[Illustration:  FIG. 12.—­Chart of case of Septicaemia followed by Pyaemia.]

#Septicaemia.#—­This form of blood-poisoning is the result of the action of pyogenic bacteria, which not only produce their toxins at the primary seat of infection, but themselves enter the blood-stream and are carried to other parts, where they settle and produce further effects.

Clinical Features.—­There may be an incubation period of some hours between the infection and the first manifestation of acute septicaemia.  In such conditions as acute osteomyelitis or acute peritonitis, we see the most typical clinical pictures of this condition.  The onset is marked by a chill, or a rigor, which may be repeated, while the temperature rises to 103 or 104 F., although in very severe cases the temperature may remain subnormal throughout, the virulence of the toxins preventing reaction.  It is in the general appearance of the patient and in the condition of the pulse that we have our best guides as to the severity of the condition.  If the pulse remains firm, full, and regular, and does not exceed 110 or even 120, while the temperature is moderately raised, the outlook is hopeful; but when the pulse becomes small and compressible, and reaches 130 or more, especially if at the same time the temperature is low, a grave prognosis is indicated.  The tongue is often dry and coated with a black crust down the centre, while the sides are red.  It is a good omen when the tongue becomes moist again.  Thirst is most distressing, especially in septicaemia of intestinal origin.  Persistent vomiting of dark-brown material is often present, and diarrhoea with blood-stained stools is not uncommon.  The urine is small in amount, and contains a large proportion of urates.  As the poisons accumulate, the respiration becomes shallow and laboured, the face of a dull ashy grey, the nose pinched, and the skin cold and clammy.  Capillary haemorrhages sometimes take place in the skin or mucous membranes; and in a certain proportion of cases cutaneous eruptions simulating those of scarlet fever or measles appear, and are apt to lead to errors in diagnosis.  In other cases there is slight jaundice.  The mental state is often one of complete apathy, the patient failing to realise the gravity of his condition; sometimes there is delirium.

The prognosis is always grave, and depends on the possibility of completely eradicating the focus of infection, and on the reserve force the patient has to carry him over the period during which he is eliminating the poison already circulating in his blood.

The treatment is carried out on the same lines as in sapraemia, but it is less likely to be successful owing to the organisms having entered the circulation.  When possible, the primary focus of infection should be dealt with.