Pediatric Sedation and Analgesia

CHAPTER 7 Pediatric Sedation and Analgesia



Paul W. Davis


Over the past decade, various professional medical societies and hospital associations have readdressed the challenging issue of sedation and pain control in children with the goal of developing multidisciplinary guidelines for what constitutes acceptable and satisfactory care. These societies have included the American Academy of Pediatrics (AAP), the American Society of Anesthesiologists (ASA), and the Joint Commission for Accreditation of Healthcare Organizations (formerly, JCAHO). Their recommendations not only rely heavily on expert opinion and consensus but openly advise that all pediatric sedation be performed under the direction of pediatric subspecialists. We respectfully disagree with the assertion that only pediatricians and anesthesiologists can safely and effectively administer these medications.


The administration of medications for analgesia and moderate or deep sedation was previously termed conscious sedation. Because these medications actually do alter a patient’s level of consciousness and perception of pain, however, the phrase is inaccurate and is now rarely used.



Historical Perspective on Undertreatment of Pain


Historically, the management of pain and anxiety in the pediatric population outside of the operating room has been inadequate. Indeed, several studies have suggested that inattention to painful conditions may be more prevalent for pediatric procedural care delivered outside of children’s hospitals. Nevertheless, any physician who has performed even minor procedures for infants and children appreciates the value of being able to safely and predictably sedate them. Aside from the psychological shock and trauma imposed on infants and children because of a limited understanding of the purpose for a procedure, developmental responses to pain vary by age and can thwart the most well-meaning clinician’s efforts to complete a needed procedure.


At least six factors have been identified as contributing to the undertreatment of pain and anxiety in the pediatric population: (1) lack of familiarity with the use of sedative agents; (2) the erroneous conception that newborns and infants do not feel pain; (3) the incorrect belief that children have a very short-term recollection of painful events; (4) the fear of adverse effects of sedatives and analgesics; (5) the fear of masking the symptoms and signs of progressive injury or complications of treatment; and (6) the overarching underestimation of pediatric pain because of the young patient’s inability to describe or quantify it.



Developmental Differences in the Perception of Pain


Although the physiologic response to pain is similar in adults and children, recent studies involving young children and fetuses suggest that they may actually experience a heightened perception of pain. A child’s perception of pain and clinical reaction to painful stimuli are influenced by several factors, including age, cognitive level, past experiences, extent of control over the situation, parental responses, and perceived cause and expected duration of the painful experience.


The plan for treatment should account for the differences in the pain response at different stages of development:


• Less than 6 months—Anticipatory fear is not present and the infant reflects the level of anxiety of the parent. Withdrawal, facial grimacing, thrashing, and brief crying are typical expressions of pain.

• 6 to 18 months—Anticipatory reactions begin to appear in response to fear of a suspected painful experience (e.g., withdrawal of a limb at the sight of a needle).

• 18 to 24 months—Children begin to use words like “boo boo” and “hurt” in response to expected painful stimuli.

• 3 years—Children are still unable to understand the reason for pain but are able to localize pain and identify its cause. They are more capable of reliably assessing the pain they feel. Their tolerance for a painful procedure is improved by allowing them some sense of control over certain aspects of the situation (e.g., when it will be performed or how they are positioned).

• 5 to 7 years—Continued improvements in understanding of purpose and necessity of painful stimuli occur at this age with consequent improved cooperation.

• 8 to 12 years—Comprehension of the whole process continues to grow with improved understanding/localization of internal pain.

• Adolescence—Children are adept at qualifying and quantifying pain and they develop coping strategies similar to those of adults that help to diminish the perception of pain.

This chapter addresses the current breadth of effective pharmacologic and nonpharmacologic methods to alleviate both pain and anxiety in the pediatric patient before surgical operations and other procedures.



Nonpharmacologic Techniques


Needlesticks represent the most common source for iatrogenic procedural pain worldwide. From simple immunizations to venipuncture for laboratory studies to anesthetic injection before dermatologic procedures, laceration repair, and orthopedic reductions, needle pain is ubiquitous. In addition, more and more children are undergoing nonmedical procedures like body piercings and tattooing (or removal of tattoos).


