Anesthesiooy

in

Dentistry - Past, Present and Fuure

(First Annual Joseph P. Osterloh Memorial Fellowship Lecture)t William Greenfield, DDStf

(Introductory Comments-I feel doubly honored today. It is certainly a distinct privilege and honor to receive the Heidbrink Award, and I am deeply moved to have been selected to join the ranks of those distinguished individuals who have received this high award in the past. I am equally proud and most gratified to deliver the first Joseph P. Osterloh Memorial Fellowship Lecture. Joe Osterloh was one of our foremost leaders in anesthesiology in dentistry-through his tremendous foresight the initial vision of a Fellowship Program was created, and it was he who guided the program in its formative years, against manv odds and many voices that were in well-meaning ways, raised against it. Intuitively he knew when to press ahead and when to hold back, and it was largely due to his tireless efforts that the Fellowship Program was able to achieve the position it now holds, a key credential of requisite background and training in anesthesiology in dentistry. He was a Charter Member of this Society and a valuable member of the Board of Directors from its start until his sudden death. Joe Osterloh was a fine man with great leadership qualities, and a good friend, and I deeply regret that he was not able to witness the culmination of his many years of effort.) As indicated by the title of the talk, this presentation will attempt to give an overview of trends in ambulatory outpatient anesthesia. Webster's Dictionary defines a trend as a general movement or a prevailing tendency, a direction in which something is going. Since the future is shaped by the past (which includes the present), I shall take the license granted to me by the generalized nature of the talk and make philosophical as well as iPresented at Scientific Meeting of the American Dental Society of Anesthesiology. Feb. 15, 1976. + f Associate Clinical Professor, the Mount Sinai School of Medicine, New York, N.Y.

10

technical comments. Drugs, agents and techniques in common use will be reviewed, together with other aspects such as equipment, personnel and training. Factors involved in making up the overall approach to the anesthetic management of the ambulatory patient will also be considered, together with some projections for the future. It would be of interest to start with some statistics that are not generally realized, just to indicate the vital significance of the subject matter at hand. Statistics indicate, first, that there are more anesthetics administered in dental offices in this country than in all of the hospitals combined. Secondly, we estimate that more than 30%o of dentists use techniques of pain control other than local anesthesia in office patient management. With increasing implementation of recommendations for teaching a broad spectrum of pain control techniques at the undergraduate school level, and increasing availability of educational opportunities at the advanced and continuing education levels (all of which 'will be discussed further), the clinical application of sophisticated techniques of pain control in dentisTry will no doubt increase even more dramatically in the future. Early Agents and Techniques Dentistry's involvement in the history of anesthesia is of course well known. Following the terrible controversy between Drs. Wells, Morton, Jackson and Long for the title of "discoverer of anesthesia," it remained for the American Dental Association first (in 1864) followed by the American Medical Association (in 1872) to officially grant the title to Wells by formal resolutions to that effect. Although Morton cannot be called the discoverer of anesthesia, he most certainly introduced anesthesia as a practical procedure and to the everlasting credit of the dental profession, it was these two dentists who gave to

A's-r islA PROGRESS

mankind one of its greatest discoveries, the use of surgical anesthesia. Additionally, it should be noted that Dr. Morton was also the first specialist in the administration of anesthesia, the first manufacturer of anesthetic equipment, and the first teacher of anesthesia. Ironically, it was a physician, Dr. Carl Koller, who first discovered the use of local anesthesia by anesthetizing the eye- with a solution of cocaine, but interestingly enough, the first application of local anesthesia by injection again involved dentistry. Dr. William Halstead, a prominent New York surgeon, employed a syringe to inject cocaine for a dental procedure, blocking the inferior alveolar nerve. The technique of block anesthesia was first taught in this country by Dr. Guido Fiscber, a German dentist, who was brought here in 1914 specifically for that purpose. As new anesthetic drugs and agents appeared, they were clinically evaluated for inchlsion in dental practice. Ethyl chloride was introduced towards the end of the 19th century as an anesthetic, was widely used in dentistry for about 50 years, and then virtually discarded because of the advent of safer agents. Ethylene enjoyed a brief period of use in the early part of the 20th century; cyclopropane, being explosive like ether, was never incorporated into dental practice. Divinyl ether (Vinethene) was first used in dentistry in 1933, and was widely used until relatively recently. Trichlorethylene (Trilene), introduced at about the same time, is still used extensively. Through the first half of the 20th century, techniques of pain control in dentistry consisted of either local anesthesia or inhalation general anesthesia, using nitrous oxide and the various volatile agents available. The introduction of intravenous barbiturate anesthesia opened an entirely new chapter in anesthesia in dentistry as well as in medicine. Several early pioneers in dentistry can be singled out for specific contributions in this area. First, it should be noted that intravenous barbiturate anesthesia with hexabarbitral (Evipal), was first used in dentistry in 1932 by S. L. Drummond-Jackson of London, two years before the introduction of Pentothal in the U.S. by Lundy. Drummond-Jackson was JULY-AUGUSr, 1976

