First, if inflammatory signs are present we should endeavor to subdue these by local applications of an emollient character, for the reason that excessive inflammation is apt to produce such changes as cause the disaggregation of the clot, and hence its detachment. In either case, whether there be or be not any local inflammatory condition, we should insist upon absolute repose and quiet. We should not permit the limb to be moved: we should be extremely careful in all our manipulations of it, and only employ those which are absolutely essential. The patient should not be permitted to raise himself in bed, nor even eat or drink without assistance. These counsels are very important, since we know how frequently a very slight movement or exertion has been followed immediately by the transport of the clot, pulmonary embolism, and sudden death. In cases of fractures or severe wounds where such a peripheral clot is discovered the surgeon should be particularly careful in applying bandages and retentive apparatus. The risk of displacement of the clot is greater after several days from the time of the fracture or wound than it is at first, and it is at this period that the most careful attention should be exercised. Instances are on record in which so late as the fifty-seventh day after a fracture of the lower extremity a peripheral thrombus was transported from its original site and caused a fatal termination (Bouchard).
Some eminent writers have thought by employing a suitable medication we might hasten the solution of the peripheral thrombi and thus prevent their migration. With this view Legroux has given the acetate of lead internally and applied it in solution over the seat of the thrombus. Richardson has vaunted the use of the carbonate of ammonium in large and frequently-repeated doses as a solvent of the fibrin. By its means he believes he prevents the fibrin from precipitating from the blood, and further helps it to resorb when it has already become solid. Prevost, Dumas, and Schutzenberger recommend specially the bicarbonate of sodium, taken internally, with a view of rendering the blood more fluid and also hastening the retrogressive changes in the clot by its oxidizing power. According to Boyer, the very object which is thus sought if it were accomplished would result injuriously to the patient, since it would favor the detachment of the clot. Further, the continued use of large and frequent doses of ammonia or soda is prone to lower the general system very much, and in this manner to act to the prejudice of the patient. According to Azam, it would appear that what we most desire to effect is the organization and adhesion of the thrombus to the walls of the vessel. This can best be accomplished by fortifying the patient in every possible way and raising his nutrition to the highest attainable point. Iron, cinchona, the most nutritious food, should be freely given. Further, the greatest attention should be paid to the hygienic surroundings. The air should be purified, and if by chance the patient is suffering from a wound close attention should be given to the renewal of the dressings and the employment of a disinfectant locally applied. One of the reasons for this last counsel is because if the thrombus were detached it is important that it should be free of any septic taint and not lead to specific accidents (purulent pneumonia, gangrenous abscess). In the above enumeration we include the means usually to be employed as preventive measures against the migration of clots.
Is there any other method which can be adopted with any chance of success? Of the surgical attempts we should mention favorably in certain cases, and especially in those where the affected vein is superficial, the adoption of persistent compression between the clot and the heart. This means has been alluded to by J. Hunter65 as far back as 1773. Ligature and section of the vein have also been supported by some writers as suitable operations to bring into use with a like intent. Unfortunately, we are obliged to make a second traumatism in order to carry out this object, and, further, we make by the ligature at least a second coagulation, which may be the origin of the very accident we seek to avoid. Nevertheless, J. Teissier66 of Lyons reports a case observed by himself in the service of Noël Guéneau de Mussey, in which a ligature was instrumental in arresting the onward progress of the clot, which otherwise would have given rise to the accidents of pulmonary embolism.
65 Observations of the Inflammation of the Internal Coats of the Veins, quoted in thesis of Levrat, p. 108.
66 Nouveaux Éléments de Pathologie et de Clinique médicale, t. ii. p. 931, quoted by Balzer.
In the event of pulmonary embolism taking place in spite of all preventive means employed, what shall we do in order to combat this terrible accident? According to Ball,67 there are three indications to be observed: 1. To establish collateral circulation in the lungs; 2. To diminish local congestions; 3. To favor the resorption of the obstacle.
67 Thèse quoted, Paris, 1862.
The first indication cannot be effectually responded to, by reason of the fact that there is no way in which a collateral circulation can be promoted in the lung, owing to its anatomical structure.
The second indication is best observed by the application to the chest-walls of dry cups in large number, mustard poultices, turpentine, blisters. In this place we must consider the propriety of bleeding. As a result of the embolism there is arterial anæmia and venous plethora. This latter condition can be temporarily relieved by venesection. In this method, indeed, we have an immediate help for the distended and burdened heart, and we give time to the system to recuperate somewhat. We should, however, remember that bloodletting establishes a greater tendency in the system to the formation of emboli, and is therefore to be avoided. Moreover, sometimes it is decidedly objectionable on account of cardiac degeneration, anæmia, or great weakness.
When this method is contraindicated we should not hesitate to recur to the use of drastic purgatives (Jaccoud). Digitalis has been recommended, so as to regulate the cardiac action and to increase its power. Bertin has gone so far as to praise emetics and the use of the faradic current over the thoracic parietes. It seems as if these were dangerous methods to employ, since if a portion of the clot is still undetached the efforts caused by these agents would be apt to separate whatever portion remained in its original site. In order that a quantity of oxygen should be inhaled in a given time sufficient to supply the needs of the economy until a greater power of oxygenating the blood is established, the inhalation of compressed air has been vaunted. The objection to this means is merely the one which arises as we reflect how improbable it is that this agent would be at hand in a serviceable form when the sudden accidents of pulmonary embolism take place.