Untreated pain in the pediatric population has been studied extensively and does have long-term emotional and medical outcomes that are lifelong. Children now receive more than 20 needlesticks for immunizations before they are 2 years of age and many develop needle phobia because only 1 in 9 is done with any kind of pain control. Adolescents subsequently avoid needed medical treatment, 16% to 75% of adults surveyed refuse to donate blood, patients with human immunodeficiency virus infection delay needed blood tests and continue to infect sexual partners, and geriatric patients refuse influenza and pneumococcal vaccines owing to fear of needle pain.


Physicians who perform neonatal elective circumcisions know first-hand the benefits associated with the oral administration of “sugar water.” The analgesic effect and safety of sucrose for procedural pain both with and without the use of a pacifier (non-nutritive sucking) in neonates have been clearly demonstrated. Effectiveness in older patients is less clear, but it is easy to administer and there are no known adverse effects. Aspiration has not been a reported complication. The influence of age, intercurrent illness, type of procedure, and location of procedure is unclear at this time.


The simplest and most common nonpharmacologic method used with children is voluntary and external distraction. Giving the child and parent verbal reassurance by providing them with information about the procedure before it is started may help allay anxiety but might also make it worse. Hypnosis has been used to help direct children’s focus away from the procedure. Young patients can be taught to repeat positive statements to themselves to distract them and relieve anxiety. These behavioral and cognitive approaches represent useful adjuncts that are frequently overlooked because of perceived time constraints in a busy office or emergency department. Distraction techniques include counting or saying the “ABCs,” music and videotapes, bubble blowing, spinning pinwheels, using party blowers, playing “I Spy” games, and the use of “medical play” as employed by child life programs. Behavioral treatments include the techniques of desensitization (the gradual, increasing exposure to a procedure over time), positive reinforcement (rewards and positive statements during or after a procedure), and relaxation technique (the use of breathing, imagery, and self-hypnosis to decrease anxiety). Although all of these techniques have been shown to be very effective, they need props, take time, and require trained personnel.


The dorsal column of the spinal cord forms a common final pathway for several kinds of afferent neurologic stimuli, including pain, position, temperature sensation, and vibration. By applying the “gate theory” and stimulating nerve fibers with either cold or vibration, the sensation of sharp pain can be decreased or eliminated by interfering with its transmission because of the other impulses. The use of cold water or ice and the application of vibrating massagers represent effective ways of ameliorating pain. Cold sprays (e.g., Painease; Gebauer, Cleveland) have been widely used but the research into their efficacy in children has been equivocal at best. A device that uses vibration is currently under investigation (Buzzy; MMJ Labs, Atlanta). Pediatric dentists frequently use tactile vibration using their opposite hand in the delivery of oral anesthesia, with great success.



Topical Analgesics for Children


Also see Chapter 10, Topical Anesthesia.


Ease of administration with minimal trauma for the child and parent would make these the medications of choice for a large variety of procedures. The reality has never lived up to the promise, however.


The topical agent most commonly used for laceration repair in children is LET (a combination of lidocaine, epinephrine, and tetracaine) with an onset of action of 20 minutes. EMLA cream is a eutectic mixture of lidocaine and prilocaine but often requires application approximately 1 hour before the procedure, limiting its usefulness. LMX 4 is a nonprescription 4% liposomal lidocaine preparation that is also effective as a topical anesthetic agent.


Recently, Zingo (Anesiva, Inc., South San Francisco) has been approved by the U.S. Food and Drug Administration (FDA) for use on intact skin to provide topical local analgesia before venipuncture or peripheral intravenous cannulation in children 3 to 18 years of age. This needle-free product has a novel delivery system using pressurized gas jets that deliver lidocaine hydrochloride monohydrate, 0.5 mg, directly through the epidermis and into the dermis. Zingo comes as a ready-to-use, sterile, single-use, disposable, needle-free delivery system. The product consists of a drug reservoir cassette filled with 0.5 mg lidocaine powder (particle size of 40 µm), a pressurized helium gas cylinder, and a safety interlock. The safety interlock prevents premature triggering of the device. Once Zingo is pressed against the skin, the interlock is released, allowing the button to be depressed to deliver the anesthetic. Triggering the device results in a sound not unlike the popping of a balloon. Because the price of this single-use product is between $20 and $25, its use can increase the cost of venipuncture considerably. Although use can be repeated, if necessary, at a different site (a frequent requirement when attempting to place an intravenous catheter in dehydrated children), repeated use at the same site is not recommended and the clinician needs to pay heed to the total dosage of anesthetic administered to avoid toxicity.


