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Back to Table of Contents | March 2011

Clinical and Health Affairs

Safe and Sound: Pediatric Procedural Sedation and Analgesia

By Patricia D. Scherrer, M.D.

■ Providing procedural sedation for pediatric patients presents unique challenges. Children’s hospitals have protocols in place to provide safe, high-quality sedation care delivered by specialists in pediatric sedation and anesthesiology. However, the demand for procedural sedation for diagnostic and therapeutic procedures is increasing. This article describes some of the key components involved in establishing a protocol for safe and effective pediatric sedation services including screening techniques for patients at higher risk for complications and appropriate monitoring and rescue plans. We also review medications commonly used for pediatric sedation and pain management and discuss resources available to physicians who provide pediatric sedation.


Tommy is a 3-year-old with a history of speech delay and staring spells. His primary care physician has ordered a brain MRI to evaluate him for underlying anatomic issues. The MRI will take approximately 45 minutes and will require him to lie nearly motionless. Tommy squirms and fights when his dad tries to put him on the MRI table.

Jasmine is a 6-month-old who has failed two newborn hearing screenings. Her audiologist needs to perform further testing, which requires Jasmine to be quiet for 30 to 60 minutes. When the audiologist attempts the test, Jasmine begins to cry, and the test cannot be completed.

Anna is a 7-year-old who suffered some “road rash” on her left knee after falling from her bike. She presents to a local urgent care with an inflamed, swollen area on her knee a week later, and the urgent care technician is concerned that she may have an abscess. Anna begins to scream and pull away when the tech tries to clean the area.

Three different scenarios, three different children who may not be able to receive the care they need without sedation and/or pain control. Such situations arise daily in medical centers around the country. Although most children’s hospitals have specialized sedation programs to address the needs of their patients, many regional and rural medical centers have sporadic experience with pediatric sedation. Nevertheless, demand for sedation is growing, and many hospitals and clinics are seeking to expand their capabilities. To ensure patient safety, physicians and health systems must develop pediatric sedation protocols that recognize higher-risk situations, provide appropriate supervision and monitoring, and tailor drug choices to the child’s needs and the providers’ skill sets.

Initial Considerations
When planning sedation and/or pain management for a child, knowing what level of responsiveness needs to be achieved during the procedure or test is essential for choosing the appropriate medication regimen. Painful procedures that require relative immobility generally mandate a deeper level of sedation than noninvasive radiological tests. Each sedation plan should take into account the age, developmental level, and personality of the child. Seven-year-old Anna, for example, may require deep sedation for incision and drainage of her abscess; local analgesia alone may be sufficient for another child her age undergoing such a procedure.

Resources for Physicians

Pediatric sedation is an evolving specialty. Currently, the practice of sedating children crosses many disciplines, and this can generate confusion, fear, and even conflict within medical systems. In an effort to provide multidisciplinary leadership in the advancement of pediatric sedation practice, the Society for Pediatric Sedation was formed in 2007 to promote safe, high-quality care, innovative research, and quality professional education. The society’s membership is composed of physicians and nurses from pediatric anesthesiology, pediatric emergency medicine, pediatric critical care medicine, and pediatric hospital medicine. It also includes pediatric dentists, child life specialists, and a variety of other individuals. Its website, www.pedsedation.org, offers a number of resources for providers and parents including article reviews, practice guidelines, and links to other programs and references. The society’s 2011 meeting will be held in Minneapolis in May and is co-sponsored by Children’s Hospitals and Clinics of Minnesota.

In an effort to clarify sedation goals, the American Society of Anesthesiologists (ASA) has defined a continuum for levels of sedation.1 Minimally sedated children may have an impaired level of cognitive functioning but maintain their airway protective reflexes and cardiorespiratory status. For example, for children undergoing voiding cystourethrograms, this level of sedation is often achieved through use of inhaled nitrous oxide. Moderate sedation is associated with blunted-but-purposeful responses to verbal or tactile stimulation. There may be subtle alterations in ventilation, but airway reflexes and cardiovascular function are generally unchanged. Infants who receive chloral hydrate often reach a moderate level of sedation. In contrast, deeply sedated children may have inadequate spontaneous ventilatory drive and/or significant upper airway obstruction and may require airway intervention. During deep sedation (as opposed to general anesthesia), purposeful responses to painful stimulation remain intact. The combination of an opioid and a benzodiazepine often results in deep sedation.