also the first dentist to use intravenous barbiturates for restorative dentistLy as well as oral surgery, and was in active practice up until his death at the end of 1975. Dr. Adrian Hubbell, who had studied with Lundy, was an early pioneer in the introduction and teaching of intravenous barbiturate anesthesia in office oral surgery practice. A major innovation in intravenous pain control techniques was achieved in 1945, when Dr. Niels Jorgenson introduced a technique to obtain light sedation using a combination of barbiturate, narcotic and belladonna in conjunction with local block. This, plus a resurgence of interest in subanesthetic (analgesic or sedative) mixtures of nitrous oxide and oxygen, laid the groundwork for an expanded broad spectrum of techniques for pain control in dentistry-ranging from local anesthesia to inhalation and intravenous sedation, to neurolept and dissociative techniques, to general anesthesia, with many variations of combinations. Current Agents and Techniques From its initial inception through today, the vast bulk of general anesthetics in dentistry has been administered by oral surgeons, but there is an ever-increasing group utilizing various forms of general anesthesia for restorative dentistry and other disciplines in dentistry. As the field of anesthesiology in dentistry has become more complex, practitioners through the years have attempted to incorporate in their office practices all of the advances in the field. The control of pain for office procedure has traditionally been achieved with either local anesthesia (analgesia) or general anesthesia. Within relatively recent years, however, the scope of anesthesia has been greatly expanded by the addition of many other modalities, with the result that the delineation of analgesia (diminution of pain without the loss of consciousness) from anesthesia (loss of all sensations including consciousness) is no longer as clear as it once was and the term "pain controlr has become widely accepted as an altemative to "anesthesiology." Often when "general anesthesia" is requested for a particular procedure, careful analysis will reveal that what is actually required are the following: analgesia, so that the patient may be free 105

cross-section of prominent qualified oral surgeons from all parts of the country-the trend is unmistakeable, and is further borne out by results of recent surveys. Since these techniques are in such wide general use, by oral surgeons and non-oral surgeons, it would be well to discuss intravenuous sedation by reviewing some general concepts as well as some specific techniques. Basically, all of these techniques make use of various combinations of drugs (barbiturates, narcotics, tranquilizers, belladonnas) via various routes of administration to bring the patient to a relaxed and sedated state just short of unconsciousness. The drugs and routes generally used can be summarized as follows: Over the years, some names liave become associated with specific techniques: Jorgensen (Since 1945) Drugs I.V. Nembutal - Sedative - 50mg/cc - 100 mg. drawn up Demerol - Analgesic - 50 mg/cc - 25 mg. draw.n up Scopolamine - Amnesic and antisialogogue - 0.32 mg. drawvn up First Nembutal injected slowly I.V. (10 mg/30 sec.) until drowsy - for "Baseline" - amount noted - then 10-15% more mild sedation. Then Demerol-Scopolamine mixture slowly added. Nembutal should always be given first - Demerol does not provide suitable sedative baseline, and occasionally causes nausea and retching when given alone.

of pain; amnesia, especially retrograde amnesia, so that the patient will not recall what occurred during the procedure; tranquility, or mental calnness, with absence of fear and apprehension; and some degree of cortical depression of the central nervous system, ranging from mild sedation to hypnosis (sleep). Since profound muscular relaxation is usually not required for office procedures, and since sleep does not necessarily imply unconsciousness, all of the above objectives can often be achieved without the loss of consciousness. Definitions for the state of consciousness vary, but since levels of depression of the central nervous system are generally determined by the presence or absence of various reflexes, one can accept the fact that from a neurologic point of view an individual is conscious if the protective reflexes (pharyngeal, laryngeaL etc.) are active and the individual is in harmony with his surroundings.

