Disinfection of the Hands.—It is now generally recognised that one of the most likely sources of wound infection is the hands of the surgeon and his assistants. It is only by carefully studying to avoid all contact with infective matter that the hands can be kept surgically pure, and that this source of wound infection can be reduced to a minimum. The risk of infection from this source has further been greatly reduced by the systematic use of rubber gloves by house-surgeons, dressers, and nurses. The habitual use of gloves has also been adopted by the great majority of surgeons; the minority, who find they are handicapped by wearing gloves as a routine measure, are obliged to do so when operating in infective cases or dressing infected wounds, and in making rectal and vaginal examinations.
The gloves may be sterilised by steam, and are then put on dry, or by boiling, in which case they are put on wet. The gauntlet of the glove should overlap and confine the end of the sleeve of the sterilised overall, and the gloved hands are rinsed in lotion before and at frequent intervals during the operation. The hands are sterilised before putting on the gloves, preferably by a method which dehydrates the skin. Cotton gloves may be worn by the surgeon when tying ligatures, or between operations, and by the anæsthetist during operations on the head, neck, and chest.
The first step in the disinfection of the hands is the mechanical removal of gross surface dirt and loose epithelium by soap, a stream of running water as hot as can be borne, and a loofah or nail-brush, that has been previously sterilised by heat. The nails should be cut down till there is no sulcus between the nail edge and the pulp of the finger in which organisms may lodge. They are next washed for three minutes in methylated spirit to dehydrate the skin, and then for two or three minutes in 70 per cent. sublimate or biniodide alcohol (1 in 1000). Finally, the hands are rubbed with dry sterilised gauze.
Preparation of the Skin of the Patient.—In the purification of the skin of the patient before operation, reliance is to be placed chiefly in the mechanical removal of dirt and grease by the same means as are taken for the cleansing of the surgeon's hands. Hair-covered parts should be shaved. The skin is then dehydrated by washing with methylated spirit, followed by 70 per cent. sublimate or biniodide alcohol (1 in 1000). This is done some hours before the operation, and the part is then covered with pads of dry sterilised gauze or a sterilised towel. Immediately before the operation the skin is again purified in the same way.
The iodine method of disinfecting the skin introduced by Grossich is simple, and equally efficient. The day before operation the skin, after being washed with soap and water, is shaved, dehydrated by means of methylated spirit, and then painted with a 5 per cent. solution of iodine in rectified spirit. The painting with iodine is repeated just before the operation commences, and again after it is completed. The final application is omitted in the case of children. In emergency operations the skin is shaved dry and dehydrated with spirit, after which the iodine is applied as described above. The staining of the skin is an advantage, as it enables the operator to recognise the area that has been prepared.
If any acne pustules or infected sinuses are present, they should be destroyed or purified by means of the thermo-cautery or pure carbolic acid, after the patient is anæsthetised.
Appliances used at Operation.—Instruments that are not damaged by heat must be boiled in a fish-kettle or other suitable steriliser for fifteen minutes in a 1 per cent. solution of cresol or washing soda. Just before the operation begins they are removed in the tray of the steriliser and placed on a sterilised towel within reach of the surgeon or his assistant. Knives and instruments that are liable to be damaged by heat should be purified by being soaked in pure cresol for a few minutes, or in 1 in 20 carbolic for at least an hour.
Pads of Gauze sterilised by compressed circulating steam have almost entirely superseded marine sponges for operative purposes. To avoid the risk of leaving swabs in the peritoneal cavity, large square pads of gauze, to one corner of which a piece of strong tape about a foot long is securely stitched, should be employed. They should be removed from the caskets in which they are sterilised by means of sterilised forceps, and handed direct to the surgeon. The assistant who attends to the swabs should wear sterilised gloves.
Ligatures and Sutures.—To avoid the risk of implanting infective matter in a wound by means of the materials used for ligatures and sutures, great care must be taken in their preparation.
Catgut.—The following methods of preparing catgut have proved satisfactory: (1) The gut is soaked in juniper oil for at least a month; the juniper oil is then removed by ether and alcohol, and the gut preserved in 1 in 1000 solution of corrosive sublimate in alcohol (Kocher). (2) The gut is placed in a brass receiver and boiled for three-quarters of an hour in a solution consisting of 85 per cent. absolute alcohol, 10 per cent. water, and 5 per cent. carbolic acid, and is then stored in 90 per cent. alcohol. (3) Cladius recommends that the catgut, just as it is bought from the dealers, be loosely rolled on a spool, and then immersed in a solution of—iodine, 1 part; iodide of potassium, 1 part; distilled water, 100 parts. At the end of eight days it is ready for use. Moschcowitz has found that the tensile strength of catgut so prepared is increased if it is kept dry in a sterile vessel, instead of being left indefinitely in the iodine solution. If Salkindsohn's formula is used—tincture of iodine, 1 part; proof spirit, 15 parts—the gut can be kept permanently in the solution without becoming brittle. To avoid contamination from the hands, catgut should be removed from the bottle with aseptic forceps and passed direct to the surgeon. Any portion unused should be thrown away.