Handbook of anæsthetics

In considering this matter, some repetition of points to which reference has already been made, is inevitable. Indeed, this chapter may be regarded as a revision of the whole subject.

Before deciding upon drug and method suitable for the individual case, we must consider the age and sex, the physical type and temperament, the possible presence of some definite pathological condition, and the nature and duration of the operation.

In relation to this last point, we must remember that an anæsthesia must be adequate to the purpose of the surgeon, but that it is improper to incur more risk to life than is necessary. For instance, an abdominal section case must be fully relaxed, and if in an individual case, chloroform is the only drug which will give that effect, there need be no hesitation in using it. On the other hand, many other methods with a far smaller mortality rate are available if all that is required is the extraction of a tooth or the incision of an abscess, and in that group of cases, unfamiliarity with such anæsthetics as nitrous oxide or “ethyl chloride and ether” will not be held as a sufficient defence if chloroform has been given with a fatal effect.

Normal Subjects.

Let us take first the case of the healthy adult about to undergo a major operation. For this, we unhesitatingly choose what we may term the “stock” method—open-ether preceded by morphia and atropine.

If the operation be brief, we have a choice of methods. For the extraction of teeth, where access to the mouth is essential, the following table will help:—

In cases where access to the mouth is not required, and where it is therefore unnecessary to “charge up” the patient with anæsthetic, we have also a choice which may be expressed tabularly:—

In this group of short operations, special reference must be made to the reduction of dislocations. Here two important features require notice. The whole object of the proceeding is to relax muscles, and therefore nitrous oxide or gas-oxygen are unsuitable. Secondly, the tendency to reflex syncope just at the moment of reduction is very great. For this reason, chloroform has here a painfully high mortality rate; closed-ether, preceded by gas or ethyl chloride, is undoubtedly the method of choice.

The Extremes of Age.

Children up to the age of ten years take ether badly, salivation and bronchial secretion being sometimes very troublesome. Atropine mitigates this nuisance to a limited degree only. Chloroform is the best drug up to five or six years; from five to ten, mixture; after that, open ether.

In children of any age, suffering from acute sepsis, the immediate annoyances and possible respiratory sequelæ of ether must be faced (see page 156), owing to the probability of acidosis.

As regards short anæsthetics in children, nitrous oxide, if given at all, should be freely diluted with oxygen, otherwise most undesirable cyanosis will occur. To children under three or four, even gas-oxygen is of doubtful safety. Short anæsthesias in such cases may be induced by open ethyl chloride, with a few drops of ether added.

Old people are, unless very feeble, best anæsthetised by a mixture of chloroform and ether. Whatever anæsthetic be chosen, the utmost care must be taken to avoid cyanosis. A cylinder of oxygen should be at hand from which to enrich the atmosphere breathed, by trickling the gas into the mouth through a rubber tube, and is a great safeguard in dealing with the old.

Sex.

On the average, women take anæsthetics much better than men, being far less liable to jaw clenching and other forms of mechanical asphyxia, and showing less excitement during the induction stage. In the female subject induction by open-ether requires very little assistance from C.E. mixture.

Physical Type and Temperament, and Habits of Life.

Heavily built muscular men are troublesome subjects. Induction requires a rather strong vapour of ether: if the open method is used, there may be to the beginner much temptation to make use during the induction stage of C.E. mixture to an extent not contemplated in the description given of that method in chapter IX.: it is therefore wise to induce either with closed-ether or with C.E. mixture as described in chapter XV., and to change to the perhalation method only when full anæsthesia is attained.

As regards alcoholics and excessive smokers, these are well dealt with by the C.E. open-ether sequence. Recourse may be made to the Ormsby inhaler as already explained on page 137. The reader is warned not to be deceived by the stout, rosy face of the typical alcoholic. He often looks a great deal stronger than he really is. Many such are really feeble subjects: although they shout and struggle no great addition to the usual vapour strength of anæsthetic is safe or required: what is required, is a little extra time. Once fully under, the robust appearance of the patient disappears, and the fact that one is dealing with a rather broken constitution and a poor circulation is obvious.

Reference has already been made to the fact that persons with defective nervous systems, neurotics, and especially epileptics, show persistence of some muscular movements for some time, and therefore require very careful watching.

Special Operations and Pathological Conditions in the Patient.

These are of the utmost importance, but to consider each fully from the anæsthetic point of view, would lead us into great detail. The anæsthetist must acquaint himself with any abnormality present, and consider it carefully in the light of the general principles already explained. The following very brief hints for selected cases and operations may, however, be found useful.

Upper Air Passages.

Artificial teeth. Must be removed before inducing.

Tongue and jaw cases.—Intratracheal ether the best—failing that, rectal oil ether, or Junker’s inhaler.

