Pediatric sedation:
Seeing patients safely through

By Barbara M. Garcia Peña, MD, MPH, and Baruch Krauss, MD, EdM

In the last few years, a growing number of physicians have started using procedural sedation and analgesia to help children tolerate unpleasant therapeutic and diagnostic procedures. This review will familiarize you with the sedatives used, when and how they're administered, and what type of monitoring patients require.

Children who must undergo painful procedures or uncomfortable diagnostic imaging studies require timely and appropriate relief of their pain and anxiety. Even simple procedures, such as laceration repair, abscess drainage, and magnetic resonance imaging (MRI) scans, can be difficult to perform with a struggling, frightened child, leading to results that are less than optimal.

LEARNING OBJECTIVES

After reviewing this article the physician should be able to:

For many years, forceful immobilization with a papoose board was the only practical and effective way to restrain pediatric patients for procedures.¹ But this method is traumatic for children, rendering them helpless. What's more, they usually remember having the procedure performed, causing them to be apprehensive about any future medical interventions.

Over the last five years, the use of pharmacologic agents to manage the pain and anxiety associated with therapeutic and diagnostic procedures in children, referred to as procedural sedation and analgesia (PSA), has become standard practice in many medical offices, emergency departments, and ambulatory care settings. Any child undergoing a painful or anxiety-provoking procedure should be considered a candidate for PSA,² which has two general benefits. First, it enables the child to tolerate the procedure by eliminating pain, discomfort, and anxiety. Second, it expedites imaging studies and other noninvasive procedures that require the patient to be motionless.³ In some cases, PSA has the added benefit of diminishing the patient's memory of the procedure.

Given the potential for adverse events whenever pharmacologic agents are used, verbal informed consent—from the parents if the patient is younger than 18 years of age and from the patient if he is older—is needed when performing PSA. In addition, physicians responsible for PSA must be well versed in the drugs of choice and their doses, administration routes, side effects, and contraindications. Physicians must also be prepared to detect and manage possible complications of PSA by monitoring their patients before, during, and after the procedure.

Defining the levels of sedation

The American Academy of Pediatrics (AAP) has defined three levels of sedation,⁴ based on the patient's level of consciousness. The first level is conscious sedation, defined as a minimally depressed level of consciousness that allows protective reflexes and a patent airway to be maintained.

The second level of sedation, deep sedation, is a medically controlled state of depressed consciousness or unconsciousness from which a child is difficult to arouse and during which he may not be able to respond purposefully to verbal or physical stimulation. Protective airway reflexes and the ability to maintain an open airway may be compromised.⁴

The third level of sedation is general anesthesia, in which the state of unconsciousness is accompanied by a loss of protective airway reflexes requiring intervention by trained personnel to establish and maintain a patent airway.⁴

Because the AAP's definition of conscious sedation was criticized for not accurately describing how procedural sedation is practiced,⁵ the American College of Emergency Physicians developed the term procedural sedation and analgesia. PSA is defined as "a technique of administering sedatives or dissociative agents with or without analgesics to induce a state that allows the patient to tolerate unpleasant procedures while maintaining cardiorespiratory function. Procedural sedation and analgesia is intended to result in a depressed level of consciousness but one that allows the patient to maintain airway control independently and continuously. Specifically, the drugs, doses, and techniques used are not likely to produce a loss of protective airway reflexes."⁶

Most practitioners will confine their sedation practice to PSA. However, when procedures are particularly painful, such as with orthopedic fracture reduction, or when a child is extremely anxious, deep sedation may be required. Deep sedation should be performed only by individuals capable of advanced airway management and pediatric resuscitation.

The most common indications for PSA, listed in Table 1, are orthopedic fracture and dislocation reduction, diagnostic imaging studies, and repair of facial lacerations.^7,8 Other common indications include repair of other lacerations, abscess drainage, arthrocentesis, lumbar puncture, bone marrow aspiration, foreign body removal, hernia reduction,^7,8 thoracostomy tube placement, and burn debridement.

TABLE 1
When is PSA used?

