THERE HAS BEEN a vast increase in the number of diagnostic and therapeutic procedures performed in the emergency department (ED) setting over the past several decades. Most of these procedures are unscheduled, unplanned, and much more likely to be successful and result in a positive outcome when the child's pain, anxiety, and movement are controlled. Due to the unique developmental and behavioral characteristics of children, the approach to pharmacologic agents and nonpharmacologic techniques is very different compared with adults. Through this pediatric lens, the use of analgesia, anxiolysis, and sedation by both nonpharmacologic and pharmacologic interventions in children is both an art and a science. Influential factors that affect a provider's clinical decision-making regarding analgesia and sedation include both the clinical situation and the child's cognitive/emotional development. To promote patient quality and safety, increase the effectiveness and efficiency of care, and improve patient and caregiver satisfaction, there has been an abundance of robust evidence produced to promote the knowledge and skill set required to achieve a positive outcome. The purpose of this article is to present an overview of pediatric analgesia, anxiolysis, and sedation to promote compassionate, evidence-based emergency care of children and optimize procedural performance and outcomes.

BACKGROUND: GUIDING PRINCIPLES

Procedural Sedation Defined

Procedural sedation (PS) is the term used to describe medications, psychological techniques, and/or physical maneuvers to support a patient's tolerance to an unpleasant or painful procedure. The term procedural sedation replaces the outdated term "conscious sedation" because effective PS does always impair consciousness (Cravero & Roback, 2021). The International Committee for the Advancement of Procedural Sedation, an interprofessional group representing several specialties, defines PS as "the administration of one or more pharmacological agents to facilitate a diagnostic or therapeutic procedure while targeting a state during which airway patency, spontaneous respiration, protective airway reflexes, and hemodynamic stability are preserved, while alleviating anxiety and pain" (Green, Irwin, Mason, & International Committee for the Advancement of Procedural Sedation, 2021, p. 603). Analgesics can be combined with sedative agents to meet the need for pain control and is referred to as procedural sedation analgesia (PSA) (Benzoni & Cascella, 2021).

Goals of Pediatric Sedation/Analgesia

The goals of pediatric PSA 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) modify behavior and/or movement; and (5) return the patient to a state in which discharge is safe (Cote, Wilson, American Academy of Pediatrics, & American Academy of Pediatric Dentistry, 2019). Within the guidelines of PSA, these goals must be achieved while the patient maintains airway control, oxygenation, and hemodynamic stability. To this end, the provider must have an in-depth knowledge level of the available pharmacologic agents so that the most appropriate drug required for a specific procedure is administered at the lowest dose and the highest therapeutic index. In addition, for every pharmacologic agent selected, the provider must be aware of the drug's time of onset, peak response, and duration of action. This is particularly critical for children who will be discharged from the ED following the procedure to avoid complications that may result from prolonged drug effects and may compromise a patient airway, ventilation, and/or hemodynamic stability (Cote et al., 2019).

Indications for Pediatric Procedural Sedation/Analgesia

There are no cited absolute indications for pediatric PSA, as it is appropriately indicated for any procedure when the child's fear, anxiety, pain, or excessive movement may interfere with safe procedural performance, optimum outcome, and patient/family satisfaction. The depth and length of the sedation desired is dependent on the unique characteristics of the child and the specific procedure to be performed. Each individual child's behavioral/cognitive developmental status must be taken into consideration when selecting the PSA intervention.

The indications for pediatric PSA are grouped into three classifications: (1) diagnostic imaging that requires sedation only (e.g., CT scan and MRI); (2) painful diagnostic procedures that require sedation and analgesia (e.g., lumbar puncture, insertion of a central venous catheter, and chest tube insertion); and (3) painful therapeutic procedures that require sedation and analgesia (e.g., closed fracture/dislocation reduction; laceration repair, foreign body removal, and abscess incision and drainage). It is important to be aware that the actual depth of sedation achieved may exceed the targeted depth of the sedation, and providers must be prepared to "rescue' the patient through emergency interventions. PSA should be viewed on a continuum and any drug (excluding ketamine) can produce a level of sedation depth extending from minimal to general anesthesia (Green et al., 2019). The therapeutic levels of sedation are presented in Table 1.

