The irrigating apparatus is composed essentially of a reservoir (ampoule or flask) fixed at a certain height above the patient's bed, with a tube (equipped or not with a drop-counting contrivance) and stop-cock, so as to allow of either continuous or intermittent instillation.

1st. The reservoir for liquid usually employed is a flask holding a litre (176 pint, 0.22 gallon). Its interior orifice has a diameter of 7 mm. (Fig. 40). To this is attached an irrigating tube of red rubber with a calibre of 7 mm. The flask is fastened to a wooden standard firmly fixed to some convenient portion of the bedstead, a portion which depends upon the situation of the wound. It is suspended at a height of from 50 cm. to 1 metre above the level of the bed.

2nd. The irrigating tube, as we have just said, has an interior diameter of 7 mm. Its length is from 1 metre 50 cm. to 2 metres. Whilst the superior extremity is attached to the flask, its lower end is united with a glass cannula, to which are fixed the smaller tubes which convey the liquid to the wound. At 10 centimetres below the flask the tube is furnished with a pinch-cock (Fig. 41). Slight pressure upon the spring suffices to open the lumen of the tube and to allow the liquid to flow. This apparatus is extremely simple, and well suited to the intermittent irrigation of wounds (Fig. 42). Every two hours a nurse stops at the foot of the bed and releases the spring of the Mohr pinch-cock for a few seconds. Instillation at once takes place.

Fig. 40.   Ampoule or flask holding a litre.

Fig. 40. - Ampoule or flask holding a litre.

Fig. 41.   Pinch cock (Pince de Mohr a ressort).

Fig. 41. - Pinch-cock (Pince de Mohr a ressort).

In the hospitals at the front, where it is difficult to provide the needful number of apparatus, the plan devised by le medecin-major Perret may be used. This consists of a support on wheels (dressing wagon) carrying the reservoir of Dakin's solution at the required height. The orderly propels the wagon from bed to bed and injects the liquid into the wounds by means of a cannula, which is changed for each patient. This proceeding simplifies the provision of apparatus, but greatly adds to the work of the staff.

Fig. 42.   Nurse using a pinch cock and so instilling antiseptic liquid.

Fig. 42. - Nurse using a pinch-cock and so instilling antiseptic liquid.

The liquid may be instilled also by means of a syringe. The most convenient syringe for this purpose has been made by Gentile. It consists simply of a glass tube drawn out to a fine jet at one end, and of a capacity of 10 c.c. (Fig. 43). The piston is replaced by a bulb of red rubber. The advantage of this syringe is that it can be used with one hand. Each case has its own syringe. It is kept half-immersed in the bottle which holds the supply of Dakin's solution belonging to the case. The use of a syringe for the instillation of liquid has also the drawback of increasing the work of the personnel. Besides, instillation done with a syringe gives results far less speedy than with the irrigating reservoir, because the quantity of liquid is much less considerable; and, the tube constituting a siphon, the moment the syringe is withdrawn the liquid immediately runs out of the wound instead of remaining there.

FiG. 43.   Syringe {Seringue de Gentile).

FiG. 43. - Syringe {Seringue de Gentile).

We have completely given up the use of the syringe for instillations. We use Gentile's syringe to test the permeability of the tubes in the course of doing the dressings.

When it is desired to practise continuous instillation instead of intermittent, the apparatus is modified after the following manner. To the lower aperture of the flask is attached a rubber tube 10 cm. long. At the extremity of this tube is attached one of Gentile's "drop-counters" (une ampoule compte-gouttes de Gentile). Between the drop-counter and the reservoir is a screw pinch-cock {une pince de Mohr a vis) which enables us to regulate the number of drops per minute which the apparatus should deliver. The lower end of the drop-counter is connected to the irrigating tube (Fig. 44). As the quantity of liquid which traverses a section of tube in a unit of time is very small, it is useless to employ an irrigating tube of diameter as great as that in use for intermittent instillation. A calibre of 5 to 6 mm. is sufficient.

Fig. 44.   Drop counter, Gentile's. Screw pinch cock {Pince de Mohr a vis).

Fig. 44. - "Drop-counter," Gentile's. Screw pinch-cock {Pince de Mohr a vis).