Sedation Dentistry

Sedation dentistry refers to the use of sedation during dental treatment. Sedation is most commonly used during extensive procedures, for patients with dental phobia or for patients who find it difficult to sit still. There are different types of sedation, including nitrous oxide ("laughing gas"), IV sedation, oral sedatives and general anesthetic.

Sedation
Sedation can range from the use of nitrous oxide to calm a patient to general anesthetics used to put patients to sleep. Patients with dental phobia, low pain tolerance, major dental treatment, physical handicaps or strong gag reflexes may require sedation. Procedures like fillings, crowns, root canals, extractions, cosmetic procedures and periodontal treatments often require sedation.
Sedation is endorsed by the American Dental Association and is an effective way to make many patients comfortable during their dental visit. Before using a sedative or anesthetic, it is important to tell your dentist about any medications or medical treatments your child is receiving. Before administering any sedative or anesthetic, your dentist will talk to you about the process of sedation and pre- and post-sedation instructions.

"Laughing Gas"
Nitrous oxide, more commonly known as laughing gas, is often used as a conscious sedative during a dental visit. The gas is administered with a mixture of oxygen and has a calming effect that helps phobic or anxious patients relax during their dental treatment. Because it is a mild sedative, patients are still conscious and can talk to their dentist during their visit. After treatment, the nitrous is turned off and oxygen is administered for five to 10 minutes to help flush any remaining gas. The effects wear off almost immediately. Nitrous oxide rarely has side effects, although some patients may experience minor nausea and constipation. Your doctor will provide you with pre- and post-sedation instructions.


Below is an article from the Journal of American Dental Association on Oral Conscious Sedation

J Am Dent Assoc, Vol 132, No 11, 1531-1539. © 2001 American Dental Association

RESEARCH
JADA Continuing Education

Adverse events and outcomes of conscious sedation for pediatric patients

Study of an oral sedation regimen
PATTARAWADEE LEELATAWEEDWUD, D.D.S., M.S. and WILLIAM F. VANN JR., D.M.D., M.S., Ph.D.

Background. The authors report on adverse events and sedation outcomes for an oral sedation regimen of chloral hydrate, meperidine and hydroxyzine with 100 percent oxygen, or O2, supplementation.

Methods. In a five-year retrospective study, the authors examined 195 records of conscious sedation performed in 111 healthy children aged 24 to 48 months (mean, 47 months). The authors analyzed age, sex, weight, methods of drug delivery, waiting time after drug administration, treatment rendered, treatment time, adverse events, sedation outcomes and the number of visits needed to complete treatment using descriptive statistics, 2 tests, t test and analysis of variance.

Results. Adverse events—including vomiting, desaturation, prolonged sedation and an apneic event—occurred in 3 percent of all sedations and were minor. Seventy-two percent of sedations had satisfactory behavioral outcomes, 23 percent had unsatisfactory outcomes, and 5 percent of the cases were aborted because of disruptive behavior. Sex was not a significant factor for the success. Patient compliance with drinking medications (P = .013) and a longer waiting time after medication intake (P = .012) yielded better sedation outcomes.

Conclusions. Minimal minor adverse events occurred with this sedation regimen. The success rate was 72 percent. Compliance with taking oral medications and waiting time appeared to be important factors in predicting sedation success.

Clinical Implications. This oral sedation regimen offers reasonable outcomes with minimal adverse events under a strict protocol and use of O2 supplementation. The results also revealed associations that give guidance for case selection and outcome prediction.
For many years, conscious sedation has been a popular pharmacological approach in the management of young uncooperative children who need invasive dental and medical procedures. While conscious sedation is believed to be used widely by general dental practitioners, or GPs, the frequency of its use by them is not well-documented. The published literature, however, does contain several reports that document the frequency with which pediatric dentists use conscious sedation. Davis1 surveyed the members of College of Diplomates of the American Board of Pediatric Dentistry in 1988 and reported that more than 76 percent of respondents used conscious sedation in their practices. In 1989 and 1993, Houpt chronicled the results of two large national surveys on the use of sedative agents by members of the American Academy of Pediatric Dentistry, or AAPD, referred to as Project USAP I2 and Project USAP II.3 The 1,497 respondents in Project USAP II3 reported 33,208 drug administrations for sedation in a three-month period. In 1996, Wilson4 reported the results of a survey that reviewed responses from 1,758 AADP members. Forty percent reported using sedation as frequently as one to five times weekly, and 20 percent reported using sedation more frequently than five times weekly.
