Anesthetic Misadventures

LETTERS

TO THE ED ITOR

Gow-Gates mandibular block □ I would like to have the opportunity to comment on an article by Dr. Levy entitled “An assessment of the GowGates mandibular block for third molar surgery” (July 1981). I am most grate­ ful for such an excellent paper, and his interest in carrying out such a unique comparative study. However, it is necessary to correct a misunderstanding. It is the anterolat­ eral, not the anteromedial, side of the condyle that establishes the injecting site. This error contributes to the in­ ability of contacting bone, as well as providing auriculotem poral anes­ thesia associated with a differential block of the buccal nerve when the so­ lution is deposited on the medial side of the condyle. G. A. E. GOW-GATES PARRAMATTA, ENGLAND

Injection system □ We have successfully used a cur­ rently marketed periodontal ligament injection system for extractions and fillings when one or two teeth are in­ volved. Care must be exercised in using only the least amount of anes­ thetic necessary to obtain anesthesia. In one case, the mandibular right first premolar was anesthesized with this method for extraction on orders of the patient’s orthodontist. The tooth was h e a lth y w ith no caries or periodontal involvement. Five minutes after the injection, the tooth became loose, and the patient was able to remove it. Apparently, hydrostatic pressure “floated” the tooth out of its support­ ing structures. This could occur with a tooth needing only a restoration, even when the doctor is careful. Don’t be surprised. PAUL W. NELSON, DDS NEDERLAND, TEX

Hemostasis after tooth extraction □ The article, “Hemorrhage after a simple extraction of the mandibular left first premolar” (July 1981), was pertinent in bringing to our attention the potential effects of a fairly com­ monly used drug on hemostasis after tooth extraction. However, we object strongly to the drug being called an an­ ticoagulant. Coagulation is only one phase of the total process of hemo­ 692 ■ JADA, Vol. 103, November 1981

stasis. Nitroglycerin has no effect on the coagulation mechanism. It is true that it could affect hemostasis by its vascular dilatation properties. In the case reported, the patient was receiving a true anticoagulant drug, dicumerol, and it is conceded that the vascular d ila tin g effect of n itro ­ glycerin might have been enough to tip the balance toward continued hemorrhage. For the patient who is not receiving an anticoagulant, and who takes nitroglycerin, we do not think that this possibility poses a serious risk. In any event, we would certainly not withhold nitroglycerin from any patient who truly needs it because of the remote possibility of inhibiting hemostasis. JAMES H. DIRLAM, DDS CHARLES E. HUTTON, DDS INDIANAPOLIS

□ This letter is in response to the clin­ ical report entitled “Hemorrhage after a simple extraction of the mandibular left first premolar” by Drs. Manne and Kramer (July 1981). The patient was receiving dicumarol after a myocardial infarction. The authors attributed the postoperative bleeding to sublingual nitroglycerin taken by the patient after the surgical procedure. A more likely cause of the hemorrhage was the low level of prothrombin activity at the time of surgery. Nitroglycerin is an effective medica­ tion for the treatment of angina pec­ toris.1 It has no direct effect on the heart itself, but acts in decreasing the oxygen expenditure of the left ventri­ cle. This is accomplished by a gener­ alized venous d ilatation and sub­ sequent decrease in venous return. Ni­ troglycerin also normalizes the in ­ creased lactate production of the myocardium during angina attacks.2 It is true that the action of nitroglyc­ erin is related to its ability to relax smooth muscle, particularly in large veins.1 However, there are no vessels of this type close enough to the surgi­ cal site to affect postoperative coagula­ tion.3 Hemorrhage from an extraction site originates from the periodontal membrane, gingiva, and alveolar bone. There are no smooth muscle cells present in these structures. Dicumarol is an oral anticoagulant used primarily to decrease the inci­ dence of secondary thromboembolism after myocardial infarction.1 The ac­ tion of dicumarol is the competitive

