Division II. Class VIII. Anaesthetics.
By the term anaesthetic we understand an agent capable of occasioning a suspension of general sensation. In other words, this class of remedial agents are resorted to, to induce a state of temporary insensibility. Their use may be carried to the extent of causing but partial anaesthesia, but they are chiefly exhibited, however, until a state of entire insensibility is attained. This class of agents may be divided into two kinds; the first, acting upon the entire system, producing a like insensibility of all parts, may be termed general anaesthetics; while the second affecting but the parts to which it is applied may be called local anaesthetics.
To induce a state of insensibility in cases of excessive pain, especially in painful surgical operations, has been an important desideratum with the profession, eagerly desired for centuries past, and various means have been adopted, at different periods, to secure the desired object.
It is asserted that the Chinese were not unacquainted with anaesthetic agents as early as the third century. A Chinese book, in the National Library of Paris, states that when about to perform painful operations, a Chinese physician, by the name of Ho-a-tho, gave his patients a preparation of hemp, which soon rendered them insensible to the operation, however painful. The Greeks and Romans are said to have used anaesthetic agents. M. Velpeau states, that "The so-called Memphis-stone, dissolved in vinegar, after having been reduced to powder, was used as an anaesthetic agent among the Greeks and Romans; and mandragore was extensively known as possessing anaesthetic properties." Again the same author states that Hugh of Lucca, an eminent physician of the thirteenth century, employed anaesthetics. "A sponge dipped in the juice of nightshade, hyoscyamus, cicuta, lactuna, mandragora or opium, was put under the nose of patients, and made them sleep during operations." The Turks, it is said, have for a long time induced anaesthesia on subjects who were going to submit to circumcision. Sir Humphrey Davy used the nitrous oxyde gas to relieve toothache, and suggested its use in surgical operations. Mr. Wells, of Hartford, employed this gas in 1842, for extracting teeth without pain; and others employed this, or some other agent, some 30 years ago, to relieve pain. From the foregoing remarks it seems various agents have, different periods of time, for many centuries past, been exhibited with a view to the induction of anaesthesia in painful operations and pain dependent upon other causes. Notwithstanding the use of these agents at different periods by certain physicians, they did not meet with general favor by the profession, for the reason, perhaps, that they were not regarded as reliable, or their use was not unattended with danger. The advantages and comparative safety of the agents now in use as anaesthetics, have but recently been discovered and fully tested. Those formerly used seem not to have been generally known—at least but few used them—and no agents of a reliable character in all respects have been known to the profession generally until within quite a recent period.
The need of praise for the discovery and introduction into general use of an agent that would render painful operations painless, was reserved for our countryman, Dr. Morton, of Boston, who made known the results of his experiments with sulphuric ether as an anaesthetic, in 1846. Through the influence of Dr. Morton, and after repeated cautious experiments, Dr. J. C. Warren was induced to employ it in an operation performed at the Massachusetts General Hospital on the 15th of Oct., 1846. Anaesthesia was but partial in this case. On the succeeding day, Professor Hayward operated, having first induced a state of complete insensibility of the subject upon whom the operation was to be performed. From this beginning the anaesthetic power of ether, in the form of inhalations, spread with great rapidity throughout the civilized world, and is now regarded as one of the most important discoveries of the present century.
About one year after the anaesthetic powers of ether had been established, Professor Simpson, of Edinburgh, after repeated experiments, announced that chloroform was a still more effective remedy for producing anaesthesia. This new agent soon acquired a reputation equal and even surpassing ether. Its advantages were its more rapid and intense action, its smaller dose, and its more agreeable taste and smell. In addition to sulphuric ether and chloroform, other general anaesthetic agents have been discovered and experimented with; yet none have been found to possess their advantages. Among these we might name the chloride of hydrocarbon, nitrate of ethyle, benzin or benzole, aldehyde, bisulphuret of carbon and amelyne.
