Blood Transfusion

by Geoffrey Keynes

It has been said that the lower end of the delivery tube reaches into the angle between the side and the bottom of the flask. When therefore the flask is nearly empty, it should be tilted so that very nearly the whole of the blood can be forced up the tube. When the flask is quite empty, the blood in the barrel of the air-lock must be carefully watched, and when its level has fallen to the bottom of this, the clip must be applied to the tube above the cannula. By this means no blood is wasted except the small quantity which remains in the tube below the air-lock. As soon as the tube has been clipped the cannula is withdrawn, the vein is ligatured above the opening into its lumen, and the edges of the skin incision are sutured.

Transfusions carried out in this way can be performed with uniform success. The technique is simple and straightforward at every stage, and can be easily demonstrated and learnt. It is, in addition, a perfectly clean process, and not a single drop of blood need be spilt. Any method which involves the injection of blood under pressure is open to the objection that it is possible to overlook the fact that the flask has been emptied and to kill the patient by injecting air into his veins. This can, however, only happen as the result of great carelessness on the part of the operator. The presence of the air-lock affords an additional safeguard, as it can hardly escape the operator’s notice that blood has ceased to flow from the nozzle of the delivery tube.

Fig. 13.—Injection of the Blood, showing use of Air-lock

The method may also be criticized on the ground that some damage is caused to the corpuscles of the donor’s blood by the shaking which is necessary to mix it with the citrate solution. This objection is, in my opinion, theoretical rather than practical. If, however, it be desired to avoid any such shaking, the apparatus designed by A. E. Stansfeld and described by him in 1918 may be used. This ensures that the citrate and the blood flow into the containing vessel together, so that no further mixing is needed. The apparatus is more cumbrous, more fragile, and less easy to clean and to sterilize than that described above. In the hands of an expert it will give excellent results, but its use requires some little practice, and it is therefore not so well adapted for general use.

The whole of my own apparatus, as described above, may be obtained from Messrs. Allen & Hanburys, Wigmore Street, London, W.1, who also provide a convenient box for carrying it.

Transfusion of Infants.—The technique of transfusions performed upon children over the age of about four years does not differ from that used for adults, except that less blood is to be given. The antecubital veins are much smaller and a finer cannula may have to be used, but this is the only source of trouble. The transfusion of infants and very young children may, however, be found to be much more difficult. The operation will have to be done for conditions such as melæna neonatorum, which was discussed on p. 48 of the present work, or for post-operative collapse, such as may follow an operation for congenital hypertrophic stenosis of the pylorus, for intussusception, or for some of the more extreme cases of harelip and cleft palate. In all such instances the transfusion will be a matter of some urgency. Speed and certainty will depend on previous knowledge of the best method to be employed.

In the case of melæna neonatorum treated by R. D. Laurie, which has been already referred to, a needle was introduced into one of the antecubital veins, and 20 cc. of citrated blood were injected with a syringe. This method, however, is not to be recommended, on account of its great difficulty.

The method used by Helmholtz and also by Howard depends on the introduction of a syringe needle into the superior longitudinal sinus through the anterior fontanelle. A needle two to three inches long attached to a 20 cc. syringe is inserted near the upper angle of the fontanelle at an angle of about 25° with the scalp. As the needle pierces the wall of the sinus, a sensation of resistance is experienced, similar to that given by the piercing of the dura mater in doing a lumbar puncture. Blood should then be allowed to enter the syringe in order to demonstrate that the point of the needle really is lying in the sinus. Abnormalities have occasionally been met with, in which the sinus was situated to one side of the middle line or was very much smaller than usual. The danger of injecting the blood in such a case into the brain or the subdural space need not be emphasized. Difficulty may also be caused by restlessness on the part of the child, and to overcome this Helmholtz has devised an apparatus which grips and fixes the child’s head at a suitable angle. All this, however, makes the process unnecessarily elaborate. As an alternative, Vincent has exposed one of the internal jugular veins into which he introduces a cannula. This again is a comparatively difficult operation, which may leave a permanent scar in a conspicuous place. Vincent had previously used the femoral vein, but he found this difficult to approach, and the wound was apt to become contaminated afterwards.

The method of choice is undoubtedly that used by Bruce Robertson, who has performed a much larger number of transfusions upon infants and children than any other worker in this field of surgery. He has found that the internal saphenous vein near the ankle is a vessel possessing a fairly wide lumen and thick walls even in infants, so that a needle or cannula can be introduced into it with comparative ease and rapidity. The vein must, of course, be freely exposed through an incision, but its situation removes any objection there might otherwise be to this operation. Robertson has usually employed the syringe-cannula method described earlier in the present chapter, but there is no objection to the use of an anticoagulant. The small amount of blood to be given, 15 cc. per pound of body weight, makes the use of the transfusion flask unnecessary. It is better to use a 20 cc. syringe, into which 2 cc. of a 10 per cent. solution of sodium citrate is drawn as a preliminary. The needle in the donor’s vein and the cannula in the infant’s saphena should each be provided with a rubber connexion, which can be clipped, or pinched by an assistant, when the syringe is not attached. The syringe containing the citrate is filled with blood and injected into the infant as often as may be necessary until the total amount decided upon has been given.