This article focuses on sedation/anesthesia of adolescent patients in the dental setting. Preoperative evaluation, treatment planning, monitoring, and management are critical components to successful sedation. The authors discuss commonly administered agents and techniques to adolescents, including nitrous oxide/oxygen analgesia. The levels and spectrum of sedation and anesthesia are reviewed. Common comorbidities are also presented as they relate to sedation of the adolescent dental patient.
This article aims to help clinicians with indications and contraindications for sedation and anesthesia of adolescent dental patients.
The article presents the spectrum of sedation and anesthesia in adolescent dentistry.
A review of basic pharmacology of sedation/anesthesia agents and the concept of rescue is presented.
Techniques require individualization. Challenges associated with perioperative management of adolescent dental patients as they relate to risk and benefit should be considered.
Dentists who provide sedation or anesthesia to adolescent dental patients are urged to have current knowledge of pharmacology. They must recognize indications and contraindications to the delivery of sedation and anesthesia medications, including epinephrine-containing local anesthetics. Management of pain, anxiety, and behavior should be the goals of sedation/anesthesia. All decisions must be made considering risk versus benefit.
Dentists are obligated to use safe prescribing practices. The goal of this article is to aid the dental provider in managing pain and anxiety and in modifying behavior to safely complete dental procedures in adolescent patients.
There have been many definitions of sedation in dentistry used over the years. Clinical standards for sedation in dentistry parallel the guidelines established by the American Society of Anesthesiology (ASA) for anesthesiologists. , The American Academy of Pediatric Dentistry (AAPD) and the Academy of Pediatrics (AAP) maintain guidelines for sedation of the pediatric patient, defined as any patient under the age of 21. The American Dental Association (ADA) also has guidelines for the use and teaching of sedation and anesthesia in dentistry.
The following definitions for levels of sedation are excerpted from the AAPD, AAP, and ADA guidelines.
(Old terminology was “anxiolysis”): A pharmacologic-induced state that retains a patient’s ability to respond normally to tactile stimulation and verbal command. Cognitive function and coordination may be impaired; ventilatory and cardiovascular functions are unaffected.
(Old terminology was “conscious sedation” or “sedation/analgesia”): a drug-induced depression of consciousness during which patients respond purposefully to verbal commands (eg, “open your eyes” either alone or accompanied by light tactile stimulation, such as a light tap on the shoulder, not a sternal rub). For older patients, this level of sedation implies an interactive state; for younger patients, age-appropriate behaviors occur and are expected.
Note: “the drug(s) and/or techniques used should carry a margin of safety wide enough to render loss of consciousness unlikely.”
A drug-induced depression of consciousness during which patients cannot be easily aroused but respond purposefully after repeated verbal 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. A state of deep sedation may be accompanied by partial or complete loss of protective reflexes.
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.
Spectrum of anesthesia and sedation
Arthur Guedel, MD introduced the concept of anesthetic signs and stages. His early work studied diethyl ether for general anesthesia. He observed 4 distinct stages as patients were administered increasing quantities of inhaled ether. The stages represent a continuum or spectrum from which no sedation becomes general anesthesia. ,
In stage 1 or the analgesia phase, consciousness is not lost. Stage 2 is the excitatory phase. Between stages 2 and 3, consciousness is lost. Stage 3 is defined as the surgical anesthesia stage. Dentists who are not formally trained in deep sedation and general anesthesia should limit their practice to stage 1, the analgesia phase.
Guedel’s classification still has value. It has been modified and adapted for new drugs and techniques. Dentists must understand that as agents are administered, they produce an effect along a “ spectrum of pain and anxiety control. ” Dosage and route determine the level of sedation or anesthesia.
Fig. 1 shows the spectrum. At the far left, there is no sedation or anesthesia. To the right, there are levels of conscious sedation up to the vertical bar. The red bar represents loss of consciousness. To the right of the red bar is deep sedation/general anesthesia. The experienced provider may not need a graphic representation to determine level of sedation or anesthesia; however, a classification system is necessary. The dentist must understand where he or she is on the spectrum and its relationship to where they want to be. Success in the minimal-moderate range is dependent on adequate pain control with local anesthesia. Increasing depth of sedation increases risk and requires additional formal training.
