A practical guide to the administration of anaesthetics / by R.J. Probyn-Williams.

  • Probyn-Williams, R. J.
Date:
1901
Catalogue details

Licence: Public Domain Mark

Credit: A practical guide to the administration of anaesthetics / by R.J. Probyn-Williams. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    valves; a larger, the inspiratory valve (I.V.), allows the air or gas, as the case may be, to be inspired through the lower slot into the face-piece. When expiration takes place this shuts down, and drives the current of air or gas through the smaller valve, the expiratory (E.V.), and out through the upper slot. When both the slots are open, air enters through the lower, passes through the inspiratory valve, into the face-piece and the patient's mouth. Then expiration takes place, the inspira- tory valve closes down, and drives the breath through the expiratory valve, and out through the upper slot. When the upper slot remains open, and the lower is closed by means of the handle, communication is established between the gas-bag and the stopcock, and the air is cut off. On inspira- tion taking place, gas instead of air now passes through the inspiratory valve and the face-piece into the patient's mouth, and the breath mixed with gas passes during expiration as before through the expiratory valve, and out through the upper slot. When the tap at the upper part of the stopcock is turned, not only is the upper slot closed, but both the valves are thrown out of action. This is done by means of the rotation of the tube on which the valves are fixed, and to understand the mechanism thoroughly the apparatus should be carefully examined. With the upper slot closed and the lower open, air is breathed backwards and forwards without the interference of any valves. With both slots closed gas instead of air is breathed backwards and forwards without any action of the valves. If the india-rubber valves are not in fairly constant use they are liable to become dry, and their edges curl up; but if a small piece of aluminium is fixed to the india-rubber it makes the valve more rigid, and prevents the curling. The administration is commenced with both slots open, the patient breathing air in and out through the valves. When