The definitions of these levels of sedation remain somewhat arbitrary. Unfortunately, there is no clear physiologic demarcation between each level. Because the various levels of sedation are not specific to any particular drug or regimen, physicians must understand that it is impossible to reliably predict the effect that a given dose of a particular drug will have on a patient. Because of the potential alterations in airway and respiratory mechanics that may occur, the different levels of sedation require different levels of expertise in patient management. Therefore, Joint Commission guidelines state that a sedation provider should be able to “rescue” a patient from sedation one level deeper than that which is intended.2

For most children, titration between moderate and deep sedation can be tricky. Pediatric sedation providers should be prepared to provide airway intervention maneuvers such as bag mask ventilation (BMV) and even endotracheal intubation in order to rescue deeply sedated children. A hospital’s sedation protocol should clearly define standards of performance and competencies for sedation providers, and these skills should be demonstrated by satisfactory performance in an observed clinical or simulation setting.3

Perhaps the most important factor for ensuring safety during pediatric procedural sedation is the immediate availability of skilled rescue resources. Adverse pediatric sedation events are most common in facilities that lack adequately trained personnel and reliable emergency response support.4,5 Physicians should carefully consider the following questions before embarking on a sedation plan: What is the skill set of the team that will be with the child at all times? If the primary team needs help, who will respond? How long will it take the rescue team to arrive? Is a member of the rescue team an anesthesia specialist who is capable of providing reliable advanced airway support to children? Satisfactory answers are critical to ensuring safety.

Patient Evaluation
What “red flags” should providers look for when evaluating a child who would benefit from sedation for a painful or anxiety-provoking procedure? Although identifying every possible risk factor can be challenging even for the most seasoned pediatric anesthesiologist, there are specific patient characteristics that have been associated with increased complications. A thorough health history and physical examination can reveal many of them.

First, the provider should find out why the child is having the procedure or test. The provider should then find out whether the child has medical issues that could put him or her at increased risk for complications. Recent upper respiratory illness symptoms, especially coughing, wheezing, or nasal congestion, can increase the risk of airway irritability and respiratory complications, including hypoventilation, desaturation, and laryngospasm. Similarly, a history of recent vomiting or symptomatic gastroesophageal reflux can be cause for concern, as emesis during sedation, when airway protective reflexes may be blunted, could lead to aspiration and initiate laryngospasm. Significant obesity, an increasing problem in the pediatric population, may be associated with an increased risk of airway obstruction, especially with deeper levels of sedation. Overt obstructive sleep apnea symptoms are clearly associated with airway obstruction during sedation; however, many families are unable to say how frequently or how badly their children snore. Even occasional audible snoring makes the need for airway repositioning and nasopharyngeal airway placement more likely.

Physicians should also be aware of underlying medical conditions that increase the potential for airway compromise during sedation. A number of genetic syndromes are associated with anatomic and/or developmental airway differences as well as altered respiratory mechanics; several excellent articles describe these.6,7 Infants born prematurely have immature respiratory drive physiology, increasing the likelihood of sedation-related apnea in the first months of life. Currently, many sedation programs choose to monitor infants less than 60 weeks post conceptual age for a longer time period than they do older children prior to discharge. For example, at Children’s Hospitals and Clinics of Minnesota, we monitor these infants for a 12-hour period, discharging them to home only if they have not had any episodes of apnea during that time. Changes in respiratory physiology during procedural sedation can aggravate underlying asthma or bronchopulmonary dysplasia, potentially leading to bronchospasm and/or desaturation.

Physical examination should focus on findings that could affect the course of the child’s sedation. The physician should look for craniofacial abnormalities that could be problematic if the patient would need BMV or endotracheal intubation. These include, but are not limited to, facial anomalies such as retrognathia that can prevent good mask seal and interfere with airway visualization, tonsillar hypertrophy that can prevent adequate air entry, and limited neck mobility that can prevent adequate airway positioning. Physicians also should remember to look for braces and other orthodontia. Many neuromuscular disorders are associated with decreased ability to handle oral secretions; these secretions can pool in the hypopharynx and lead to coughing, laryngospasm, or aspiration when airway reflexes are blunted. Children who have obvious wheezing or other respiratory difficulties should have their test or procedure rescheduled. If the procedure or test is deemed to be emergent, an anesthesia consultation should be sought. Significant abdominal distension can increase the risk of vomiting and aspiration.

