The change in practice which we have just noticed, with regard to Inflammation, has extended itself to Fevers; and blood-letting is now, comparatively speaking, rarely resorted to, unless some peculiar and urgent symptoms demand its employment. The circumstances more especially requiring recourse to vascular depletions, may be summed up as follows: - a, inordinate excitement or irritation, with rigidity of fibre, and general increase of the animal heat; b, when the patient is robust, plethoric, or young, the sanguiferous system being so surcharged as to prevent the free exercise of the functions; c, when the general reaction of the vascular system is such as to endanger vital parts, or too strong to allow a salutary or critical change, or so vehement or tumultuous as quickly to exhaust vital power; and d, when the blood is determined to, or vascular action is inordinately increased in, an important organ. In these conditions blood-letting is employed with the following intentions: - α, to remove the excitement and irritation, and relax the exhaling and secreting surfaces and organs; β, to diminish the load which oppresses the vascular system, congests it, or overpowers the organic nervous influence that actuates it; γ, to reduce the excessive reaction, and thereby to guard important viscera, to prevent consequent exhaustion, and to favour the supervention of salutary evacuations; 8, to remove or divert the increased impulse or action from important organs. (Copland.*)
2999. In the Continued Fevers of Temperate Climates, the practice of blood-letting, once so much in vogue, has been almost entirely abandoned. Most modern physicians, observes Dr. Murchison. would regard such a practice, in the treatment of Typhus Fever, as almost fatal. Modern observation has shown that the effect of blood-letting, in Typhus, is to increase the mortality; while, even in the patients who recover after it, the nervous symptoms occur sooner, and with greater intensity, and are of longer duration; the eruption is darker and more copious, and convalescence is greatly retarded. In Typhoid (Enteric) Fever, the practice of blood-letting is still pursued, in some parts of the Continent; but it has never obtained favour in this country, nor is it a plan of treatment justified by the results obtained. Some, however, think much advantage is derived from leeches for the relief of the abdominal symptoms. Dr. Murchison* states that, in several cases, at an early stage, he has applied leeches both to the abdomen and round the anus, and that he has usually found them afford marked relief to the pain, and sometimes cause subsidence of diarrhoea. At the same time, he observes, he has often seen equal relief from the constant application of poultices and warm fomentations; so much so, that he is inclined to believe that the good effects of the leeches are, in a great measure, due to the fomentations which succeed them. In the Relapsing or Famine Fever at Edinburgh, in 1817-19, wonderfully good effects were said to have followed venAesection; but in the epidemic of 1843 it was tried in several instances, but was almost universally repudiated as worse than useless. (Murchison. ) In the Ardent Continued Fevers of Tropical Countries, occurring in strong, robust Europeans recently arrived from temperate climates, a full blood-letting at the outset is a measure generally fraught with great advantage. Blood-letting may be practised to the extent of allaying the vascular disturbance, relieving the pain in the head, and reducing the temperature of the body. These, observes Sir R. Martin, are the tests and proof that the operation has been successful. In natives of the Tropics, generally, venAe-section is wholly inadmissible.
* Dict. Pract. Med., vol. i. p. 924. On Fevers, &c., Ed. 1862, p. 255.
3000. In the Remittent Fevers of India and the Tropics generally, blood-letting is an expedient and useful measure, sometimes a very necessary one, in reducing the high vascular excitement of the early exacerbations in sthenic and lately arrived Europeans, as well as in lesser degrees of excitement, when in this state of constitution and stage of fever there co-exists considerable determination of blood to important vital organs. The extent to which blood-letting should be carried, in suitable cases, is a point on which the physician must exercise his discretion; keeping in view the ultimate advantage of effecting the indication aimed at, with as little loss of blood as practicable, and recollecting that the judicious removal of sources of irritation, the adoption of free ventilation, the well-timed use of emetics, cold affusion, tepid sponging, and antimonials, are all measures of considerable influence in lowering febrile excitement, which it is of essential consequence to employ with assiduity, in order to lessen the necessity of large evacuations. In the treatment of Remittent Fever in Europeans some time resident in India, and in all classes of the native community, general blood-letting is, with few exceptions, an unnecessary and often injurious proceeding. In all cases it is to be borne in mind - 1. That, in the great majority of instances, the danger in Remittent Fever consists in prostration of the vital actions of the heart and nervous system. 2. That not only exhaustion, but also the protraction, of the disease, is favoured by needless and undue evacuations. 3. That evacuant means used in the exacerbation have no power in shortening the duration of the attack. (Dr. Morehead. *) In Bilious Remittent and Yellow Fever, we must be guided by the same general principles as we have above cited from Dr. Morehead's valuable work.
* Op. cit., p. 567. Op. cit., p. 378.