The preferred agents for PSA

The drugs used for PSA can be grouped into two general classes: pure sedatives and sedative-analgesics. Pure sedatives are anxiolytic—they have a calming effect on the patient and decrease apprehension about the procedure, but they do not reduce the sensation of pain. Sedative-analgesics possess both anxiolytic and analgesic properties.

A discussion of sedatives and sedative-analgesics follows. Dosing recommendations and times for onset and duration of drug action appear in Table 2.

TABLE 2
PSA agents

Sedatives of choice

The sedatives most commonly used for PSA are benzodiazepines, barbiturates, and chloral hydrate.

Benzodiazepines have emerged as the preferred sedatives for most painless procedures. These drugs have anticonvulsant, anxiolytic, and central nervous system­mediated skeletal muscle-relaxant actions. Since they have no analgesic properties, they should be combined with an analgesic or local anesthetic for painful procedures.

Common adverse effects include dose-related respiratory depression and paradoxical reactions. Paradoxical reactions are infrequent episodes of agitation that occur during the early stages of benzodiazepine administration. Respiratory depression is more pronounced when the intravenous route is used, when drug administration is rapid, and when benzodiazepines are used in combination with opioids.²

The benzodiazepines used most frequently for PSA are midazolam (Versed), diazepam (Valium), and lorazepam (Ativan). Midazolam, a short-acting, water-soluble agent, is the most commonly used of the three. It produces a calm child who is receptive to most nonthreatening interventions, with the added benefit of causing retrograde and anterograde amnesia.

Midazolam can be administered orally, intranasally, intravenously, intramuscularly, or rectally. With IV use, onset of action is two to three minutes and duration of action is 45 to 60 minutes. The intranasal and oral routes have been used to produce sedation before laceration repair. However, results with these routes have been inconsistent,² and intranasal administration is painful and not well-tolerated by most children.

Diazepam has a slower onset of action than midazolam (four to six minutes with IV use) and a prolonged duration of action (two to three hours), especially with repeated use. It is used mostly for sedation for intermediate-length procedures, such as MRIs or angiograms. It is also used for muscle relaxation in orthopedic reductions.² The drug may be administered orally, intravenously, or rectally, though the oral and rectal routes are not practical for procedural sedation. Intramuscular administration is discouraged because it is painful and drug absorption is poor. Pain is also a problem with IV administration.⁹

Lorazepam has a longer half-life than diazepam and produces a longer effect—approximately three to four hours. Its use is limited to situations requiring extended sedation, such as when a child is on a ventilator or must be transported to another hospital.² It can be given intramuscularly with good absorption, as well as intravenously.

Chloral hydrate is a sedative-hypnotic that has no analgesic properties. It's commonly used for diagnostic imaging studies in children less then 3 years old.⁹ The drug, which can be administered orally or rectally, is primarily given orally because absorption by the rectal route is erratic. The time to onset of sedation is variable—15 to 30 minutes or longer. Recovery occurs in approximately one to two hours, although residual effects may be seen for 24 hours after administration. Complications of chloral hydrate are similar to those of other sedative-hypnotics and include hypoventilation leading to oxygen desaturation and airway obstruction secondary to loss of upper airway muscular tone, as well as vomiting and, in rare cases, death.^2,10­12

Barbiturates are a long-standing, safe class of sedative-hypnotics now used almost exclusively for diagnostic imaging studies. Like other sedative-hypnotics, these drugs have no analgesic properties unless the patient becomes unconscious. Barbiturates can cause respiratory depression, loss of protective airway reflexes, and decreases in blood pressure.

The most frequently used barbiturates for PSA are pentobarbital (Nembutal), thiopental (Pentothal), and methohexital (Brevital). Pentobarbital is most commonly used when performing diagnostic imaging studies in children over 3 years of age. It can be administered orally, rectally, intramuscularly, and intravenously. The IV route has the fastest effect, producing sedation within three to five minutes; duration of action is 15 to 45 minutes.

