A system of practical medicine. By American authors. Vol. 3

by Unknown

2d. He thinks that in acute cases, after the subsidence of the fever, if the pleura is one-third full of fibro-serous fluid, Nature will probably do her work of removal promptly. If she shows no sign of doing so, we should come to her assistance in about ten days or two weeks, and draw off a portion of the fluid—enough to relieve pressure and to encourage the absorption of what is left in the sac.

3d. In the subacute or chronic fibro-serous effusions it is not well to wait over three weeks before operating. As he shall show in the study of the dangers and objections, he considers the operation a perfectly safe one if the simple rules now generally observed by operators are faithfully carried out.

In studying the advisability of operating where there are not urgent indications we must ever bear in mind that while it takes a large quantity of fluid to compress the lung, the retracted lung may, by neo-membranes, be kept to its diminished volume. As long as the lung is able to lift up the fluid and the diaphragm it is in no danger of atelectasis. It is in a state of physiological rest. In a subject of bad constitution interstitial changes may indicate an earlier operation, but, if an effusion exists on the side on which there is already lung disease of a phthisical nature, we should be loath to interfere; for "experience has shown that an effusion checks, and sometimes arrests, the tubercular process" (Powell).

Contraindications.—These are principally in connection with the general condition of the patient. If it is such that there is no hope of his rallying, if he is very old, or if he has intervening croupal pneumonia, the operation is not justifiable. If the quantity of fluid is not large and does not interfere with organic functions, we can wait for some time.

Mode of Operating.—The old trocar method of operation is now abandoned. It was not always an easy one, was painful, and there was more or less danger of cutting the intercostal artery, of introducing air, and of establishing, by the size of the puncture, a fistulous orifice. If, perchance, the lung was perforated by the trocar, pneumothorax was established. In some cases of sacculated and limited effusions, and in chronic cases where the membranes were thick, it was not effectual, and if the fluid was not reached, the operator hesitated to introduce the trocar elsewhere. When the fluid flowed through the trocar, it came frequently in jets with painful coughs. The above operation was quite a formidable one. Now thoracentesis is always performed with very fine perforated needles attached to aspirators of some modern pattern, and guarded by Fitch's dome-trocar or Castiaux's protected point. We employ Dieulafoy's Potain's bottle-aspirator, Castiaux's of Paris, or Raumussen's of Copenhagen. Flint recommends the use of Davison's syringe. We fear it would be found too rough an instrument for so delicate an operation. The points of attachment of the bulb with the tubing are not sufficiently air-tight. The valves are very imperfect, and easily get out of order. In our efforts to pump out the fluid we might throw air in, and with it particles of organic matter.

The operator has his choice among no less than thirty-odd instruments similar to Dieulafoy's. They all work upon the same principle—the close operation, the withdrawal of the fluid by aspiration. The needle or trocar must be capillary: the smallest that is effective is the best—say a half millimeter in diameter—in order to make the orifice as minute as possible.

If we prefer the syphon, we must use a larger canula than we employ for aspiration—one of four millimeters in diameter. It should have two outlets—one straight, for the trocar, and one at an angle, for the attachment of the tubing. It should also be guarded by an air-tight collar. Into the syphon tubing a T-tube may be inserted for the purpose of attaching a side tube to be connected with a mercurial manometer, by means of which the exact intra-thoracic pressure may be observed during the operation. The syphon tube should be long enough to provide a fall of one, two, or three feet, as may be necessary. A fall of twelve to eighteen inches is usually enough, as we wish to remove the fluid slowly. We can easily increase the force by lengthening the tube. If the canula should become obstructed, lowering the basin suddenly will probably remove the piece of lymph. The trocar can be pushed again through the canula if necessary. In case the aspirator should be needed, the end should have a metallic joint affixed to it. In all the instruments used, absolute cleanliness should be observed. The tubing previous to operation should be filled with a solution of carbolic acid (1:40).

