Blood Transfusion

by Geoffrey Keynes

During the war the value of blood transfusion in shock was amply demonstrated. In civilian practice I have found it to be of value when given after operations such as removal of the rectum, whether by the perineal or abdomino-perineal route, amputation of the leg through the hip joint, or removal of a sarcoma from the nasopharynx. Transfusion should be given towards the close of the operation before the evidences of shock have reached their maximum. The depletion of the blood volume is then actually remedied as it takes place, and transfusion becomes almost as much a prophylactic measure as warmth and the administration of morphia.

It is probable that the mortality following very severe operations such as those mentioned above would be considerably reduced if blood transfusion were to be given as a routine measure. Reference has already been made to the bad effect of the ordinary anæsthetics, and the best effects are obtained by a blood transfusion in conjunction with gas and oxygen or with spinal anæsthesia. It is necessary, however, to draw attention to the fact that a blood transfusion if given to a patient under the influence of a spinal anæsthetic must not be performed until the operation is very nearly completed, for it will very often produce a much more rapid return of sensation than would otherwise occur.

In advocating the use of blood transfusion to combat the effects of shock and hæmorrhage, it would be misleading to imply that this is necessarily the only treatment that is available. Something must be said of the substitutes for blood that have been used, and in particular the value of gum acacia must be considered. In the days before the war it was customary to treat post-operative shock or hæmorrhage with large quantities of normal salt solution given intravenously or subcutaneously. During the earlier part of the war also this was used, and there can be no doubt that for the less severe cases this treatment is often beneficial. Occasionally even the lives of patients who were desperately ill have been saved by it; I have seen a saline infusion cause the recovery of a man who had a dozen perforations of the small intestine and who had, in addition, lost several pints of blood intraperitoneally from a wound of a large mesenteric vessel. Such cases are, however, exceptional. In the presence of severe shock or hæmorrhage a saline infusion may cause an immediate rise in blood pressure, but the fluid exudes so rapidly into the tissues that the effect is usually very transient. This fact is universally admitted to be true and need not be further emphasized. Saline solution administered by the rectum is likely to have a more lasting effect, but the process of absorption is slow, and the patient may be dead before it has had time to act. The same applies to water given by the mouth. A patient suffering from severe shock is unable to tolerate more than a very small quantity of fluid in his stomach without vomiting. Some success was attained by Oswald Robertson in treating cases of hæmorrhage by the method of “forced fluids,” large quantities being given by the mouth and by the rectum (245). In many serious cases, however, this treatment is inapplicable, and it is clear that transfusion is more rapid and more certain in its effect. Isotonic saline having been found ineffectual, it was suggested that a hypertonic solution (2 per cent. sodium chloride) might be of more value. This was tested clinically and in the laboratory, and was found to have no advantage over the isotonic solution (11).

When the association of increased hydrogen-ion concentration with shock was demonstrated, it was at first supposed to be one of the factors producing the condition. It was therefore natural that the effect of a solution of sodium bicarbonate (4 per cent.) should be tried. The effect upon certain cases suffering from extreme “acidosis” and air hunger was very striking, but in general the alkaline solution was no more effective than the ordinary isotonic saline. I soon abandoned its use for intravenous infusion, but it was of service in serious cases when given by the rectum.