Zingo provides local dermal analgesia within 1 to 3 minutes of application and analgesia diminishes within 10 minutes of treatment. Most adverse reactions were application site–related and included bruising, burning, pain, contusion, and hemorrhage. These occurred in 4% of pediatric patients. The most common systemic adverse reactions were nausea (2%) and vomiting (1%). Erythema, edema, pruritus, and petechiae occurred in approximately half of all patients and were brief and self-limited.



Pharmacologic Agents for Sedation and Analgesia


The ideal pediatric agent for procedural sedation would have certain characteristics. First, it would be both 100% safe as well as completely effective for the full range of desired properties—amnesia, analgesia, anxiolysis, motor control, and sedation. It would have rapid onset, fast recovery, a predictable duration of action, and would be completely reversible. In addition, it would be easy to titrate and painless to inject, provide choices for administration route, and be easy to administer. Finally, such an ideal agent would be entirely free of adverse effects and complications.


Needless to say, this ideal pediatric sedative agent has yet to be discovered. A wide range of approved short-acting agents are currently available for use as sedative–hypnotics or analgesics in infants and children. Each of these agents offers advantages in select situations and for specific patients. Procedures that are not painful but require patients to cease moving can be performed with sedation alone. Painful procedures, however, require both sedation and analgesia.


The American College of Emergency Physicians has developed an evidence-based clinical policy for the use of pharmacologic agents for sedation and analgesia in children. This policy focuses on etomidate, fentanyl/midazolam, ketamine, methohexital, pentobarbital, and propofol. The specific uses, recommendations, and cautions for both these and other agents are addressed in the following section. Specific indications and contraindications are addressed individually for each medication. The important characteristics of selected agents are summarized in Table 7-1 for easy reference.



TABLE 7-1 Summary of Important Characteristics of Selected Agents

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Sedative–Hypnotic Agents


These medications provide anxiolysis, control of movement, sedation, and often amnesia for the painful event, but do not provide analgesia.



“Lytic Cocktail”


This time-honored mixture is addressed briefly here for historical reasons and because many older primary care physicians have used this regimen extensively in the past with great success. The “lytic cocktail” consists of chlorpromazine (Thorazine), promethazine (Phenergan), and meperidine (Demerol) and is given intramuscularly according to the weight of the child: chlorpromazine, 0.5 mg/kg; promethazine, 0.5 mg/kg; and meperidine, 0.7 mg/kg. It is not recommended because (1) the physician must deal with the side effects of three medications instead of one (polypharmacy); and (2) its effect can be erratic and unpredictable.



Benzodiazepines (Midazolam)


Benzodiazepines provide sedation, anxiolysis, and amnesia, but do not provide analgesia. There are several reasons why midazolam (Versed) is the most commonly used agent in this category and the clear drug of choice for pediatric procedures requiring merely sedation and anxiolysis. Midazolam has a rapid onset of action, short duration of action, and rapid recovery time. Although patients may not appear sedated when it is used as a single agent, they become more relaxed and cooperative, and there is the frequent (but not universal) benefit of a marked amnestic response for the event. Controversy exists as to whether this marked amnestic response actually blocks “intrinsic memory”—that is, although patients may not consciously recall the painful incident, the traumatic event is still recorded in the brain at the subconscious level. For this reason, it is advisable to coadminister an appropriate analgesic agent for painful procedures.


Midazolam offers great flexibility in route of delivery because it can be administered by the oral, intranasal, sublingual, rectal, intramuscular (IM), or intravenous (IV) route. Its efficacy is well established. When used as a single agent (i.e., not combined with an opiate, ketamine, or droperidol), however, it is inferior to other regimens or single agents, and patients may appear to be wide awake.