“Rescue” is an essential concept of safe sedation. Because sedation and anesthesia are a continuum, a provider must be able to recover a patient from unintended entry to a more profound level of central nervous system (CNS) depression. , , , The ASA’s guidelines for sedation by “nonanesthesiologists” stress this concept in an effort to reduce morbidity and mortality. ,
Because sedation and general anesthesia are 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 diagnose and manage the physiologic consequences (rescue) for patients whose level of sedation becomes deeper than initially intended. , ,
For all levels of sedation, the qualified dentist must have the training, skills, drugs and equipment to identify and manage such an occurrence until either assistance arrives (emergency medical service) or the patient returns to the intended level of sedation without airway or cardiovascular complications. , ,
Sedation without drugs is iatrosedation. Techniques include acupressure, acupuncture, biofeedback, electronic dental anesthesia, and hypnosis. These modalities may be an alternative to traditional sedation/anesthesia for adolescent dental patients. However, for purposes of this article, the authors focus on the use of pharmacotherapy to obtain a desired outcome.
Communication improves outcome. There is no substitute for good verbal and nonverbal communication in adolescent dentistry. The style should be developmentally age-appropriate and nonjudgmental. Good communication alleviates fear and anxiety, allowing treatment to proceed in a “normal” fashion. Traditional behavior management/guidance techniques, such as distraction, tell-show-do, guided imagery, topical anesthesia, and hypnosis, may reduce the need for or depth of pharmacologic sedation. , Adolescent dental patients benefit from effective communication.
Dental treatment can affect both the physical and the psychological “well-being” of adolescent patients. Before treatment (with or without sedation), patients should have a complete physical examination and psychological assessment to evaluate risk. This assessment allows the provider to determine need.
Medical, dental, and psychological histories guide the dentist in choosing a treatment modality. The evaluation should include a medical history questionnaire, physical examination, and a discussion with the patient, parent, and/or caregiver. For the adolescent patient, extra time and attention should be spent on understanding the reason for their behavior (fear, anxiety, developmental disability). With the information collected, the dentist can establish a physical status classification and determine risk factors. Medical consults can be obtained as needed.
A preoperative consult/evaluation with a physician is not medical clearance. The purpose is to evaluate and make recommendations. Preoperative goals include medical optimization using strategies to reduce risk and improve outcome. ,
Physical status classification
The ASA has a physical classification system for estimating medical risk for patients receiving general anesthesia for surgical procedures. The system was adopted in the early 1960s and has remained virtually unchanged. Currently, it is used to evaluate risk associated with procedures regardless of anesthetic technique. ,
The ASA Physical Status Classification System :
Class 1: A healthy patient (no physiologic, physical or psychological abnormalities)
Class 2: A patient with mild systemic disease without limitation of daily activities (ie, controlled asthma; controlled hypertension)
Class 3: A patient with severe systemic disease that limits activity but is not incapacitating (ie, uncontrolled hypertension: uncontrolled diabetes)
Class 4: A patient with incapacitating systemic disease that is a constant threat to life
Class 5: A moribund patient not expected to survive without the operation
Class 6: A brain-dead patient whose organs are being removed for donor purposes
∗If the procedure to be performed is an emergency, an “E” is added to the above classification system (eg, ASA PS 2E). In the outpatient medical and dental settings, classes 5 and 6 have been eliminated.
Adolescent patients who are ASA PS class 1 or 2 are appropriate candidates for minimal, moderate, or deep sedation in the dental office. Individual consideration is recommended for patients in ASA PS classes 3 and 4. , Dentists are encouraged to consult with appropriate subspecialties for patients at increased risk for adverse events because of their underlying conditions. Remember, the ultimate responsibility and liability rest with the dentist who decides to treat or not treat.
Sedation of adolescent patients for the delivery of oral health care uniquely is challenging. A sedation plan should maximize benefit and minimize associated risks for adverse outcomes. Each sedation patient requires individual consideration. Patient extremes in responsiveness and acceptance will vary depending on a host of factors.