An oral sedation of chloral hydrate, meperidine and hydroxyzine pamoate offers reasonable outcomes with minimal adverse events under a strict protocol and use of supplementary oxygen. Practitioners are aware that conscious sedation procedures carry risks from the potential side effects of the medications. For example, nausea and vomiting are not uncommon with sedation agents such as chloral hydrate, meperidine and nitrous oxide.5–7 The most serious adverse outcome of pediatric conscious sedation is respiratory compromise and its related consequences.8–14 Respiratory compromise can lead to hypoxemia and predispose children to a range of deleterious conditions.14
Morbidity and mortality from pediatric conscious sedation have been reported periodically.15–18 Since the publication of Goodson and Moore’s19 1983 article on sedation misadventures, the safety of sedation regimens for children has received considerable scrutiny. In 1985, the emergence of the Guidelines for the Elective Use of Conscious Sedation, Deep Sedation, and General Anesthesia in Pediatric Patients20 elevated the professional standards for the safe provision of sedation of children. Professional discourse on the standards and their subsequent revisions by American Academy of Pediatrics in 199221 and AAPD in 199322 and in 199623 has led to increasing attention on the safety of conscious sedation of children, especially in a dental setting. Even so, conscious sedation for children still appears to carry significant potential for adverse outcomes. Wilson4 noted that of the 1,758 pediatric dentists who responded to his 1996 survey, 30 percent had experienced compromised airways in patients sedated with sedatives and nitrous oxide/oxygen analgesia, and 5 percent noted that they had activated emergency medical services secondary to sedation procedures.
Many drug regimens and routes of administration have been investigated and reported for conscious sedation of children in the dental setting. One regimen that has been the subject of several studies10,12,24,25 is an oral elixir of chloral hydrate (50 milligrams per kilogram), meperidine (1.5 mg/kg) and hydroxyzine pamoate (25 mg). In this context, we will refer to this elixir as the ChMH regimen. Previous studies have reported success rates with this regimen ranging from 60 to 66 percent.24,25
The rationale for ChMH. The rationale for the ChMH regimen is based on its potential for anxiolytic, analgesic and antiemetic effects. Chloral hydrate is a psychotropic agent with anxiolytic, sedative and hypnotic properties.6,26 It has a wide margin of safety and has been studied extensively as a sedative drug for children. It is relatively easy to administer and is well-absorbed orally, requiring approximately 30 to 60 minutes to reach its peak effect.5 Chloral hydrate is the most common sedative agent used in conscious sedation for pediatric dental patients.2,3
Meperidine is a narcotic analgesic with effects similar to, but less potent than, morphine.6 Its therapeutic actions include sedation and analgesia. Meperidine can cause respiratory depression, which can be potentiated by anxiolytic agents such as chloral hydrate. Oral meperidine has a rapid onset of 10 to 15 minutes; however, it requires one to two hours to reach its peak effect.27
Hydroxyzine pamoate is an antihistamine and psychotropic agent that possesses antiemetic, anxiolytic, sedative and hypnotic properties. Oral hydroxyzine is absorbed rapidly with onset within 15 to 30 minutes.28 It has a wide margin of safety and is a popular drug in pediatric conscious sedation.2,3 Hydroxyzine commonly is used as a sole agent or in combination with chloral hydrate and meperidine.26,28 When used as a combination drug with other central nervous system depressants, hydroxyzine can potentiate the central nervous system depression effect.6,28 The antihistamine and antiemetic properties of hydroxyzine are used to overcome the histamine-releasing effect of meperidine, as well as the nausea and vomiting effects of both chloral hydrate and meperidine. The adverse effects of hydroxyzine are mild and transitory in nature.6
Nathan and West24 reported better sedation outcomes by adding meperidine to chloral hydrate and hydroxyzine than with the same regimen without meperidine. Hasty and colleagues10 corroborated this finding and reported that meperidine did not increase the risk of experiencing complications, including respiratory compromise. They attributed the more favorable outcomes to the analgesic effects of meperidine that decreased the perception of pain from dental procedures and increased the sedative impact of the regimen.
