January 6, 2016
by Gino Gizzarelli, BScPhm, DDS, MSc (Dental Anaesthesia); David Farkouh, Bsc, DMD, MSc (Pedo), FRCD(c)
The following is a summary of the use if oral sedatives for pediatric dentistry. This information is not intended to present a comprehensive review, the reader is therefore encouraged to seek additional and confirmatory information.
Sedation is used to increase the cooperation of children during treatment. When behaviour management techniques such as tell-show-do, voice control, non-verbal communication, positive reinforcement, distraction and parental presence are insufficient for dental treatment, sedation or general anesthesia may become necessary.1
Conscious sedation or minimal sedation is part of various techniques that are used by dentists, especially pediatric dentists, alongside behaviour management techniques. The goal is to provide quality dental treatment in both cooperative and uncooperative children. Depending on the personality of the child, oral sedative medications and nitrous oxide can be used successfully and safely during dental procedures. Psychosomatic behaviour problems and/or an inflexible temperament trait often contribute to sedation failure in children undergoing dental treatment. Therefore, appropriate patient evaluation and selection contribute to sedation success in children.1
It is important to manage a child’s pain and anxiety early in their treatment. Inadequate pain control for initial procedures in young children may diminish the effect of adequate analgesia in subsequent procedures.2 Sedative medications will then have to overcome increased anxiety from previous appointments.
Levels of Sedation
For both adults and children, there is a continuum of levels of sedation. These have been clearly described by the American Society of Anesthesiologists.3
Minimal Sedation (anxiolysis) is a drug-induced state during which patients respond normally to verbal commands. Although cognitive function and physical coordination may be impaired, airway reflexes, ventilatory and cardiovascular functions are unaffected.
Moderate Sedation/Analgesia (“conscious sedation”) is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway and spontaneous ventilation is adequate. Cardiovascular function is usually maintained.
Deep Sedation/Analgesia is a drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully following repeated or painful stimulation. The ability to independently maintain ventilatory function may be impaired. Patients may require assistance in maintaining a patent airway, and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained.
General Anesthesia is a drug-induced loss of consciousness during which patients are not arousable, even by painful stimulation. The ability to independently maintain ventilatory function is often impaired. Patients often require assistance in maintaining a patent airway, and positive pressure ventilation may be required because of depressed spontaneous ventilation or drug induced depression of neuromuscular function. Cardiovascular function may be impaired.
Due to the fact that sedation is a continuum, it is not always possible to predict how an individual patient will respond. Hence, practitioners intending to produce a given level of sedation should be able to rescue patients whose level of sedation becomes deeper than initially intended. Individuals administering moderate sedation/analgesia (“conscious sedation”) should be able to rescue patients who enter a state of deep sedation/analgesia.3 As the level of sedation deepens, the muscle tone in the pharynx and the soft palate decreases and the epiglottis falls back causing obstruction. In addition, the risk of laryngospasm increases.4
Evaluation and Preparation of the Child for Sedation
Children younger than the age of three years are often unable to fully comprehend the procedure. This child is likely to require deeper levels of sedation to achieve desired results because the combination of non-pharmacologic (behaviour management) and pharmacologic techniques are unlikely to result in a more cooperative patient.5 If larger doses of sedative medications are used, the child may enter a deeper level of sedation than intended and the risk of adverse events increases.
A thorough review of the medical history of the child with the parents must be completed. Frequent or recent upper respiratory infections may delay treatment with sedation. Any other respiratory issues, such as asthma, should be reviewed. Any cardiovascular concerns must be addressed in advance. Parents or guardians should always be asked if their child has any sleep apnea or related breathing problems while sleeping. Any evidence of this should be investigated before any sedation is used. Airway assessment is strongly recommended. A review of the child’s chin, oropharyngeal and tonsillar size, as well as their Mallampati classification, does help to determine the risk of obstruction during sedation. Patients who are obese and/or have anatomic airway abnormalities, especially related to certain syndromes (such as Pierre Robin) may have difficulty maintaining an airway during sedation for the procedure and during recovery.
The American Society of Anesthesiologists Physical Status is a classification system that categorizes the medical status or fitness of a patient. It is not intended to measure or predict operative risk but it does evaluate or describe the health of a patient prior to a planned procedure.
