the culprit, it does seem that the energetic use of sodium bicarbonate occasionally saved life during an era when diabetic coma was almost always fatal. The two cases related by Dr. Kirk are therefore of considerable interest. Nevertheless it is important to remember that sodium bicarbonate is a potentially dangerous drug. There is always a tendency for the

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Page 1: SODIUM BICARBONATE IN DIABETIC COMA

521

Prof. Parsons ends his book with a brief tour ofSt. Thomas’s today, and in passing College House hereminds us that the residents’ photographs includenotorious as well as famous characters. All old St.Thomas’s men should read thit little book, and thereis much in it to interest those who grew up in lessvenerable institutions.

CARCINOGENESIS IN THE LUNG

How far the results of animal experiments oncancer can be interpreted as applying to man is a

question raised again in a paper by Valade.1 The

suggestion has been made by more than one observerthat the apparent increase of pulmonary cancer

in recent years is attributable to the inhalation oftar-laden dust from the modern roads, and experi-ments on animals have been cited as supporting this.It has been shown for example that application oftar to the skin of mice is often followed by cancer ofthe lungs, and Argyll Campbell has succeeded indemonstrating that in mice exposed to an atmospherecontaminated with road dust there is a high incidenceof these tumours. Campbell suggests that his experi-mental results can be applied to man, or in otherwords that they indicate tar as the probable causativefactor in cancer of the human lung ; but Valadequestions this. He points out that mice are especiallyprone to spontaneous pulmonary cancers, and thattheir lung tissues are susceptible to carcinogenicagents. Other animals do not necessarily have asimilar susceptibility ; in the rat, for instance, hefound that intratracheal injections of methylcholan-threne in oil has no carcinogenic effect on the lungs.Out of 50 rats which he subjected to this procedure14 developed connective-tissue tumours about thetrachea and oesophagus, but none developed epithelialtumours of the bronchi or lungs, notwithstanding thefact that after the rats were killed crystals of methyl-cholanthrene could be demonstrated lying in directcontact with their lung tissues. Valade argues thatif an agent so strongly carcinogenic as methylcholan-threne fails to produce pulmonary cancers in ratsthere must be great variations in the susceptibilityof different animals, and we cannot assume that whatis true for a mouse will also be true for a man.

INFANT FEEDING IN CHINA

IN an inquiry into Chinese methods of infantfeeding carried out for the Henry Lester Institute atShanghai, Platt and Gin 3 found that the greatmajority of the 400 babies investigated were breast-fed. Wet-nurses were employed in 36 cases, in 6

imported milk powder was used and one motherclaimed that she had brought up her child on a foodbased on rice-starch powder, entirely without milk.The usual procedure in the breast-fed baby is to givea solution containing some cathartic substance ofnative manufacture immediately after birth and

again a few hours later. This is intended to driveout of the body all the " heating " substances. Breast-feeding is begun on the second day. A thin sweetenedpaste of rice flour or starch cake (if the family canafford it) is given once or twice daily. In a few days’time if the supply of milk is adequate the child mayrefuse to take any additional food ; but most childrencontinue to take small amounts of rice flour. Breast-feeding when established is irregular, the frequencyof feeds being determined by the baby’s cry. Theinfant is fed less often during the night, and some

1. Valade, M. P., Bull. Acad. Méd. Paris, 1939, 121, 115.2. Campbell, J. A., J. industr. Hyg. 1937, 19, 449.3. Platt, B. S., and Gin, S. Y., Arch. Dis. Childh. 1938, 13, 343.

8-10 feeds are usually given in the course of twenty-four hours. There is no accepted time for the durationof a feed, which is usually continued until the babyfalls asleep. Mixed feeding begins at about five monthswith some preparation of soft rice, and vegetablesoup is added after six months. At about eightmonths a greater variety of soups are introduced

together with egg, biscuit and oranges.The importance of feeding the mother or wet-nurse