Thiopental and methohexital are short acting barbiturates that have been safely used by the rectal route for diagnostic imaging studies.^13,14 Methohexital has less of a respiratory depressant and hypotensive effect than thiopental.^2,14

Sedative-analgesics

The sedative-analgesics used most often are the opioids. Ketamine (Ketalar) and nitrous oxide, two other drugs in the sedative-analgesic class, are also commonly used for PSA.

Opioids. All medications in the opioid class exert their effect by binding with CNS and non­CNS opioid receptors, thereby decreasing pain sensation and generalized awareness. The opioid doses used for PSA, however, generally do not inhibit the perception of pain; their main effect is to make the pain more tolerable. The higher doses used in general anesthesia usually do block all pain sensation. The sedative effect of opioids, like their analgesic effect, is dose dependent, and ranges from mild anxiolysis to coma.² The most common adverse reactions include respiratory depression, vomiting, nausea, smooth muscle spasm, constipation, and urinary retention. The potential for respiratory depression increases when opioids are administered concomitantly with other sedatives and in infants younger than 3 months of age.⁹

Fentanyl is the most potent of the commonly used opioids; it has a potency 100 times that of morphine. It is used primarily in combination with midazolam for painful procedures, such as orthopedic fracture and dislocation reduction, repair of facial lacerations, and incision and drainage of abscesses. It can be administered either intravenously or intramuscularly. When given IV, fentanyl has a rapid onset of action (two or three minutes) and its effect usually lasts 30 to 60 minutes. Possible side effects include dose-dependent, severe respiratory depression, especially when the drug is administered rapidly, and chest wall rigidity. The latter, an uncommon but life-threatening side effect, occurs with rapid administration of high doses (greater than 5 mcg/kg).

Morphine is a longer acting opioid that is commonly used when a painful procedure is expected to last more than 45 to 60 minutes. It can be administered intravenously, intramuscularly, or subcutaneously. When given IV, its onset of action is between four and six minutes and its duration of action is between two and four hours.

Of note: The combination of IM meperidine (Demerol), promethazine (Phenergen), and chlorpromazine (Thorazine), otherwise known as the "lytic cocktail" or DPT, has fallen out of favor for pediatric sedation. Once widely used for minor outpatient procedures, the AAP has discouraged the use of this drug combination for PSA because of its many disadvantages, including inability to titrate to effect, variable time of onset, inadequate sedation, prolonged recovery time, and the potential to cause significant respiratory depression.^15,16

Ketamine is a dissociative agent similar to phencyclidine (PCP). The drug, which is commonly used for high-pain and high-anxiety procedures, produces a trance-like state accompanied by profound analgesia, amnesia, and sedation. Ketamine may be given intravenously, intramuscularly, orally, or rectally. When given IV, it has an onset of action of 30 to 60 seconds and a duration of action of 45 to 60 minutes.¹⁰

The clinical state produced by ketamine differs from the sleep-like state produced by other PSA medications. The child's eyes may remain open with a disconnected stare and she may have nystagmus.² In addition, due to inhibition of muscle tone, there may be nonpurposeful, random movements of the extremities.

Ketamine has been associated with agitation, hallucinations, and vivid dreams, mostly in patients older than 10 years and particularly in adults. Hallucinatory emergence reactions when waking up from sedation have been reported in up to 50% of adults, but in only 0% to 10% of children.² These reactions may decrease with concomitant administration of a benzodiazepine, such as midazolam.

Because ketamine stimulates salivary and tracheobronchial secretions, concomitant administration of an antisialagogue, such as atropine or glycopyrrolate, is recommended. Ketamine is also known to elevate intracranial and intraocular pressures and is contraindicated in cases where this is a concern, such as head trauma, intracranial mass lesions, hydrocephalus, globe injuries, and glaucoma. Lastly, due to ketamine's sensitization of the gag reflex and its potential to cause laryngospasm, it should not be used in patients with active upper respiratory or pulmonary infections.²

Nitrous oxide is a short-acting inhalational sedative-analgesic with a rapid onset of action (three to five minutes) and a similarly rapid onset of recovery. It is most commonly used for orthopedic fracture and dislocation reductions in conjunction with a hematoma block, as well as for abscess incision and drainage. Self-administered mixtures of 30% to 60% nitrous oxide with oxygen have been shown to produce mild to moderate analgesia and anxiolysis in several ED studies.^17,18 To deliver the gas mixture with a demand-valve mask, the child must be coordinated enough to hold the mask to his nose and mouth.

