Ian Brett and Douglas Stewart. London, England. The declining use of general anesthesia for outpatient dental care has led to an increasing use of sedation.
Anesth Prog 36:140-149 1989
MONITORING
Intravenous Sedation for Conservatve Dentsty for Disabled Patients Stanley F. Malamed,* H. William Gottschalk,* Roseann Mulligan,* and Christine L. Quinnt *University of Southern California, Los Angeles, CA USA, and tOhio State University, Columbus, OH USA D ental care for the pediatric patient is relatively easy to obtain. The majority of pediatric dentists are trained in the management of such patients from their infancy through early adulthood. On the other hand, the adult disabled-or should I say the fully grown disabled-patient frequently has extreme difficulty locating dental services. This is essentially a problem for the adult disabled patient who also presents as a management problem. The Section of Geriatric & Special Patient Dentistry at the University of Southem Califomia School of Dentistry in Los Angeles inaugurated a clinical program for the management of the adult disabled patient in 1985. Within several months it became apparent that although the majority of these patients were manageable through conservative treatment techniques (including oral and/or inhalation sedation), approximately 35% of these patients were unable to tolerate the planned dental care. In September 1985 the Section of Anesthesia & Medicine inaugurated an IM/IV sedation program for disabled adult patients. This paper presents the findings obtained from the management of 96 adult disabled patients in an outpatient dental school setting. Dental care for adult disabled patients has traditionally required hospitalization and general anesthesia. Our aim in this study was to determine: (1) if intravenous (IV) sedation would provide suitable treatment conditions, and if so (2) which drug regimens were most applicable. We were attempting to provide adequate clinical conditions for treatment yet maintain the patient in a state not exceeding "moderate" sedation, in which they would be able to maintain their own airway without assistance. Additionally, it was considered to be of major importance that postsedation recovery not be prolonged. In most cases these patients were part of a group of disabled patients who were transported to our clinical facility together in a minivan under the supervision of only one
counselor. It was therefore important that recovery not be prolonged. This recovery factor has had considerable impact on our selection of medications for intramuscular (IM) and intravenous (IV) use with these patients.
TECHNIQUE
Ninety-six adult disabled patients have received dental care with IM and/or IV sedation since the inception of this program. Fifty patients were female; 46 were male. Ages ranged from 12 years to 81 years. Among the disabilities presented by the patients were: Alzheimer's disease, autism, cerebral palsy, mental retardation, muscular dystrophy, and Parkinson's disease. A significant percentage (65%) had seizure disorders as well. All patients were evaluated for appropriateness for IM/IV sedation at a visit before the planned procedure by a member of the Anesthesia and Medicine faculty. Signed informed consent and a written physical evaluation from the patients' physician were mandatory before treatment could begin. Patients were categorized as A.S.A. 11 (n = 88) or A.S.A. III (n = 8). The treatment team consisted of the following: Member IV student Dental student Dental assistant IV faculty Dental faculty
Function Sedation Dental care Assist dental student Supervise sedation Supervise dental care
INTRAMUSCULAR SEDATION An effort was made to have the patient voluntarily enter the treatment room and sit in the dental chair. Where such efforts failed, an intramuscular (IM) injection was administered. Fourteen (14.6%) patients have required IM sedation. Midazolam (11 patients) and meperidine (3 patients) have been employed successfully in all but one
Received March 1, 1989; accepted for publication June 5, 1989. Address correspondence to Dr. Stanley F. Malamed, Dentistry 4317, University Park MC-0641, USC, Los Angeles, CA 90089-0641, USA. © 1989 by the American Dental Society of Anesthesiology
ISSN 0003-3006/89/$3.50
140
Anesth Prog 36:140-149 1989 patient (midazolam). The vastus lateralis and the mid-deltoid were the sites of choice for IM administration. Once seated an IV line was established using a 21gauge indwelling catheter. Sixty percent of the patients tolerated the venipuncture well, while restraint was required for 39.6% during venipuncture. Nitrous oxide and oxygen were administered to all patients via nasal hood. Concentrations of nitrous oxide ranged from 30% to 66% as needed. Local anesthesia was administered as required for treatment. Once patients were stabilized in the chair, monitors were added. All patients were monitored via pulse oximetry, pretracheal stethoscope, electrocardiogram, and vital signs (every 5 minutes). The selection process for the appropriate sedation technique was designed as follows: a benzodiazepineinitially diazepam and with its introduction in September of 1985, midazolam-was the first drug administered. The patient was titrated to a light to moderate level of sedation (patient responded appropriately to verbal and/ or sensory stimulation and was able to manage his or her airway without assistance). Where possible, a minimum of respiratory depression, as well as a relatively rapid recovery period, was noted, thereby permitting the patient to be discharged earlier. Where, however, the benzodiazepine failed to provide suitable clinical conditions, a second drug was added. The nature of the planned dental procedure dictated the choice of this agent. Two drug groups were considered: narcotic agonists or barbiturates. Where the duration of the procedure was estimated at one hour or less, and, where the level of sedation desired remained light to moderate, a narcotic agonist (such as meperidine) was added. With a planned duration of two or more hours or if patient movement was detrimental to the success of the procedure-e.g., in taking radiographs, pentobarbital was the agent of choice. Early in our clinical experience with these patients a third technique, the Jorgensen (a combination of pentobarbital, meperidine, and scopolamine), was employed. In some cases it was also necessary to add a benzodiazepine to the Jorgensen technique. In essence then, five drug combinations were employed with varying degrees of success in the management of the adult disabled patient: (1) benzodiazepine alone; (2) benzodiazepine + narcotic; (3) benzodiazepine + barbiturate; (4) Jorgensen technique; and (5) Jorgensen technique + benzodiazepine.
