Hereditary haemophilia : deficiency in the coagulability of the blood the only immediate cause of the condition / by Thomas Addis.

  • Addis, Thomas, 1881-1949.
Date:
1910
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Licence: In copyright

Credit: Hereditary haemophilia : deficiency in the coagulability of the blood the only immediate cause of the condition / by Thomas Addis. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Here also there is the same progressive increase in coagulability. It happened that the very last drop of blood before complete coagulation set in was not obtained, but, if it had been, the instantaneous coagulation seen in the last drop from the wound in the normal person would also have been observed here. The difference is one of degree only, though it is a very marked one. For the last specimen of blood obtained, some of which had remained in the wound in contact with the tissues for nearly five minutes, did not show the immediate coagulation which was found in normal blood after two and a half minutes in spite of the fact that in that wound the blood was being constantly forced out by fresh blood. The difference is much greater than the figures themselves indicate, and reveals a great delay even under these most favourable circumstances in the formation of thrombin in haemophilic blood. It may be objected that this is not the only explanation, for thrombin might have been formed, but yet have been inefficient or unable to act because of some fault in haemophilic fibrinogen. I hope to enter fully in a subsequent paper into the cause of the delay of coagulation in haemophilic blood, and there I shall show in detail that haemo- philic blood is quite as easily and readily coagulated by haemophilic thrombin as is normal blood by normal thrombin. The only possible explanation then is that the thrombin took an abnormally long time to form. This fact alone goes some way towards explaining the length of time during which haemorrhage may continue in haemophilia, although, as will be shown, it is not in itself a sufficient reason. In this particular instance, bleeding was stopped mechanically by the closing of the skin over the mouth of the wound, and time was given for thrombin to form in the blood enclosed in the cavity of the wound. If, however, an incision had been made of such an extent as to allow the skin to retract and leave the wound open, it is easy to see that bleeding might have continued for a long time without there being any chance of the blood coagulating. But the special characteristic of haemorrhages in haemophilia, and the point which is difficult to understand, is that in spite of the sometimes massive forma- tion of firm clots in and around the wound, the bleeding still continues or ceases for a time only to recur. Thus in Case I, who had had a tooth extracted, the bleeding went on for ten days, and, but for treatment, would have continued for a still longer time, although large clots formed and adhered firmly to the con- tused gum. Fresh blood filtered up slowly and continuously through the clot and ran over into the mouth. How is the continuance of bleeding to be explained in such a case ? How can it be attributed to any deficiency in the coagulability of the blood since firm coagulation has nevertheless obviously taken place ? And yet, paradoxical as it may appear, it is because of the coagulation that the bleeding continues. In such wounds in haemophilics coagulation is local instead of general. Only that part of the blood which is in immediate contact of any more blood. On account of this plugging of the wound by the elastic recoil of the tissues it is possible with safety to introduce small hollow needles into the veins of haemo- philics for the purpose of obtaining blood.