WVhile general anesthesia is still widely used as a standard technique for certain categories of patients (those who cannot or will not cooperate to any degree whatsoever; true allergies to local anesthetics; severe gagging problems; small children, etc.), these seems no doubt that the movement in the U.S. is towards those techniques of pain control that keep the patient at a conscious level, but fulfill the objectives previously outlined. In interviewing and examining candidates for Fellowship status in the American Dental Society of Anesthesiology-and this includes individuals in all fields of dentistry with training in anesthesiology as well as a broad Premedication P.O., I.-i., Rectal

Barbiturate (Nembutal, Seconal) Narcotic (Demerol)

Tranquiilizer

(Valium, Atarax, Phenergan, etc.) Belladonna (Atropine, Scopolamine) 106

I.V. Sedation

Nembutal Seconal Valium Atropine Scopolamine

)

Demerol Nisentil Fentanyl Phergan Brevital

)

One Initial Dose

Other

N20-0, sedation (analgesia) Local blocks

Single dose with increments or dilute

drip AxNTEsrinsu PROGREss

Generally require: Nembutal 100 mg. ) same Demerol 25 mg. Scopolamine 0.32 mg. ) syringe Plus local, with many variations.

Shane (original technique) Nisentil and Hydroxyzine (Vistaril, Atarax) and Atropine and Brevital P.R.N. Generally require: Child Adult Nisentil 6 mg. 30 mg. Vistaril 25 mg. 50 mg. (nov I.M. originally I.V.) Atropine 0.3 mg. 0.6 mg. Plus local, plus 10-30 mg. Brevital as needed. Bens -

Seconal and Demerol and Brevital Generally: Seconal 25-75 mg. Demerol 25-30 mg. Brevital 10-20 mg. increments as needed. Plus local anesthetic. Mlore recently, with the advent of the use of Valium, this has been incorporated into virtually all techniques, and is now no doubt the most widely used drug for intravenous sedation. As an example of the type of technique that we have found works very well: First - Scopolamine 0.32 mg. I.V. then - Valium 10-15 mg. (Slowly-5 mg./min.) then - Demerol 23-50 mg. (long case - at least 1 hr.') or - Fentanyl 0.05-0.1 mg. (short case) Plus - N,0-0, (50:50), plus local, plus Brevital 0.2% drip as needed. For long cases (several hours), additional increments of drugs may be added P.R.N. This technique provides deep sedation and hypnosis.

It should be noted that with most of these techniques, particularly those using several combinations of drugs, patients generally drift in and out of consciousness, and anyone utilizing this type of technique should be knowledgeable in the care and management of an unconscious patient. JuiLY-AUGUsr, 1976

Also, when narcotics are used, as they commonly are in these techniques, reSDiratory depression is very often produced which is not seen clinically ( as will be ditcussed later), and it would probably be advisable to use a narcotic antagonist at the conclusion of the case to reverse any respiratory depression produced. Neurolept and Dissociative Techniques With all of the techniques discussed so far, which may be referred to as techniques of "psychosedation," the patient generally has some awareness of his surroundings, and the analgesia obtained is generally inadequate to perform a surgical procedure without the addition of local anesthesia. More recently, several drugs have been introduced which produce, in addition to the effects previously outlined, a state of psychic detachment of the individual from his environment-a total indifference to the surgical procedure being performed, often without the loss of consciousness. This state has been termed "neuroleptanalgesia," and may be defined as "a state of central nervous system depression 'with tranquilization and intense analgesia, produced without the use of barbiturates or volatile agents." A related term that has come into use is "dissociation analgesia," produced by drugs which "dissociate" the patient from his environment into a state of catalepsy, in addition to producing analgesia and amnesia. If unconsciousness is also induced, the terms "neuroleptanesthesia" or 'dissociation anesthesia" could more properly be applied. As opposed to conv,entional anesthetic agents, these drugs act on subcortical levels of the brain, producing these effects while leaving cortical and vital protective functions relatively intact. The prime example of a dissociative agent is ketamine HCl, which can be administered intramuscularly or intravenously and produces analgesiai so profound that no supplementary agents are required for anesthesia. Studies have indicated that the most effective anne ofutilization of ketamine for ambulatory patients is at a greatly reduced osae range,farbeiow that recommended by the manufacturer. A revised weightdosage relationship has been established, based on intramuscular administration, as follows: 107

