Pain Reaction Control
Minimal and Moderate Versus Deep Sedation: A Critical Question
Reliance on the Guidelines as the Standard of Care for Minimal and Moderate Sedation
Practical Utilization of Inhalation Sedation Techniques
Pharmacologic Agents for Sedation
The majority of pediatric dental patients can be treated in the conventional dental environment. By establishing good rapport with the patient and parent and by relying on sound behavior management techniques (see Chapter 23), the anxiety and pain of many pediatric dental patients can be managed effectively using only local anesthesia. In those children who are unable to tolerate dental procedures comfortably despite gentle encouragement and adequate local anesthesia, anxiety and pain control will have to go beyond communicative behavioral modification and physiochemical blockade of the anatomic pathways. Pharmacologic management is indicated for children who cannot be managed with traditional behavioral management techniques and local anesthesia.
The primary purpose of pharmacologic management of young patients is to minimize or eliminate anxiety. General anesthesia totally eliminates anxiety and elevates the pain reaction threshold. Sedation, depending on its depth, produces a relative reduction in anxiety facilitating (1) an increased opportunity for the patient to use learned coping skills, and (2) a reduction in the reactions to painful stimuli. However, sedation and general anesthesia are not without risks against which the benefits of these techniques must be weighed. The degree of sedation depends on a host of factors related to both the drug(s) administered and certain characteristics of the patient. Prominent drug factors include dose, route, and rate of administration, and important patient factors are age, general health, size, and metabolic rate. Importantly, sedation represents a continuum whose effects vary from minimal sedation (previously termed “anxiolysis”) to moderate sedation (previously termed “conscious sedation”) to deep sedation and general anesthesia. For the purposes of this textbook, the new terminology of minimal and moderate sedation will be adopted and replace conscious sedation, which is used in previous editions. Many dental schools teach some form of minimal sedation to the competence level, usually nitrous oxide/oxygen inhalation sedation and possibly oral minimal sedation. When moderate sedation is taught to competence in dental schools, it is usually an elective for select senior dental students and almost always focuses on techniques for adult patients. Specialized pediatric training is highly desirable for those planning on using moderate sedation for pediatric patients, particularly those 12 years and younger. Residency training beyond dental school that is formally accredited by the Commission of Dental Accreditation (CODA) is required for those providing deep sedation and general anesthesia.
In 1985, the American Academy of Pediatrics (AAP) and the American Academy of Pediatric Dentistry (AAPD) jointly endorsed “Guidelines for the Elective Use of Conscious Sedation, Deep Sedation, and General Anesthesia in Pediatric Patients.”1 These guidelines set the current standard of care for those who practice these sedation techniques for pediatric patients. The most recent cosponsored guidelines using the definitions of minimal, moderate, and deep sedation appeared in 2006 and can be broadly summarized2 (Table 8-1).
The guidelines emphasize that the goals of sedation are to (1) guard the patient’s safety and welfare; (2) minimize physical discomfort and pain; (3) control anxiety, minimize psychological trauma, and maximize the potential for amnesia; (4) control behavior and/or movement, which allows the safe completion of the procedure; and (5) return the patient to a state in which safe discharge from medical supervision, as determined by recognized criteria, is possible.
The purpose of this chapter is to focus on minimal and moderate sedation and its use, as an adjunct, in the management of anxiety and pain control in pediatric patients. Because of the potential overlap of minimal sedation with moderate sedation and moderate sedation with deep sedation and general anesthesia, these modalities must be defined and delineated in the context of outlining what minimal and moderate sedation are, and more importantly, what they are not.
Minimal and Moderate Sedation
Minimal sedation is a drug-induced state during which patients respond normally to verbal commands. Although cognitive function and coordination may be impaired, ventilatory and cardiovascular functions are unaffected.
Moderate sedation is a drug-induced depression of consciousness during which patients respond purposefully to verbal commands (e.g., “open your eyes,” either alone or accompanied by light tactile stimulation—a light tap on the shoulder or face, not a sternal rub). The caveat that loss of consciousness should be unlikely is a particularly important aspect of the definition of moderate sedation. The drugs and techniques used should carry a margin of safety wide enough to render unintended loss of consciousness highly unlikely.