Importance of Anaesthetics.—As to the importance of anaesthetics as therapeutic agents, it appears to us no division of opinion can obtain. That the severity of the sufferings in many painful operations depresses the vital powers, exhausts the nervous energies, or communicates such a shock to the nervous system, and inflicts such an injury on many constitutions as to destroy life almost immediately, and in other to jeopardize the recovery of the patient, are truths which none are disposed to dispute. The induction of anaesthesia most effectually counteracts such results. Again, the powerful shock, the great depression, the exhausting and insupportable effects which the dread of pain, or the fear of an operation exerts upon the nervous and timid, serve, in many instances, to overwhelm the patient and sink his vital powers beyond the possibility of reaction; hence the prospects of a favorable termination are materially lessened, or, perhaps, entirely destroyed. Nothing more effectually destroys the recuperative powers, or the early reactive energies of the system, than fear; fear as to the final result, or dread of pain, overpowers or almost destroys life in many instances, even before the operation is commenced. Again, an operation is performed much more deliberately, and with much less perturbation by the surgeon, when the patient is not writhing in agony—when he is known to be enjoying entire immunity from pain, even though the operation be one of great severity.
All the circumstanees here alluded to, and many more, tend to imcrease the immediate danger, and lessen the prospects of a speedy convalescence—results which are counteracted by the induction of anaesthesia.
Does anaesthesia diminish the mortality following severe operations? This is a very important question, and if decided in the affirmative, adds much weight to the reasons already advanced in favor of its employment. That this is the case, we believe is not disputed at the present day. Mr. Curling says: "I have carefully watched the progress of cases, after operations of various kinds performed upon persons in a state of anaesthesia, and I can, with confidence declare that, so far as my present experience has reached, the constitutional symptoms have been milder, and the cases have proceeded more satisfactorily, than after operations in which no means had been taken to prevent pain. Several of my surgical friends can fully confirm this statement." Prof. Syme says: "As to the cases in which chloroform should be employed, it may be said that there are hardly any in which pain would otherwise be inflicted, where its use is not desirable for the patient, and incumbent upon the practitioner to propose. At an early period of our information on this subject, it was thought that in a state of collapse, or extreme depression from weakness, fatal sinking would be apt to result from the effect of chloroform. But so far from this being the case, it has been found that the most serious operations may be performed under the influence of this agent, in circumstances of the most extreme exhaustion, with results infinitely more successful than could have been anticipated otherwise." These authorities might be multiplied, but we wish next to see, from statistics, to what extent the mortality is diminished. The following table of the mortality of amputation of the thigh, with or without etherization, collected by Dr. Simpson, will illustrate this point:
|Names of Reporters.||No. of Cases.||No of Deaths.||Percentage of Deaths.|
|Parisian Hospitale—Malgaine,||201||120||69 in 100|
|Edinburgh Hospital—Peacock,||48||21||49 in 100|
|General Collection—Phillips,||987||485||44 in 100|
|Glasgow Hospital—Laurie,||127||46||36 in 100|
|British Hospitals—Simpson,||284||107||38 in 100|
|Upon patients in an etherized state,||146||87||25 in 100|
"The preceding figures" says Dr. Simpson, "speak a language much more emphatic than any mere words that I could employ in favor of anaesthesia, not only as a means of preserving surgical patients from pain, but as a means of of preserving them from death. Between even the lowest mortality in the table without anaesthesia, 36 in 100, and the rate of mortality with it, 25 in 100, there is the difference of eleven per cent. That is to say, according to this standard, out of every 100 patients submitted to amputation of the thigh without anaesthesia, eleven more would die from the operation than if the same 100 patients were submitted to the same operation in a state of anaesthesia."
The same arguments may he adduced in favor of anaesthesia in parturition. Although they check the pains for a short time, yet they promptly return and are often more efficient and the labor progresses with greater rapidity than when they are not employed. In painful and difficult labors, in cases of rigidity of the os uteri, or of the perineum, vaginal muscles, and surrounding soft parts, in cases of turning, use of forceps, and other operations, in spasms or convulsions, adherent or retained placenta, hour-glass contractions, etc., anaesthetics merit our special attention.