Revied weight-dose relatioohip

weit

for Ketiue

lobtscw Dosage Up to 50 lbs. 0.5 mg. to l.0 mg. per lb. 50 to 100 lbs. 1.0 to 1.5 mg. per lb. Above 100 lbs. 1.5 mg. per lb. plus N20-02 (50:50) At these dosage levels, dissociation analgesia is produced, consciousness is generally maintained together with protective reflexes, and vital signs are stable. The duration of effect varies from 20 to 40 minutes, and can be prolonged by the addition of N.0-0, in a 50:50 mixture. Recovery is geealy smooth and uneventth a ye lowincidence of naua an vom egree of retroand a grade amnesia. The only premedication suggested is scopolamine, to inhibit the ced by ketamne copious secretio which probably accounts for the nausea and vomiting often produced in unpremedicated patients receiving higher doses of ketamine. It must be emphasized that ketasWn_esnot a Cmxertionalrug. and that conventional guidelines for anesthetic management cannot be directly applied. When using conventional anesthetic agents, one expects specific actions to be followed by specific results. When a barbiturate is injected, for example, one expects to get a "collapse" of the patient into a relaxed or nonresponding state. If such a response does not occur, the inference is that not enough agent has been administered, and a higher dosage is needed. In using dissociative drugs, the typical "collapse" does not take place and there are few physical changes discernible in the patient except for the characteristic cataleptic state produced. At the reduced dosage level presented, there are rtually none of the undeiale postopDerative pEchotomimetic effects often encountered with higher dosage levels. However, since this is an unconventional drug, the same effect cannot always be predic4ahh~di~plip~om patient to patient. After prolonged study, it is apparent that the most reliable effect is p d in c . with the least satisfactory result in adults or adolescents weighing more than 100 pounds. Most of these can, however, be successfully man108

aged by the addition of nitrous oxide and oxygen in sedative mixtures. Apart from its use in oral surgery, there are many other potential applications of ketamine to ambulatory patients. In many emergency room procedures, such as suturing lacerations, manipulation and closed reduction of fractures, and various painful diagnostic procedures, ketamine can be of great value, particularly in children. It can also be used, when properly applied, in restorative dentistry for unmanageable patients. After an initial widespread surge of interest in ketamine in anesthesiology in medicine, the unpredictability of effect coupled with the high incidence of stormy recovery periods caused the drug to fall into relative disuse. However, at reduced dosage levels, ketamine has a definite area of usefulness in ambulatory patients, often where no other drug is suitable, and I feel it will find its own slot in the overall scheme of patient management. The same is currently seen in medicine, with a resurgence of interest in ketamine for specific applications. Neuroleptanalgesia is generally produced by using Innovar, a combination of fentanyl (Sublimaze), an extremely potent synthetic narcotic derived from Demerol; and droperidol (Inapsine), a potent tranquilizer and antiemetic, in a fixed mixture of 50:1 of droperidol to fentanyl (2.5 mg. per cc of droperidol: 0.05 mg. per cc of fentanyl). Innovar can be used for premedication or for induction of anestbesia, but studies have indicated that its use is probably best confined to hospitalized patients because of prolonged and unpredictable recovery time and depressant effects on respiration. The components of Innovar are, however, available separately, and by varying the doses of fentanyl and droperidol, a new range of usefulness for the ambulatory patient can be achieved. has an analgesic potency which o is times that of morphine and 1000 times that of DemeroL and since it has a short duration of action ( 30 to 60 minutes intravenously) as well as a rapid onset, it is particularly suitable for ambulatory office patients. As with all potent narcotics, there exists the possibility

10NESTHEsIA PRoGREss

of respiratory depression, and fentanyl when yse aloner prduces a sigficant incidence of nausea. When droperidol is added to fentanyl in a mixture such as Innovar, there is no nausea, but it must be kept in mind that the addition of droperidol to fentanyl prolongs recovery time and potentiates respiratory depression in addition to producing a detached and lethargic state. Accordingly, if droperidol is to be used in ambulatory patients, it is best used in minute quantities, by diluting one cc. (2.5 mg.) of droperidol in 250 cc. of saline solution to produce a concentration of 0.01 mg. (10 micrograms) per cc. At this concentration, droperidol can be used, following appropriate doses of fentanyL at a dosage range of 10-15 micrograms per kg. of body weight, in conjunction with local blocks and N.200. to produce analgesia, sedation and a high degree of retrograde amesia. When narcotics are used as part of an anesthetic regimen in hospitalized patients, it is common practice to use a narcotic antagonist postoperatively to partially reverse the depressant effects of the drugs and to hasten the recovery period. Until quite recently, the use of narcotic antagonists has never had a significant role in the management of ambulatory patients, due partly to a common belief that no significant respiratory depression is produced by narcotics in ambulatory patient techniques and partly to the fact that most narcotic antagonists exhibit agonistic properties of their own. While nalorphine hydrochloride and levallorphan tartrate have respiratory and circulatory depressants effects similar to those of narcotics, a more recently introduced narcotic antagonist, naloxone hydrochloride (Narcan) differs from other antagonists in that it does not have agonistic properties of its own, it does not induce tolerance or possess abuse potential, and when administered to a patient who has not had a narcotic, acts as a placebo. Clinical studies have shown that narcotics such as fentanyl and Demerol, as commonly used in ambulatory patient management, can produce significant respiratory depression that is generally not clinically evident. Since narcotics are widely used in techniques of intravenous sedation