Table 1. Terminology to describe levels of procedural sedation

PREPARING THE PATIENT

Patient Presedation Risk Assessment

There are no absolute contraindications for PSA in the ED; however, there are certain conditions when it should be avoided. The American Society of Anesthesiologists (ASA) Physical Status Classification (see Table 2) is the most used guideline for patient selection based on risk stratification (ASA, 2020). It is widely recommended that pediatric patients who undergo PSA in the ED are classified as Class I or Class II (ASA, 2020; Cote et al., 2019; Green et al, 2019). Children who are evaluated to be in ASA III or higher are at greater risk of adverse events and therefore should not be considered a candidate for PSA. Other conditions that should be evaluated as a high-risk situation for PSA include children with special needs, challenging airways, and/or significant medical comorbid conditions (e.g., severe sleep apnea and tonsillar hypertrophy) (Benzoni & Cascella, 2021; Cravero & Roback, 2021). The ED provider should consult with a pediatric anesthesiologist for any high-risk condition prior to PSA.

Table 2. American Society of Anesthesiologists physical status classification

The need for fasting prior to PSA is a controversial topic. Current ASA guidelines for fasting prior to PSA recommend 2 hr for clear liquids, 4 hr after breastfeeding, 6 hr for formula, and 8 hr for solids (ASA, 2017). The American College of Emergency Physicians advises that PSA may be safely administered to pediatric patients in the ED for urgent or emergency procedures regardless of any recent oral intake and that fasting status is not a contraindication to sedation. The risk and benefits associated with administration of sedation prior to a procedure should be evaluated on a case-by-case basis. The factors to consider include the urgency of the procedure, the child's risk of aspiration, and the intended depth of sedation (Klick, Serrette, & Clingenpeel, 2017).

Informed Consent

The decision to implement any level of PSA should be made jointly with the patient's caregiver(s) grounded in informed decision-making. Written consent must be obtained prior to the administration of PSA. Information should be provided to the caregiver regarding the goals of the sedation, and expected changes in behavior before, during, and after the sedation. The provider must confirm caregiver understanding regarding the following components prior to obtaining written consent: proposed benefits of pain relief, anxiolysis and sedation to facilitate the efficient and effective performance of a procedure, and the possible associated risks, which may include vomiting, airway compromise, and hypoxia. The consent process should also include other available alternatives with a discussion of risks and benefits (e.g., local anesthesia only) (Cravero & Roback, 2021).

Health History and Physical Examination

Prior to the administration of any PSA medications, a focused health history and physical examination of the child must be conducted. The essential components of the health history should include the following: past and current medical illnesses/injuries, current medications, allergies, prior adverse reactions to anesthetic/sedative agents, history of disordered breathing during sleep, and last oral intake. The physical examination should focus on the vital signs including patient weight measure in kilograms, airway evaluation, respiratory, cardiac, and neurologic systems. This is also an opportune time for the provider to explore information regarding the child's behavioral/cognitive developmental level, prior experience with painful procedures, ability to cope with stress, and the desire of the caregiver(s) to be present during the procedure per institutional policy.

Nonpharmacologic Interventions

Age-appropriate distraction techniques are strongly advocated as the patient is being prepared for sedation, as these techniques may optimize the experience for the child. Using techniques to promote relaxation in a child may also increase overall satisfaction with the ED experience for the caregiver(s). Behavioral-cognitive interventions have been shown to complement pharmacologic interventions during PSA (Chan et al., 2019; Sinha, Christopher, Fenn, & Reeves, 2006). Child-life specialists are particularly helpful in this regard, and it has been shown that their presence may ease the transition into a state of sedation, reduce the amount of medication required and therefore the depth of sedation, and decrease the frequency of adverse events (Cravero & Roback, 2021; Cotes et al., 2019). Examples of age-specific distraction techniques for children include bubbles, interactive toys, video games, movies, songs, and storytelling and books.

