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THE ADMINISTRATION OF PURE OXYGEN.
1092 As Prof.
says, " thereis a constant battle among dietetic elements as regards the calcification of bone, some substances stimulating and others preventing the process, and the ultimate structure of the bone is the outcome of the conflict." The final word on this matter may not be said for
going
Mellanby
on
long time to
come. Prof. Mellanby has performed great amount of careful experimental work, which is worthy of serious consideration, and has raised issues of which we had not previously thought. a
a
But, on the other hand, it is certain that his results should be applied with caution to problems of human dietaries. The great amount of prominence which has been given to work on the vitamins, and to allied questions in the science of nutrition, largely on account of the conditions of restriction of choice which were imposed on us by the war, is in danger of leading to an exaggeration of their importance. Everyone who has worked on nutrition will admit that in a properly chosen diet the vitamins will look after themselves, and it is only under special circumstances that it becomes necessary to take special vitamin-containing foods. Without question the same applies to the regulation of diet in connexion with the prevention of rickets. While Prof. Mellanby’s results have undoubtedly great scientific value, they are in danger of being misunderstood by lay people, many of whom take a great interest in diet. It must not be forgotten that the diets given to the puppies under experimental conditions are highly abnormal diets for such animals, and would not be chosen voluntarily by them. It might be suggested, for instance, that a diet of meat would probably lead to definite disturbances in the economy of a growing human infant, but it would be foolish to argue from such an experiment that meat is an unsuitable article of diet for puppies. Conclusions from these valuable and suggestive experiments should not, then, be pushed too far, and it must not be forgotten that Prof. Mellanby would certainly be the last to apply them unreservedly to human nutritional problems. The matter must be subjected to further careful investigation before we can say how far they can be applied.
THE
cases.
CRIPPLING DUE TO FRACTURES: THE REMEDY. THE Lady Jones Memorial Lecture in Orthopaedics in the University of Liverpool was delivered this year by Sir Robert Jones on May 12th before a large and representative audience of the medical profession. The lecturer chose as his subject Crippling Due to Fractures, its Prevention and the Remedy. After some preliminary remarks designed to emphasise the great frequency of preventable deformities after fractures, he dealt with the different types of disablement that might be present and the simple way in which most of them could be obviated. He instanced more particularly the serious results following badly treated fractures of the neck of the femur, the supracondylar region of the humerus, and the lower end of the fibula. He pointed out plainly that students were not adequately trained in the treatment of fractures and that this was often because the general surgeon had not the interest in nor the up-to-date knowledge of the treatment of fractures necessary if the subject was to find the place in his teaching which its importance to the man in practice demanded. To some extent this was inevitable, as the field of general surgery was now too large to be profitably traversed by any one man. The lecturer then entered a plea for a better thought-out and more efficient scheme for the education of the student. Every teaching hospital, he said, should have its special fracture department--usually, no doubt, in association with an existing orthopsedic department. It should be under the charge of a man of consultant rank or if shared between several, an assistant of high standing should be appointed, whose specific duties should be the supervision of the department under Beddard and M. S. Pembrey : Brit. Med. Jour., 1908, his various chiefs. The department should include 2 THE LANCET, May 2nd, 1925, p. 916. ward accommodation and out-patient rooms in
ADMINISTRATION OF PURE OXYGEN. IT is not often that pure oxygen is administered to patients, but when such administration is required it has long been the custom to use the ordinary apparatus for nitrous oxide anaesthesia, substituting .a cylinder of oxygen for one of gas. This method was used. by Beddard and Pembreyin their early work Its practical disadvantage as on the effect of oxygen. .a routine method in the wards is that it requires the constant supervision of a nurse to regulate the flow of oxygen to keep the bag filled. The advantage of Haldane’s apparatus, which came into use at the end of the war, was that the expiratory valve on the mask also acted as an air inspiratory valve, as required, so that if the supply of oxygen suddenly ran short the patient would breathe atmospheric air, and constant supervision to prevent suffocation was not necessary. Some oxygen is, of course, lost by this method. Dr. H. W. Davies and Dr. A. R. Gilchrist have recently in THE LANCET2 elaborated the older method by adding a flow metre to measure the oxygen, a reducing valve on the cylinder to steady the flow, arid an adjustable opening to the mask, so that the concentration of oxygen in the air breathed can be varied. Such alterations, though presenting obvious advantages, may still lead to certain practical diffi.culties, and it would be interesting to know if they Is constant supervision of the have been met. apparatus still necessary ? Reducing valves are very apt to leak, since the junction between valve and cylinder head has to stand the total internal pressure of the cylinder. Again, the Haldane reducing valve offers so much resistance that the last part of the oxygen of the cylinder often fails to escape. Have 1
A. P.
ii., 45.