JULY-AuGus-r, 1976

as well as general anesthesia, and since naloxone will reverse any respiratory depression produced without any significant adverse effects, the use of naloxone postoperatively should be consied whenevr a narcotic is used in ambulatory patient management. General Anesthesia - Basic Considerations While techniques of conscious sedation are widely employed in ambulatory office practice, as already indicated, general anesthesia is still required for certain categories of patients. The three basic comerstones of sound anesthetic management in ized as follows: the office may be 1. Adequate background and training, 2. Adequate personnel, 3. Adequate equipment and facilities. Background and training of the operating team are of primary importance. We have long advocated, and the A.DA. has now adopted as part of a standard (Council on Dental Education Guidelines) that a dentist should have a minimum of one year's training in anesthesiology, beyond the undergraduate school level, prior to the use of general anesthesia in practice. Oral surgery training programs incorporate such adequate taining in anesthesiology. Additionally, there are hospitals throughout the country where dentists who are not oral surgeons may obtain residency training in anesthesiology. The interest in, and availability of such programs is constantly increasing. Our residents are trained in the use of a team approach, with the operating team consisting of at least three people, all trained in their respective capacities. In this regard, it would be well to mention the excellent program currently in existence at Boston University, where a new breed of auxiliary is being trained-an oral surgery assistant grounded in basic sciences and clinical anesthesia-a hybrid nurse and anesthesia assistant. Such programs are certainly to be encouraged, and the future will no doubt see more of these developing. When we speak of adequate equipment and facilities we mean that wve must be prepared to cope with any problem 109

that may arise. Such things, for example, as well-functioning anesthetic equipment and suction are of course taken for granted, as is adequate lighting. A wellorganized emergency tray should be readily available, and all personnel should be completely faniiliar with its contents. Recovery rooms should also be equipped with adequate suction, a source of oxygen, and ready access to all emergency equipment. With the increase in sophistication of techniques of pain control must come an increase in self-surveillance. One of the hallmarks of a profession is the ability to police itself. A prime example of this is the ASOS Office Anesthesia Evaluation Program, which started as a voluntary program and has just now become mandatory, all part of an ongoing system of internal peer review which is constantly expanding in scope.

Selection of Patients In selection of patients for ambulatory office anesthesia, a careful history and physical evaluation of every patient is of course mandatory, and should be both subjective and objective, including evaluation of vital signs. A careful selection of patients is important, since it is generally recognized that only Physical Status Class I patients, and certain Class II patients, are suitable candidates for ambulatory office general anestbesia. By definition, these would be patients free from organic disease or patients in whom ordinary physical activity does not cause undue fatigue or dyspnea. This category may include, for example, well-controlled diabetics and patients with well-compensated valvular heart disease provided it is not associated with hypertension, or patients with hypertension not complicated with other cardiovascular disease. I would exclude from this category any of the following: 1. The extremes of age-very small children, or those past an arbitrary age of 60, in whom artiosclerotic changes are inevitable. 2. Very obese patients-it is well known that obesity predisposes to cardiovascular disease, impaired liver function and post-op thromboembolic phenomena, in addition to airway and 110

respiratory problems during general anesthesia. 3. Patients with congenital defectsthese are often multiple and may include cardiac congenital defects of which the patient is unaware. 4. Patients with more than one pre-existing systemic disease, since this can compound potential problems-for example, a diabetic patient with hypertension. 5. A patient with a C-the primary s problem v j m become hyperactive, and are not ohtunded uintil the patient is brought to a much eeperl anesthesia than is usually required. For emxmple, pharyngeal reflexes are often not obtunded until the third plane of Stage III, and patients may c gag_nd "buck" until brought to this level. None of our office procedures are true emergencies in the medical sense, so that it is not absolutely essential to give a general anesthetic to any patient who does not fit the categories outlined. Premedication Premedication should be carefully considered for every patient scheduled for a general anesthetic. Apart from the benefits of sedation and diminution of secretions which can be obtained, two other aspects are of equal importance. One is -to lower the metabolic activity, and the other is to obtund undesirable parasympathetic (vagal) effects. After having gone through countless combinations of drugs for premedication, we have returned to the routine use of a short-acting tj e (nembutal or seconal) and a ldonna (atroe e). Sedation makes for pine or a much smoother and easier induction, particularly with inhalation anesthesia, and by lowering the BMR we decrease the oxygen consumption required, thereby diminishing the likelihood of hypoxia. With regard to obtunding vagal reflexes, the argument is often advanced that the amount of atropine we use is too low to achieve this effect. While it is true that the dose (Continued on page 129)