Pharmacologic Interventions

Institutional policies will dictate who is authorized to administer PSA agents. The responsible provider must have in-depth knowledge of the pharmacologic agents used including the early identification of adverse reactions. The provider must also have the knowledge and skill set to initiate and manage the team resuscitation interventions. This is particularly true regarding management of the pediatric airway, as the most common adverse effects of sedation include airway compromise or depressed respirations that may lead to laryngospasm, hypoventilation, hypoxemia, and apnea (Cote et al., 2019). The presence of support personnel (e.g., PALS certified nurse and respiratory therapist) is mandatory for continuous direct visualization of the patient during all phases of the sedation, physiologic monitoring, and assistance with resuscitative measures if required. Pediatric emergency resuscitation equipment must be readily available and must include specific age- and size-appropriate equipment required for resuscitation, as listed in Table 3.

Table 3. Necessary equipment for safe administration of pediatric sedation "SOAPME"

Preoxygenation and Capnography

There is evidence to support the use of preoxygenation using supplemental oxygen and continuous end-tidal carbon dioxide (ETCO₂) capnography monitoring during PSA. The American Society of Anesthesiology recommends preoxygenation for levels of moderate and deep sedation (ASA, 2018). However, evidence is limited regarding the safety effect of preoxygenation or continuous administration of supplemental oxygen specific to children during PSA (Cravero & Roback, 2021). The potential benefits of preoxygenation include maximizing bloodstream oxygen and lung storage of oxygen, and maintenance of oxygenation during early periods of apnea (Godwin et al., 2014). Conversely, it is cited that preoxygenation may delay the identification of desaturation through observation of noninvasive pulse oximetry monitoring and the child may maintain acceptable oxygenation saturation levels despite hypoventilation (Fu, Downs, Schweiger, Miguel, & Smith, 2004). The application of a facial mask or nasal prongs may also cause an increase in anxiety in children prior to sedation.

The use of continuous capnography (ETCO₂) is strongly recommended during moderate or deep sedation in children. ETCO₂ is used as an early physiologic indicator for hypoventilation, hypoxemia, and subsequent apnea. Rising ETCO₂ levels via continuous capnography have been noted to be identified earlier than through clinical assessment alone (Cravero & Roback, 2021; Godwin et al., 2014).

Continuous Patient Monitoring

Comprehensive preparation of the patient and the environment is paramount. A standard evidence-based checklist should be used by each institution for implementation of PSA. Prior to initiation of PSA, the individual role and responsibility of each team member should be confirmed. Since 2014, The Joint Commission advised that a standard "time-out" be performed on every patient, every time immediately before sedation. This serves as a safety measure to verify the correct patient, procedure, and site (The Joint Commission, 2014).

Prior to the administration of any pharmacologic agent, vital signs including heart rate, respiratory rate, blood pressure, SaO₂, and ETCO₂ should be obtained. Complete vital signs should also be obtained after the administration of any additional sedative agent(s), at the completion of the procedure, during early recovery, and at completion of recovery. If deep sedation is targeted, vital signs should be measured at least every 5 min (Cravero & Roback, 2021). The patient must be in full view of one team member throughout the whole sedation process for ongoing visual monitoring. Complications from sedation are most likely to occur within 5-10 min following administration of intravenous sedative agents, and immediately after the procedure is completed (Krauss & Green, 2006).

CHOICE OF PHARMACOLOGIC AGENTS

The selection of the pharmacologic agent for sedation depends on the depth of the sedation required for the procedure to be performed, associated predicted level of associated pain and the cognitive/behavioral developmental level of the child. Most pediatric procedures performed in the ED are of short duration; therefore, the provider is advised to select an agent that can be titrated to a specific level of sedation to facilitate patient safety and comfort and allow for optimal completion of the procedure. The ideal agent used in the ED should possess the qualities of sedation, analgesia, and amnesia. A description of the most common agents used in children is discussed next and the properties of these pharmacologic agents are listed in Table 4.