In the Pediatric Sedation Clinic, or PSC, in the School of Dentistry at the University of North Carolina at Chapel Hill, ChMH has been used as one of several regimens for more than a decade. Supplemental 100 percent oxygen, or O2, is added to ChMH based on the theoretical concept that 100 percent O2 elevates the partial pressure of arterial oxygen, or PaO2, in the sedated child, and this elevated PaO2 provides an extra measure of safety during conscious sedation.12
To date, there have been no reports or studies of adverse events using the ChMH/O2 sedative regimen. Therefore, the purpose of this article is to report adverse events and sedation outcomes from five years of experience using the ChMH/O2 regimen of chloral hydrate (50 mg/kg), meperidine (1.5 mg/kg) and hydroxyzine pamoate (25 mg) with 100 percent O2 supplementation.
We reviewed patients’ dental and anesthesia records during the five years from July 1, 1992, through June 30, 1997. All sedations were performed in healthy children referred to PSC because of their inability to cooperate for needed dental care in the conventional dental setting. Before sedation, the children’s pediatricians or family physicians evaluated them to ensure that they had no contraindications for outpatient conscious sedation.
A variety of sedative regimens with and without inhalation agents were employed in the PSC. In this study, we are reporting only on those children who received ChMH/O2 in all of their sedation visits. Our study focuses on ChMH/O2 because of its popularity among general and pediatric dentists and because there has been no report of adverse effects with this regimen. Our data are limited to children 24 to 84 months of age because our case files contain few ChMH/O2 cases for children younger than 24 months of age or older than 84 months of age.
Conscious sedation procedures. The PSC standard for conscious sedation protocol was followed for all cases included in this study. This protocol required dietary restrictions that permitted no milk or solid food up to eight hours and no clear liquid for up to four hours before oral drug administration in accordance with the AAPD’s Guidelines for the Elective Use of Pharmacologic Conscious Sedation and Deep Sedation in Pediatric Dental Patients.22,23 On the day of sedation, the child was weighed, and the oral medications, or meds, were dispensed by weight in a small cup. The child was asked to drink the meds from the cup. If the child refused, the meds were administered by syringe with a parent’s assistance. The method of administration and approximation of lost meds (in milliliters) were documented in the patient’s record. After drug administration, the child waited in a quiet, dimly lit holding area. Parents were urged to cuddle the children and rock them in a rocking chair to encourage a quiet waiting time.
We defined and recorded waiting time as the interval between drug administration and the seating of the child in the dental chair. Based on the sedative and analgesic agents in the ChMH, the recommended waiting time is 45 minutes. If the child was not drowsy or sleeping after 45 minutes, the operator had the prerogative to wait longer.
The parent or the operator carried the child to the operatory, and all children were secured on an immobilizing board to control involuntary movements that might occur during the dental procedure. Monitoring probes were attached. A nasal cannula was placed, and supplemental 100 percent O2 was administered continuously throughout the operation. The maximum dose of local anesthetic was limited strictly to 4.4 mg/kg for all patients.
Patients were monitored continuously using a pulse oximeter, a precordial stethoscope and visual observation. Capnography was adopted for routine use in the PSC in 1995; accordingly, end-tidal carbon dioxide, or ETCO2, measures were recorded in the anesthesia record from that time forward. A resident or attending faculty member was appointed as a dedicated monitoring assistant for each sedation. The monitoring assistant communicated as needed to help the operator with airway positioning and to leave the primary provider/dental operator (also a resident or attending faculty member) free to concentrate on the dental procedures. The monitoring assistant used a written time-based anesthesia record to document physiological signs every five minutes. Pulse rate; respiratory rate, or RR; oxyhemoglobin saturation, or SpO2; and ETCO2 (starting in 1995) were recorded. The monitoring assistant also documented the details and timing of any unusual or adverse events that occurred during the procedure. The dental operator documented the treatment rendered at each visit and the sedation outcome.
As a part of the protocol, each parent was given written postoperative instructions that included a telephone number at which to call the primary provider to report and discuss any postoperative sequelae or concerns. All such concerns were recorded in the patients’ records.