Health of the Patient–ASA Physical Status
(American Society of Anesthesiologists)3
ASA I: Normal, healthy patient
ASA II: Mild systemic disease (well controlled and no functional limitations)
ASA III: Severe systemic disease (controlled with no
immediate danger but has some functional limitation)
ASA IV: Severe systemic disease that is a constant threat to life (poorly controlled or at end stage)
ASA V: Patient not expected to survive longer than 24 hours without surgical intervention
ASA VI: Brain dead (maintenance for organ harvesting)
ASA E: Emergency operation of any variety
Certainly, dentists should only use sedation in the dental office for patients that are ASA I or well controlled ASA II patients.5
Fasting prior to the appointment is thought to be important regardless of the level of sedation.5 Stomach contents can be regurgitated or vomited depending on the medication used (ie: nitrous oxide). Depending on the level of sedation, stomach contents can be aspirated, resulting in pneumonia or pneumonitis.
Dental offices and hospitals have their own fasting guidelines (Table 1). This explains the time range for clear fluids and solids prior to deep sedation/general anesthesia appointments. For minimal or moderate sedation, clinicians may individualize their fasting guidelines. For example, parents may be instructed to have their child fast for four hours prior to their dental treatment with nitrous oxide.
The dentist must have a discussion of treatment options, including risks and benefits of sedation. Verbal confirmation must be received and recorded in the chart. In addition, pre-printed consent forms are often given for the parents to sign and these are kept in the patient’s chart.
Preoperative and Postoperative Instructions
Written instructions must be given to parents of children receiving sedation. Preoperative instructions should include the type of sedation the child will receive and the fasting requirement prior to the appointment. Postoperative instructions should include rest for the remainder of the day and fluids following the appointment. If there is no postoperative nausea and vomiting, soft, easily digested foods can be given to the child following the appointment. The parents should be cautioned regarding tongue, lip and cheek biting if local anesthesia was used. A 24-hour contact telephone number should be provided for any issues or concerns.
Common Routes of Pediatric Sedation
Table 2 compares various routes of sedation in clinical practice. Among the routes of sedation for pediatric dentistry, nitrous oxide is the most frequently used. This is mostly due to its efficacy, ease of use and safety.5 Over-sedation is a possibility in all routes of sedation. There is a risk of over-sedation especially with the parenteral routes and where high doses of drugs are used for oral sedation. The intranasal route is a method of giving sedation that seems to be increasing in popularity. The influenza vaccine can now be given through this route. It is considered a parenteral route of administration that carries a risk of over-sedation. Advanced training and monitoring is required where there is a risk of over-sedation in any route of administration.
TABLE 2. Comparison of various routes of sedation in clinical practice:
Training and Monitoring
Especially with deeper levels of sedation, dentists must have adequate training in both sedation and emergency medical care. Dentists should have certificates in Advanced Cardiac Life Support (ACLS) and/or PALS (Pediatric Advanced Life Support) and these should be kept current. This helps the dentist manage the patient in respiratory distress or cardiac failure, or patients who are in an unintended deeper level of sedation until emergency care arrives. Automated external defibrillators (AED’s) come equipped with adult and pediatric pads and are found in an increasing number of dental offices especially those providing sedation.
The monitoring of vital signs is imperative during sedation. Pulse oximetry measures the heart rate and oxygen saturation of the patient. Blood pressure monitoring is also required (Fig. 1). This should be measured at regular intervals and recorded on a sedation record kept in the patient’s chart. Electrocardiography and capnography are typically used for deep sedation and general anesthesia. No monitoring other than visual recognition of the patient’s status is acceptable for nitrous oxide sedation.
In the event of a power failure, for obvious reasons, a portable light source and a portable suction is required in dental offices providing sedation.