While in a state of anaesthesia the patient enjoys entire freedom from the sufferings which in many cases are extreme, and the shock that would otherwise be inflicted upon the nervous system. Not only so, but the freedom from pain, and loss of consciousness renders the patient passive, when otherwise her restlessness might prove injurious, rigidity of the soft parts is removed, the vaginal secretion increased, and yet the contractions of the uterus are said to retain all their expulsive force. It must be evident that the dread of pain or fear of suffering, must cause a voluntary if not involuntary resistance on the part of the patient to the progress of labor, and to the operations incidental to obstetrical practice. Is it not then apparent that when the system is in a perfectly passive state, when entire relaxation exists, all resistance of a voluntary character being withdrawn, and all spasm or rigidity of the muscular fiber calculated to retard the advancement of labor being overcome, while the uterine contractions remain in full force, labor must be greatly expedited, and that at far less expense to the physical and nervous energies of the system. The facts in the case bear out the arguments adduced above in favor of the use of anaesthesia, if the statistics of European hospitals as well as private practice are reliable data upon which to base a conclusion. Labors have been more rapid, the system less exhausted, recoveries more speedy, while the occurrence of rigors, ephemeral fevers, abdominal pains, convulsions, puerperal inflammation and fever, and many other serious diseases incidental to the the puerperal state, is greatly reduced by the employment of anaesthesia.
Anaesthetics have been employed with unequivocal advantage in puerperal convulsions. The violence of the spasm yields promptly to their influence, and is often immediately arrested. If other measures fail, their importance in these cases should never be overlooked.
They have been used in both idiopathic and traumatic tetanus, more especially in the former variety, with much success. Their influence should be maintained for a considerable length of time, in order to secure the advantages to be derived from their exhibition. They have also afforded temporary relief in cases of hydrophobia, although not a prolongation of life.
Spasmodic asthma is another affection in which entire and immediate relief of the paroxysm has followed their exhibition. The relief they afford in these cases, is but temporary, it is true, nevertheless it is a respite devoutly desired by the patient.
In delirium tremens their effects are said to be very satisfactory. The induction of anaesthesia is often somewhat difficult to be attained in this affection—more especially if ether be the anaesthetic used; but so soon as quietude ensues an artificial sleep follows, which is soon succeeded by a natural sleep, more or less protracted. When the patient awakes to a state of consciousness, he is calm and perfectly composed. If the patient is weak, and the system already exhausted by continued debauchery, the induction of anaesthesia should be gradual.
Anaesthetics have been used with great success in cases of neuralgia. Their exhibition in this disease is seldom unattended with temporary relief of pain; and should the pain return, a repetition of the anaesthetic again removes it, and by two or three repetitions it has, in many instances, been entirely subdued.
In other painful affections, as toothache, rheumatism, sciatica, colic, spasm of the stomach or bowels, etc., their use is salutary and desirable; even in the more painful and spasmodic forms of Asiatic cholera, we have no doubt but partial anaesthesia would afford much relief; but it should not be allowed to interfere with other medication for the radical cure of the disease. If used at all in this case, it should be only with a view to the relief of the extreme sufferings of the patient.
Action of Anaesthetics.—General anaesthetics no doubt act directly upon the cerebrospinal centers. The inhaled vapors are first absorbed into the blood, as is proved by the detection of them in different parts of the body,—even in amputated limbs,—and in their exhalation by the breath for a considerable length of time after the cessation of the inhalation. Their first effects are loss of mind and volition, then follow loss of sensation and motion, and lastly the power of respiration.
Anaesthetics first cause excitement, attended with ringing in the ears, restlessness, confusion of intellect, and partial insensibility. In some cases, great excitement, accompanied with screaming and violent efforts are among the first manifestations of its action on the system. Very soon a sleep, more or less profound, follows, consciousness is lost, the muscles are rigid, and the sensibility blunted. Soon, however, a state of general relaxation follows, with a profouud sleep, and an entire loss of sensibility; respiration in this stage becomes stertorous, though regular; the pulse is also regular. Finally, the respiration becomes irregular, or interrupted, and the pulse weak and fluttering, and if permitted to continue in this state for but a few seconds, respiration would cease and death ensue. The order here stated is not always observed, for the effects are irregular in many cases. In some instances no period of excitement is observable, the patient at once sinking into a state of profound narcotism. In others, the sensibility in lost, while consciousness remains unimpaired. Although this is denied, yet cases of parturition, as well as painful operations are reported, in which consciousness remained unimpaired, perception clear, yet sensibility was greatly diminished, or entirely destroyed. In other cases, sensibility remains, as is evinced by the screams and evident suffering—the patient, however, being unconscious, and having no recollection either of suffering, or of any thing that occurred during the operation.
