Nitrous oxide and oxygen anesthesia for dental surgery

Original NITROUS

OXIDE

y.

PHIIA

AND

GROSS,

Articles

OXYGEN ANESTHESIA SUR.GERY F.I.C.A.,

I).l).s.,

PHIIAI)EIJ’HI.\,

FOR

DENTAL

PA.

HERE is a great deal of difference between the patient being prepared for surgery in the hospital for a serious operation and the average pat’ient who walks into a dental office for the extraction of teeth and associated oral surgery. Nitrous oxide is administered daily to thousands of patients for dental operations by men untrained in its USC! and ignorant of the phases of anesthesia. Deaths resulting from the use of nitrous oside arc so rare in dental offices that when death does result, it is the subject of much adverse publicity in the press. The safet,y factor in nitrous oxide and oxygen anesthesia in dentistry is due to the fact that :

T

1. Dental operations are of short duration. 2. Anesthesia is usually light. 3. The operations are carried out on patients health. EXAMISATIOS

OF

THE

commonly in fairly

good

PATIEXT

The question of a complete physical examination for the dental patient is a controversial problem. The feelings of the patient demand consideration. An elaborate physical examination will, in many inst,ances, so fill the patient with apprehension that the difficulties we are tryin, 11,to avoid will be greatly increased. K. C. McCarthy says, “Nitrous oxide properly administered is such a safe anesthetic that it may be given with safety to any paCent who is capable of going about his daily work without signs of obvious distress. ” It is commonly said that, if a patient can walk to the dental office unaided, he may be considered a good risk for nitrous oxide and oxygen anesthesia. Whenever possible, however, it is the part of wisdom for both the patient and the operator that a preliminary physical examination be made. One simple test that will give the operator valuable information, yet will not fill the patient wit,11 undue apprehension, is the breath holdin, 0’ test. The patient is inst,ructcd to take a deep breath and hold it as long as possible. If he can hold the inspired breath for t,hirty seconds, he has usually no grave functional disturbance of the heart or lungs. It does not follow that patients who cannot hold their breath for half a minute are seriously ill, but, such patients should be given the benefit of a thorough examination by their family physician. If the operator has had any clinical experience in cardiac examination, it would be well to spend a few minutes observing the heart action, its muscle tone, its rate and rhythm, and the presence or absence of adventitious sounds. New

Read York

before the City. 1941.

American

Society

for

the

Advancement 539

of

General

finesthesia

in Dentistry,

540

P. Philip

Gross

An examination with the stethoscope through clothing, means nothing. It may impress the patient, but as a scientific procedure it is useless. Much can be learned about the physical status of the patient by inspection. The general appearance of a patient, whether he looks healthy, or is thin, emaciated, anemic or pallid helps in conjunction with the following signs: 1. Bulging eyes (hyperthyroid) 2. Puffy eyes (nephritis) 3. Yellow conjunctiva (jaundice and bleeding) 4. Blue nails, and lips (circulatory disease) 5. Clubbed fingers and cyanotic fact (cardiac and pulmonary disease) 6. Hard and tortuous temporal arteries (arteriosclerosis) ‘7. Wheezing breathing (ast,hma, and allergy to drugs) The patient should be questioned about shortness of breat,h, swelling of the ankles toward evening, pain about the heart, chronic headaches, or any recent serious illness. If there is any doubt about the patient’s fitness for the anesthetic, a medical consultation is advised. It is essential to know definitely, before applying the nasal inhaler, that the patient can breathe freely through the nose. Obstructions in the pharynx and the larynx are also to be excluded. The larynx may easily be inspected by drawing t,he tongue forward wit,11 a pierc of gauze, and asking the patient to say “IS,” which lifts the larynx to mirror view. It is advisable to carry out the diagnostic measures previous to the day of the operation if possible; if not the examination ma57 be carried out immediately preceding the operation. A good time to examine patients is while the x-rays for the case arc being developed. Patients appreciate your spending a few minutes for an examination, rather than leaving them alone in the operating room. I’HEMEUICATIO\’