inhibition of vitamin K in the liver. This leads to a decreased production of prothrombin and factors VII, IX, and X.4 The amount of anticoagulation caused by dicumarol is measured by the prothrombin time (PT). PT is ex­ pressed in seconds, compared with a control, or as a percentage of normal activity. A normal therapeutic range of anticoagulation is usually 2 to 2.5 times the control or 20% to 30% activ­ ity.5 When a patient receiving an an­ ticoagulant is about to undergo a sur­ gical procedure, the treatment objec­ tive is to increase the prothrombin ac­ tivity to sufficiently decrease postop­ erative hemorrhage without causing a thromboembolic event. This value is approximately 1.5 times the control or 45% activity.6 In this case, the patient’s PT was 30 seconds. W ith a usual control of 12 or 13 seconds, the patient’s prothrombin activity was approxim ately 30%. Therefore, the postoperative bleeding episode would more correctly be at­ tributed to insufficient prothrombin activity. The surgical treatment of patients undergoing anticoagulant therapy must be approached with great care. A delicate balance of prothrombin activ­ ity must be reached to avoid excessive p o s t o p e r a t iv e h e m o r r h a g e or thromboembolism. STEPHEN E. NEEDLE, DDS, MS UNIVERSITY OF CALIFORNIA LOS ANGELES 1. Goodman, L.S., and Gilman, A. The phar­ macologic basis of therapeutics, ed 5. New York, MacMillan Publishing Co, Inc, 1975. 2. Chiong, M.A., and others. Influence of nitroglycerin on myocardial metabolism and hemodynamics during angina induced by atrial pacing. Circulation 45:1045-1056,1972. 3. Gray, H., and Goss, C.M. Anatomy of the human body, ed 29. Philadelphia, Lea & Febiger, 1973. 4. Guyton, A.C. Textbook of medical physiol­ ogy, ed 6. Philadelphia, W. B. Saunders Co, 1981. 5. Beeson, P.B., and McDermott, W. Textbook of medicine, ed 13. Philadelphia, W. B. Saunders, 1971. 6. Papper, S. Manual of medical care of the surgical patient, ed 1. Boston, Little, Brown and Co, 1976.

Anesthetic misadventures □ Dr. Okuji’s excellent report entitled “Hypoxic encephelopathy after the a d m in is tr a tio n of a lp h a p ro d in e hydrochloride” (July 1981) merits ad­ ditional comment. Anesthetic misad-

LETTERS TO

THE ED ITOR

ventures are often attributed to drug idiosyncracies or patient hypersen­ sitivity, when in fact the mishap is the result of the wrong technique, with the wrong drug or drugs, for the wrong pa­ tient. As reported, a 34-month-old boy re­ ceived intramuscularly 20 mg of alphaprodine and 25 mg of prometha­ zine. A prudent approach is to start an intravenous drip through w hich a drug or drugs of choice are introduced in small increments at calculated intervals. A bolus dose invites a point of no return. In Dr. Okuji’s report, the child was described as resting and responsive to verbal commands 15 minutes after the bolus dose. The operative procedure began shortly thereafter. Synthetic, narcotic, sedative, and analgesic agents are respiratory de­ pressants. Response to verbal com­ mands is important because these are used to instruct and remind the patient to breathe. I point this out to illustrate the fragility of a technique that places the responsibility of life-sustaining in ­ structions on a frightened, drugged, 34-m onth-old boy w ith a c o m ­ promised airway. Dr. Okuji properly noted that vital signs were not recorded. Too often, dependence on electronic and me­ chanical devices are misplaced. Reli­ able monitors in eyeball range of the dentist are cyanosis (nail beds, pallor, eyelids), and the variety of movements of the bared chest cage and muscula­ ture. These give early warnings of res­ piratory distress. Finally, I would like to comment on the resumption of the operative proce­ dure after resuscitation at a local hos­ pital shortly after clonic and tonic sei­ zures developed in a patient who was then referred to a major hospital. Prob­ lems tend to be cumulative and the de­ cision to postpone further treatment is not hard to make, especially when given the choice of a healthy child w ith u n fille d prim ary teeth, or a brain-damaged child with temporarily filled primary teeth. CONRAD E. MOSES, DDS WILMINGTON, DEL