ANEsnEfsiA PRoGREss

e.tis

-Past

F

Cornuued from page 110

of atropine that would be necessary to completely obtund the vagus is 6 or 7 times the usual physiologic dose (0.4 mg. of atropine is required to obtund all vagal effects), this is not an all-or-none response, and we can see a veryG with 0.4 mg. of atropine. Agents and Techniques Since this presentation is meant to be an overview, only a few generalizations will be made in this context. With children, an inhalation induction is generally used (Fluothane, N20, 02), and if the procedure is short they are maintained on the same agents. Whenever .infusion is started on every feasible, patient, and for long procdures on children intravenous barbiturates are used in addition to inhalation agents. With adults, induction is generally accomplished with an I.V. barbiturate (Brevital), and maintenance with a combination of dilute and concentrated Brevital, supplemented with Penthrane, N20 and 02. The use of a dilute drip barbiturate (0.2% Brevital) in addition to concentrated barbiturate (1% Brevital) permits patients to be maintained at a smooth and even level of anesthesia. All patients should be carefully monitored. Monitoring to me means two things -it allows us to determine: 1. the patient's physiologic status-specifically, the status of his cardiovascular and respiratory systems, which is indicated by an evaluation of vital signs, and 2. the level or depth of anesthesia-specifically, where is the patient at any given time? The anesthetic level is determined by a determination of the presence or absence of various reflexes in addition to evaluation of vital signs. While we are on the subject of depth of anesthesia-it is my feeling that most of the problems we come across in ambulatory office anesthesia (general anesthesia) are caused by the patient being too lightnot too deep. The patient should be maintained at a surgical level of anesthesia

JULY-AUGUSr, 1976

(Stage III, Plane I). If the patient is too light, we are operating at a level where all of the undesirable reflexes (paryngeal, laryngeaL etc.) are most active, and where the highest level of endogenous epinephrine is being liberated, and so most likely to produce arrythmias in reacting with halogenated anesthetic agents such as Fluothane. In addition to an evaluation of vital signs, monitoring can include: 1. Finger on pulse-still excellent 2. Precordial stethoscope 3. Electronic stethoscope leading to audible amplifier 4. Finger pleythsmograph 5. EKG, EEG 6. Capillary refill time-best indication of tissue perfusion We are in an era of electronic devices, and the day is probably not too far off when EKG monitoring will be standard practice in office anesthesia. Techniques in common use: 1. Nosepiece 2. Nasopharyngeal tube under nosepiece

3. Nasal endotracheal 4. Controlled hyperventilation - produces a curare-like effect even with light levels of anesthesia, due to exhausting Hering-Brauer reflex receptors. There are two potential complications (respiratory alkalosis and prolonged apnea), but these are never seen clinically. Some other generalizationsIn ambulatory office anesthesia, almost all of the problems and complications that one encounters are either respiratory problems themselves or else started out as respiratory problems. I believe it can be said that the single major cause of almost every complication is chronic hypoxia with attendant CO2 retention. Since all anesthetic agents depress respiration, I think it's always a good idea to assist respiration. As techniques become more sophisticated, we often have to learn also to cope with more sophisticated problems. For ex129

ample, several cases of malignant hyperthermia have been reported in oral surgery patients, which, if not recognized and treated rapidly and vigorously, will result in death. Is there some maximum length of time beyond which we should not extend our office cases? What is a long case, and what is a short case? This has always been quite arbitrary, depending on many factors. However, some investigational work seems to indicate that the corticosteroid level begins to fall after about an hour under general anesthesia, so it may be well to keep that in mind. When should one discontinue a case? Since an office procedure is never of such emergent nature that it cannot be stopped, probably the best answer to that question is that a case should be discontinued when one starts actively thinking about doing so. Fortunately, there often are other alternatives, already discussed, that may permit a case to be continued under light levels of sedation and analgesia supplemented %vith local anesthesia. Nonpharmacologic Techniques of Pain Control All of the areas discussed depend on the use of drugs. There are various nonpharmacologic approaches to the control of pain, such as hypnosis, electro-anesthesia and acupuncture. Of these, acupuncture, although the oldest, offers the newest and most important challenge. While acupunc£ure has many potential applications, those of greatest significance to us are its applications to the management of chronic facai statessuc asi eminal neuralso-called gia and pical" facial pain. Due of the most valuable spinofs in the intense interest in acupuncture has been a great increase in research into pain, and the future of acupuncture in this countrv w%ill be determined by a combination ot the results of both research efforts and clinical studies now underway. It seems apparent, however, that acupuncture wvill be a useful research and clinical tool in pain control. Education and Research While only three undergraduate dental schools have an independent Department 130

