The third stage is that of stupor, i. e., unconsciousness from which one can be aroused only with difficulty. The pupils are contracted as in sleep, the heart is strong and regular and slower than before (though not slower than normal), the breathing is deep and regular, the color of the skin is good.

The intoxication stage is over, but there is not complete anesthesia, for if the knife is used in this stage, the patient will wince, or may be aroused by the pain and try to get up. The muscular relaxation is also incomplete. The pupil dilates with pain and contracts readily to light. The patient may be kept in this stage for any length of time, or may quickly be brought into -

The fourth stage, which is characterized by great muscular relaxation and complete unconsciousness, from which the patient cannot be aroused, i. e., coma.

Most of the voluntary muscles are relaxed. An arm or a leg raised in the air falls limp, and the face is expressionless from relaxation of the face muscles. The sphincter ani is one of the last of the voluntary muscles to be paralyzed. The respiratory muscles, of course, are not paralyzed. Smooth muscle loses its tone less readily than voluntary muscle, and intestinal peristalsis is sometimes observed on opening the abdomen. The skin is usually flushed and hot, and is covered with sweat (hence the need of protecting the patient from catching cold). In the mouth and throat saliva and mucus are abundant. The pupils are in mid-dilatation and react so sluggishly to light that their contraction may be difficult to detect. The eye reflexes disappear, the absence of the corneal or conjunctival reflex being one of the indications that the patient is well anesthetized. The heart is regular and of fair force. Its rate is moderately increased. Arterial pressure is good, but in prolonged anesthesia alowly falls. The respiration is regular and may be stertorous or snoring, or may be impeded by the tongue or the collection of saliva and mucus, large amounts of which are secreted in the throat and bronchi (the throat must be kept clean, the jaw and tongue kept forward). The temperature falls, so that the patient must be kept well covered. All sensation and nearly all the reflexes are abolished. This is complete surgical anesthesia, a state in which the patient may be kept for a considerable length of time. The anesthetist recognizes this stage when the corneal reflex is absent, and the raised arm falls limp, i. e., is completely relaxed.

If the patient passes beyond this stage, he goes into collapse, with depression of the vasoconstrictor and respiratory centers and of the heart muscle; the pupils usually become dilated and do not react to light.

The common danger-signs in ether anesthesia are:

1. Increasing weakness or increasing rapidity or irregularity of the pulse. It should be remembered that the heart may be quite weak before its rate increases.

2. Slow, shallow respiration, with cyanosis.

3. Pupil dilated and without reaction to light.

Recovery

In recovery from the anesthesia the third and second stages may be passed through slowly, and there is a tendency for the patient to remain asleep until awakened by nausea or vomiting or some other disturbing factor. But there may be a period of struggling and incoherent speech, followed by a deep, quiet sleep; or a period of prolonged quiet with regular breathing as if the patient is deep in anesthesia, and then suddenly a cry, or vomiting, or an attempt to get up. A careless or inexperienced anesthetist may allow such a partial recovery before the end of the operation, or even before the surgeon begins work, this state of "false anesthesia" being recognized only when the patient moves or gives signs that he is going to vomit. It is a standing rule that if the pupil reacts readily to light, more of the anesthetic is required.

Vomiting is expected when, the pulse remaining good, there are a long pause in the breathing and a paling of the face. The vomitus consists of swallowed mucus and saliva, and any other material that may be in the stomach, such as food. As muscular relaxation prevents its full expulsion, the head should be turned to one side, to allow the vomitus to run out of the mouth; otherwise the vomitus may be drawn into the lungs.

After-Effects

1. Usual - (a) Vomiting is a regular sequel of ether anesthesia; and nausea may persist for two or three days, with disgust for food, headache, lassitude, and sometimes a persistent taste of ether. The vomiting may be due to irritation of the stomach by the ether in the swallowed secretions; it is said to be absent usually in rectal or intravenous anesthesia or intratracheal insufflation. The taste of ether is due to suggestion, or to the slow excretion of the last portions of the ether. It has been attributed to a condition of acidosis. If it persists after a few hours, the stomach may be lavaged with a solution of sodium bicarbonate; or 30-grain (2 gm.) doses of sodium bicarbonate may be administered, or 1 ounce (30 gm.) of glucose (Beddard) or olive oil (Graham). Thirst is marked, but because of the vomiting tendency cannot be allayed. Most surgeons allow very little liquid for the first few hours, e. g., one or two teaspoonfuls of water each hour or half hour. The thirst is less if the patient drinks freely of water two or three hours before the operation. It may be absent if hypodermoclysis of saline is kept up during the operation (see Saline Infusion).