Data collection. Based on a comprehensive review of all sedation cases performed during the five-year period, 111 children met the inclusion criteria, which resulted in 195 conscious sedation appointments. All of the children were 24 to 84 months of age and received only ChMH/O2 for all sedation appointments. From these 111 children, we collected the following data from dental and anesthesia records: age, sex, weight, medical history, current medical conditions, total sedation visits, compliance in taking meds, waiting time, total milligrams of local anesthetic given, treatment duration, vital signs, SpO2, ETCO2 (starting in 1995), adverse events, treatment rendered, sedation outcomes and postoperative sequelae.
We defined true desaturation as a pulse oximeter reading of SpO2 below 95 percent taken while the patient was quiet and still. We defined true apnea as no visual signs of breathing, no breath sounds audible via precordial stethoscope and a capnograph reading of zero for RR and ETCO2 for 25 seconds.10 We defined prolonged sedation as one in which the child needed more than 30 minutes after the conclusion of dental treatment to recover and meet the discharge criteria recommended in AAPD’s guidelines20; in brief, the child needed to be walking, talking and drinking to be dismissed.
We recorded a sedation outcome based on the operator’s judgment using a subjective classification, wherein satisfactory sedation was defined as completion of planned care without difficulty. Unsatisfactory sedation was defined as a completion of planned care with difficulty due to disruptive behavior or completion of less care than planned. Aborted sedation was defined as discontinuation of care resulting from disruptive behavior with concerns for patient or dental team safety.
We collected the completed treatment as relative based value units, or RBVU, wherein all types of dental work were converted to numeric scores to make valid comparisons of the treatment rendered across all sedation appointments. For example, the score of a one-surface amalgam restoration in a primary tooth was 1.0, the score of a two-surface amalgam was 1.5, and the score of a prefabricated stainless steel crown in a primary tooth was 4.0.
The relative based value system called Dental Relative Based Value Scale/Units29,30 was developed in 1985 through surveys that collected input from practitioners valuing each dental procedure based on its time and difficulty. The data were received from thousands of dentists from all specialties and were analyzed for validity and normal distribution. Standard deviations and means were used to develop the scale. The relative value has been used as a way to value dental procedures across disciplines and specialties and is considered to be a reliable measure. It is used widely by health insurance organizations and Medicaid agencies to determine the value of procedures for reimbursement.30
Data analyses. Descriptive statistics were employed to illustrate results in frequencies and percentages. Each sedation visit was analyzed independently. We used 2 tests to assess statistical differences in categorical data, while we used Student t test and analysis of variance, or ANOVA, for continuous data. We used Bonferroni inequality tests to determine the difference between group studies when 2 tests revealed significant difference and Scheffé tests if ANOVA showed statistical significance.
RESULTS The study patients’ demographics are given in Table 1. There was no difference in sex distribution. Eighty-seven percent of the children (97/111) cooperated in drinking all their meds from a cup during 174 visits. Although parental and operator coaxing were sometimes needed, for only 13 percent of the children (14/111) in 21 sedation visits was it necessary to administer meds via syringe. The patients received all meds via the syringe in 10 of 21 visits, while the remainder lost some meds because of their refusal to swallow; for example, they expectorated at least some of the meds.
The mean waiting time was 60 minutes. Once they were in the dental chair, all of the patients were monitored continuously using visual assessment, a precordial stethoscope and a pulse oximeter. A capnograph was used in 41 percent of visits (80/195). The overall mean treatment duration was 63.5 minutes (range 15–120 minutes). Treatment included alloy and resin restorations, pulp therapy, stainless steel crowns, extractions, space maintainers, sealants and preventive care. Data sorted by sedation outcome are illustrated in Table 2. The proportion of satisfactory, or S; unsatisfactory, or U; and aborted, or A, sedations were 72 percent, 23 percent and 5 percent, respectively. There were no significant differences by age (P = .232) or weight (P = .768) among the three sedation outcomes. Among boys, outcomes were 77 percent S, 21 percent U and 2 percent A; among girls, the outcomes were 68 percent S, 24 percent U and 8 percent A. While boys tended to have more favorable outcomes, this sex distribution was not statistically significant (P = .092). Among the patients who drank all their meds from a cup (174/195), 75 percent had satisfactory sedation appointments, while 25 percent had either unsatisfactory or aborted sedation appointments. Only 48 percent of the patients who refused to drink their meds had satisfactory appointments. Sedation outcomes were higher among those children who drank all meds from a cup, and this difference was statistically significant (P = .013).