A

The realization of the importance of preliminary medication, is one of the major advances in anesthesia. Such medication facilitat,es the psychologic manPreanesthetic drugs have definite functions in agement of the nervous patient. anesthesia. They produce a basal or partial anesthetic state, thus lowering the level of the reflexes. Upon this basal condition is superimposed the anesthetic, which carries the patient to the level of surgical anesthesia, where all the reflexes except the vital reflexes of respiration and circulation are abolished. It is due to the effect of the basal anesthesia, produced by premeditation, that a maximum amount of oxygen can be used, with a minimum amount of nitrous oxide t,o product surgical anesthesia. The selection of premedieation depends upon the following: 1. Psychic state of the patient. 2. Length and character of the operation. 3. Physical make-up of the patient. The great majority of oral surgical procedures are performed on ambulatory patients. PremedicaGon of a case requires time and cooperation of the patient before surgery. No patient should be premeditated unless accompanied by someone to take care of him upon leaving the office, and to stay with him

Nitrous

Oxide-Oxygen

Anesthesia

541

at home after the operation. Nembutal and sodium amytal are the preanesthetic drugs most commonly used for dental anesthesia. Great care must be observed by those in attendance to refrain from making Do not earrr on a conversation in the presdisturbing remarks to the patient. ence of a patient who has been premeditated. Such patients misconstrue or often misinterpret the meanin, 0‘ of what is heard while under the influence of the drug. I do not make it routine practice to premeditate patients before SWgery in the office. PREANESTHETIC

TREATMENT

For operations in the dental office, t,he patient is advised to miss one meal previous to the operation. This will keep the upper alimentary tract empty Tight clothing should be loosened. Free and thus avoid nausea and vomiting. t.he neck, chest and abdomen. Evacuation of the bladder should be advised immediately preceding the anesthetic, and if possible, emptying the lower alimentary canal. For dental operations it is not necessary to resort to cathartics and enemas the night before. Protect the patient’s clothing with a gown, or have female patients remove the dress and wear an operating gown. Protect the hair with a suitable headdress made of towels. Inspect the mouth, remove all loose appliances, foreign bodies such as chewing gum, lozenges, etc. Examine the mouth for loose teeth, frail fillings or any parts of the dental mechanism that may become dislodged and act as a mechanical embarrassment during anesthesia. It is my The mouth should be made as clean as possible before operating. followin practice to apply the g solution to the operative area : Potassium Iodide Iodine Crystals Oil of Wintergreen Glycerin cl.s. ad

18 24 24 8

grains grains minims ounces

Then I spray the entire mouth with an antiseptic solution. The patient is seated, the back of the chair and the headrest are adjusted so that the head and neck are in line. The hands should be clasped and the feet crossed at the ankles (Fig. 1). The lips should be protected with Vaseline or cold cream. Alcoholics and muscular patients should be strapped to the chair after the induction period of the anesthetic. Care should be exercised in placing restraining straps so as not to interfere with the respiration or circulation. Keep the patient warm during the anesthesia. Under no circumstances should an anesthetic be given to a patient against his will. Exclude friends and relatives from the operating room. Keep the instrument trays covered and out of view. Psychic disturbances should be corrected by words of explanation, reassurance, and encouragement. ANESTHETIC

AND

OPERATIVE

TREATMENT

It is difficult and unwise for a man to be both the operator and the anesThe care of the patient during the anesthetic stage requires the mainthetist.

P. Philip

Gross

tenance of a free airway through which the patient may breathe without interference (Figs. 4 and 5). The technique of induction of anesthesia is likened by McKesson to traveling along a dark corridor. First we locate one wall by light anesthesia, then we touch t,he other wall with a dcepcr narcotic sign, note the margin of mixture

Fig.

L-Position

of

patient chair

in chair, feet tilted backward.

crossed at ankles, Head and neck

hands clasped are in line.

and

placed

Fig.

Fig.

pntimt’s

in

Fig. Fig.

Z.--Front view of head drape made of towels and clipped together. used 3.-Detailed \-iew showing arrangement of towel. ‘. for draping clothing and hair.

fol.

protection

lap.