Although the need for strict NPO guidelines for urgent and emergent sedations continues to be a topic of debate, most physicians should plan to adhere to the recommended ASA guidelines.1 These suggest the following NPO times:

  • Clear liquids—two hours
  • Breast milk—four hours
  • Infant formula, other nonhuman milk, solids—six hours
  • Full meal—eight hours

For children requiring sedation who do not meet the ASA NPO guidelines, recommended options include delaying the procedure or seeking an anesthesia consultation.

Monitoring, Equipment, and Documentation
The single best way to monitor a sedated child is continuous direct observation by one or more trained providers not directly involved with the procedure itself. Beyond this basic tenet, the frequency and intensity of monitoring depend on the depth of the sedation being performed. At a minimum, all sedated patients should be monitored with continuous pulse oximetry. The ASA also recommends that respiratory function be continuously monitored by observation, auscultation, and/or capnography. Electrocardiography should be used, and blood pressure should be measured intermittently during deep sedation.

Equipment needs are based on patient management and rescue. A number of mnemonics can help the sedation provider remember the essentials; one of the most popular is “SOAPME”:

Suction—appropriately sized large-bore suction catheters, smaller catheters for nasal or endotracheal suctioning, functional vacuum apparatus;

Oxygen—adequate supply, functioning flow meters;

Airway equipment—appropriately sized masks, self-inflating or anesthesia BVM systems, nasopharyngeal and oropharyngeal airways, laryngeal mask airways, laryngoscope blades and handles, endotracheal tubes;

Pharmacy—sedative analgesic medications, reversal agents, emergency resuscitation and airway medications;

Monitors—pulse oximetry, cardiorespiratory monitor with ECG and BP capability, stethoscope, end tidal carbon dioxide monitor; and

Extras—intravenous access catheters, isotonic resuscitation fluid, emergency drug sheet, calculator.

The type of procedure being performed may also dictate other equipment needs. Documentation of sedation encounters should include informed consent, postsedation instructions, and contact information for the parent or guardian. A focused history and physical examination should be performed and documented at the time of the sedation. The plan for procedural sedation as well as an assessment of the child’s sedation risks and ASA classification should be included in the documentation.8 Time-based recording of vital signs, sedation scores, and administered medications is required. Also, any adverse events and associated interventions should be noted.

Sedatives and Analgesics— A Potpourri of Choices
A number of medications are used for pediatric procedural sedation. There is rarely a right or wrong choice with regard to medication selection; however, the physician’s familiarity and experience with various agents are important considerations. Many of the more commonly used sedation agents have no analgesic component, so adding a medication for pain control or choosing a different regimen may be more appropriate for painful procedures.

Benzodiazepines have been a mainstay of procedural sedation for years. A drug in this class can be used as a single agent for brief, nonpainful procedures and as an adjunct in combination with opioids or ketamine for more painful ones. The pharmacokinetics of midazolam make it most suited for procedural sedation. Onset of action occurs in less than 60 seconds when administered intravenously (IV), and its duration is usually 15 to 30 minutes. Midazolam may be administered via many different routes: IV, orally, rectally, intramuscularly, or intranasally. Although the combination of midazolam and an opioid analgesic can provide excellent sedation and analgesia for painful procedures, the combination is also associated with a higher incidence of respiratory depression.

Nitrous oxide, a longtime favorite sedative/analgesic agent for dental procedures, is becoming increasingly popular as a minimally sedating agent for a variety of pediatric procedures, including IV catheter placements, VCUGs, lumbar punctures, and other brief, painful procedures. Nitrous is delivered as either a fixed 50/50 mixture with oxygen or in titratable concentrations of 30% to 70%. Onset of action generally takes place within two to three minutes, and its effect rapidly ends when the gas is discontinued. Nitrous may also be combined with an opioid analgesic for more painful procedures such as joint taps; but this combination can induce moderate or even deep levels of sedation. The incidence of nausea and vomiting following nitrous administration is approximately 5%.9 Challenges with inhalation equipment and appropriate waste gas scavenging have limited the use of nitrous oxide in some locations.