The mean waiting time was statistically significantly different among S, U and A sedation outcome groups (61, 58 and 49 minutes, respectively, P = .012). Scheffé test revealed that the mean waiting time of the S group was significantly longer than that of the A group.
The mean treatment duration of S and U groups were 65 and 64 minutes, respectively, and this difference was not statistically significant. Likewise, the RBVU was 11 and 12 in groups S and U, respectively, a difference that was not statistically significant (P = .193). In summary, there were no significant differences in the duration of treatment and amount of treatment achieved between the U and S groups.
Adverse events were reported in six of the 195 visits, or 3 percent of the sedation appointments. Adverse events included postoperative vomiting, true desaturation, true apnea and prolonged sedation (Table 3). All of the patients who experienced adverse events had satisfactory sedation appointments.
DISCUSSION We conducted this retrospective study to report the overall sedative outcomes using the ChMH oral regimen and assess the incidence of adverse effects. Although all sedation visits were performed in the same clinic setting and under the same strict protocol, multiple operators and monitoring assistants were involved. The findings must be interpreted recognizing these design limitations. Compliance with drinking meds. The oral route of administration is the most popular choice by pediatric dentists,28,31 but few studies have investigated acceptance for oral meds in children. Haas and colleagues32 compared the acceptance of oral chloral hydrate with oral midazolam for children 3 to 10 years of age, finding no difference in acceptance when both meds were mixed with syrup and orange juice. The ChMH oral regimen is a well-tolerated mixture, and we found that 91 percent of the children drank all their meds from the cup at their first sedation visit and only four patients refused to do so at the second visit. This was not surprising, as most children are accustomed to drinking meds from a cup and the bitterness of chloral hydrate is masked by the sweet taste of hydroxyzine in the ChMH regimen.
Among the noncompliant children, nine girls refused to drink meds compared with five boys. Ten children refused to do so in their first sedation visits, though they had no previous experience with the taste of these meds. In general, our findings suggest that a child’s refusal to drink meds should signal a concern; we recorded a loss of 5 to 30 percent of the meds using a syringe, and the percentage of successful sedation was lower in this group.
Waiting time. The waiting time for a given oral regimen varies depending on pharmacodynamics of the drugs in the specific regimen. Drug onset is the time in which the effect of the drug can be detected. For sedatives, onset might induce sleep in a nonstressful situation. Because dental procedures usually consist of multiple stimulations that include mild to moderate painful stimuli, the waiting time should be calculated to coincide with onset of the drugs’ peak effect.
PSC’s protocol recommends a waiting time of approximately 45 minutes. Occasionally children will go through a paradoxical excitation stage, which can prolong waiting time significantly. When the child is not sleeping or drowsy, more waiting time usually is given. There are, however, many occasions when the child may fall asleep soon after administration of meds, and this presents a temptation to initiate treatment sooner than the 45 minutes’ waiting time. On the basis of our findings, a strong argument can be made for waiting a minimum of 45 minutes for the ChMH regimen to take effect, no matter how profoundly the child is sleeping before this critical time. In some situations, children will fall asleep soon after receiving ChMH meds because of the rapid onset of the meperidine and hydroxyzine; however, the peak effect of the ChMH regimen is most likely in the range of 60 to 90 minutes. Hasty and colleagues10 speculated that sedation outcome would be better if invasive stimuli, such as injection and rubber dam clamp placement, are timed to occur as nearly as possible to the time of peak effect of meperidine.
Our findings suggest that waiting time may be a critical variable for a successful sedation outcome. Accordingly, physicians should thoughtfully consider this factor and pay attention to the specific actions of their sedation drugs. Most reported sedation studies do not describe or manage the waiting time variable; we suggest that waiting time should be analyzed more carefully in future sedation studies.
Waiting a sufficient amount of time between anesthetic administration and treatment may be a critical variable for a successful sedation outcome.
Sedation outcomes. We acknowledge that our assessment of sedation outcomes was highly subjective. The standard of research methodology for assessment of child behavior in the dental setting should rely on video technology using valid and reliable behavior assessment scales.33 We made no attempt to achieve this standard, and, thus, our sedation outcome results must be viewed as global and subjective. Nevertheless, our findings are consistent with other studies that have used the ChMH regimen with the same dosages for healthy children 24 to 48 months of age.