adequately is thoroughly appreciated by the Chinese.There are recognised rules as to the special foodsrequired, and the mother is expected to consume adefinite number of eggs as well as chicken, fish, soupand so forth shortly after delivery. Even with thevery poor every effort is made to fulfil the require-ments of tradition. Emphasis is laid on a sufficientsupply of fluid, and when milk secretion is poordrinks of many kinds are prescribed. A large numberof substances have a reputation as lactagogues, suchas mashed lean pork, a mixture of pork fat and creambeans, cuttle-fish in the form of soup, shrimps cookedwith red wine, and cooked sea-slugs. When aninfant’s requirements cannot be wholly met by themother wet-nursing is often resorted to, and in mostbig cities there is a subdivision of a general servants’agency which provides wet-nurses. Apart from

wet-nursing the commonest way of supplementingbreast-milk is to give rice flour or starch-cake powdertwo or three times a day. In nearly a third of the babiesbreast-feeding was discontinued by the end of thefirst year, but about half were still breast-fed duringtheir second year, and the commonest reason givenfor weaning was a fresh pregnancy. From theEuropean standpoint perhaps the most surprisingfinding of this inquiry was that in the 300 cases inwhich the indications for weaning were investigated" doctor’s advice " was recorded in only one.

SODIUM BICARBONATE IN DIABETIC COMA

ALTHOUGH during the last year or two surprisinglylittle has been written about the treatment ofdiabetic coma, it would be rash to infer that the lastword has been said on the subject. It is of coursetrue that inmost cases the response to insulin leavesnothing to be desired. Yet from time to time theclinician still meets with patients who give him graveanxiety. While delay in starting treatment isoften responsible it is well to admit that other factors,at present unknown, may be concerned and to searchwidely for methods of reducing the mortality. Whenthe treatment of a disease is revolutionised in theway that the treatment of diabetes has been revolu-tionised by the discovery of insulin there is always atendency to discard prematurely the older thera-peutic weapons. In the early days of insulin treat-ment, for instance, little attention was paid to theextreme dehydration that attends diabetic coma,and it was several years before the importance ofsaline was recollected. Elsewhere in this issue Dr.Kirk suggests reviving another old remedy-namely,parenteral sodium bicarbonate-which was widelyused in pre-insulin days in the belief that the

symptoms of coma were due to acidosis. Althoughnowadays it is agreed that it is ketosis rather thanacidosis that is the culprit, it does seem that the

energetic use of sodium bicarbonate occasionallysaved life during an era when diabetic coma wasalmost always fatal.The two cases related by Dr. Kirk are therefore of

considerable interest. Nevertheless it is importantto remember that sodium bicarbonate is a potentiallydangerous drug. There is always a tendency for the

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522

hydrogen-ion concentration of the blood to risewhen insulin begins to restore the normal oxidationof fat, and injudicious use of bicarbonate during thisperiod is apt to exaggerate the drift towards alkalosis.And alkalosis is to be avoided, for three reasons :it can rarely be recognised clinically ; it is as difficultto dispel as it is easy to provoke ; and it is some-times fatal. Another obstacle to the treatment is thatsolutions of bicarbonate cannot be sterilised by heat.Dr. Kirk is evidently alive to these drawbacks andthe only object in underlining them is to make itclear that the indiscriminate use of sodium bicar-bonate is likely to do more harm than good, especiallywhere facilities for emergency measurements of the

pH or bicarbonate content of the plasma are not athand. But the physician who, like Dr. Kirk, cancommand such facilities will no doubt be encouragedto try bicarbonate in cases where response to insulinis dangerously delayed.

THE NEW SCHOOL AT NEWCASTLE

DURING their visit to Tyneside last week the Kingand Queen formally opened the new medical schoolattached to King’s College, Newcastle, and made atour of the building. The school, which has beenin use since October, is planned on the pavilionsystem, in three main blocks joined by a corridor.The south block contains the dean’s offices, the com-mittee-room, and common-rooms for men and womenstudents, with a cafe and gymnasium. Above theseare the physiological chemistry laboratories andlecture theatre. The lower floors of the central blockare taken up by the laboratories of the bacteriologicaland public-health departments. On the first flooris the histological laboratory and demonstration-rooms and on the second the Sutherland Hall, alarge room for examinations, the museum, and awell-equipped animal-house. The north block housesthe pathology department on the ground floor andthe anatomical museum, dissecting-rooms and lecturetheatres above. The school now has 409 under-

graduates, of whom 50 are women.

