[8] Lehmann believes it is a bad sign when a patient who is taking an anesthetic keeps the eyes partially or completely open, or frequently reopens them after being under the influence of the drug. He holds it to be a premonitory symptom of more or less serious complications.
Death from chloroform usually occurs when it is assumed that no accident is likely to happen, as when it is given to an athlete, or to drunkards who are supposed to be secure from any reflex influences. Patients with weak hearts can be conducted safely through a prolonged anesthesia if there be time to prepare them. (See chapter on the [Preparation of Patients].)
The after-dangers of chloroform are smaller than those of ether, due in part to the fact that a much smaller amount of the drug suffices; in other words—that it is the stronger.
After anesthesia has been produced and the patient is unconscious it requires but small additional amounts to maintain unconsciousness, as it is necessary to add only as much as may be required to replace what is lost by evaporation and exhalation. It is sometimes advantageous to commence with nitrous oxide gas, for there are fewer unpleasant reflexes, less salivation, and less disturbance of every kind. Shallow breathing may be improved at almost any time with a few drops of ether.
Many anesthetizers have a habit of testing the degree of anesthesia by touching the cornea with their fingers. A piece of sterile gauze will prove equally effective and less irritating.
When the mask upon which chloroform or ether is given is held over the face free salivation will frequently be excited, and the patient will be tempted to swallow as well as inhale. In this way the vapor of the anesthetic is taken into the stomach as well as into the air passages, and when the stomach is empty this comes into direct contact with the gastric mucosa. This may produce not only irritation, but, in extreme cases, gastritis. It has been suggested that to allow the patient to drink a quantity of water at intervals before taking the anesthetic, and especially a half-pint or more immediately before beginning it, will be to permit of absorption and dilution of the anesthetic vapor without their causing this irritation.
Fig. 40
Harcourt inhaler.
The simplest method of administering chloroform is upon an ordinary mask, the covering of which should be thin in order to permit of easy play of air. By this method a patient can always be anesthetized, but with a waste of the anesthetic and with absolute uncertainty as to the proportion of chloroform vapor in the inspired air. A variety of expedients have been suggested in time past, and chloroform inhalers of various patterns are constantly upon the market. The Junker inhaler, introduced some twenty-five years ago, was a great improvement upon its predecessors, but only recently has a really scientific measuring inhaler been placed before the profession. This is the one devised for and introduced by a committee of the British Medical Association, and is the result of the study and ingenuity of Prof. Vernon Harcourt. It has already been stated that more than 2 per cent. of chloroform vapor in the inhaled air is dangerous. The Harcourt apparatus consists of a two-necked bottle, nearly filled with chloroform, into which are dropped two colored glass beads, which serve to indicate when the temperature is between 55° and 59° F. If the temperature be below 55° F., both beads will float; if it be above 50° F. both will sink. If the former, the proportion of chloroform will be below that indicated by the pointer; if the latter, it will be greater. Inasmuch as during inhalation the chloroform is cooled by evaporation, it is necessary to occasionally place the warm hand over the bottle until the blue bead has sunk and the red bead is beginning to sink, indicating that the temperature is again approaching 59° F. A stopcock is so constructed that when the pointer is at one end of the arc the maximum amount of chloroform which may be taken up is 2 per cent.; when the pointer is at the opposite end, the patient breathes only pure air. There are valves which prevent the entrance of expired air into the apparatus, and which show whether the stopcock is working. They also show the character of the respiration. Administration is begun with the pointer at 0.2, and while it may require 2 per cent. of vapor to produce narcosis; i. e., the complete and final stage of anesthesia, it will take scarcely more than 1 per cent. to maintain it. The mouth-piece has an expiratory valve, and the apparatus can be held in any position, but should be kept nearly vertical. The mask is fitted with an air cushion, which can be molded in hot water so as to fit the patient’s face. Buxton, who is the leading authority on anesthetics in London, has abandoned all other apparatus for this. While he is a most skilled expert, he has shown that by means of this apparatus chloroform can be given with almost absolute safety.