Nathan and West24 used a dichotomous behavioral rating scale and reported successful sedation (defined as treatment achieved without restraint) for 60 percent of their cases in a ChMH study involving 135 children whose mean age was 34 months. They also found that the ChMH regimen was 45.6 percent more successful than the regimen that used chloral hydrate and hydroxyzine alone. Croswell and colleagues25 reported a 66 percent success rate in 44 patients (mean age 39 months). Our findings are in the same general range, with a 72 percent success rate reported for 195 sedations (mean age 47 months).
Most previous sedation studies for preschool children have not addressed sex differences per se. One exception is a study by Needleman and colleagues11 that reports 15.5 percent greater success for boys than for girls in a sample of 385 sedations in 336 patients (mean age 30 months). In our study, we found that boys were more complaint in taking meds. Although not statistically significant, we found a clear trend that male sedation outcomes were more successful. Boys also had fewer aborted sedation visits—only two aborted appointments compared with eight aborted appointments for girls. Future pediatric sedation studies should examine potential sex differences more closely.
We found no difference in age and weight among our group of patients with different sedation outcomes, a similar finding to that reported by Needleman and colleagues.11 Our sample size, however, was too small to draw valid conclusions about age and weight as predictors of sedation outcomes.
Treatment outcomes. RBVUs represent unit values reflecting the time and effort to complete various dental procedures. We found these unit values to be useful in converting various types of dental procedures to a common denominator for comparison purposes. Although the system has not been used often in clinical research, it has been used widely for management and cost analysis purposes.30
We found no significant differences in mean value of care delivered in the satisfactory vs. unsatisfactory groups; indeed, the results showed slightly more work completed for the unsatisfactory group. We point out again that our sedation outcome assessment was subjective and based not on the quantity of treatment completed, but on the difficulty of completing care in a given situation and the operator’s judgment. The most likely explanation for our finding is that operators made every effort possible to complete the care for those children who were the most challenging in an attempt to limit future sedation visits or avoid care under general anesthesia.
We found that 93 children had all their treatment completed while under conscious sedation. Of the remaining 18 patients, five whose sedations were aborted were referred to have the remaining treatment completed while under general anesthesia. For the other 13 patients, treatments were not completed during the study period because of failed appointments or family relocation.
Vomiting as an adverse event. Although nausea and vomiting are common adverse reactions for both chloral hydrate and meperidine,5,6 we found only one such incident among the 195 sedations in this study. Hasty and colleagues10 reported no vomiting with ChMH/O2 for the 20 sedations in their study. In contrast, Needleman and colleagues11 reported 8.1 percent vomiting intraoperatively using chloral hydrate/hydroxyzine/nitrous oxide/O2. Nausea and vomiting are not uncommon side effects of N2O/O2.7 While we attribute the low incidence of vomiting in this study to our rigid adherence to the preoperative patient dietary restrictions, the absence of N2O/O2 cannot be discounted.
Apnea as an adverse event. A well-controlled study by Rohlfing and colleagues12 reported that the risk of experiencing apnea during conscious sedation was 39 percent, and the risk was equal in patients who received supplementary 100 percent O2 and those who did not. The respiratory depressive effects of narcotics plus synergistic drug reactions with sedative agents can increase the respiratory depression effect of a drug regimen, a phenomenon exacerbated by local anesthetics.19,25,34 We found only one episode of true apnea in this study, but this number probably is artificially low because a capnograph was not used in the first one-half of the study. Almost certainly we would have diagnosed more apneic episodes if a capnograph had been used in all cases.
Desaturation as an adverse event. There is compelling evidence that oxygen desaturation events occur during conscious sedation of pediatric patients; however, most desaturations are artifacts.35 We defined true desaturation as a pulse oximeter reading of SpO2 below 95 percent while the patient is quiet and still. We found only one episode of true desaturation in this study.
The benefit of O2 supplementation during conscious sedation has been suggested in several studies.9,10,12,25,36 It is our routine practice to provide all children with supplementary 100 percent O2 intraoperatively via nasal cannula. This technique is convenient, easy and inexpensive. Furthermore, this approach is well-tolerated by children and does not compromise the operator’s access in any way. We did not see desaturation after the one apneic episode reported here.