(b) Distention of stomach and intestines with gas, sometimes lessened by carminatives, stupes, enemata, colon irrigations, the continuous rectal drip method of Murphy, or by pituitary or physostigmine hypodermatically.

(c) Pain in the back, between the shoulders, or in the small of the back. Lessened by change of posture, special pillows, etc.

2. Untoward Sequelae

(a) Of the respiratory organs - bronchitis, pneumonia, edema of the lungs, or the lighting up of a quiescent tuberculous process in the lung. The danger of pneumonia is said by Muller to be greatly increased if ether is administered a second time within a few days. N. G. Davis and also Stursberg have brought forward some evidence that in some cases the post-ether respiratory troubles may be due to the patients catching cold rather than to ether irritation. Stursberg, in experimenting with dogs, found that if the ether were allowed to evaporate freely there was a surface chilling, with pronounced rise in arterial pressure from reflex contraction of the internal arteries. This did not occur from chloroform. With the open cone, too, the ether refrigeration by evaporation at the mouthpiece makes the inhaled vapor very cold, and this in itself might be enough to irritate the bronchi and lungs. Hence the resort to warmed vapor on the part of some anesthetists, the container being placed in warm water. There is evidence, both pro and con, as to the value of warming the vapor. Seelig (1911) found that the gas inhaled caused no cooling in the trachea, but that the evaporating vapor cooled the air about the patient.

(b) Of the kidneys - albuminuria and sometimes acute nephritis.

(C) Postoperative Gastric Or Intestinal Paralysis

Treated by strychnine and lavage, intestinal irrigations, enemata, or hypodermics of pituitary or physostigmine.

(d) Local injuries, as conjunctivitis, from ether getting into the eye, or from injury done by the finger of the anesthetist in testing the corneal reflex; and a sore tongue from the use of tongue forceps, or from the passing of a suture through the tongue to hold it forward.

Helpful Or Preventive Measures In Ether Anesthesia

1. Preliminary anesthetization with nitrous oxide or ethyl chloride. - This practically does away with the irritation, struggling, and intoxication of the first and second stages. The ether is begun when the patient is in the third stage. There may be a long movement of cessation of breathing as the change is made, but regular breathing is soon resumed.

2. Preliminary Anesthetization With Chloroform

This shortens the first and second stages. In athletes, alcoholics, or the obese it is easier to bring on the anesthesia with chloroform, ether being substituted as soon as the patient is well anesthetized.

3. Preliminary Administration Of Sedative Drugs

About half an hour before the operation morphine sulphate, 1/4 grain (0.015 gm.), or morphine sulphate, 1/6 grain (0.01 gm.) with scopolamine hydrobromide, 1/100 grain (0.0006 gm.), or chlore-tone, 15 grains (1 gm.) by mouth; or by rectum, 30 grains (2 gm.) of hedonal or 1 to 2 drams (4-8 c.c.) of paraldehyde. These quiet the patient's mind and lessen fear, anxiety, and other psychic disturbances. They also expedite the anesthetization and make less of the anesthetic necessary. Crile has shown that shock is less if the patient's mind is at ease. The morphine is a powerful depressant of the respiratory center, and may cause contraction of the pupil.

4. Injection of atropine sulphate - 1/100 grain (0.0006 gm.), or 1/50 grain (0.0012 gm.), to stimulate the respiratory center, to lessen the secretions of saliva and mucus, and to prevent primary vagus stimulation. It may interfere with the usual pupil reactions.

5. Warming The Vapor And Diluting With Oxygen Instead Of Air

Gwathmey gives data of experiments on cats which indicate that either of these procedures lessens the toxicity of both ether and chloroform. He warms the ether with a thermolite bottle or by setting the container in hot water. This at least tends to counteract the great coldness about the mouth caused by the evaporation of more or less of the vapor.

6. Reassuring The Patient

Crile states that psychic disturbances, fear, anxiety, etc., distinctly increase the chance of collapse; and in very nervous cases, especially those with hyperthyroidism, he takes time - even days - to get the patient into a calm mental state.

7. Having The Stomach Empty

To avoid the danger of vomiting food and having it drawn into the lungs. This is accomplished ordinarily by abstention from food for several hours, but in an emergency by lavage.

8. Preliminary feeding with carbohydrates and water - just long enough before the operation to allow the stomach to empty itself. This has been shown to prevent fatty degeneration and necrosis of the liver and to lessen postoperative nausea. Fat food, however, promotes the liver destruction. It has been demonstrated that the dangers of ether are greater in starvation and fatigue, so it is considered wise not to leave the patient without food and rest for too long a period before the operation.

9. Administering sodium bicarbonate, ounce (15 gm.) in solution by rectum half an hour before the anesthetic.