The ideal sedation should
Be easy to administer
Have rapid and reliable onset
Alleviate pain and anxiety
Have minimal undesirable sided effects
Once pharmacosedation is planned, the dentist must consider which agents to use and how to administer. The choice will depend on the desired level of sedation. Developmental and chronologic ages are important considerations. Younger patients and severely developmentally disabled patients may require deeper levels of sedation to gain control of their behavior as compared with more cooperative patients.
The following routes are available for delivery of drugs to adolescent patients:
Intrathecal (in spinal fluid)
Transdermal (through epidermis)
Techniques (oral, rectal, sublingual) that administer agents that are absorbed through the gastrointestinal (GI) tract or oral mucosa are termed enteral sedation. Parenteral techniques (IM, IV, intranasal, submucosal, subcutaneous, intraosseous) bypass the gastrointestinal tract and enter directly into the systemic circulation. Oral (mostly) and rectal routes are subject to the enterohepatic circulation and first-pass effect before the drug is released to the systemic circulation. This significantly reduces the amount that is bioavailable and should be considered when choosing an agent and dose.
The most popular route used for dental sedation is the oral route. Advantages over the parenteral routes include acceptance by patients, low cost, ease of administration, decreased incidence of adverse reactions, and no equipment needed for delivery. However, oral sedation does have some significant disadvantages, such as reliance on patient compliance, a prolonged latent period, erratic and incomplete absorption from the GI tract, inability to titrate, inability to lighten or deepen sedation as needed, and a prolonged duration of action. With oral sedation, “stacking” or adding additional agents after the initial dose is discouraged.
Drugs administered topically are readily absorbed from nonkeratinized tissue. Topical applications in dentistry are usually local anesthetics. They are highly effective at relieving pain associated with intraoral injections.
Intranasal administration has become increasingly popular in pediatric dentistry. It is easily administered to resistant, uncooperative, or precooperative patients. , Although there is brief discomfort with administration, direct absorption into the systemic circulation makes the drug rapidly bioavailable. Compared with oral sedation, there is reduced time to onset and total time spent in the office. Midazolam, a water-soluble benzodiazepine, is a commonly used drug via this route. , The mucosal atomization device is the preferred method for administration.
Inhalational administration occurs when gaseous agents pass from the respiratory apparatus (nose/mouth, trachea, and lungs) into the cardiovascular system. There are a variety of agents available for inhalational sedation and anesthesia. In dentistry, nitrous oxide/oxygen (N 2 O/O 2 ) sedation is the main drug used for inhalation sedation. , It is easily titrated to effect, with minimal side effects or complications. A disadvantage of nitrous oxide is that it is not a potent anesthetic, so there may be failure. Also, a delivery system is required with a fail-safe and scavenging system. The equipment must be calibrated annually, and there needs to be adequate office ventilation to prevent chronic exposure to those administering the sedation. Other more potent inhalation agents include sevoflurane, isoflurane, and desflurane. They are used in the maintenance of general anesthesia. Sevoflurane is also indicated for mask induction of general anesthesia.
Subcutaneous injection is administration of a drug beneath the skin into the subcutaneous tissue. Rate of absorption is directly proportional to the vasculature in the area of injection. Slow rates of absorption limit its usefulness in dentistry.
The IM route administers the drug directly into the muscle. This parenteral technique allows for quick onset with rapid maximal clinical effect. The disadvantages include prolonged deep sedation, injury to tissues at the site of injection, and overdose. IM administration is often unpredictable, and there is no mechanism for titration to effect. Ketamine, a dissociative anesthetic, is the most commonly used drug via the IM route and is often used for sedation and induction of the uncooperative patient.
Intravascular drug administration represents the most effective, predictable method of delivery for adequate sedation of most patients. Advantages include rapid onset with short duration of latency and a shortened recovery period. However, complications at the site of venipuncture and risk for overdose are disadvantages. Many drugs given intravenously do not have reversal agents; therefore, the dentist must be prepared to manage deeper sedation and other complications, such as allergic reactions, which may not be seen with other less effective modes of delivery.
A variety of drugs are available for sedation and anesthesia of the adolescent patient. These drugs primarily include inhalation sedation/anesthesia, benzodiazepines, sedative hypnotics, antihistamines, alpha agonists, and analgesics. Table 1 lists available drugs for sedation.
a Not recommended for use in IV moderate sedation without anesthesia training.
