Antiseptic powders or applications in dry form are useful for many purposes. At one time iodoform was very popular; it was supposed to act by virtue of the iodine set free in the presence of decomposing organic material. It is now seldom used, partly because of its tell-tale odor, and partly because of the disappointment which its use often brings. It is, moreover, an active toxic agent of itself, and has many times given rise to symptoms of intoxication, such as mental depression, delirium, nausea, and anorexia. Under all these circumstances free iodine can be detected in the urine.
There are numerous substitutes for iodoform, many of which are superior to it in antiseptic properties, while most of them are free from odor and toxic qualities. Two substances, however, are used extensively—naphthalene and bismuth subiodide or red iodide. The former has a marked odor and is more or less volatile, which makes it particularly valuable. The latter is odorless, non-toxic, and of much greater value as an antiseptic than most of the others, because it will give off free iodine under favorable circumstances. A good plan is to use it in the preparation of gauze and dressings, as well as for a dusting powder upon the skin.
The absolute value of these local applications is questionable, because a wound will sometimes heal under the protection of a piece of foil or gutta-percha tissue as well as when dressed in any other way. This is true only of wounds in part surgically clean.
Drainage.
—Drainage has been resorted to, more or less intermittently, since earliest historical times. It is provided for the removal of deleterious fluids or of superfluous exudates or transudates. It is a recognition sometimes of a necessity, at other times a confession of fear which may or may not be justified. It is bad practice to cover a focus of previous gangrene or suppuration in such a way that the infected cavity is closed to the escape of accumulating fluid. This may be prevented by the use of a suitable drain. At times a clean operation may be made, and yet in such loose tissue, or to such an extent, that it is preferable to provide for the escape of blood rather than let it occur and force apart surfaces which should be in close contact. A drainage tube may serve as a vent through which blood may escape that has oozed after closure of the wound. After pelvic operations provision should be made for the withdrawal of accumulating fluid which might serve as a culture medium for germs. Drainage is therefore necessary in many instances.
It will suffice sometimes to suture loosely a part or the whole of a wound, so that should tension occur from retention there may be spontaneous escape. This may be termed indirect drainage, and sometimes has to be made still more complete by leaving out some sutures, or by placing secondary sutures, which are only utilized some days later, when previously infected surfaces have become healthy and are granulating, so that they can be brought together.
By direct drainage secretions and fluids are guided toward the dressings, which should be absorbent or so arranged as to provide for their accommodation; thus in drainage of the gall-bladder or of the urinary bladder the tube may be connected with a suitable receptacle by siphonage. Capillary drains may be made of a few strands of silkworm-gut, which is non-absorbable, or of catgut, which is absorbable, and to which, perhaps, no further attention need be paid. This will answer for conducting away small amounts of fluid which exude. Gauze, or its equivalent in the shape of some form of wicking, affords an excellent material for removing fluid by osmosis. The thinner the fluid the more perfectly it serves this purpose. The gauze must be changed frequently, as these lesions may become filled with coagulated material, in which case it would act merely as a plug. The so-called cigarette drain consists of folds of gauze, or a small roll of it, surrounded by sterilized oiled silk or gutta-percha tissue, in which are cut numerous holes. The same purpose may be achieved, but often not so well, by a piece of rubber tubing split down one side. The gauze drains by osmosis, and the rubber prevents any adhesion to the wound margins and any pain in the removal of the drain; while a certain amount of fluid may escape around and outside the smoother surface.
When the fluids to be removed are more dense—e. g., pus—tubular drains should be provided. These vary in size from that of a lead-pencil to that of the finger. A tube which is too small becomes easily plugged. They are perforated with numerous openings for the ready entrance of fluid save in those cases, like the gall-bladder or the pelvis, where it is desirable to drain only the depths of a cavity. These tubes are usually made of rubber, the purer forms of gum being preferable. For some purposes, especially in the pelvis, tubes of glass or aluminum are used; these are non-collapsible. They may be emptied by a capillary drain, or by the frequent use of a small syringe with a long nozzle, by which they are pumped out at regular intervals. Metal and glass tubes can be resterilized and used again. All other drainage material should be burned as soon as removed. There are occasions when it is well to use a dressed drain—i. e., a tube surrounded by absorbent gauze, and this again by rubber tissue or oiled silk. In many instances it is well to prevent the loss of a drainage tube by passing through its outer end a safety pin, or by stitching it to the margin of the skin wound. Tubes have been lost, especially within the thoracic cavity after operating for empyema, more often than is perhaps generally known, and for a lack of precaution in this respect.
Tubes of decalcified chicken bone have been used and are occasionally serviceable. They are made by cleaning the cooked bones of the fowl, soaking them in 20 per cent. hydrochloric acid solution until decalcified, trimming the ends, cleaning the interior, and are then sterilized by boiling in a saturated solution of ammonium sulphate. They are then washed in sterile water and preserved in alcohol. They correspond to catgut, and will ordinarily last in the tissues for about eight days. They may be chromicized, as is catgut, in which case they endure considerably longer.