1st. Method of carrying out the Dressing. - As soon as the tubes are in position, gauze compresses soaked in Dakin's solution are applied. These compresses help to fix the tubes on the surface of the wound. The tubes have been selected long enough to allow several centimetres of their non-perforated portion to be outside the dressing (Fig. 58). Also the perforated part must be buried wholly in the wound, because otherwise the free openings would allow fluid to escape unused, possibly doing harm.

Fig. 58.   Dressing: a, Conducting tube kept in the wound by gauze placed in the orifice; b, Squares of gauze sterilised in vaselin placed on the skin around the wound.

Fig. 58. - Dressing: a, Conducting tube kept in the wound by gauze placed in the orifice; b, Squares of gauze sterilised in vaselin placed on the skin around the wound.

After the application of the compresses to the wound, the adjoining skin is protected by squares of gauze, sterilised in vaselin (Fig. 58). Pieces 8 or 10 cm. square are placed in yellow vaselin and sterilised. At the moment of dressing, they are taken up with dressing forceps and applied to the surface of the skin, to which they immediately adhere. They form an excellent protection for the skin, which, on the posterior aspect of the trunk or limbs, has a tendency to become irritated by the hypochlorite.

Fig. 59.   Sheets of dressings, composed of layers of absorbent cotton wool, non absorbent cotton wool, and gauze.

Fig. 59. - Sheets of dressings, composed of layers of absorbent cotton-wool, non-absorbent cotton-wool, and gauze.

The dressing is completed by a sheet of cotton-wool protected on either surface by one thickness of gauze. This dressing is prepared beforehand in three different sizes (Fig. 59). It is composed of four strata; a layer of gauze, a sheet of absorbent cotton-wool, a sheet of non-absorbent cotton-wool {coton carde), and a final cover of gauze (Fig. 60). The side which has the absorbent cotton-wool is applied next the wound.

Secretions are thus absorbed, without being able to escape readily to the exterior, by reason of the presence of the non-absorbent cotton-wool. At the same time, evaporation goes on quite easily through this almost waterproof layer. Waterproot fabrics should never be used.

Fig. 60.   Section of the sheet of dressing: A, Gauze. B, Carded (non absorbent) cotton wool. C, Absorbent cotton wool. D, Gauze.

Fig. 60. - Section of the sheet of dressing: A, Gauze. B, Carded (non-absorbent) cotton-wool. C, Absorbent cotton-wool. D, Gauze.

The application of the dressing is speedy. The middle part of the dressing is placed under the limb and the two sides are fastened on the anterior surface of the limb by two or three safety-pins. The use of a bandage is thus avoided. Besides, the dressing is easily undone, and the wound can be examined and the position of the tubes ascertained without disturbing and distressing the patient. When the dressing is first applied, two scissor-cuts are made in the layer of cotton-wool to allow the rubber tubes to emerge readily from the dressing (Figs. 62 and 63).

Fig. 61.   Dressing applied around a compound fracture of the leg, and fastened by safety pins; the distributing tube is fixed to the plaster apparatus by safety pins.

Fig. 61. - Dressing applied around a compound fracture of the leg, and fastened by safety-pins; the distributing tube is fixed to the plaster apparatus by safety-pins.

2nd. Fixation of Tubes and Cannulae. - When the dressing is finished, the ends of the supply-tubes emerge at different points from the layer of cotton-wool and gauze. These tubes are connected up in groups of two or four by means of the branched unions or cannulae which have been described (Figs. 62 and 38). In the case of a compound fracture of the thigh, the eight tubes are divided into two groups and united by two cannulae of four branches each (Fig. 63). In the case of a very extensive wound where certain of the small conducting tubes are too short to be connected up with the branches of the cannula, they are lengthened by pieces of rubber tube and "unions" or connecting tubes of glass (Fig. 39). This work can be done after the dressing, when the irrigating apparatus is installed.

Fig. 62.   Position of the distributing tube on the surface of the dressing. The conducting tubes penetrate the dressing, either at the point where the end of the layer of cotton wool and gauze overlaps, or through windows cut with scissors.

Fig. 62. - Position of the distributing tube on the surface of the dressing. The conducting tubes penetrate the dressing, either at the point where the end of the layer of cotton-wool and gauze overlaps, or through windows cut with scissors.

After the tubes have been joined up to the cannula, this latter is fixed to the highest part of the dressing. For example, in a compound fracture of the thigh, the cannula is fixed above the middle of the anterior aspect of the limb. This fixing is simply done by nipping the largest part of the glass cannula in a big safety-pin, itself attached to the dressing. Then the larger end of the cannula is united to the irrigating tube which is attached to the flask or other reservoir of liquid. The correct fixing of the cannula to the surface of the dressing is important. Thanks to it, the small conducting tubes lie in the wound, in the positions in which they have been placed, without either the weight of the irrigating tube or the movements of the patient being able to shift them.

Fig. 63.   Arrangement on the surface of a dressing of a Y connecting tube, and of two distributing tubes with four branches.

Fig. 63. - Arrangement on the surface of a dressing of a Y-connecting tube, and of two distributing tubes with four branches.

Fig. 64.   Method of fixing a distributing tube to the surface of a dressing.

Fig. 64. - Method of fixing a distributing tube to the surface of a dressing.

3rd. Immobilisation of the Limb. - Naturally the limb should be prevented as much as possible from moving. Either plaster apparatus, suspension, or continuous traction will be used. In every case where it is indicated, the patient is placed on a Bradford's frame. When the time for dressing comes, the frame is raised, and one or two bands are removed, so that the posterior portion of the limb or trunk can be examined or dressed without moving the patient.

The dressing is renewed every twenty-four hours. If, however, before the expiration of this period, the cottonwool has become very wet, the outer layer of the dressing may be changed without disturbing the tubes or the layer of gauze which covers the wound. The changing of the dressing consists in removing the gauze compresses which are on the surface of the wound, and at the entrance to it. The position of the tubes is carefully checked, and modified if there should be need. No washing is done, simply fresh gauze and an external dressing applied. The manipulations are thus extremely simple, and, in a short time, the surgeon can personally dress a large number of cases.

The mattress is protected by a waterproof sheet. The quantity of liquid used should be always so small that the bed is not flooded.