In cases of rapid effusion, especially during the febrile stage and when the intra-thoracic pressure of fluid is great, some prefer using the feeblest form of aspiration. Southey's capillary trocar, with drainage-tubes attached, is used as a syphon for this purpose. The fluid is drained off through a narrow india-rubber tubing which is placed under water to prevent air being drawn into it. Ordinarily, the use of the fine aspirating-needle without much force, and slowly drawing off the fluid, answers the same purpose. The fear some have expressed, of the danger of injuring the lung by the force of the rarefied space, is more theoretical than real. Even with a canula of the size that Southey employs there is some danger of leaving a fistulous orifice, for it has to be kept in for hours. If the smallest tube is used, from which the fluid simply comes in drops, the operation consumes five or even ten hours. Southey speaks of cases where the flow was kept up for twenty-four hours. Unless aspiration is resorted to, flocculi may easily stop up the canula, and then we are compelled to reintroduce the trocar, and afterward to reattach the tubing. Oxley, who thinks that the best results are obtained by the use of these tubes, acknowledges that so much time was consumed that he inserts four canulas, drawing off 44 fluidounces of fluid in one hour and ten minutes, thus defeating the object of using this method, which was to draw off the fluid very slowly, so as to enable the lung to expand gradually and healthfully.

There are cases where, to withdraw the fluid, more suction force than is usually employed with the syphon has to be used in order to antagonize the negative force exercised by the traction of the lung and the passive tension of the diaphragm. The author recently had a case where, notwithstanding the presence within the right pleural sac of a quantity of fluid large enough to obliterate the Skodaic resonance under the clavicle, not a drop could be drawn out by a syphon attached to a canula of 2 mm. in diameter. Having no additional tubing to increase the force of the syphon at hand, he used Dieulafoy's rack aspirator, ½ mm. in diameter, and drew off a quart of fluid—enough to relieve the symptoms of oppression. Stone reports a case of the kind where, although there were two quarts of fluid in the pleural sac, no fluid could be drawn out with a syphon exerting a force of 1½ pounds to the square inch, or one-tenth of an atmosphere. In the same case there was actually, in inspiration, a negative pressure exercised by the lung of two inches of water. Stone mentions another case where a boy fifteen years of age died from the quantity of fluid, which would not flow out when tapped. If he had had an instrument by which he could have used aspiration he would have saved the life.

The value of this syphon method has within a few years grown much in favor. It is simple and inexpensive. It allows the fluid to be drawn out with a uniform and feeble aspiratory force. The flow is very slow, which gives the lung time to expand gently, and the displaced organs to return gradually to their normal position. With the manometer attached we can judge accurately as to the intra-thoracic pressure. The size of the canula has to be larger than when we employ the aspirator—4 mm.—whereas with the latter we use ½ mm. or 1 mm. in diameter. If by any accident the lung should be perforated, the larger orifice would not be as harmless and insignificant as the smaller one. It must be borne in mind, especially in cases of long standing, that the neo-membranes are very vascular, and that with a 4 mm. perforator we may rupture the blood-vessels and complicate matters by the escape of blood into the pleural cavity. It is claimed that when the canula and syphon tubes have been introduced the patient can be left in charge of the nurse. This, the author thinks, should never be done, for nurses are rarely competent to judge whether a sufficient amount has been withdrawn, nor are they fit to assume the responsibility of acting in cases where promptness of treatment may be of the utmost importance. The operator or a competent substitute must remain until the operation is over. The withdrawal of fluid must, moreover, be slow, for slowness contributes in a great degree to lessen the dangers. Fraentzel recommends testing the force of the aspirator in the palm of the hand. Garland⁸⁰ employs needles which are 1–2 mm. in diameter and remove only 50 to 100 grammes per minute. The thoracic pressure must be relieved by the withdrawal of only enough fluid to effect that purpose. It has been objected that the negative force of the aspirator is uncertain. It is a well-founded objection, yet we can employ with it a feeble force by exhausting only a portion of the air from the cylinder or bottle, and thus remove the fluid cautiously and very deliberately. It is admitted that if there is no intra-thoracic pressure the fluid will not flow out unless we introduce air or negative force. We claim that the syphon and the aspirator with capillary needles, employed with the precautions dictated by modern experience, are both safe and effective. Ordinarily, we prefer the bottle aspirator of Potain, or Dieulafoy's instrument with the manometer attachment.