Prolonged sedation/slow recovery. Concern about the recovery period and discharge criteria were emphasized in AAPD’s guidelines.20,22,23 The discharge protocol in our study was to dismiss children within 15 to 30 minutes after the conclusion of the dental procedures if cardiovascular and respiratory functions were within normal limits. We expected to see more slow recoveries because both meperidine and chloral hydrate have reasonably long half-lives and wear off gradually within several hours.5,6 However, we found only three instances of prolonged sedation/slow recovery among 195 sedations. Furthermore, we had no documented circumstances of postoperative sedation–related sequelae after the patients were dismissed to return home.
CONCLUSIONS We acknowledge that this study is retrospective in nature, and it involved multiple operators over a five-year period. The method of assessing patient cooperation was subjective. The study, however, involved a highly standardized sedation protocol, including a written record of anesthesia and close attention to detail in record-keeping and chart documentation. Under the conditions of this study:
– adverse events occurred in only 3 percent of the sedation appointments when a strict sedation protocol was adhered to;
– the ChMH/O2 regimen yielded a 72 percent success rate, while 23 percent of the cases were unsuccessful, and 5 percent were aborted;
– compliance with taking oral medications and waiting time after medication intake were important factors in predicting sedation success.

FOOTNOTES
Dr. Leelataweedwud is a lecturer, Department of Pediatric Dentistry, Mahidol University, Faculty of Dentistry, 6 Yothi St., Bangkok 10400, Thailand, e-mail "dtple@mahidol.ac.th". Address reprint requests to Dr. Leelataweedwud.
Dr. Vann is a Demeriit Distinguished professor and the graduate program director, Department of Pediatric Dentistry, The University of North Carolina at Chapel Hill.
This study was supported by Maternal and Child Health Training for Leadership in Pediatric Dentistry Education grant MCJ 379494.
The authors are grateful to Miss Chulalak Komoltri for her statistical consultation for this investigation.
REFERENCES
Davis MJ. Conscious sedation practices in pediatric dentistry: a survey of members of the American Board of Pediatric Dentistry College of Diplomates. Pediatr Dent 1988;10:328–9.[Medline]
Houpt M. Report of project USAP: the use of sedative agents in pediatric dentistry. ASDC J Dent Child 1989;56:302–9.[Medline]
Houpt M. Project USAP the use of sedative agents in pediatric dentistry: 1991 update. Pediatr Dent 1993;15:36–40.[Medline]
Wilson S. A survey of the American Academy of Pediatric Dentistry membership: nitrous oxide and sedation. Pediatr Dent 1996;18:287–93.[Medline]
Hobbs WR, Rall TW, Verdoorn TA. Hypnotics and sedatives: ethanol. In: Hardman JG, Limbird LE, Molinoff PB, Ruddon RW, eds. Goodman & Gilman’s the pharmacological basis of therapeutics. 9th ed. New York: McGraw-Hill, Health Professions Division; 1996:381–2.
Gray M, Noueihed LA. Physicians’ desk reference. 3rd ed. Mont-vale, N.J.: Medical Economics; 1997:605–6, 2036–8.
Houck WR, Ripa LW. Vomiting frequency in children administered nitrous oxide-oxygen in analgesic dosage. ASDC J Dent Child 1971;28:404–6.[Medline]
Houpt M, Manetas C, Joshi A, Desjardins P. Effects of chloral hydrate on nitrous oxide sedation of children. Pediatr Dent 1989;11:26–9.[Medline]
Iwasaki J, Vann WF Jr., Dilley DC, Anderson JA. An investigation of capnography and pulse oximetry as monitors of pediatric patients sedated for dental treatment. Pediatr Dent 1989;11:111–7.[Medline]
Hasty MF, Vann WF Jr., Dilley DC, Anderson JA. Conscious sedation of pediatric dental patients: an investigation of chloral hydrate, hydroxyzine pamoate, and meperidine vs. chloral hydrate and hydroxyzine pamoate. Pediatr Dent 1991;13:10–9.[Medline]
Needleman HL, Joshi A, Griffith DG. Conscious sedation of pediatric dental patients using chloral hydrate, hydroxyzine, and nitrous oxide—a retrospective study of 382 sedations. Pediatr Dent 1995; 17:424–31.[Medline]