Dr. Snow divides the action of anaesthetics into five stages, or degrees; and though it will be almost a repetition of what we huve already stated, yet as our object is to present the subject in the plainest form, we will quote his remarks.
"In the first there exists a kind of inebriation, which is usually agreeable when induced for curiosity, but is often otherwise, when the patient is to undergo an operation. Consciousness to surrounding objects remains unimpaired, though the power of vision seems slightly affected, and sensation is so much blunted that the pain of disease, which is generally due to a morbid increase of the common sensibility, is in many cases removed or relieved, according to its intensity.
"In the second degree, the mental functions are impaired, but not entirely suspended; consciousness, however, no longer continues correct, and a sort of dreamy state supervenes. This degree may be considered analogous to delirium, and to certain states of the patient in hysteria and concussion of the brain; and it corresponds with that condition of an inebriated person, who is not dead drunk, but in that state described by the law as drunk and incapable. It is very transitory, and if the inhalation be suspended, the patient in a very few minutes recovers the perfect possession of the mind. A considerable degree of anaesthesia is induced, even in this stage; and sometimes a high amount of mental excitement, that renders the patient difficult to manage, shows itself.
"In the third degree, all voluntary motion is paralyzed; and often a rigid, spasmodic contraction of the muscles of the extremities occurs. The mental faculties are completely in abeyance, the eyes are most frequently drawn forcibly upward, and the vessels of the conjunctiva sometimes become injected with red blood. It does not follow, however, that an operation may always be commenced immediately the narcotism reaches this degree, for anaesthesia is not a necessary part of it.
"The fourth degree brings with it relaxation of the voluntary muscles, together with complete insensibility to external impressions, so that no pain is felt even on the infliction of severe personal injuries. Yet, although reflex movements can not be excited by touching even the most sensitive parts of the frame, still some functions of the spinal cord remain, as the sphincters continue contracted, and according to most of its advocates, the action of the uterus in labor is not materially interfered with. The breathing is not unfrequently attended with some degree of stertor.
"The fifth degree of narcotism, is the commencement of dying. The breathing first becomes irregular, slow, and difficult; then soon ceases altogether—while the heart continues to beat for a short time, even after the last breath is drawn."
Mode of Administration.—General anaesthetics are all of them administered in the form of vapor. All the anaesthetic agents yet discovered are very volatile, the vapor being inhaled and absorbed into the blood, through the capillaries of the lungs, is conveyed by it to all parts of the system, specially affecting the brain and spinal cord. Many forms of apparatus have been invented for exhibiting these agents, but like many other things in medicine and surgery, the simplest means has proved the best. The mode in which ether and chloroform are now principally administered in this country, is to take a handkerchief or napkin, folding it three or four double, and pouring on the center of it about a drachm of the anaesthetic. This is applied to the nose, yet not so close as to prevent the inhalation of a sufficient quantity of air it with the vapor: it is brought gradually closer to the face, as the patient comes under the influence of the agent. M. Chassaignac recommends a sponge, about as large as a man's fist, wetted with the anaesthetic, and tied up in the corner of a napkin. "The napkin, which contains the sponge in its knotted corner, covers up the patient's eyes, so as to hasten and facilitate the anaesthetic stupor. It prevents also too large a proportion of air mingling with the vapor of chloroform." He also recommends that the patient be always placed in a recumbent position. This though the best position, is not indispensable, for we have seen many cases in which it was administered in a sitting posture, with perfect safety.
The question now arises, To what degree should anaesthesia be carried in order to obtain its beneficial effects, and yet incur the least danger of a fatal result? In reference to this question there has been much difference of opinion, some maintaining that the second and third degrees are sufficient, illustrating their views by keeping their patients in a half-sleeping, half-waking state, requiring the almost continued administration of small portions of the anaesthetic; while others contend that the fourth degree, or stage of toleration, should be secured in all cases before commencing an operation.
M. Chassaignac thus describes the symptoms to be noticed, and the stage of tolerance in the exhibition of chloroform, Which he believes is the proper degree of anaesthesia to be obtained. After describing the first few inhalations, he says: "I then concentrate my whole attention on the symptoms which reveal the degree of anaesthetic action; the following are the sources of information to which I apply:
"a. The state of the pulse.
