Blood Transfusion

by Geoffrey Keynes

A second objection is the extent of the injury which is necessarily inflicted on the donor. His radial artery must be exposed through an incision of considerable length, and must be ligatured at the conclusion of the process. The operation becomes, therefore, a matter of some moment to the donor, who will be permanently scarred, and can under no circumstances be used for transfusion more than twice.

A third objection is that the transfusion cannot be done with due regard to the condition of the patient. A delicate and difficult operation has to be performed with the donor and recipient lying side by side, their arms close together. It is therefore almost imperative that both should be on operating-tables of a convenient height. Often, however, with an exsanguinated patient it is very important that he should not be moved from his bed, but as a bedside operation direct transfusion becomes difficult indeed!

A final objection is that in some people the radial artery is of very small calibre, so that when all preparations have been made, and the artery exposed, it is found to be quite impossible to proceed. Another element of uncertainty is thus introduced.

There is, therefore, little to be said in favour of direct transfusion, and much to be urged against it. This method has, indeed, in my own opinion, come to be of historical interest only. For this reason the different methods have only been very briefly described. For more detailed information, reference must be made to the various original communications, which will be found in the Bibliography.

Indirect Transfusion.—The methods of indirect transfusion may be divided into those which depend upon the use of an anticoagulant mixed with the blood and those in which the blood is given unaltered. The technique of either process is simple compared with that of direct transfusion, though any method which makes use of whole blood can never be quite as free from uncertainty or difficulty as one which introduces the use of an anticoagulant. If the blood is prevented from clotting, the chief cause of failure in performing blood transfusions is removed. With any whole-blood method of transfusion speed is exceedingly important, frequent practice is a very great advantage, and it is essential, as with direct transfusion, that the donor and recipient should be in close proximity to one another, if not actually side by side.

On the other hand, the use of an anticoagulant renders speed and frequent practice of less account. The blood can be drawn, and can then be put on one side until the best moment for giving it has arrived. Due regard may be had to the patient’s condition, since the blood can be carried about and can be given at leisure to the patient in his bed without disturbing him and almost without his knowing it. The donor, too, is not exposed to the mental shock of lying for some time side by side with a patient who may be in extremis, or may even expire during the operation.

There are, however, those who consider that the use of whole blood, instead of blood which has been chemically treated, has advantages which outweigh the possible disadvantages mentioned above. Two methods of using whole blood are, therefore, described first; the use of anticoagulants is then described in detail, and their advantages and possible dangers are enlarged upon.

Whole Blood Transfusion with Syringes.—It is obvious that, if blood can be drawn from the donor’s vein into a glass syringe and injected into the recipient so rapidly that clotting has no time to occur, then a transfusion of any quantity of blood that may be wished can be given by this simple means. The measure of the amount of blood transfused is given by the number of syringes that have been filled and emptied. This method has been successfully used by several workers, and it has the advantage that no very special apparatus is necessary. It does, however, require that several syringes, and more than one assistant, should be available, since clotting will take place in the syringes, unless they be frequently washed out. There is also the possibility that clotting may take place in the needle which is introduced into the donor’s vein, since this cannot be withdrawn and replaced for each syringeful of blood that is transferred. With practice, however, and with good assistants, the process can be done quickly enough to avoid this. Wide-bore needles with short rubber connexions are introduced into the veins of donor and recipient; if, as often happens, this is difficult to do through the skin in the case of the recipient, his vein must first be exposed through an incision and a glass or metal cannula introduced into it. The operator then fills the syringes with blood in quick succession and hands them to his first assistant, who injects the blood into the recipient. Blood is prevented from escaping from the needles when the syringes are disconnected by nipping the rubber connexions with the fingers. The first assistant passes the empty syringes to the second assistant, who washes them out with normal saline, and hands them back if needed to the operator. This can be done with six 20 cc. syringes used in rotation, possibly with only four.

The most recent description of this method has been published by J. M. Graham of Edinburgh, who has introduced an improved form of needle. This consists of a double tube; the inner tube has a needle point which is used for puncturing the vein, and can be withdrawn into the blunt outer tube when the vein has been entered. Any further wounding of the vein is thus avoided. In addition, movement of the needle-cannula is prevented by a bull-dog forceps attachment, which is clipped to the skin. Graham finds it advisable to lubricate the cannulæ and syringes with vaseline before being used. He also states that: “As the absence of clotting depends upon the rapidity with which the syringes are filled and emptied, a series of syringes should be used in strict rotation, and all trace of blood must be washed out with saline before the syringes are used again. One or two additional assistants are necessary for this method.” The disadvantages are evident, and it is not suitable for general use.

A modification of the method has been described by Unger, in which only one syringe is used. The barrel of this is cooled by an ether spray so that clotting is discouraged or prevented.