Chloral hydrate has been employed as a sedative hypnotic agent for more than 100 years. It is particularly useful for inducing a sleep state in children younger than 2 years of age for a nonpainful procedure such as a CT/MRI scan or an auditory brainstem response test for hearing. Chloral hydrate is administered orally, with an onset of action usually within 20 to 30 minutes, although onset can be somewhat variable. Duration of action can be even more unpredictable. Most children sleep for 60 to 120 minutes, but the long elimination half life of chloral hydrate occasionally can result in prolonged sedation states that can last more than 12 hours. Because of the unpredictable duration of action, there have been reports of serious adverse events and even death following discharge for children who received chloral hydrate for sedation.10 Rates for successful sedations are between 85% and 95%. In rare instances, younger children never achieve the depth of sedation required to complete the associated procedure. The rate of failed sedation increases markedly for children over the age of 3 years. Although chloral hydrate administration is generally associated with a moderate level of sedation and rarely with respiratory depression, the incidence of respiratory complications is higher in infants, especially those younger than 2 months of age.11

Barbiturates, most commonly pentobarbital, have also been mainstays of sedation for nonpainful pediatric procedures in the past. Although the use of pentobarbital has been largely supplanted by newer agents such as propofol and dexmedetomidine, it is still used for moderate sedation for procedures such as MRI scans. Advantages of pentobarbital include its one- to two-minute IV onset time, the ability to provide repeat dosing in as little as five to 10 minutes, and limited respiratory and hemodynamic effects in otherwise healthy children. However, children with underlying respiratory or cardiovascular issues may be more susceptible to associated cardiopulmonary instability. Although children can become quite deeply sedated, and even anesthetized, with pentobarbital, it does not provide any analgesic effects. The disadvantages of using pentobarbital for procedural sedation include its potential for prolonged deep sedation and unpredictable recovery time, which can range from 60 minutes to more than 12 hours, as well as its association with recovery dysphoria and agitation (unaffectionately labeled “pentobarb rage”).12

Dexmedetomidine is a relatively new highly selective central alpha 2 agonist with both sedative and analgesic properties. Already in use as an ICU sedative analgesic, dexmedetomidine has migrated to the procedural sedation arena, where it is a preferred agent for many providers because of its limited effects on respiration. Dexmedetomidine is generally associated with a moderate level of sedation that, according to electroencephalogram, mimics normal sleep. Therefore, many pediatric neurologists prefer dexmedetomidine for children who require sedation for successful completion of EEGs. Dexmedetomidine has also proven to be useful for sedation of children with autism or other developmental concerns; as the recovery period seems to be associated with a much less troublesome emergence.13 Most often, dexmedetomidine is administered as an IV agent, with a slow initial bolus over five to 10 minutes followed by a continuous infusion; it also can be given orally or buccally with good success. Dexmedetomidine can be associated with clinically significant cardiovascular effects, especially bradycardia, because of its effects on cardiac conduction times.

Many children’s hospitals have built their sedation programs around the sedative/anesthetic agent propofol. By far the most commonly utilized agent for pediatric procedural sedation, it is used both as a single agent for nonpainful procedures such as CT, MRI, and ABR testing, and in combination with analgesics such as ketamine and fentanyl for a variety of painful procedures. Propofol is administered intravenously, and its many advantages include onset in 30 to 60 seconds, offset generally in five to 15 minutes, and ease of titration to effect. For longer procedures, bolus propofol is used for induction, and deep sedation is maintained by a continuous IV infusion. Propofol use is associated with a high incidence of respiratory depression, and induction can easily lead to rapid loss of airway reflexes and apnea.14 Physicians who administer propofol must be able to rescue patients from a general anesthetic state and have expertise in both BVM ventilation and endotracheal intubation. Because of the risk of rapid respiratory decompensation, some hospitals restrict use of propofol to anesthesia providers. In addition, propofol can lead to bradycardia and hypotension, although these effects are typically mild and do not become clinically significant in otherwise healthy children.