3.

of

OF the gases and then attempt to steer a straight course midway between the two extremes. Having established anesthesia, the maintenance depends upon a free flow of gases from the machine through the nasal cavity, the nasopharynx, the oropharynx, larynx, trachea, and bronchi. The most common cause of asphyxia is mechanical respiratory embarrassment. Asphyxia also produces an excessive back pressure upon the heart and may cause heart failure. Take a deep breath, hold it, then contract the ab-

Intrathoracic pressure is thus dominal muscles, thus forcing up the diaphragm. greatly increased-the heartbeat is slowed and almost stopped for a momcut. Try this and note the reaction while taking the pulse. Much of the mechanical embarrassment to respirat,ion is produced by the operator and the anesthetist, and can easily be avoided. The weight of the mandible and the tongue, resting on the larynx, tends to depress the larynx and interfere with the normal flow of gases. The anesthetist should at all times hold up the mandible. A downward and backward pressure on the tongue forces it against the postpharyngeal wall. The finger during the operation should not be placed over, but to the side of the tongue (Figs. 6 to 9). Slumping of the patient in the chair and flexion of the head also impedes the airway (Fig. 21).

OROPHARINX

Fig.

4.-Airway

mouth

closed.

Fig.

5.-Mouth

open--dental

anesthesia.

One often sees complete closure of the narcs by pressure of the improper placement of the nasal inhaler. See that the nasal inhaler is well spread before applying it to the nose, since lateral pressure may also close the nares. Pressure upward on the nasal inhaler should be avoided (Fig. 17). The so-called throat pack has been discussed by various men. Feldman suggested the name of throat curtain, Archer, that of oropharyngeal partition. The purpose of the throat pack or curtain is to prevent the entrance of inspired air through the mouth, thus diluting the anesthetic gases. Its most important purpose, however, is the prevention of the aspiration of foreign bodies into the larynx, trachea, and esophagus. It is not the function of the pack or curtain to absorb blood; this should be removed by the suction apparatus. Cotton should never be used as a throat pack. Too small a pack may accidentally pass down the airway into the larynx and the trachea. A safety prec?aution is always to have a string securely at,tached to the pack, to facilitate its quick removal should it slip back into a dangerous position when saturated with blood and saliva. Curved hysterectomy forceps can be used to remove a sponge or pack which has slipped down into the laryngopharynx. The pack should be placed anterior to the pillars of the fauces at the junction of the hard and soft palates. Pressing the pack back too far pushes the soft palate against the postpharyngeal wall, thus closing the nasopharynx from t,he oropharyns, resulting in a complete blockage of the airway (Figs. 10 to 12). Too large packs cause too much pressure upon the soft palate and tongue L41ways have a illld t,oo large a mouth prop causes depression of the mandible.

P. Philig

Gross

Fig.

6.

Fig.

Fig.

8.

Fig.

nduction

period.

,peratire

stage

operative to

Fig.

lO.-Proper

position

of throat

pack.

throat

stage, pack.

Fig.

Mandible using using

one

held

up.

hand

Nasal

to hold

two

hands,

one

A second

mouth

prop

Il.-Improper

placement

inhaler

mandible to

hold

9.

held up

and

mandible

hanging

of throat

outside

pack.

second mouth prop tied to the first, and let it hang outside of the mouth (Figs. 6 to 9). This serves a double purpose; a dislodged prop can easily be removed and also can be used in bilateral operating. When bilateral surgical procedures are contemplated, do not remove the prop until a second prop is placed on the opposite side. It is well to insert the mouth prop or bite block between the teeth before or during induction. Some men prefer to insert the bit,e block after anesthesia is established.

Fig.

12.-Cotton

Fig.

13.

Fig. Fig.

or

small

packs

become saturated and form slipping into the laryngopharynx.

a viscous

mass

in

the

pharynx

Fig.

13.-A method 14.-Preferred

of placing nasal inhaler method of placing nasal

in position. inhaler in

14.

position.