For the very young patient or those patients with intellectual or physical impairments who are incapable of giving the usually expected verbal responses, a minimally depressed level of consciousness for that individual should be maintained. Unfortunately, this is usually contrasted with the need to overcome more primal and emotional responses often associated with such patients, necessitating deeper levels of sedation or general anesthesia. Note that moderate sedation suggests that a child may be in a state wherein eyes are temporarily closed; however, the child is arousable following a verbal prompt (i.e., opens his or her eyes) or responds to the degree that withdrawal and crying occur following mildly painful stimulus, such as an injection of local anesthetic. Withdrawal from painful stimuli and crying are prominent at this level of sedation, whereas deeper levels of sedation may result only in reflex withdrawal or reflex withdrawal and moaning only. If arousal, as described previously, does not occur, especially following a repeated moderately painful stimulus (e.g., trapezius muscle pinch), then the child is in a state of deep sedation and must be managed and monitored accordingly.
Currently, the minimal monitoring requirements for moderate sedation are:
• Pulse oximeter for monitoring oxygenation and pulse rate (Figure 8-1, A)
FIGURE 8-1 A, Pulse oximeter. B, Automatic blood pressure monitor. C, Pediatric stethoscope. D, Capnograph. (A and D, courtesy Criticare Systems, Inc., Waukesha, Wis; B, courtesy Zewa Inc., Fort Myers, Fla; C, courtesy 3M™ Littman© Stethoscopes, St Paul, Minn.)
• Blood pressure cuff for monitoring circulation (Figure 8-1, B)
• Precordial stethoscope or a capnograph to monitor ventilation (Figures 8-1, C and D). Observation of chest movements and continuous verbal communication are acceptable for moderate sedation, but because continuous verbal communication may be undesirable for the child patient, a precordial stethoscope or capnograph is usually required for moderate sedation and always required for deep sedation.
If the patient enters a deeper level of sedation than the dentist is qualified to provide, the dentist must stop the dental procedure until the patient returns to the intended level of sedation.
Deep sedation is a controlled state of depressed consciousness or unconsciousness from which the patient is not aroused easily. Deep sedation may be accompanied by a partial or complete loss of protective reflexes, including the ability to maintain a patent airway independently and to respond purposefully to physical stimulation or verbal command. Young patients who are in deep sedation may respond with only a reflex withdrawal to an intensely painful stimulus, if at all. Monitoring requirements for deep sedation require a minimum of a pulse oximeter, capnograph or precordial stethoscope, electrocardiograph, and blood pressure cuff.
General anesthesia is a controlled state of unconsciousness accompanied by a loss of protective reflexes, including the inability to maintain an airway independently and respond purposefully to physical stimulation or verbal command.
Minimal and Moderate Versus Deep Sedation: A Critical Question
The difference between minimal and moderate versus deep sedation is a concept that must be comprehended thoroughly by those who sedate pediatric dental patients. Practitioners must realize that the goal of minimal and moderate sedation is a level of sedation that does not render the patient unconscious or unresponsive to verbal prompting or, at the most, to minimally painful stimuli. A reflex withdrawal response alone to repeated minimal or moderately painful stimuli is not appropriate for minimal and moderate sedation and is indicative of deeper levels of sedation. The patient under minimal and moderate sedation can respond appropriately to verbal commands or minimally noxious stimuli and is able to maintain a patent airway at all times. If sedation techniques are practiced in this manner, the patient’s cardiovascular and respiratory functions should always be well maintained and acceptable for the age of the child.
Why is it a problem for the practitioner to move from the threshold of minimal and moderate sedation to deep sedation? The answer is simple: The patient has a much more frequent and serious risk of respiratory or cardiovascular complications during deeper levels of sedation. When the patient has a partial or complete loss of protective reflexes and cannot maintain an airway independently, hypoxemia, laryngospasm, pulmonary aspiration, and apnea may be serious or life threatening outcomes.3 Because the separation between moderate and deep sedation can sometimes be difficult to discern, it is the wise practitioner who obtains proper training in monitoring techniques and managing sedation before using pharmacologic management for children. Furthermore, the current guidelines indicate that the practitioner should be sufficiently trained to “rescue” the child should he or she enter a deeper level of sedation than that intended or otherwise become compromised. Although it is appropriate to activate Emergency Medical Services (EMS; call 911) in an emergency, the practitioner must not rely solely on the arrival and intervention of the EMS personnel. In other words, active intervention using basic or advanced life support must be accomplished by the practitioner and his or her staff while awaiting arrival of the EMS team. Management of the airway and ventilation is usually the most critical task to accomplish and master while awaiting the EMS team. Since the depth of sedation level is not always predictable, especially with oral routes of administration, the practitioner needs to be trained and able to rescue a child who enters a deeper level of sedation than originally intended or planned for the procedure.