these facts been taken into account ? While everyone who has studied the subject would agree with the authors that the method of giving oxygen by a funnel is useless, it does not necessarily follow that the extremely simple method of giving oxygen through a nasal catheter or a tube passed into the mouth should be condemned. No reducing valve is required, and the rate of flow can be gauged by the rate at which the oxygen bubbles through water in a bottle, though a flow meter is preferable. Such a method will not give pure oxygen and there will be some waste, but the inspired air will be considerably When pure enriched and the patients benefited. oxygen is required, the method of gas-bag with mask and valves in some form or other is essential. Perhaps the chief indication for pure oxygen is coal-gas poisoning, since the higher the concentration of oxygen the more readily will the CO be excreted from the body and the patient recover. Dr. Leonard Hill and Dr. Argyll Campbell, in their paper in the same issue of THE LANCET, mention Dr. Haldane’s observation that a mouse poisoned with CO can be kept alive in pure oxygen under two atmospheres of pressure. The technical difficulty of administering oxygen under pressure to patients is considerable, and fortunately in coal-gas poisoning pure oxygen under atmospheric pressure is good enough. However, the use of oxygen under increased pressure may be of advantage, since it has been pointed out that a perfect gas and oxygen anaesthesia with no cyanosis can only be obtained by such means. The reason is that such a high concentration of nitrous oxide is necessary for the anaesthesia, that the oxygen must be deficient if the ordinary atmospheric pressure is used, and visions have been conjured up of surgical operations being carried out in a steel chamber. An alternative method is to choose a gas with greater anaesthetic power, such as ethylene, so that perfect anaesthesia by means of ethylene and oxygen without oxygen-want may be obtained. Unfortunately, ethylene is highly inflammable, though there is every prospect that with proper precautions it may come into regular use for special
says, " thereis a constant battle among dietetic elements as regards the calcification of bone, some substances stimulating and others preventing the process, and the ultimate structure of the bone is the outcome of the conflict." The final word on this matter may not be said for
going
Mellanby
on
long time to
come. Prof. Mellanby has performed great amount of careful experimental work, which is worthy of serious consideration, and has raised issues of which we had not previously thought. a
a
But, on the other hand, it is certain that his results should be applied with caution to problems of human dietaries. The great amount of prominence which has been given to work on the vitamins, and to allied questions in the science of nutrition, largely on account of the conditions of restriction of choice which were imposed on us by the war, is in danger of leading to an exaggeration of their importance. Everyone who has worked on nutrition will admit that in a properly chosen diet the vitamins will look after themselves, and it is only under special circumstances that it becomes necessary to take special vitamin-containing foods. Without question the same applies to the regulation of diet in connexion with the prevention of rickets. While Prof. Mellanby’s results have undoubtedly great scientific value, they are in danger of being misunderstood by lay people, many of whom take a great interest in diet. It must not be forgotten that the diets given to the puppies under experimental conditions are highly abnormal diets for such animals, and would not be chosen voluntarily by them. It might be suggested, for instance, that a diet of meat would probably lead to definite disturbances in the economy of a growing human infant, but it would be foolish to argue from such an experiment that meat is an unsuitable article of diet for puppies. Conclusions from these valuable and suggestive experiments should not, then, be pushed too far, and it must not be forgotten that Prof. Mellanby would certainly be the last to apply them unreservedly to human nutritional problems. The matter must be subjected to further careful investigation before we can say how far they can be applied.
THE
cases.