The sedation/anesthetic regimen for adolescent dental patients should carry a high therapeutic index with a wide safety margin and a low probability for abuse. It should be modified based on the adolescent’s physical, developmental, mental, sensory, behavioral, cognitive, and emotional needs. Selection of the fewest agents paired with the procedural goals results in safe practice. Painful procedures require analgesics; diagnostic procedures use sedatives, and anxious patients benefit from benzodiazepines. Combinations of different classes of medications are often used. However, when 3 or more agents are administered simultaneously, the potential for an adverse outcome increases. , ,
Agents available for sedation of adolescent patients
Nitrous Oxide/Oxygen Sedation
Short-term exposure to nitrous oxide induces sedation, euphoria, giddiness, elation, and a general sense of well-being. The pharmacologic mechanism of action of nitrous oxide is not fully understood. Multiple mechanisms are accepted. Nitrous oxide modulates ligand-gated ion channels, with activity on the gamma-aminobutyric acid type A (GABA-A) receptor and the N -methyl- d -aspartate (NMDA) receptor. Anxiolysis is the result of activation of the GABA-A receptor either directly or indirectly through at the benzodiazepine binding site. , The sedation/anesthetic, hallucinogenic, and euphoriant effects are likely caused by inhibition of NMDA-mediated currents. Analgesic effects are linked to endogenous opioids and the noradrenergic systems.
Nitrous oxide is the least potent of the inhalation anesthetics, but in dentistry, it is the most frequently used. The minimum alveolar concentration of an agent that prevents movement in 50% of patients to a surgical incision for nitrous oxide is 105%. It is difficult to reach this level unless administered under hyperbaric conditions. However, Guedel’s stage 2, delirium, can be reached if nitrous oxide is not properly administered. , Nitrous oxide may be administered alone or in combination with other agents.
There are relatively few absolute contraindications to nitrous oxide. Fail-safe mechanisms prevent the percentage of oxygen from going below 30%. Relative contraindications to nitrous oxide include the following :
Chronic obstructive pulmonary disease
Upper respiratory tract infections
Middle ear/sinus disease
Emotional disturbances or drug-related dependencies
Treatment with bleomycin sulfate
Methylenetetrahydrofolate reductase deficiency
Cobalamin (vitamin B12) deficiency
Nitrous oxide/oxygen inhalation effectively reduces anxiety, produces analgesia, and enhances communication for adolescent dental patients.
The following was excerpted from the Handbook of Nitrous Oxide and Oxygen Sedation by Clark and Brunick. It is a good checklist when using nitrous oxide analgesia.
Be enthusiastic and confident about the experience.
Have confidence. Also, be knowledgeable about the limitations.
Recognize that patients in your care represent the best opportunity you have to express genuine care and concern.
Obtain informed consent before N 2 O/O 2 administration.
Start and end with 100% oxygen.
Do not leave the patient alone.
Document all procedures, reactions, complications, and so forth in the patient’s record.
Place patient in a comfortable position before administration.
Inform the patient to ask for assistance at any time, if needed.
If nitrous oxide is planned for the next visit, recommend not having a large meal before their appointment.
“ Titrate to the level of sedation that is determined by patient comfort and relaxation. There is no percentage for sedation for a given experience or patient. There is also no pre-set liters per minute of nitrous oxide/oxygen. The percentage of nitrous oxide/oxygen given to a patient or experience will not reflect the amount necessary for any other experience. The goal is to keep the patient relaxed and comfortable. ”
During emergence from nitrous oxide, the patient should return to his/her original emotional state. Terminate nitrous oxide flow; continue delivering 100% oxygen during the final minutes of the procedure. This begins the postoperative oxygenation phase of 3 to 5 minutes. Following this period, the patient should be recovered from the pharmacologic effects.
N 2 O/O 2 sedation may augment or balance other modalities of sedation and anesthesia. This can add safety because the patient is getting a minimum of 30% oxygen, which is greater than the 21% of room air. However, some states do not allow polypharmacy, so augmentation may not be an option. Box 1 lists potential adverse effects of nitrous oxide analgesia.