Because of the potential for diffusional hypoxia, in which nitrous oxide diffuses out of the blood and into the lungs where it can displace oxygen, supplemental oxygen should be administered throughout the recovery phase after the nitrous oxide is turned off.² Nausea and vomiting are seen infrequently in children using nitrous oxide.

Reversing the effects of sedation

Reversal agents are available for two classes of PSA medications—the opioids and the benzodiazepines. Reversal agents may be administered to improve spontaneous breathing and effort in children who have a depressed or absent respiratory drive. They can be especially helpful in cases where positive pressure ventilation and airway control are difficult.³ Specific reversal agents should be available at the bedside whenever opioids or benzodiazepines are administered.

Naloxone (Narcan), the opioid reversal agent, works as a competitive antagonist at the opiate receptor site. It has a short half-life (20 to 40 minutes) in most children, and because its duration of action may be shorter than the opioid being reversed, relapses can be a problem and additional doses of the reversal agent may be required. Naloxone needs to be used judiciously, since acute reversal of opioid-induced analgesia may result in intense pain, hypertension, tachycardia, and, rarely, pulmonary edema.²

Flumazenil (Romazicon) is a competitive benzodiazepine antagonist that has a higher affinity for the GABA (

-aminobutyric acid) receptor than benzodiazepine, and can therefore displace bound benzodiazepine. However, since flumazenil blocks all action of the drug, it can precipitate seizures in certain patients, particularly those on long-term benzodiazepine therapy or with tricyclic antidepressant overdose.²

Choosing the appropriate agent

Several considerations help guide the selection of a PSA agent. First and foremost, the potential risks of the medication must be balanced against its benefits. Second, the presence of anxiety with or without pain should determine whether a sedative with or without an analgesic will be required. Third, certain PSA medications may be contraindicated depending on the child's cardiorespiratory or neurologic status, or other patient-specific contraindications. Fourth, the duration of the procedure and whether or not the child has intravenous access should determine the type and route of medication.¹⁰ Figure 1 provides an overview of PSA medications that might be selected for specific indications.

Patient monitoring

The safety of children who undergo PSA by non-anesthesiologists has become an increasing concern among health-care professionals. Reports of life-threatening adverse events, and even death,^10­12,19,20 have heightened awareness of the potential hazards of PSA and resulted in mandates and guidelines for the monitoring and care of sedated children.^3­6 The 1992 AAP guidelines for monitoring and managing these patients—the most recent ones published—are summarized in "Pediatric sedation: AAP guidelines for monitoring and management".

Pediatric sedation: AAP guidelines for monitoring and management

The goals of sedation in the pediatric patient are:

The AAP recommendations include:

Condensed and adapted from: AAP Committee on Drugs⁴

Monitoring should begin prior to drug administration following a baseline assessment of the patient, and continue through the recovery phase. A minimum of two experienced persons, usually one physician and one assistant (a nurse or clinical assistant, for example) is required when PSA is performed. The physician oversees the administration of the medications and may also perform the procedure, while the assistant continuously monitors the patient's vital signs, including heart rate, respiratory rate, oxygen saturation level, and blood pressure. The frequency of vital sign measurements depends on the level of sedation. The patient's mental status and response to sedation must be monitored as well.

Postprocedure monitoring should continue until cardiorespiratory and neurologic status have returned to baseline. It is especially important to closely monitor the patient in the immediate postprocedure period, when procedural stimuli have ceased; in some situations, such as after orthopedic reduction, the danger of respiratory depression has been shown to increase once the painful stimulus is removed.