CRIPPLING DUE TO FRACTURES: THE REMEDY. THE Lady Jones Memorial Lecture in Orthopaedics in the University of Liverpool was delivered this year by Sir Robert Jones on May 12th before a large and representative audience of the medical profession. The lecturer chose as his subject Crippling Due to Fractures, its Prevention and the Remedy. After some preliminary remarks designed to emphasise the great frequency of preventable deformities after fractures, he dealt with the different types of disablement that might be present and the simple way in which most of them could be obviated. He instanced more particularly the serious results following badly treated fractures of the neck of the femur, the supracondylar region of the humerus, and the lower end of the fibula. He pointed out plainly that students were not adequately trained in the treatment of fractures and that this was often because the general surgeon had not the interest in nor the up-to-date knowledge of the treatment of fractures necessary if the subject was to find the place in his teaching which its importance to the man in practice demanded. To some extent this was inevitable, as the field of general surgery was now too large to be profitably traversed by any one man. The lecturer then entered a plea for a better thought-out and more efficient scheme for the education of the student. Every teaching hospital, he said, should have its special fracture department--usually, no doubt, in association with an existing orthopsedic department. It should be under the charge of a man of consultant rank or if shared between several, an assistant of high standing should be appointed, whose specific duties should be the supervision of the department under Beddard and M. S. Pembrey : Brit. Med. Jour., 1908, his various chiefs. The department should include 2 THE LANCET, May 2nd, 1925, p. 916. ward accommodation and out-patient rooms in
ADMINISTRATION OF PURE OXYGEN. IT is not often that pure oxygen is administered to patients, but when such administration is required it has long been the custom to use the ordinary apparatus for nitrous oxide anaesthesia, substituting .a cylinder of oxygen for one of gas. This method was used. by Beddard and Pembreyin their early work Its practical disadvantage as on the effect of oxygen. .a routine method in the wards is that it requires the constant supervision of a nurse to regulate the flow of oxygen to keep the bag filled. The advantage of Haldane’s apparatus, which came into use at the end of the war, was that the expiratory valve on the mask also acted as an air inspiratory valve, as required, so that if the supply of oxygen suddenly ran short the patient would breathe atmospheric air, and constant supervision to prevent suffocation was not necessary. Some oxygen is, of course, lost by this method. Dr. H. W. Davies and Dr. A. R. Gilchrist have recently in THE LANCET2 elaborated the older method by adding a flow metre to measure the oxygen, a reducing valve on the cylinder to steady the flow, arid an adjustable opening to the mask, so that the concentration of oxygen in the air breathed can be varied. Such alterations, though presenting obvious advantages, may still lead to certain practical diffi.culties, and it would be interesting to know if they Is constant supervision of the have been met. apparatus still necessary ? Reducing valves are very apt to leak, since the junction between valve and cylinder head has to stand the total internal pressure of the cylinder. Again, the Haldane reducing valve offers so much resistance that the last part of the oxygen of the cylinder often fails to escape. Have 1
A. P.
ii., 45.
these facts been taken into account ? While everyone who has studied the subject would agree with the authors that the method of giving oxygen by a funnel is useless, it does not necessarily follow that the extremely simple method of giving oxygen through a nasal catheter or a tube passed into the mouth should be condemned. No reducing valve is required, and the rate of flow can be gauged by the rate at which the oxygen bubbles through water in a bottle, though a flow meter is preferable. Such a method will not give pure oxygen and there will be some waste, but the inspired air will be considerably When pure enriched and the patients benefited. oxygen is required, the method of gas-bag with mask and valves in some form or other is essential. Perhaps the chief indication for pure oxygen is coal-gas poisoning, since the higher the concentration of oxygen the more readily will the CO be excreted from the body and the patient recover. Dr. Leonard Hill and Dr. Argyll Campbell, in their paper in the same issue of THE LANCET, mention Dr. Haldane’s observation that a mouse poisoned with CO can be kept alive in pure oxygen under two atmospheres of pressure. The technical difficulty of administering oxygen under pressure to patients is considerable, and fortunately in coal-gas poisoning pure oxygen under atmospheric pressure is good enough. However, the use of oxygen under increased pressure may be of advantage, since it has been pointed out that a perfect gas and oxygen anaesthesia with no cyanosis can only be obtained by such means. The reason is that such a high concentration of nitrous oxide is necessary for the anaesthesia, that the oxygen must be deficient if the ordinary atmospheric pressure is used, and visions have been conjured up of surgical operations being carried out in a steel chamber. An alternative method is to choose a gas with greater anaesthetic power, such as ethylene, so that perfect anaesthesia by means of ethylene and oxygen without oxygen-want may be obtained. Unfortunately, ethylene is highly inflammable, though there is every prospect that with proper precautions it may come into regular use for special