□ It must jar the senses of any practic­ ing dentist who uses sedation tech­ niques to read Dr. Okuji’s report enti­ tled “Hypoxic encephalopathy after the administration of alphaprodine hydrochloride” (July 1981). .. . 694 ■ JADA, Vol. 103, November 1981

Use of drug regimens with indefen­ sible routes of administration should be assigned to the realm of the teratologist or to the pharmacologist who is researching drug combinations and dosages. THEODORE P. CROLL, DDS DOYLESTOWN, PENN

□ This letter is in reference to the arti­ cle by Dr. Okuji entitled “Hypoxic en­ cephalopathy after the administration of alphaprodine hydrochloride” (July 1981). It is a disservice to title this article “alphaprodine”; it should be titled, “polypharmacy.” The case report was that of a 34 month-old child who was medicated with diazepam, alphapro­ dine, promethazine, and injected with 2% lidocaine. The combination of drugs and their dosages given this child approaches amounts frequently given to adults to remove impacted third molars. No mention was made of the use of nitrous oxide I oxygen or oxygen alone by inhalation. Many practitioners believe that oxygen by inhalation is absolutely essential to maintain oxyhemoglobin saturation at satisfactory levels when intraveous sedatives are used. Alphaprodine is a relatively safe narcotic with a lower incidence of nausea, vomiting, and hypotension than meperidine. It has been used safely by obstetricians in childbirth for many years; respiratory depression certainly is one c o m p lic atio n in childbirth that no one wants, and it is not a problem if proper doses of Al­ phaprodine are used. Another important point that needs to be emphasized is that the respira­ tory depressant effect of large doses of alphaprodine can be mitigated by the addition of Levallorphan in the con­ centration of 1 mg Levallorphan to 60 mg alphaprodine. This combination does not materially affect the sedative I analgesic qualities of alphaprodine. It is regrettable that a drug such as alphaprodine with so many beneficial indications can be withdrawn from the market because of a few adverse reac­ tions caused by improper use. ALBERT F. STAPLES, DMD, PhD THE UNIVERSITY OF OKLAHOMA OKLAHOMA CITY

□ Author’s comment: I am in com­ plete agreement with Dr. Staples that alphaprodine is a clinically safe and beneficial agent when administered

judiciously. I think that Dr. Staples may be a bit harsh in describing the ar­ ticle title selection as a “disservice.” For title brevity, “alphaprodine” was chosen because it is the agent with respiratory depression properties. Also, the article did state that the dos­ age of alphaprodine should be reduced when used in conjunction with other agents. I cannot comment about the administration of nitrous-oxide I oxy­ gen or oxygen alone during the re­ ported case, because the medical rec­ ord made no mention of its use. Fi­ nally, I would hope that this case re­ port has reminded all practitioners th a t the a d m in is t r a t io n of any therapeutic agent should be done pru­ dently and with care. DAVID M. OKUJI, DDS GILROY, CALIF

Ankyloglossia □ In the photograph of the lesion of the tongue in the article, “Papillary, exophytic lesion of the tongue” (Au­ gust 1981), I notice the patient is “tongue-tied” (ankyloglossia). In their summary, the authors state, “The cause of this lesion is unknown.” I would like to venture an-educated guess that this lesion would not have formed if a lingual frenectomy had been done when the patient was a young child. Protrusion of the tongue would probably place the lesion right on the incisal edges of the lower in­ cisors. After the tongue had rubbed there for approximately 31 years, one would expect at least a callous to form. This case exhibits another reason for correcting ankyloglossia when it inter­ feres with normal tongue function. ROBERT F. RIMSTIDT, DDS BLOOMINGTON, IND

Radiopaque plastics □ I think that the Council on Dental Materials, Instruments, and Equip­ ment should include a requirement for all plastics used in the mouth to be radioscopic. I have seen previous com­ ments in articles about the need for radioscopic visibility in situations in which there is evidence that a person has ingested or aspirated dental plas­ tic. This has now happened to one of my patients. A radiologist thought he could detect the acrylic partial denture in the patient’s stomach at one time,