The physician must be fully prepared for possible adverse events, including cardiorespiratory compromise, anaphylactic reactions, vomiting, seizures, and frank arrest.⁴ Standard resuscitation equipment, including age-appropriate bag-valve masks and endotracheal tubes, oxygen, and suction, must be available at the bedsides of all patients undergoing PSA (Table 3).

TABLE 3
Equipment and medication needs for performing PSA

With urgent and emergent procedures, it is impossible to follow strict NPO guidelines before performing PSA. With elective procedures, the AAP guidelines on dietary precautions for sedation should be followed.⁴

Patients may be discharged from the ED once level of consciousness, behavior, and vital signs have returned to baseline. Table 4 contains suggested discharge criteria. It is important to note that the guidelines do not require that a child be able to walk unaided to be discharged. Verbal and written discharge instructions covering such topics as diet, activity, sleep, and common postsedation problems should be provided to the patient's caregivers. These instructions should be concise, clear, and easy to understand, and include the names of contact persons and their phone numbers in case a question arises.²¹ The Guide for Parents below provides discharge instructions.

TABLE 4
AAP recommended discharge criteria for children undergoing sedation

Ensuring the safe use of PSA

Procedural sedation and analgesia has become an essential component in the management of acute pain and anxiety in pediatric patients. Physicians who practice PSA must be competent in the use of the various pharmacologic agents and knowledgeable about their potential adverse effects and contraindications. In addition, vigorous monitoring is essential until discharge criteria are met. By following these precautions, physicians can play a major role in alleviating unnecessary pain and anxiety in already frightened children, while optimizing the clinical results of many "scary" procedures.

REFERENCES

1. Schuman AJ: A protocol for pediatric sedation. Contemporary Pediatrics 1994;11(1):74

2. Sacchetti A, Schafermeyer R, Geradi M, et al: Pediatric analgesia and sedation. Ann Emerg Med 1994;23:237

3. American Society of Anesthesiologists Task Force on Sedation and Analgesia by Non-Anesthesiologists: Practice guidelines for sedation and analgesia by non-anesthesiologists. Anesthesiology 1996;84:459

4. American Academy of Pediatrics, Committee on Drugs: Guidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures. Pediatrics 1992;89:1110

5. Maxwell LG, Yaster M. The myth of conscious sedation. Arch Pediatr Adolesc Med 1996;150:665

6. American College of Emergency Physicians: Clinical policy for procedural sedation and analgesia in the emergency department. Ann Emerg Med 1998;31:663

7. Garcia Peña BM, Krauss B: Adverse events of procedural sedation and analgesia in a pediatric emergency department. Ann Emerg Med 1999;34:483

8. Krauss BS, Harakal T, Fleisher GR: General trauma in a pediatric emergency department: Spectrum and consultation patterns. Pediatr Emerg Care 1993;9:134

9. Cote CJ: Sedation for the pediatric patient: A review. Pediatric Anesthesia 1994;41:31

10. D'Agostino J, Terndrup TE: Comparative review of the adverse effects of sedatives used in children undergoing outpatient procedures. Drug Safety 1996;14:146

11. Jastak JT, Pallasch T: Death after chloral hydrate sedation: Report of case. J Am Dent Assoc 1988;116:345

12. Cote CJ, Alderfer RJ, Notterman DA, et al: Sedation disasters: Adverse drug reports in pediatrics—EDA, USP and others [abstract]. Anesthesiology 1995;83:A1183

13. O'Brien JF, Falk JL, Carey BE, et al: Rectal thiopental compared with intramuscular meperidine, promethazine, and chlorpromazine for pediatric sedation. Ann Emerg Med 1991;20:644

14. Manuli MA, Davies L: Rectal methohexital for sedation of children during imaging procedures. Am J Roentgenol 1993;160:577

15. Algren JT, Algren CL: Sedation and analgesia for minor pediatric procedures. Pediatr Emerg Care 1996; 12:435

16. American Academy of Pediatrics, Committee on Drugs: Reappraisal of lytic cocktail/Demerol, Phenergan, Thorazine (DPT) for sedation of children. Pediatrics 1995;95:598