Table 4. Properties of procedural sedation agents used in pediatrics

Ketamine is an ideal sedative agent in the pediatric population and is frequently used in the ED. It provides a unique dissociative state, is effective, well-tolerated, preserves upper airway reflexes and airway drive, and has an overall robust safety profile. There is a "dissociative threshold" for ketamine and increasing dosages will not increase its effect. Ketamine has sedative, amnesiac, and analgesic properties and can be used as a single pharmacologic agent for painful procedures (Doctor, Roback, & Teach, 2013; Kraus, 2014). However, it is recommended that a local anesthetic (e.g., topical lidocaine-epinephrine-tetracaine [LET] gel or infiltration with a local anesthetic) is used concomitantly for painful procedures, such as wound repair or incision and drainage of cutaneous abscesses (Cravero & Roback, 2021). If the caregiver(s) are present, they should be advised that the child will manifest a vacant stare during induction and that during sedation the patient's eyes remain open with nystagmus frequently observed (Benzoni & Cascella, 2021). Older children should be advised prior to drug administration that they will dream during recovery and should be advised to "plan" for a happy dream. Emesis is the most associated common side effect, and it is recommended that patients are pretreated with ondansetron (Klick et al., 2017).

Midazolam is a short-acting benzodiazepine that is used to provide sedation, amnesia, and anxiolysis. The advantage for use over other benzodiazepines is the short half-life and recovery time. Midazolam has no analgesic properties; therefore, it must be administered with some form of analgesia (e.g., topical, local infiltration, oral, intramuscular, or intravenous) for any painful procedure. It can be given in various routes of administration, which makes this drug especially valuable in children so that intravenous access is not required. One specific advantage of midazolam is that it can be given via the intranasal route, which is relatively painless, has a rapid onset of action due to the highly vascular nasal mucosa, avoids first pass metabolism through hepatic pathways, and avoids placement of an intravenous line (Sorrentino, 2015). An atomizer is recommended for delivery of intranasal medication and volume of 0.3 ml per nostril is easily tolerated by most children (Long, 2016). Flumazenil may be used for rapid reversal of midazolam (Klick et al., 2017).

Fentanyl is an opiate, which is 100 times more potent than morphine, and can be used in combination with sedative agents for painful procedures (Krauss & Green, 2006). Fentanyl may also be administered via the intranasal route and therefore is ideal when rapid analgesia is needed and there is no intravenous access. Naloxone may be used for rapid reversal (Klick et al., 2017). When used in combination with a benzodiazepine, fentanyl provides the addition of sedation and anxiolysis for moderate sedation for painful procedures.

Propofol is a powerful sedative agent but does not possess any analgesic properties and requires an analgesic to be administered for painful procedures. Use of propofol in children carries a higher risk for respiratory depression, airway obstruction, and hypotension as compared with other sedative agents. Because propofol may cause a deeper level of sedation than desired, the providers must anticipate and be prepared to manage the pediatric airway. The risk of these adverse effects is further exacerbated when propofol is combined with an opioid. Propofol may also cause pain on injection, which may be reduced by ensuring a large vein is used, and/or administering a small amount of lidocaine prior to the propofol. The advantage of propofol is rapid onset, short sedation and recovery time, easy titratability, and its antiemetic property (Klick et al., 2017).

Ketamine and propofol (ketofol) in combination have been shown to provide effective analgesia and sedation in children without the dose-dependent side effects seen with the use of these drugs as single agents. Lower doses of both drugs are needed and therefore the likelihood of side effects such as hypotension and respiratory depression is less commonly encountered. It is recommended that administration is in varying ratios (ketamine to propofol) at the discretion of the provider.

Nitrous oxide (N₂O) administered via inhalation has been shown to be a weak dissociative agent that provides anxiolysis, moderate analgesia, sedation, and amnesia, with a minimal effect on respiratory function and a rapid recovery. Nitrous oxide is administered as a nebulized premixed blend most commonly in a concentration of 50% N₂O and 50% O₂. This agent has a wide margin of safety in children (Long, 2016).

RECOVERY

Following completion of the procedure, the patient must continue to be monitored closely until they have age-appropriate stable vital signs, their level of consciousness returns to baseline, they are easily arousable, able to sit up unsupported (if age appropriate), and able to take fluids by mouth. Caregivers should be instructed for discharge and demonstrate informed verbal understanding of these instructions.

CONCLUSION

There is an abundance of valid and reliable evidence that supports the use of pediatric PS in the ED. Interprofessional team performance and communication is essential to promote quality and safety during any PS/PSA procedure. With proper education and skills verification, PS/PSA can be safely and efficaciously performed in the ED setting to decrease a child's pain, fear, and anxiety and minimize movement to allow for the optimization of procedure performance.

REFERENCES