of Anesthesia, several schools are in the process of integrating a coordinated program of teaching pain control techniques. As a prime example, the University of Southern California School of Dentistry has just implemented such a program, and one of the country's foremost leaders in pain control has left private practice to be appointed Professor of Dentistry and Director of the new Pain and Anxiety Control Program at U.S.C. A program such as this not only involves teaching at all of the educational levels, but also necessarily includes research projects as well. The dentist of the future will have received training in all phases of techniques of conscious sedation at the undergraduate level. Additionally, the demand for and quality of programs at the advanced and continuing education level is increasing constantly. Role of Other Agencies There are several organizations and agencies concerned wNith anesthesiology and pain control in dentistry, and longterm mutual efforts have enabled enormous advances to take place in recent years. Extensive joint efforts of the American Dental Society of Anesthesiology, the American Society of Oral Surgeons, the American Association of Dental Schools, and the A.D.A. Council on Dental Education culminated in the adoption by the American Dental Association in 1971 of "Guidelines for Teaching the Comprehensive Control of Pain and Anxiety in Dentistry.' This historic document provided, for the first time, a set of guidelines as to wvhat constituted adequate background and training in anesthesiology in dentistry at each of the educational levels, together with recommended qualifications of teachers of techniques of pain control at each of these levels, and recommended sites of instruction. Other joint efforts produced the recommencdation that techniques of conscious psvchosedation should be taught at the undergraduate level, to be implemented by the American Association of Dental Schools in conformity with the "Guidelines." Concurrent with these efforts was the establishment and gradual implementation by the ADSA of the Fellowship Program in General Anesthesia, which provided for the first time, recognition of ade130

ANESTHESIA PROGRESS

quate background and training in anesthesiology in dentistry, in accord with the principles of the "Guidelines." The Fellowship, which has gradually become accepted at all levels as a recognized credential, will play an even more important role in the future, as will be indicated shortly. Another important inter-agency activity has been the creation by the A.D.A. Council on Dental Education of an Ad Hoc Committee on Anesthesiology, composed of representatives of the ASDS and ADSA, together with representatives of the Council, which meets regularly with representatives of the American Society of Anesthesiologists as a Liason Committee to discuss matters of mutual concern. This is a most important liason activity, since it has included such significant actions as approval by the ASA of the principles of the "Guidelines," acceptance of the Fellowship Program, and recommendations regarding training programs in anesthesiology for dentists. Another agency to be singled out for major significant contributions to anesthesiology in dentistry is the National Institute of Dental Research of the N.I.H. Early on, the NIDR had the vision and foresight to pinpoint Pain Control as a top priority item many years ago. The people in leadership positions have their ears to the ground, recognize the trends, and help to shape them in the best interests of the profession and the public. Witness the role of the NIDR in organizing conferences on teaching pain control and coordinating concepts of facial pain, supporting research on investigation of new drugs and techniques such as acupuncture, supporting training grants in anesthesiology in dentistry. and now a new involvement in an area about which we will be hearing a lot more in the very near future-the effect ential hazards of trace anesthetic gases. In these days of critical review of govenimental agencies, these activities serve as an ongoing example of spending public funds in the public welfare. We are witnessing major changes in the involvement ofesa e with particular gi reference to anesthesiology. Several of the State Boards have adopted regulations requiring special certification for the adminis-

JULY-AUGUST, 1976

tration of general anesthesia and other forms of pain control, in which the requisite background and training is clearly outlined. In some states, such as in Ohio, these regulations are well-conceived and wTill accrue to the benefit of all concerned, since they are the result of careful planning as a joint effort of many agencies. In some states such regulations often leave much to be desired, generally the result of hastilyconceived efforts to stave off restrictive legislation which would prohibit dentists from administering general anesthesia. As in all such matters, the elective carefullyplanned approach is certainly more desirable, but it is well to recognize the role of the Fellowship in these regulations as a major yardstick in determining requisite background and training, particularly since we will be seeing the involvement of many more states in this type of activity. With increasing governmental and third party insurance programs, it is important to discuss the impact on anesthesiology in dentistry. WVithout commenting on the desirability of such programs, it is clear that most of them delineate anesthesia as a separate service, and more important, they have done what private practice was generally reluctamt to do-namely, to put a separate fee on anuesthesia in dentistry. While admittedly the fee is woefully inadequate, the concept of putting a monetary figure on anesthesia as a separate service moves forvard the held of pain control in dentistry. Where is all of this leading? Again, the trend seems to be clear. With an increase in the educational level and the availability of more graduate programs, together with