17. Gamis AS, Knapp JF, Glenski JA: Nitrous oxide in analgesia in a pediatric ED. Ann Emerg Med 1989;18:177

18. Burton JH, Auble TE, Fuchs, SM: Effectiveness of 50% nitrous oxide/50% oxygen during laceration repair in children. Acad Emerg Med 1998;5:112

19. Malviya S, Voepel-Lewis T, Tait AR: Adverse events and risk factors associated with the sedation of children by non-anesthesiologists. Anesth Analg 1997;85:1207

20. Yaster M, Nichols DG, Deshpande JK, et al: Midazolam-fentanyl intravenous sedation: Case report of respiratory arrest. Pediatrics 1990;86:463

21. Zempsky W: Postsedation evaluation, in Krauss B, Brustowicz RM (eds): Pediatric Procedural Sedation and Analgesia, Philadelphia, PA, Lippincott, Williams and Wilkins, 1999, p 143

DR. PENA and DR. KRAUSS are staff physicians in the Division of Emergency Medicine, Department of Medicine, Children's Hospital, Boston, and Instructors of Pediatrics in the Department of Pediatrics, Harvard Medical School, Boston.

GUIDE FOR PARENTS

When your child has been sedated

Today your child received medication to provide sedation during a procedure. The medication was given to help relieve the child's anxiety and minimize discomfort while the doctor provided treatment. Your child has recovered sufficiently to be safely discharged home. Some mild effects of the medication may linger on, so your child will need close supervision by you or another adult for six hours.

Caring for a child who has been sedated

Activities: Your child may be slightly groggy, dizzy, and inattentive for six hours. Therefore, restrict activities to those that do NOT require good coordination and concentration. For example, do not allow bike riding or skate boarding. Adolescents should not drive a car.

Diet: Avoid giving your child a heavy meal for the next few hours. Some children will have mild nausea and may vomit once or twice following these medications. If frequent vomiting occurs,call your child's doctor. Give clear liquids (such as juice, ginger ale, Popsicles, Jell-O, broth, tea) at first. Advance the diet slowly as tolerated. Advise adolescents to absolutely not drink alcohol for at least 24 hours.  

Sleeping: If your child naps or goes to bed for the night within two hours after discharge from the emergency department, you will need to check him or her once more within two hours of falling asleep. Make sure the child awakens briefly, is breathing normally, and has normal skin color at that time.

Contact your doctor or return to the emergency department if:

• breathing appears difficult, too shallow, too slow, or unusual.

• skin color has become extremely pale or grayish.

• it is very difficult to wake your child from sleeping.

Adapted with permission from "Sedation Discharge Instructions," © 1996, Children's Hospital, Boston

This parent guide may be photocopied and distributed to families in your practice without permission of the publisher.

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This activity has been planned and implemented in accordance with the Essentials and Standards of the Accreditation Council for Continuing Medical Education through the joint sponsorship of Jefferson Medical College and Medical Economics, Inc.

Jefferson Medical College of Thomas Jefferson University, as a member of the Consortium for Academic Continuing Medical Education, is accredited by the Accreditation Council for Continuing Medical Education to sponsor continuing medical education for physicians. All faculty/authors participating in continuing medical education activities sponsored by Jefferson Medical College are expected to disclose to the activity audience any real or apparent conflict(s) of interest related to the content of their article(s). Full disclosure of these relationships, if any, appears with the author affiliations on page 1 of the article.

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FACULTY DISCLOSURES

Jefferson Medical College, in accordance with accreditation requirements, asks the authors of CME articles to disclose any affiliations or financial interests they may have in any organization that may have an interest in any part of their article. The following information was received from the authors of "Pediatric sedation: Seeing patients safely through."

Barbara M. Garcia Peña, MD, MPH, has nothing to disclose.

Baruch Krauss, MD, EdM, has nothing to disclose.

 

Barbara Pena, Baruch Krauss. Pediatric sedation : Seeing patients safely through. Contemporary Pediatrics 2000;8:42.