The bite block should be removed during complete anesthesia or after the patient is completely awake. Removal during the period of awakening with a pulling motion, makes some people imagine they feel pain. ANESTHESIA

ACCIDESTS

Accidents will happen in the best of regulated families. Some anesthesias will encounter difficulties in spite of premeditation and careful and skillful administration. The throat pack may be dislodged by a struggling patient. A portion of tooth or instrument may slip down into the lower air or food passages. In event that this should occur the patient should be told, and an x-ray study of the alimentary tract, neck, and chest should be requested. Failure to do this might bring the charge of negligence.

Fig.

IS.-Proper

Fig.

placcmcnt

17.-Closure

Fig.

of nasal

of narcs

18.--Finger

by pressure

PTCSSUI‘~

Fig.

inhaler.

on

of the

tongue

16.-Improper

improper

and

trachea

placement

placement

should

of nasal

of nasal

be avoided.

inhaler.

inhaler.

If little or no ot)crativc hemorrhage occurs, it is an indication of a drop in blood pressure, which calls for immediate administration of oxygen. The lack of essential oxygen results in increasing depression of the vital centers with respiration usually ceasin g first, to be followed shortly by cardiac arrest. R,espiratory depression may also bc causrd by excessive preliminary medication or by a failing circulation. The respiration and pulse are the t,wo important guards in anesthesia. The anesthetist should hear every breath and note its rale and volume. Respiratory failure durin, 0 anesthesia calls for immediate clearing of the upper respiratory passages and insertion of an artificial airway.

Fig.

19.-Finger

presSure

Fig. Fig. Fig.

SO.-Flexion %l.-Position

forcing

tongue

against

the

postpharyngeal

20. of the head of head too

wall

Fig. impeding far forward

the

airway. causing

slumping,

impeding

and

against

21. the

airway

trachea.

548

P. Philip

Gross

Clement states, “when in doubt, give oxygen and watch its effect and results. ” Coramine, I to 5 cc., may be given intravenously in the presence of serious depression or cessation of respiration. Caffeine sodium benzoate, 7% grains, may be given to stimulate t,he circulation. POSTOPERATIVE

TREAl’MEKT

After completion of the operation, the patient is restored to consciousness. Some men advocate the removal of the nasal inhaler to allow inflow of air; others give the patient 100 per cent oxygen. This is a matter of choice. I prefer allowing the patient to inhale fresh air. When premedicat,ion has been employed and where the operation has been The patient should be allowed extensive, the recovery period will be prolonged. t,o recline in the rest room and should be kept warm. Until consciousness has been completely restored, the patient must be constantly watched in case the tongue should drop back and close the airway, vomitus be inspired into the lungs, and in a stage of excitement self injury be inflicted. Stimulants in the form of hot tea, black coffee, whiskey, or brandy may be administered when indicated. The use of a basin under thr chin does away with the necessity of moving the patient toward the cuspidor. For persistent nausea, give bicarbonate of soda in hot water or one dram of aromatic spirits of ammonia in water. The cardiac patient is best placed postoperatively in a semi-reclining position rather than in t,he horizontal plane. Elderly patients and children should not be allowed to leave the office unless accompanied by a responsible person. Following brief anesthesia the majority of patients require only a short rest, until they return to normal and are able to leave the office. REFERESCFX General anesthesia for Dental Surgery, J. A. D. A. 22: 1497, 1935. Harry W.: Nitrous Oxide anesthesia, 1939, Lea and Febiger. F. W.: M. H.: Some Aspects of Nitrous Oxide and Oxygen Anesthesia of Practical Application to Exodontia for Office Practict, Dental Digest 34: 311, 1928. Gunter, John H.: Local and General Anesthesia, 1939, Kopy Komposers. Mason, Robert L.: Pre-Operative and Post-Operative Treatment, 1937, W. B. Saunders. Mead, S. V.: Anesthesia in Dental Surgery, 1935, St. Louis, The C. V. Mosby Co. McCarthy, K. C.: Safety of Nitrous Oxide-Oxygen Anesthesia in Dentistry, J. A. D. A. 26: 197, 1939. McKesson, E. I.: Hand Book-Nitrous Oxide and Oxygen Anesthesia in Dentistry. Se&n, H. : Practical Anesthesia for Dental and Oral Surgery, 1934, Lea and Febiger. Archer, Clement, Feldman,

6740

TORRESDALE

AVEUJE