an expansion of interest, increasing patient demand for pain control services, special certification requirements in many states outlining required background and training, delineation of anesthesia as a separate service by many third party plans, and increasing numbers of properly trained individuals, we have all the makings of a separate specialtv-particularly now that the concept of dual specialization in more than one specialty area has been sanctioned by the ADA. I believe that it would be safe to predict the advent of a separae suoeiAt in anesthesiology in dentistry within the next dec-ae. F tose who find this diffi131

cult to accept, may I remind them of the thought expressed by Christopher Mforley when he said, "There is no squabbling so violent as that between people who accepted an idea yesterday and those who will accept it tomorrow."

Summary How does one summarize a paper that deals with past, present and future? Perhaps it is well to look only to the future, since that is our primary concern. Our efforts to constantly upgrade the level of patient care in terms of safety and efficiency in providing pain control for ambulatory patients is shared by medicine, where outpatient general anesthesia is currently undergoing extensive evaluation as one of the concepts of the future. The lead article and editorial in a recent issue of Anesthesiology (September 1975) are devoted to this subject, emphasizing the potential significance of expanding ambulatory outpatient care. To say that wve have come a long way, but much remains to be done, has very little meaning-there is always much that remains to be done. However, it is important to recognize that we are part of an ongoing process in which the present is only an interim stage between the past and the future. When progress does take place, it is generally slow and gradual, the result of much effort, even though it may appear to be a sudden change. Stated another way, from the Hebrew (Ethics of the Fathers )-"The day is short. The work is hard . . . Ours is not to complete the task. Yet neither are we free to neglect it." Bibliography Archer, H. WV.: Life and letters of Horace Wells, discoverer of anesthesia, J Amer Col Dent 11:81, 1944. Bennett, C. R.: Monheim's general anesthesia in dental practice, ed. 4, St. Louis, C. V. Mosby Co., 1974. Bennett, C. R.: Conscious-sedation in dental practice, St. Louis, C. V. MIosby Co., 1974. Drummond-Jackson, S. L.: Intravenous anesthesia, ed. 3, London, SAAD, 1967. Epstein, B. S.: Recovery from anesthesia, Anesthesiology, 43:285, 1975. Foreman, P. A.: Pain control and patient management in dentistry-A review of current intra-

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venous techniques, J Amer Dent Ass, 80:101, 1970. Greenfield, W.: Neuroleptanalgesia and dissociative drugs, Dent Clin North Am, 17:263, April 1973. Greenfield, M. and Granada, MI. G.: The use of a narcotic antagonist in the anesthetic management of the ambulatory oral surgery patient, J Oral Surg, 32:760, 1974. Guidelines for teaching the comprehensive control of pain and an-xiety in dentistry, Amnerican Dental Association, Council on Dental Education, Chicago, 1971. Jorgensen, N. B. and Hayden, J.: Premedication. local and general anesthesia in dentistry, Phila., Lea & Febiger, 1967.

Dear Member, During the month of April you received a notice from the American Fund for Dental Health requesting a contribution. In past years, a number of members of the American Dental Society of Anesthesiology have contributed to this most worthy cause. By contributing to the American Fund for Dental Health and specifying on your check that the contribution is to be earmarked for the Anesthesia Research Foundation of the American Dental Society of Anesthesiology, you may get dual credit for this contribution. In this way both the American Fund for Dental Health receives a contribution and in tum they send the receipts of the contribution to the Anesthesia Research Foundation after deducting a small percentage for handling the transaction. Of course, you receive only one tax deduction, but you receive credit for the contribution to the American Fund for Dental Health and the Anesthesia Research Foundation. We hope that you will make your contribution again this year and be certain it is marked to be distributed to the Anesthesia Research Foundation of the Americ-an Dental Society of Anesthesiology. Your assistance is appreciated. Sincerely yours, J. D. Whisenand, D.D.S. President-elect A.SEsmnsIA PROGREcss

Anesthesiology in dentistry--past, present and future. (First annual Joseph P. Osterloh Memorial Fellowship Lecture).

Anesthesiooy in Dentistry - Past, Present and Fuure (First Annual Joseph P. Osterloh Memorial Fellowship Lecture)t William Greenfield, DDStf (Intr...
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