Classes of drugs commonly used for oral sedation include the benzodiazepines, first generation antihistamines, opioids and drugs in their own categories such as chloral hydrate, ketamine and dexmedetomidine. Table 3 summarizes their use as sedatives in pediatric dentistry. Diazepam has a long half-life with active metabolites. The incidence of resedation is common and it has largely been replaced by midazolam by most practitioners. Currently, midazolam is considered to be the safest and most effective of all oral sedatives. According to the drug monograph, the safety and effectiveness of triazolam in individuals below 18 years of age has not been established. There is limited data however, for the clinical use of triazolam as a pre-operative sedative in dentistry for children of various ages. Clinicians tend to use it for older children (for example, eight years of age and older) to avoid using large doses of midazolam. Triazolam has a longer half-life than midazolam and recovery may be prolonged. The effects of benzodiazepines can be reversed with flumazenil. The use of chloral hydrate and promethazine has fallen out of favour because there is no reversal agent for these drugs, they have a longer half-life and due to a higher incidence of adverse events.5
First generation antihistamines are used for allergic reactions and cross the blood brain barrier. Drowsiness is a side effect of these antihistamines and this sedation is used in children. First generation antihistamines also have antiemetic and antisialogogue effects that can be beneficial in dentistry. Second generation antihistamines are considered non-drowsy and are not used for sedation in dentistry.
Opioids decrease pain and anxiety and are used to sedate children but respiratory depression is an adverse effect of opioids. Opioids can be reversed with naloxone.
Ketamine is an NMDA receptor antagonist that can be used orally in children. It produces a dissociative or cataleptic state and because of this, it is often given with midazolam. It also has very good analgesic, sedative and amnestic effects.
Dexmedetomidine is one of the newest agents used for sedation. It is an alpha-2 agonist like the older drug, clonidine. The intranasal route is common for dexmedetomidine and it is quite effective in children. Large doses are required for the oral route, as compared to the intravenous route. There is limited data on the oral use in children, however, the sedative effects and application of this drug in pediatric dentistry appear quite promising.
There are other oral sedatives used for adults for insomnia, however, these are not necessarily appropriate for pediatric use because of the lack of clinical studies, Health Canada approval or dosage formulations to allow for weight-based dosing in pediatric patients.
Combinations of drugs are often used by practitioners for children so that dosages of the individual drugs can be decreased and adverse effects can be minimized. Nitrous oxide is commonly found in drug combinations. However, the risk of over sedation increases with polypharmacy.
Emergency Drugs (including reversal agents) and Emergency Equipment
A portable and dedicated E cylinder of oxygen, with a regulator and a portable apparatus to give positive pressure ventilation, such as a bag-valve-mask (ie: Ambubag®) with varying sizes of masks, is required (Fig. 2). Should the patient have apnea or hypopnea due to a deeper level of sedation, this apparatus when used properly will usually maintain the patient’s ventilation and oxygenation until help arrives, or the sedative medication wears off or is reversed. A laryngoscope with different sizes of blades, endotracheal tubes and laryngeal mask airways are recommended. These can assist with obstructed airways, however, they are useless in untrained hands. Oropharyngeal airways are S-shaped devices that hold the tongue away from the posterior wall of the pharynx and soft palate. A nasopharyngeal airway is a soft rubber or plastic tube that is flexible and is inserted down the nose to the pharynx and can assist with an obstructed airway. Oropharyngeal and nasopharyngeal airways can be used quite effectively in combination with a bag-valve-mask device to provide ventilation for a child that is obstructed or not breathing.
Epinephrine, nitroglycerin, non-enteric coated ASA, parenteral diphenhydramine, and a salbutamol inhaler are emergency drugs that should be part of every emergency kit in a dental office. Atropine is another emergency drug that should be in the emergency kit, especially with parenteral sedation. Flumazenil is a parenteral benzodiazepine reversal agent that is administered intramuscularly or intravenously. Its dose is 0.01 mg/kg and it may be repeated every two to three minutes up to a maximum of 0.05 mg/kg or 1 mg (whichever is lower). Naloxone is a parenteral opioid reversal agent that is also administered intravenously or intramuscularly. For a child less than five years old (≤ 20 kg), its dose is 0.1 mg/kg with repeat doses every two to three minutes up to 2 mg. For a child older than five years (> 20kg), its dose is 2 mg with repeat doses up to 10 mg.6 For an intramuscular injection of flumazenil, injecting into the vessel rich tissues below the tongue provides a reversal effect in approximately two to three minutes.7 This is a very long period of time if the child is not breathing, therefore airway maintenance skills are paramount. The intravenous route of administration of reversal agent is clearly the most rapid. It is extremely important to know the dosages of reversal agents and their use in the event of an emergency. Dental offices will often write their dosages and keep this information where the medications are stored, as well as their expiry dates.