"b. The state of the respiration, appreciated by inspecting the epigastric region, which expresses in a far more significant manner the state of that function than the costal walls of the thorax.
"c. The patient's face, which, by its sinister expression, often indicates the approach of danger, long before the respiration and pulse have caused any serious apprehension.
"d. I attend with particular care to the last manifestations of the period of agitation, and the first appearance of the stage of collapse. At this moment I immediately remove the sponge, and wait for the stage of 'tolerance.' Lastly, when this stage is fully established, on the slightest manifestation of returning sensibility, I give the patient small quantities of chloroform by means of the above-mentioned apparatus.
"This, then, is the manner in which I proceed, and these are the means by which I seek to obtain, before operating, what I call 'anaesthetic tolerance.' The inhalation is commenced with all due caution, and when the period of agitation arises, I allow it to pass off without suspending the inhalation, until the patient arrives at the state of collapse. As soon as this is manifested, I suspend completely the inhalation. I wait until the respiration and pulse become regular, and until the patient is plunged into that peaceable sleep which in many persons succeeds to the first stages of anaesthesia. This sleep—with perfect regularity of the great functions, with decrease in the number of pulsations, with complete equilibrium of the respiration, which is deep and calm—constitutes for me the state of anaesthetic tolerance.
"I can affirm, from having experimented a great number of times, that when the patient has arrived at this state he is subject to no kind of danger, whatever may be the time during which it is prolonged. It is to be remarked, that in this state the general insensibility and muscular resolution are present almost in the same degree as in the period of collapse. But when the 'tolerance' exists, sensibility will revive, if we do not take, in this respect, particular precautions. And it has been observed that, in patients arrived at this state of almost saturation, very small quantities of chloroform, in doses incapable of bringing on any accident, suffice to sustain the anaesthesia, without disturbing in any way the state of 'tolerance' in which the economy is plunged. We have, then, every kind of security that we can wish for; first, against pain, complete insensibility; secondly, against dangerous functional disturbance, perfect regularity of the functions. And besides, the surgeon, exempt from all anxiety on the score of the anaesthesia, can give himself up entirely to the operative department.
"This state of 'anaesthetic tolerance,' unfortunately, is not always as easy to obtain as one might believe; there are subjects whose constitution is, in some manner, opposed to it. It would seem that we can only obtain from them excitement or collapse, and that the medium state, which constitutes essentially 'tolerance,' can not be produced. They commence, as do nearly all subjects, by excitement, and arrive at collapse; but as soon as this is about to finish, it gives place to new excitement. It is only in children, in certain women, or in adults very debilitated, that we pass from the period of excitement to that of 'tolerance,' without observing the state of collapse."
It has already been stated that the fourth degree of anaesthesia, according to Dr. Snow, is the stage termed by M. Chassaignac that of "toleration"; but this is not exactly the case, it being a medium between that and the third degree. Thus, when we exhibit chloroform, we find that when we reach the fourth stage,—relaxation of all the voluntary museles, and complete insensibility, or as it is termed by M. Chassaignac, "the stage of collapse,"—there is more or less irregularity of the respiration and circulation. As soon as this subsides, we have the state of "tolerance" described.
Contra-Indications.—Some states of the system are less favorable to the use of these agents and the induction of anaesthesia than others. Organic diseases of the heart and large vessels, as hypertrophy of the heart, ossification of its valves or of the large arteries, aneurisms, etc., contraïndicate their use, or at least lessen the probability of a successful termination. These conditions do not, however, absolutely forbid their use; but in such cases they should not be employed without they are imperatively demanded, and should then be used with the greatest care and caution. In cases of great plethora, anaesthesia is effected with greater difficulty, and with less regularity. To obviate this, a hydragogue cathartic should be prescribed, and abstinence enjoined previous to the use of the anaesthetic, unless the delay will augment the danger.
In order to insure success, quietude or a state of perfect tranquillity should be enjoined and obtained, if possible; not that it is impossible that a state of anaesthesia may be secured without the observance of these rules. Talking to the patient, or loud talking in the room, should always be prohibited, as it always increases the difficulty of bringing the patient under the influence of the anaesthetic.