For those practitioners who choose to practice deep sedation for pediatric patients, the guidelines are specific about requirements for a higher level of personnel training as well as a higher level of vigilance in monitoring the patient’s vital signs and level of sedation. They spell out requirements for personnel, the operating facility, intravenous access, monitoring procedures, and recovery care that carry a higher level of expectation and training than is the case with the use of minimal or moderate sedation.2 In short, for practitioners who choose to use deep sedation, the standard of care specified in the guidelines is nothing less than stringent, and it is doubtful that many general practitioners or pediatric dentists currently have the training or facilities to undertake deep sedation in an office setting.
Reliance on the Guidelines as the Standard of Care for Minimal and Moderate Sedation
The AAP/AAPD guidelines establish a standard of care for minimal and moderate sedation of pediatric patients. In considering presedation events, the guidelines focus on parental instructions, dietary precautions, and a preoperative health and physical evaluation. Essentially, the guidelines intensify the presedation activities with a keen eye toward eliminating the possibility of sedation complications. They call also for documentation and recording of events during treatment (i.e., vital signs, medications given, and patient response).
The three standards in the guidelines that have most dramatically changed the manner in which pediatric sedation is practiced in the office setting relate to (1) personnel, (2) patient monitoring, and (3) preprocedural prescriptions. Relative to personnel, the guidelines specify that an assistant other than the dental operator must participate in the sedation procedure and that this assistant must be trained to monitor appropriate physiologic parameters and assist in any support or resuscitation measures required. Relative to intraoperative monitoring procedures during sedation, the guidelines specify continuous monitoring by a trained individual. A precordial stethoscope, blood pressure cuff, and pulse oximeter are considered the minimal equipment needed for obtaining continuous information on heart rate and respiratory rate.4,5
Preprocedural prescriptions refer to the practitioner giving a written prescription to the parent to obtain and administer the sedative agent(s) outside of the treatment facility. Preprocedural prescriptions to relieve anxiety (e.g., diazepam [Valium]) for older children who are extremely anxious may be helpful, although no strong evidence is available to support this notion. For younger children (i.e., preschool age), use of prescriptions outside of the treatment facility and without professional supervision is not appropriate. Drugs intended for sedation, particularly in a dose that has even a slight potential to make the child difficult to arouse or potentially lose consciousness, should never be administered at home by parents or guardians on the night before or during the day of sedation before transporting a child to a facility where a procedure will be performed (e.g., chloral hydrate, meperidine [Demerol], or high dose benzodiazepines). Again, chloral hydrate or meperidine are not considered minor tranquilizers or antianxiety agents and thus should not be administered to a child outside of the dental office.
In summary, the guidelines have had a major impact on how the practitioner must approach the sedation of children. There are no systematic evaluations of the impact of the guidelines on safety in pediatric sedation; however, it is our opinion that these guidelines are having a dramatic impact in improving the safety of sedation in the dental office environment. Unfortunately, significant morbidity and mortality have occurred6–9; however, no deaths have occurred, to our knowledge, when the guidelines have been faithfully followed by the practitioner.
Routes of Administration
The primary routes of administration for minimal and moderate sedation are (1) inhalational; (2) enteral (e.g., oral or rectal); and (3) parenteral (e.g., intramuscular, subcutaneous, submucosal, intranasal, or intravenous). In reviewing these techniques, only the primary advantages and disadvantages will be discussed.
Inhalational Route (Nitrous Oxide)
Nitrous oxide and oxygen administered with fail-safe dental delivery systems (Figure 8-2) produce minimal sedation or light moderate sedation. Loss of consciousness and/or the inability to maintain a patent airway are almost impossible to achieve. The primary advantages of nitrous oxide for sedation in pediatric dentistry are discussed in the following sections.