In a critical analysis of adverse sedation events in case reports from the Food and Drug Administration in the United States, Cote et al. wrote a landmark paper. Negative outcomes (death and permanent injury) were often associated with drug overdose and they mostly occurred in dental offices. Negative outcomes were also attributed to the use of three or more sedative medications, despite appropriate dosages of each individual sedative drug. The addition of nitrous oxide to any other class of sedative medication was frequently associated with adverse outcomes.7 Negative outcomes were also associated with drugs administered by non-medically trained personnel and drugs that were administered at home. These injuries occurred both on the way to the treatment facility and on the way home in the vehicle. Other injuries occurred at home post-discharge from medical supervision. Deaths and injuries after discharge were associated with the use of medications with long half-lives (chloral hydrate, pentobarbital, promethazine and chlorpromazine).8
Inadequate resuscitation was a determinant factor in the negative outcomes. In addition, lack of pulse oximetry (that measures oxygen saturation) was associated with an unsuccessful outcome.9 Factors that affect the risk of adverse events include the type of monitoring, the level of training of the practitioner and their ability to detect abnormal values or clinical signs, the age of the patient, the choice of sedative medication(s), and the distance to a hospital.9
A review of closed malpractice insurance claims in the United States between 1993 and 2007 by Chicka et al. found that most negative outcomes were due to sedative drug combinations. These combinations included hydroxyzine and diazepam, chloral hydrate and hydroxyzine, meperidine and promethazine. Another negative outcome occurred with chloral hydrate alone. They made the following conclusions from their study:
1. Very young children (three years and younger) are at a greater risk when given sedative drugs and/or local
2. Often there is inadequate monitoring during sedation.
3. Local anaesthetic dosages should be lowered when used in combination with other CNS depressants (sedative drugs).10
Children commonly experience motor imbalance, restlessness, agitation, trauma to anaesthetized tissues, nausea, vomiting, sleep during transit and persistent sleepiness. Parents should be educated that their child may experience these postoperative sequelae. Parents should help their child walk because they are at risk of falling. Ideally, either parents or two adults should drive the child home. The second person would monitor the child from biting their lips or tongue, as well as their breathing, while the other is driving. During the dental procedure, the child may be responsive and somewhat alert because of the noxious stimuli from the dental treatment. Upon discharge, the child is no longer stimulated and this is when resedation occurs and they are at risk of obstruction and other breathing diffulties.11 This warrants vigilant adult supervision.
Vital signs should be stable and the patient should be easily rousable. When significant effort must be made to wake the child post sedation (shouting or shaking), they will often become resedated if left alone for a period of time (riding in the car). There must be adequate head control and muscle strength to maintain a patent airway.4 A return to the level of consciousness that is similar to baseline is ideal. If flumazenil or naloxone reversal agents have been given, observation should continue for an extended period of time (two to four hours) due to the possibility of resedation occurring as the reversal agent wears off and the sedative drug still has a therapeutic level.4 OH
Note from the authors:
These drugs were not designed and brought to the market by drug companies to sedate children and facilitate dental treatment. Clinicians have used the side effects of some of the drugs to their benefit or they have modified the dosages and route of administration of other drugs and given them to children to complete their dental treatment. If the desired effect after a specific dose of a sedative drug has not been achieved, then KNOW YOUR LIMITS and abort the appointment. Treatment options for the next visit will include a higher dose of the same drug, a combination of drugs with lower dosages or the use of general anesthesia. All three of these options are associated with an increased risk and will require increased training and monitoring.
Dr. Gino Gizzarelli completed his first degree in 1995 at the University of Toronto in pharmacy. He worked as a full-time clinical pharmacist at Toronto General Hospital for two years before returning back to the University of Toronto to study dentistry. Following his dental degree in 2001, he continued his studies in the same university and completed a three-year Master’s degree in Dental Anesthesia. Throughout his studies and until present, Dr. Gizzarelli has maintained a part-time clinical pharmacist position in the same hospital. He is an itinerant dentist anesthesiologist and teaches occasionally at the University of Toronto Faculty of Dentistry and at various conferences and CE courses.
Oral Health welcomes this original article.
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