This measure may be also useful in the way of preventing or checking acute pulmonary oedema by lessening the blood-pressure. Should venesection be thought inadmissible, cups may be applied to the chest in front or behind, and at the same time the volume of the blood may be temporarily lessened by placing ligatures around the thighs, so as to check the flow of blood in the veins near the surface. Revulsion from the congested vessels of the lungs may also be effected by mustard foot-baths or the application of mustard poultices to the chest. Aconite may be serviceable by controlling over-action of the heart, and may be given in the dose of 1 or 2 drops of the tincture of the root at intervals of half an hour until some effect on the circulation is produced.
It is of importance to remove any blood or serum that may be present in the air-cells and smaller bronchi; and for this purpose one of the quickly-acting and non-depressing emetics may be given, such as apomorphia hypodermically or the sulphate of zinc or turpeth mineral by the mouth. Respect must be had to the condition of the patient's strength in ordering an emetic, since if there be much prostration, or if the interference with respiration has seriously depressed the heart, more harm than good might result from its use. Expectorants may somewhat later supplement the action of emetics, or serve to keep up the good effects gotten from them by helping to remove the residual fluids from the air-passages. Among the best of these are the syrup of senega and the carbonate or hydrochlorate of ammonium.
Passive congestion of the lungs, being dependent upon a weakened condition of the circulation, requires the use of means to sustain and reinforce the heart's action. The alcoholic and ammoniacal stimulants are here of great importance, and digitalis may be of sovereign efficacy, especially in cases where the congestion is associated with dilatation and attenuation of the heart. The power possessed by this drug of increasing arterial pressure, and thus producing diuretic action, may render it further serviceable when the congestion is accompanied with oedema, as in this way the serous infiltration may be absorbed and removed. From 10 to 20 drops of the tincture or from 2 to 4 drachms of the infusion of digitalis may be given every two hours until some effect on the pulse or the kidneys is noticed. If the stomach should not bear digitalis well in either of these forms, as is the case with some patients, the alkaloid digitalin in the dose of 1/60 grain may be given. The convallaria recently introduced as synergistic with digitalis may be substituted for it, and in the dose of from 20 minims to 1 drachm of the fluid extract it will be found not uncommonly to be an efficient heart-tonic. Like digitalis, too, it possesses diuretic power from the increased arterial pressure that it occasions.
Passive pulmonary congestion may assume a chronic form in connection with chronic cardiac and renal disease, and without presenting urgent symptoms may cause almost constant embarrassment of respiration in greater or less degree. Under such circumstances the preparations of iron are helpful by enriching the blood and increasing the tone of the heart. One of the best preparations is the mixture of acetate of iron and ammonium,2 known as Basham's mixture, which combines diuretic with chalybeate action. This may be given in the dose of from 1 to 4 drachms.
2 U. S. Pharm., 1882.
It is of great importance in all cases of passive congestion and of hypostatic pneumonia to change the patient's position from time to time, so as to counteract the influence of gravity and relieve dependent portions of the lungs.
Pulmonary oedema occurring in an acute form in the course of either congestive nephritis or chronic renal disease may seriously imperil life, and therefore it demands prompt and bold treatment. When it results from acute nephritis, it is more immediately dangerous than when dependent on chronic disease of the kidneys; yet in this acute form it may admit of perfect cure if proper remedial measures be at once instituted. Cups may be applied to the loins with the view of relieving the engorged kidneys and enabling them to resume their work of removing fluid from the body. In cases where the strength of the pulse is sufficient, it may even be good practice to abstract blood by the lancet to the amount of six to eight ounces. According to Oppolzer,3 this treatment may be proper even when somnolence indicates oedema of the brain, provided there be no irregularity of respiration or intermission in the pulse—signs which contraindicate bloodletting.
3 Ziemssen's Cyclop., v. p. 285.
Active diaphoretics are among the best medicinal agents to be employed, their good effects being due to their derivative action and to the large discharge of fluid from the skin which they occasion, thus promoting the removal of what is effused in the lungs. The fluid extract of jaborandi in the dose of from 20 minims to a drachm, or the hypodermic injection of 1/8 to 1/6 grain of nitrate or muriate of pilocarpine, frequently causes prompt and profuse perspiration. The writer is confident that he has seen life saved by the use of this drug when it has been in urgent peril from pulmonary oedema. In the absence of this agent, or along with it, the hot-air bath, which can almost always be extemporized in an efficient form, may serve to promote or increase fluid discharge from the skin. If the patient's strength is sufficient, one of the hydragogue cathartics may be given, and among them the most prompt and active is elaterium in the dose of 1/12 to 1/8 grain every four hours. The action of this drug must be carefully watched and its depressing tendency guarded against by the use of alcoholic stimulants.
When pulmonary oedema results from weakness of the heart, as in dilatation of that organ, or from chronic renal disease, all lowering measures must be avoided. Bloodletting, whether general or local, would still further depress the heart, and by increasing the hyperæmia of chronic Bright's disease would favor the further effusion of serum into the lungs. Dry cupping over the chest before and behind may be serviceable as a revulsive measure. Stimulants and tonics are called for, and digitalis or convallaria is directly indicated from the special power possessed by these agents of improving the cardiac tone and promoting the action of the kidneys by increasing blood-pressure. Digitalis has been thought objectionable when there is much irregularity of respiration, and perhaps it would be safest to postpone its administration until this symptom is relieved by the use of alcohol, ammonia, musk, or other prompt diffusible stimulants.