Rohlfing GK, Dilley DC, Lucas WJ, Vann WF Jr. The effect of supplemental oxygen on apnea and oxygen saturation during pediatric conscious sedation. Pediatr Dent 1998;20:8–16.[Medline]
Moore PA, Mickey EA, Hargreaves JA, Needleman HL. Sedation in pediatric dentistry: a practical assessment procedure. JADA 1984;109:564–9.[Abstract]
Anderson JA, Vann WF Jr. Respiratory monitoring during pediatric sedation: pulse oximetry and capnography. Pediatr Dent 1988; 10:94–101.[Medline]
Canfield DW, Reiber K, Bennett CR. Oversedation in a pediatric patient: case report. Pediatr Dent 1987;9:229–31.[Medline]
Tsinidou KG, Curzon ME, Sapsford DJ. A study to compare the effectiveness of temazepam and chloral hydrate/hydroxyzine combination in sedating paediatric dental patients. Int J Paediatr Dent 1992;2:163–9.[Medline]
Roelofse JA, Roelofse PG. Oxygen desaturation in a child receiving a combination of ketamine and midazolam for dental extractions. Anesth Prog 1997;44:68–70.[Medline]
Ashkenazi M, Greenberg BP, Samat H. Severe hypoxia following local anesthesia in a sedated patient: case report. Pediatr Dent 1998;20:359–60.[Medline]
Goodson JM, Moore PA. Life-threatening reactions after pedodontic sedation: an assessment of narcotic, local anesthetic, and antiemetic drug reaction. JADA 1983;107:239–45.[Medline]
Guidelines for the elective use of conscious sedation, deep sedation, and general anesthesia in pediatric patients. Pediatr Dent 1985;7:334–7.
Guidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures: American Academy of Pediatrics Committee on Drugs. Pediatrics 1992;89:1110–5.[Abstract/Free Full Text]
Guidelines for the elective use of pharmacologic conscious sedation and deep sedation in pediatric dental patients. Pediatr Dent 1993;15:297–301.
Guidelines for the elective use of pharmacologic conscious sedation and deep sedation in pediatric dental patients. Pediatr Dent 1996;18(special issue):30–4.[Medline]
Nathan JE, West MS. Comparison of chloral hydrate/hydroxyzine with and without meperidine for management of the difficult pediatric patient. ASDC J Dent Child 1987;54:437–43.[Medline]
Croswell RJ, Dilley DC, Lucas WJ, Vann WF Jr. A comparison of conventional versus electronic monitoring of sedated pediatric dental patients. Pediatr Dent 1995;17:332–9.[Medline]
Moore PA. Pain control in dentistry: pediatric pharmacosedation. Compend Contin Educ Dent 1987;8:28–39.
Reisine T, Pasternak G. Opioid analgesics and antagonists. In: Hardman JG, Limbird LE, Molinoff PB, Ruddon RW, eds. Goodman & Gilman’s the pharmacological basis of therapeutics. 9th ed. New York: McGraw-Hill, Health Professions Division; 1996:540–3.
Malamed SS. Sedation: A guide to patient management. 3rd ed. St. Louis: Mosby-Year Book; 1994:127–8.
Unit values. In: Relative values for dentists. Denver: Relative Value Studies Inc.; 1997:93–117.
Lee JY, Vann WF Jr., Roberts MW. A cost analysis of treating pediatric dental patients using general anesthesia versus conscious sedation. Pediatr Dent 2000;22:27–32.[Medline]
Moody EH, Mourino AP, Campbell RL. The therapeutic effectiveness of nitrous oxide and chloral hydrate administered orally, rectally, and combined with hydroxyzine for pediatric dentistry. ASDC J Dent Child 1986;53:425–9.[Medline]
Haas DA, Nenniger SA, Yacobi R, et al. A pilot study of the efficacy of oral midazolam for sedation in pediatric dental patients. Anesth Prog 1996;43:1–8.[Medline]
Wilson S. A review of important elements in sedation study methodology. Pediatr Dent 1995;17:406–12.[Medline]
Verwest TM, Primosch RE, Courts FJ. Variables influencing hemoglobin oxygen desaturation in children during routine restorative dentistry. Pediatr Dent 1993;15:25–9.[Medline]
Wilson S. Conscious sedation and pulse oximetry: false alarms? Pediatr Dent 1998;12:228–32.
Papageorge MB, Hunter MJ, Norris LH, Rosenberg MB. Supplemental oxygen after outpatient oral and maxillofacial surgery. Anesth Prog 1992;39:24–7.[Medline]