RESULTS
Employing the techniques described above, we have been able to complete the dental treatment for 92 of 96 adult disabled patients (96%). Four patients proved un-
Malamed et al. 141
manageable and have been referred for dentistry under general anesthesia. The most difficult dental procedure for us to complete successfully, yet the first and most frequently required, was radiographs. Absolute immobilization was necessary for satisfactory x-rays. In order to accomplish this, moderate to deep levels of sedation were necessary. Pentobarbital was found to be the most consistently reliable agent, providing both adequate depth and duration. Periodontal procedures were considerably easier to complete because slight patient movement was tolerable. Lighter levels of sedation were necessary, and agents such as benzodiazepines or benzodiazepines plus narcotics were quite adequate. Restorative dentistry, like periodontal dentistry, was successful at lesser levels of sedation, and slight patient movement was quite tolerable. Use of benzodiazepines with or without narcotics permitted earlier discharge of the patient at the completion of the procedure.
DISCUSSION Of a group of adult disabled patients requiring dental care, 65% were able to receive the necessary care via conservative treatment techniques, including local anesthesia and inhalation sedation. Parenteral sedation was required for the remaining 35%. Conservative dental care has been successfully provided to 96% of those patients requiring parenteral sedation. Four percent have been referred for dentistry under general anesthesia. Intravenous sedation (with nitrous oxide, oxygen, and local anesthesia) provided adequate treatment conditions in 85.4% of these patients, while the use of IM sedation before IV sedation in the remaining 14.6% enabled virtually all patients to receive dental care. Probably the most critical safety factor in our management of these patients, many of whom were unable to communicate, was continuous monitoring before, during, and after the procedure. Our preference in monitoring is (1) pretracheal stethoscope; (2) pulse oximetry; (3) continuous vital signs (q 5 m); and (4) electrocardiography. All intravenously administered drugs were titrated to clinical effect. The dosages required to achieve clinically adequate sedation varied significantly from patient to patient, from procedure to procedure, and from visit to visit. IV drug dosages employed for this patient population were within the limits usually seen with a typical, nondisabled, adult population. Intramuscularly administered drug dosages were based upon weight for the initial visit and thereafter "titrated by appointment." Initial midazolam dosage was based upon 0.15 mg/kg, and meperidine on 1.0 mg/kg (not to exceed 50 mg).
142 Monitoring IV Midazolam/Methohexital
Lighter levels of intravenous sedation were quite adequate and permitted the successful completion of restorative dentistry, periodontal procedures, and oral surgery. Benzodiazepines either alone or in combination with narcotics were most often employed. Endodontics could be managed with these same techniques except for radiographs, which required the depth of sedation to be increased, usually with a barbiturate. The most taxing procedure proved to be completing radiographs successfully, due to the requirement that the patient be immobile. Use of the barbiturate pentobarbital permitted us to complete this successfully on all patients. The judicious
Anesth Prog 36:140-149 1989
administration of local anesthesia enabled us to minimize the required dose of barbiturate by depressing patient response to placement of the x-ray.
CONCLUSION The use of IV sedation, either alone or in combination with IM sedation, has permitted a population of adult disabled patients to receive routine dental care, where such patients had previously required general anesthesia for the same treatment.
The Monitoring of Patents Undergoing Intravenous Midazolam/Methohetal Ian Brett and Douglas Stewart London, England
The declining use of general anesthesia for outpatient dental care has led to an increasing use of sedation technique and a continuing search for the ideal sedative drug or combination of drugs. In the U.K. midazolam (Hypnoval) has been available for the past 5 years and is undoubtedly the most widely used agent in that country. But, like all sedative drugs, it has an incidence of failure in outpatient work. Various drugs have been combined with midazolam in an attempt to reduce this failure rate. These have included nitrous oxide and oxygen supplementation, and the combination with methohexital to enhance the sedative effect of midazolam. Again, none of these adaptations is 100% successful: the midazolam-methohexital combination, however has considerable advantages along with some disadvantages. One suggested disadvantage was the possibility of very considerable drops in blood pressure that may accompany this technique. METHODS It was to test this theory that we conducted a small trial. We selected, from a much larger group, ten patients who had all been sedated for conservative treatment utilizing Received March 1, 1989; accepted for publication June 5, 1989. Address correspondence to Dr. Ian Brett, 53 Wimpole Street, London, England. ©) 1989 by 1. Brett and D. Stewart
the same drug combination and dosage, in this case the slow (2-minute) IV injection of 5 mg midazolam followed by the slow (approximately 1-minute) addition of 20 mg methohexital. Local anesthesia was then administered and the dental treatment carried out. Systolic and diastolic blood pressures were measured at the beginning of treatment, after the administration of the midazolam, methohexital, and local anesthesia and then measured again at the end of the procedure.
RESULTS AND DISCUSSION The results suggest that whereas mean blood pressure does fall somewhat after the administration of the midazolam, the addition of 10 mg methohexital does not greatly increase this fall. The pulse rate and the baroreceptor reflexes that influence it are affected by sedation and anesthesia. An increase in pulse rate takes place when cardiac output decreases (unless complete beta-adrenergic blockade has been instigated).1 Cardiac output is controlled by the interdependent influence of venous return, myocardial force of contraction, and heart rate.2 Blood pressure depends on the vascular tone and cardiac output. A drop in blood pressure is commonly seen in sedated patients and, if significant, can be detrimental. The electrocardiogram (ECG) is a recording of the electrical activity of the heart via noninvasive electrodes.