For decades, opioids have been the most commonly administered analgesic medications. Although they have no inherent amnestic qualities and limited sedative effects when used independently, they may be used in combination with sedative/hypnotic agents to facilitate deep sedation for painful procedures. Fentanyl is the most commonly used procedural opioid because of its pharmacokinetic profile and low cost. The onset of an IV dose of fentanyl occurs within two to three minutes, with peak effect at five minutes,. This more rapid onset allows for more titratable dosing for procedural analgesia than morphine, which has an onset of action of five to 10 minutes. As with all opioids, fentanyl leads to dose-dependent respiratory depression, especially when used in combination with another sedative agent.

Ketamine is a favorite medication to facilitate sedation for painful procedures in the emergency department. Ketamine is a derivative of phencyclidine, and it is uniquely associated with sedative, dissociative, amnestic, and analgesic properties. At lower doses, ketamine leads primarily to anxiolytic and analgesic effects. With higher doses, ketamine produces antegrade amnesia and a dissociative state of sedation/anesthesia. Upon awakening, children often report having experienced very vivid dreams or hallucinations. Ketamine may be administered via IV, intramural, oral, rectal, or nasal routes. Deep levels of sedation are generally achieved. Typically, patients maintain spontaneous respiratory drive and adequate airway protective reflexes, although ketamine is a sialagogue, and the additional saliva it produces can increase the risk for laryngospasm. Ketamine also leads to increased heart rate, blood pressure, and cardiac output in previously hemodynamically stable children. Unique side effects associated with ketamine include a potential increase in intracranial and intraocular pressure as well as negative neuropsychiatric effects with emergence delirium and significant agitation. The incidence of vomiting with ketamine sedation ranges from 12% to 25% but does seem to be decreased with co- administration of midazolam and/or ondansetron.15,16

Postsedation Recovery and Discharge
Ongoing monitoring and observation are critical during recovery from procedural sedation and should continue until the child’s vital signs and level of interaction have returned to their presedation baselines. Significant adverse events can occur during emergence, especially if medications with longer half lives were used. The recovery area should be equipped with the same monitoring and resuscitation equipment as the sedation and procedural area itself, and the same rescue resources should be available. Children should be discharged only when they have met specific pre-established recovery criteria and after the family has received detailed instructions for postsedation care, including instructions about how to seek follow-up medical care if needed.

Conclusion
Pediatric sedation requires careful consideration of the balance between the patient’s risk factors, the procedure being performed, and the provider’s experience and expertise. With appropriate preparation, physicians can offer safe and effective procedural sedation to meet the needs of their pediatric patients. Minnesota is home to a number of institutions whose physicians have extensive expertise in pediatric sedation and anesthesiology. These specialists should be considered a resource for providers who seek to establish a pediatric sedation protocol or who wish consultation for a specific pediatric sedation case. MM

Patricia Scherrer is a pediatric intensivist with Children’s Respiratory and Critical Care Specialists, P.A., and medical director for pediatric sedation services at Children’s Hospitals and Clinics of Minnesota. She is also a member of the executive board of directors of the Society for Pediatric Sedation.
 
REFERENCES
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2. Joint Commission on Accreditation of Healthcare Organizations. Comprehensive accreditation manual for hospitals. Oakbrook Terrace, IL: Joint Commission on Accreditation of Healthcare Organizations, 2005.
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7. Butler MG, Hayes BG, Hathaway MM, et al. Congenital malformations: the usual and the unusual. ASA Refresher Courses in Anesthesiology. 2001;29123-33.
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13. Lubisch N, Roskos R, Berkenbosch JW. Dexmedetomidine for procedural sedation in children with autism and other behavior disorders. Pediatr Neurol. 2009; 41(2):88-94.
14. Cravero JP, Beach ML, Blike GT, et al. The incidence and nature of adverse events during pediatric sedation/anesthesia with propofol for procedures outside the operating room: a report from the Pediatric Sedation Research Consortium. Anesth Analg. 2009; 108(3):795-804.
15. Wathen JE, Roback MG, Mackenzie T, et al. Does midazolam alter the clinical effects of intravenous ketamine sedation in children? A double-blind, randomized, controlled emergency department trial. Ann Emerg Med. 2000; 36(6):579-88.
16. Langston WT, Wathen JE, Roback MG, et al. Effect of ondansetron on the incidence of vomiting associated with ketamine sedation in children: A double-blind, randomized, placebo-controlled trial. Ann Emerg Med. 2008; 52(1):30-4.
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