To save the perineum and better to control the patient, when the head is about to pass the vulva, it is wiser to abandon the gas for chloroform or ether.
Obstetrical operations, such as forceps and version, require ether or chloroform, and not gas. The dangers vary with the anæsthetic chosen, as well as the amount and the method of administration. Ether affects the respiration, chloroform attacks the heart. Ether must not be given near an open flame. Chloroform is not explosive but is decomposed by fire into an irritating gas. Chloroform must be diluted with 90 per cent of air, hence the mask must be open, or the napkin held free from the face, so that plenty of air can enter. Ether and chloroform, when given “a la reine;” i. e., a few drops on the mask at the beginning of each pain and increased up to the acme, is relatively free from danger. They have the additional advantage that the sleep may be instantly deepened if operation is required. Chloroform, it is now believed, predisposes mildly to post partum hæmorrhage. Davis has shown that neither ether, gas, nor chloroform affects the child injuriously if the administration is intermittent and not too greatly prolonged.
To summarize: Morphine and scopolamine combined is a first stage analgesic, which has too much value to be neglected.
Gas, if an apparatus is to be had, may work well for the greater part of the second stage, while for operations, or for the period of expulsion, during which the head passes the perineum, chloroform and ether give bests results. Moreover, chloroform “a la reine” may be given safely and efficiently by a competent nurse and in many instances must be given by the nurse, if at all.
When the perineum bulges, or the head becomes visible at the vulva, the nurse should anoint the lips, cheeks and tip of the nose with cold cream or olive oil, to avoid burning the skin, and lay two or three thicknesses of handkerchief or gauze over the nose (an inhaler is best). An abundance of room must be left underneath and at the sides of the mask for air to enter.
At the beginning of the pain a few drops of chloroform are poured on the cloth and the patient instructed to breathe vigorously. The cloth is removed as soon as the pain ceases and when the next contraction comes on, the process is repeated. As the head passes the perineum, the chloroform should be pushed to complete anæsthesia, both to save suffering and to give the doctor full control of the perineum. When the nurse gives the anæsthetic, she should watch the doctor for his signal to increase the vapor or remove the mask.
Summary.—Cover the eyes with a wet towel and anoint the face with cream or oil before using chloroform. Remove false teeth, if present.
Obstetric degree—a few drops on mask at beginning of each pain.
Surgical degree—complete anæsthesia.
Watch pulse and respiration.