Food should not be taken a short time previous to the exhibition of the anaesthetic; in other words, the last meal should have time to digest before its administration. The reason for this is, that otherwise the anaesthetic would be very apt to produce vomiting as its effects were passing off, or even during an operation, providing the agent happened to be suspended, and the patient commenced to recover from its effects.
A free supply of atmospheric air is absolutely required in conjunction with the anaesthetic at all times; for without it life is endangered. The failure to observe this precaution has undoubtedly given rise to most of the fatal results arising from the use of chloroform.
It is an imperative rule that the one who administers the anaesthetic should watch the pulse, the respiration, and the general state of the patient, closely, from the first inspiration until sensibility and consciousness are completely restored. "Not one beat (says a writer) should the heart give that the finger does not take note of." We think, however, that the signs furnished by the respiration are of more importance. As soon as the pulse begins to sink or flutter, the anaesthetic should be removed, and fresh air admitted. If the respiration becomes stertorous, the inhalation should be discontinued; and should it be irregular and interrupted, the the danger is great, and active measures to restore the patient should be adopted. Among these we might mention blowing in the face, dashing cold water in the face, the application of strong nasal stimulants, as the ammonia, etc. The importance of this last is so great, that surgeons who make much use of these agents invariably have the ammonia in the room. Should these measures fail, artificial respiration, or the ready method of Marshall Hall, is not to be neglected; it is, indeed, the sheet-anchor of our hopes, or, as a certain in writer remarks, the alpha and omega in this emergency; and if long withheld death must be inevitable.
Local Anaesthetics.—On this division of anaesthetic remedies we will not have much to say, for as yet they have proved only partially successful. While general anaesthetics act upon the nervous centers, in great part stopping innervation, and producing complete insensibility of all parts of the body, these act directly upon the nerves of the part, so changing their condition that they no longer transmit impressions.
If perfect local anaesthesia could be attained, there is no doubt but what it would prove preferable in many cases to its general induction, as it must be admitted that there is more or less danger in the administration of the latter class of agents. Still, we as yet see no prospect of a much greater access than has already been obtained.
The first mode of producing local anaesthesia, that is well authenticated, was proposed by Dr. Moore, in 1784. It consisted in compressing, by torniquete and pads, the nervous trunks going to the limb to be operated upon. It was tried with partial success by John Hunter, in a case of amputation of the leg. It is stated that in this case, "at the circular incision through the skin, the patient did not cry out, change a muscle of his face, or show any symptoms of pain. At the subsequent parts of the operation, particularly during the sawing of the bones, he showed marks of uneasiness in his countenance, but did not cry out." Dr. James Amott proposed to employ a freezing mixture, to induce local anaesthesia. His mode of applying it consisted in filling a bladder partly full of tepid water, placing it upon the part as to cover the portion of skin to be rendered insensible; then gradually dropping in ice, and lastly salt, so as to bring the temperature gradually below the freezing point. This method has proven successful in operations upon the skin and superficial parts, but can never be employed as a substitute for general anaesthetics in the major operations. We have employed it with success in removing a small subcutaneous tumor, in removing inverted toe-nail, and to remove the sensibility when lancing felons, abscesses, etc.
Experiments have been made with the vapor of chloroform and other agents, applied locally; but they have not proved successful. It has been proved, however, that they are capable of relieving the pain attendant upon many morbid states, both of the skin and mucous membrane. Thus the vapor of chloroform, directed upon the part in a jet, will remove the pain of irritable ulcers, and when injected into the vagina, will remove many painful and neuralgic conditions of the uterine and adjacent organs. For this latter purpose, however, it is not equal to carbonic acid gas, which we have found eminently useful in relieving dysmenorrhea, irritation of the uterus, bladder, urethra, rectum, etc., and to relieve the pain in malignant disease of these parts.
(The remedies: I haven't scanned + OCR'd them, as they're not herbal. They are: Aether sulphuricus, Chloroform, Chloric Ether, Nitrogenii monoxidum, Carbonei bisulphidum, Carbonei tetrachloridum, and Amyl nitris. -Henriette.)
The American Eclectic Materia Medica and Therapeutics, 1898, was written by John M. Scudder, M.D.