Nasal operations.—If adrenalin is to be used, it must precede, not follow, chloroform—many fatalities have occurred from injecting or even packing with adrenalin in light chloroform narcosis. Some surgeons object to ether because of the bleeding, but this can be largely remedied by raising the head and shoulders, and by packing with adrenalin. Many surgeons prefer local to general anæsthesia.

Nasal insufficiency.—Don’t allow a patient to continue to make ineffectual attempts to breathe through a narrow nose. Establish mouth breathing, or use Silk’s tubes (see Fig. 9).

Tonsils and adenoids.—Give ethyl chloride by the vapour method.

Tumours and inflammatory swellings obstructing respiration.— Don’t use closed methods. Have tracheotomy instruments at hand, and a cylinder of oxygen.

Gôitres, especially exophthalmic gôitre.—Don’t use chloroform: it has caused many fatalities; morph-atropine, followed by open-ether is the safest. In bad cases, use rectal oil ether if intratracheal is not available. The “sitting up posture” is a great help (see page 168). Use anoci-association if surgeon is willing.

Chest.

Bronchitis and pneumonia (see remarks in chapter XVII).

Emphysema and rigid chest wall.—Patients take anæsthetics badly; they cyanose quickly, the abdominal wall cannot be made either lax or quiet, since the patient’s natural method of respiration is abdominal rather than thoracic. Lastly, there is frequently a dilated heart with degenerate cardiac muscle, giving an abnormal tendency to secondary syncope. Give a trickle of oxygen through a tube from a cylinder: don’t be tempted to overdose with anæsthetic in the vain hope of securing ideal relaxation of the abdominal wall.

Empyæma.—Be careful: a good many accidents have happened. Use chloroform with added oxygen: aim at an anæsthesia just deep enough to prevent straining which might rupture the empyæma into the lung and drown him in his own pus. Withdraw the anæsthetic as soon as the abscess is opened.

Phthisis.—Don’t use closed-ether: it may start hæmorrhage—open-ether rarely does any harm unless the condition is very acute.

Circulatory System.

High tension, arterio-sclerosis, and aneurysm.—Avoid pure nitrous oxide: in severe cases, C.E. mixture and oxygen is the safest.

Heart.—Well compensated cases of valvular disease take chloroform or open-ether well, provided a free air-way is maintained. Closed methods should be avoided. Cases of myocardial disease with dilated cavities present special dangers. Open-ether with added oxygen meets the case better than any other anæsthetic. Pericarditis, both acute and chronic, has been found as the determining factor in many anæsthetic fatalities.

Acute Infectious Disease.

Febrile patients absorb anæsthetics very rapidly and therefore go under very quickly. Acute septic cases must not have chloroform or ethyl chloride (see page 155): nitrous oxide and oxygen is ideal, ether the next best. Patients who have suffered from acute infectious disease, especially diphtheria and influenza, may present some weakness of heart muscle for many months after the attack.

Exhausted and Shocked Cases.

Give nitrous oxide and oxygen if possible—failing that, ether. Closed-ether sometimes does very well for the induction stage.

Diabetes.

Chloroform is wholly inadmissible.

Genito-urinary System.

Kidneys.—Avoid ether in acute or sub-acute nephritis: give it, however, for nephrectomy when the other kidney is sound.

Bladder.—Distending the bladder with lotion often causes reflex inhibition of respiration: if that happens, stop the anæsthetic, give artificial respiration, and ask the surgeon to get on with opening the bladder. Morphia usually arrests temporarily the secretion of urine: it should therefore not be given if chromocystoscopy or catheterisation of the ureters is contemplated.

Prostatectomy cases are often rather broken subjects: give a fairly deep anæsthesia until the shelling out of the prostate is begun: then be careful—the patient is breathing deeply as a rule, and can readily get an overdose. He will inevitably suffer a fair amount of shock: be ready to lower the table at the head end if any serious collapse occurs. Don’t be shy of starting a little artificial respiration even though the natural function is not entirely abolished.

Circumcision usually causes a good deal of laryngeal spasm, especially in children. Don’t try to abolish this by deepening the anæsthesia. You won’t succeed unless you nearly kill the patient. Rub the lips, and if very severe ask the surgeon to stop a minute until the crowing becomes less.

Castration.—Always give ether, or gas-oxygen. Castration and reduction of dislocation are the two commonest causes of reflex syncope under chloroform.

Menstruation, Pregnancy, and Labour.

It is usual to avoid anæsthetics during the menstrual period if possible, the nervous system being unlikely to be at its best at that time.

Pregnant patients take no harm from an anæsthetic properly given, but undue cyanosis must be avoided or abortion may occur. The pains of labour may be alleviated by chloroform given to an early second stage only, or by “twilight sleep” (see page 44). For the major operations of obstetrics, however, ether has its usual advantages, provided no bronchitis be present. The shock of such operations as a difficult version is considerable, and quite sufficient to call for ether rather than chloroform.