During the war the necessity for the conservation of time—and of blood—was evident. The search for a satisfactory substitute for blood was therefore prosecuted with great energy, most of the research being done by, or under the direction of, Professor W. M. Bayliss. The object of the research was to discover a non-toxic solution which possessed the same “viscosity” as the blood, and the same osmotic pressure due to contained colloid. It was believed that such a solution would not tend to exude so rapidly into the tissues and would therefore augment the blood volume more effectively than the fluids previously used. After many experiments it was claimed in 1916 that a blood substitute had been found in a 6 per cent. solution of gum acacia with ·9 per cent. sodium chloride. It was even stated on the evidence of laboratory experiments that the gum solution was as effective as blood in the treatment of shock and hæmorrhage. It was therefore used very extensively among the wounded, and favourable reports upon its value were made by various workers. It is difficult, however, to control the results in giving treatment of this kind. If a patient dies after being given a gum infusion, no one can state definitely that he would have lived had he been given a blood transfusion instead. If a patient lived after having a blood transfusion, it would be equally rash to state that he would have died had he been given gum. Nevertheless, after giving the gum solution a number of trials, I formed the opinion that the results were inferior to those obtained with blood. Patients did not recover whom from previous experience with blood transfusion I should have expected to do so. I accordingly continued to use blood in preference to gum whenever it was available, although justice must be done to those who so strongly advocated gum by saying that there can be no doubt that it is very much more effective than other solutions previously used. The same opinion was formed by many other surgeons, although it was natural to feel a bias in favour of gum which could be given with much greater economy of time and effort than blood. Up to the present time I have seen no reason for altering this opinion, and should always prefer to treat hæmorrhage and shock with a blood transfusion if possible.

Recently the relative values of a number of intravenous infusions for shock have been put to an extensive experimental test by F. C. Mann. The shock was produced by handling the abdominal contents, and the effect on the blood pressure of the various fluids was mechanically registered. The conclusion was reached that far the best results were obtained by a transfusion of blood or blood serum, the effect of these being more permanent than that of any other substance used. The use of gum acacia was found to give results which were “variable and sometimes disastrous,” but this may have been due to some extent to errors in the technique of preparing the solution.

This draws attention to a possible objection to the use of gum, namely, that some samples of the solution have been found to be actually toxic; but it is said that this can be avoided if proper care be exercised in its preparation. Full instructions for this are given in a paper by S. V. Telfer.

Into the discussion of the relative merits of blood and gum solutions may be profitably introduced the further question as to which is the more valuable constituent of transfused blood, the corpuscles or the plasma. It has been seen that the essential factor in producing the symptoms of shock and hæmorrhage is a reduction of blood volume, and treatment is therefore directed in the first place towards the restoration of this volume, with a fluid of the same viscosity and osmotic pressure as blood. This might be done with plasma or, some may say, equally well with gum. From the point of view only of volume, the corpuscles and plasma are of equal value, since each forms approximately half the total volume of a given quantity of blood. There is, however, another aspect to be considered. One of the results of loss of blood volume is imperfect oxygenation in the tissues. When the volume is increased by the addition of plasma or gum, the corpuscles in the circulation are diluted, and this by itself would tend further to impair oxygenation. The dilution is, however, compensated for by the improvement in circulation which in its turn improves the supply of oxygen to the tissues, and it is still further counteracted by the restoration to the circulation of the blood corpuscles which were stagnating in the capillary system. It seems clear that these successive processes will be accelerated by the use of a fluid which itself contains corpuscles, and this may afford a theoretical explanation of the clinical observation that blood is more effective than gum. Its use will tend to establish more quickly the “virtuous circle” following increased volume, and so undo the “vicious circle” due to insufficient volume. It has been questioned whether the corpuscles of transfused blood really do play an active part in the economy of their new host, or whether their new environment may not quickly render them effete. This has been answered by the exceedingly interesting and ingenious series of experiments carried out by Winifred Ashby. She has transfused blood of a known group (see Chapter IV) into an individual of a different, but compatible group, and then shown that it is possible by selective agglutination with a suitable serum to demonstrate the presence in the blood of the two kinds of corpuscles side by side. In this way she has shown that transfused corpuscles are still present in the circulation and of normal appearance thirty days after they were introduced.

It is therefore justifiable to make the inference that transfused corpuscles can for some little time carry out their normal function. If it be true that their presence is an advantage in the treatment of deficient blood volume, it may also be conjectured that their presence is likely to be of greater importance in treating hæmorrhage than it is in the treatment of pure shock, for in the latter condition all the original corpuscles are still present in the body, while in the former they are not.

I should sum up the discussion of the relative merits of blood and gum by saying that on the grounds of experiment and clinical experience I believe blood to be the more efficient of the two, particularly in the most serious cases. Every patient who needs it should therefore have the advantages conferred by blood transfusion if it can be done. If it cannot, then gum and saline is much the most satisfactory substitute that is at present known.