EMBOLISM.
An embolus is generally produced by a thrombosis in a bloodvessel or in one of the cavities of the heart. If the thrombotic process is evident or suspected prevention of embolism will lie in absolute rest. 'Thus in the inflammation of the veins which is so common in the lower extremity the utmost precaution must be maintained to secure immobility of the limb until the thrombus has become organised or absorbed. Friction and massage are answerable for many deaths by detaching large emboli from the interior of inflamed varicose veins. Once these have reached the right side of the heart,little can bedone to relieve the sudden asphyxia, as death may be almost instantaneous when the plug is large. If the patient survive the initial shuck, the hypodermic injection of Strychnia to keep up the ventricular contractions, and of Ammonia by the veins with the faint hope of aiding the absorption or solution of the embolus, may he resorted to; and Oxygen when available may be useful, especially in the later stages of pulmonary infarction. The ideal treat ment of embolism of venous or arterial origin would he the free administration of Citrates to cause solution of the clot, but the mechanical effects of the plugging are usually too urgent to permit time for this, though in hepatic. splenic, or renal infarction or in cerebral syphilis such treatment may be practicable.
Embolism of the superior mesenteric artery or vein, like thrombosis in the same vessel, may be treated by abdominal section and resection of the bowel.
Emboli originating in the walls of arteries or in the left side of the heart may suddenly cut off the arterial blood supply from the brain or limbs. The treatment of Cerebral embolism is discussed in the article on Apoplexy. When the main artery of a limb is occluded gangrene is liable to follow, but by absolute rest and warmth to the part it is sometimes possible to avoid this when the collateral circulation is free, though the artery he completely blocked, the blood finding its way into the main trunk beyond the obstruction through anastomosing branches.
If the embolus is septic, as in ulcerative endocarditis, the condition recognised as arterial pytemia supervenes, and the after-consequences of tlse breaking up into abscesses of the infected plug must be met by the usually accepted which should govern the treatment of septic infections, though such cases arc almost necessarily fatal, notwithstanding vaccine treatment and the free administration of Sulphocarbolates.
Air Embolism occurs sometimes in surgical operations involving large veins about the base of the neck or axilla, and should always be prevented by clamping the vein on the proximal side before cutting it. Once air has been drawn in by the open mouth of a divided vein or through a button hole incision in its coats the only resource open to the surgeon is to block the opening instantly with his finger and to syncope by lowering the head and injecting Strychnine or Ether hypodermically, and if the symptoms continue to inject serum.
Fat Embolism sometimes follows fru( tures and operations involving the marrow of long bones. It may not give rise to any symptoms, or the asphyxia may be so great as to demand prompt treatment. The heart must be assisted by the hypodermic administration of Strychnine or by stimulants given by the bowel, the aim being to keep the patient alive till the fatty material has been eliminated by the kidney or expelled along with bronchial mucus in the frothy or blood-stained expectoration. Oxygen is safer than artificial respiration, and the intravenous injection of serum may he requisite.