FAMILIAL PERIODIC PARALYSIS

SiNCE the demonstration by Allott in 1935 of thediminution of serum-potassium during attacks offamilial periodic paralysis our knowledge of thecondition has advanced considerably. Some of therecent developments were referred to in these columnsin August last.1 During an attack of paralysis theaffected muscles are entirely flaccid, and cannot bemade to contract either by direct electrical stimulationor by stimulation of their nerve-supply. This factseems to point to a peripheral rather than a centralabnormality, and until lately the evidence suggestedthat the paralysis was due to an abnormal demandfor potassium in the muscles of affected subjects.Last year Pudenz, McIntosh and McEachern foundthat if potassium was injected intravenously theparalysis was relieved before the level of potassiumin the serum rose, which is in agreement with theconception that the additional potassium is takenout of the blood-stream by the tissues suffering frompotassium lack. They have now shown,2 however,that if the venous return from one arm is preventedby a cuff at 60 mm. pressure the intra-arterial injectionof potassium chloride in the affected limb does notproduce any return of function. On the other hand,if the circulation in one arm is completely cut off

1. Lancet, 1938, 2, 443.2. Pudenz, R. H., McIntosh, J. F., and McEachern, D.,

J. Amer. med. Ass. 1938, 111, 2253.

by a cuff at 200 mm. pressure, and potassium chlorideis injected intravenously in the other, the occludedlimb recovers as quickly as the unoccluded. Theseexperiments seem to show that a central factor isinvolved, but the creatmuria found by these Montrealworkers, as well as by Ferrebee, Atchley and Loeb,3still seems more likely to be due to a concomitantmuscular abnormality than to purely nervous

influences. The choline-esterase level in the bloodis normal during an attack, but recovery can bebrought about without potassium salts by the intra-venous administration of the choline esters doryl ormecholyl. Under the influence of these drugs theserum-potassium level rises in the same way as itdoes in spontaneous recovery, suggesting that potas-sium is liberated from some organ or tissue andbecomes available for use by the affected muscles.At present there is no evidence as to the whereaboutsof this potassium storehouse. Whatever the eventualmechanism of the disease may turn out to be, it isclear that there is in affected subjects some metabolicabnormality affecting potassium, and the conditionshould probably be added to the growing list ofinborn errors of metabolism.

CANCER CLINICS

A RECENT deputation to the Minister of Healthexpressed the hope that the proposed cancer schemeswould utilise the facilities of the larger hospitals,voluntary and municipal, rather than lead to theestablishment of special clinics not closely linkedwith general hospitals. The deputation also askedfor consultant facilities in the homes of patients. Onboth these policies Mr. Elliot’s reply was encouraging,subject to the advice given him by the medicaladvisory committee shortly to be appointed. For

many reasons he thought it would clearly be desirablefor a large and well-equipped hospital to serve theareas of more than one local authority. At present,whatever the future may hold, the only practicalmethods of treatment for cancer are surgery andradiation. Surgery in this country has definitestandards, radiation has not ; it is therefore necessarybefore framing a scheme of clinics to define theminimum requirements for adequate radiation

therapy. X-ray apparatus should be available for allpatients requiring it to be treated within a fortnightof being identified. Radium should be at the disposalof the therapist in such quantities as will allow himto treat any case with correct doses, using suitablecontainers. Such treatment must be in the handsof fully trained radiotherapists and it is a questionwhether a diploma in radiology can in itself beconsidered as a full qualification ; prolonged experi-ence or a complete course of instruction at a recognisedcentre is also essential. In view of the expensivenature, in time and money, of this training the radio- ,

therapist may expect to have .the same status as thesurgeon, notwithstanding the nature of the workrequires a full-time appointment. At present thenumber of fully trainect radiotherapists is limited,and this fact has a bearing on the possibility ofusing effectively in the near future any considerableincrease in the quantity of radium available. Despiteany impression to the contrary given by the recentreport (Lancet, Feb. 18, p. 403) there are already anumber of large treatment centres where all formsof radiation are available in charge of a trained staff.In Manchester, for instance, this centre is attached toa cancer hospital, with adequate surgical service, and

3. Ferrebee, J. W., Atchley, D. W., and Loeb, R. F., J. clin.Invest. 1938, 17, 504.