Pyæmia (from the Gr. pyon, 'pus,' and haima, 'blood'), or purulent infection of the blood, is a disease whose exciting cause is the introduction of decomposing pus or wound discharges, or the products of decomposition of animal fluids, into the circulation, through an ulcer or a wound, or an imperfectly closed vein (see PHLEBITIS and PUERPERAL FEVER). The term Septicæmia is applied by some to the same disease, by others only to very grave cases of pyæmia; while by many it is restricted to cases of blood-poisoning by putrid animal matters in general, such as those obtained from decomposing hides or dead bodies, or borne on foul air or septic gases. The two conditions have a general resemblance to each other. The poison is rapidly absorbed and diffused, and the blood undergoes certain changes, the nature of which chemistry has as yet failed to detect; it is certain, however, that the blood contains micro-organisms (micrococci and bacteria; see GERM). Within twenty-four hours, in very acute cases, there are severe shiverings, headache, and giddiness followed by heat, perspiration, and accelerated circulation. In twenty-four hours more the patient may be in a hopeless condition, delirious, and rapidly sinking. In less acute cases the symptoms closely resemble those of typhoid fever, and in this form the disease is a common cause of death after surgical operations; such cases are invariably characterised by the formation of secondary abscesses in the lungs, liver, kidneys, and other internal organs, in the various glands (the parotid gland in President Garfield's case), in the joints, and in the tissues immediately under the skin. The pus of such abscesses always contains bacteria. There is usually more or less delirium. The patient generally dies of exhaustion. Recovery is rare. It is chiefly, however, in the presence of predisposing causes, such as previous illness, prostration from organic disease or surgical complaints, or from difficult parturition, unhealthy occupations, &c., that the poison acts so severely; these, with the occurrence of putrefaction in a wound, may convert a comparatively slight local mischief into infection of the whole mass of the blood.
Bearing in mind the manner in which pyæmia originates, it is clear that this disease is one to be prevented rather than cured. Until comparatively recently, when it was acknowledged that pyæmia was the cause of death in 10 per cent. of all cases of amputation, and of 43 per cent. of all fatal primary amputations, the careful preparation of a patient before operation was, with justice, most strenuously insisted on. 'Patients must be strengthened,' said Mr Callender, 'by tonics, such as quinine and iron; and their secretions must be set right by appropriate alternatives; this treatment must be continued for a considerable period.' Diet should be attended to, and intemperate patients 'should be accustomed to a more healthy mode of life.' After operation, also, patients should be adequately supported with nutritious diet, and with stimulants and opium if necessary. No judicious surgeon will ever neglect such measures. But the really essential matter in the prevention of pyæmia is the prevention of putrefaction in the wound discharges. This was clearly proved by the results achieved by Sir Joseph (afterwards Lord) Lister and other surgeons at home and abroad, who have adopted the antiseptic method of treating wounds (see ANTISEPTIC SURGERY). For several years Lister's wards in Glasgow Royal Infirmary, formerly ravaged by pyæmia, remained free of the disease after the adoption of the antiseptic system; after two years' practice of this treatment purulent infection disappeared from the wards of the hospital. at Lyons, where it formerly had a permanent home; and similar testimony might be quoted from every quarter and to any extent. The use of antiseptics, adopted early and followed out intelligently, may be said to have abolished the risk of purulent infection in wounds from operation or injury.
Even when the disease has shown itself, the use of antiseptics (perchloride and other salts of mercury, carbolic acid, boracic acid, boroglyceride, iodoform, thymol, eucalyptol, &c.) should be resorted to locally. The bowels, skin, and kidneys may be acted on by suitable purgatives, diaphoretics, and diuretics, with a view to the elimination of the poison; but the patient must be carefully watched for signs of depression, which must be combated with opium and stimulants, both of which should be given in small and frequently repeated doses. Quinine in moderately large doses is very serviceable throughout the whole course of such a case; larger doses may occasionally be given to reduce excessively high temperatures, though antipyretics in general must be used with extreme caution. Various antiseptic drugs have been recommended for internal use, such as salicylic acid and the salicylates, the hyposulphite of sodium, and the hyposulphites generally. This treatment, combined with the most assiduous nursing and generous dieting, and the appropriate surgical management of such secondary abscesses as form, will sometimes prove successful.