Recommended dosages vary depending on route of administration. Oral midazolam is given at doses of 0.5 to 1 mg/kg and results in the onset of mellowness at 15 to 30 minutes. Intranasal midazolam at recommended dosages of 0.3 to 0.5 mg/kg has a more rapid onset of action at 5 to 15 minutes, duration of action of 15 to 20 minutes, and some effects lingering for up to several hours. The solution is drawn up into a tuberculin syringe, the needle removed, and the drug then instilled into the child’s nares with the child supine or the headed tilted back. Recommended rectal doses of midazolam are 0.45 to 1 mg/kg, with efficacy reported variably from 62% to 93% for laceration repair. Agitation (reported in up to 17%) has been the major drawback of this route of administration. The recommended IV dose of midazolam is 0.05 to 0.1 mg/kg and the IM dose is 0.05 to 0.15 mg/kg; time to peak effect is 3 to 5 minutes for the IV route and variable for the IM route. Duration of action is 2 to 4 hours.


Adverse effects are uncommon and include the atypical effects of paradoxical agitation and euphoria after administration or an emergence reaction when given IV (1.4%) or orally (6%). Hypotension and respiratory depression are rare but can occur, especially if a narcotic agent is coadministered. The antagonist flumazenil (Romazicon) at a dose of 0.002 to 0.02 mg/kg IV can be given to reverse the effects of midazolam, but patients will require a longer period of observation in recovery (2 hours is commonly recommended) because this agent may have a shorter duration of action than the benzodiazepine, with consequent recurrence of sedation or respiratory depression.



Chloral Hydrate


Not very many years ago, chloral hydrate was considered the mainstay of safe, effective pediatric sedation. Although it has a wide margin of safety, chloral hydrate is primarily used to sedate children younger than 3 years of age for diagnostic imaging because its effects on older children are unreliable. It can be administered orally or rectally at a dose of 25 to 100 mg/kg up to 1 g/dose for infants and 2 g/dose for older children. Chloral hydrate has an unpleasant smell and taste, making it difficult to entice a child to take much of it orally. Peak action occurs at 60 minutes, making it much less useful than other agents in the emergency setting. Its duration of action is quite variable, with sedation lasting from 1 to 4 hours after administration.


Adverse effects include prolonged sedation, paradoxical agitation, and coma, but airway obstruction and respiratory depression can occur and there is no consistent dose below which complications do not occur; deaths have been reported. In one published series, adverse events were reported in 33% of children who received chloral hydrate either alone or in combination with other sedatives. This relatively high rate of complications contrasts markedly with the widespread perception of its safety. There is no reversal agent for chloral hydrate and its use is contraindicated in patients with cardiac, hepatic, and renal disease as well as porphyria. In addition, its sedative effects can be difficult to predict. In the past, this agent was frequently used in unmonitored settings. In light of the difficulty in predicting its sedative effects and the attendant risks with its use, it is imperative that procedural sedation protocols for monitoring patients during and after administration of this agent be strictly followed.



Barbiturates (Methohexital, Thiopental, and Pentobarbital)


Barbiturates are primarily used for sedating children younger than 3 years of age to perform diagnostic imaging. They are relatively safe but are contraindicated in patients with porphyria. Major side effects include respiratory depression with apnea and hypotension, both of which are more common when barbiturates are used in combination with opiates or benzodiazepines.


Methohexital (Brevital) is an ultra–short-acting agent with an onset of action of 30 to 60 seconds and duration of effect of 5 to 10 minutes. It can be administered intravenously at a dose of 1 to 1.5 mg/kg to children 3 to 12 years of age. It is contraindicated in children with temporal lobe epilepsy because it can cause seizures in this subgroup.


Thiopental (Pentothal) is also a short-acting barbiturate with an onset of action of 30 to 60 seconds but a slightly longer duration of effect of 15 minutes. It is generally given rectally to children at a dosage of 5 to 10 mg/kg and has the notable side effect of decreasing intracranial pressure. It is therefore particularly useful in patients for whom increased intracranial pressure is a concern.


Pentobarbital (Nembutal) is a very useful barbiturate sedative for longer radiologic procedures like magnetic resonance imaging and positron emission tomography scans. It has an onset of action of 3 to 5 minutes when given IV and a duration of effect of 30 to 45 minutes. For children and infants more than 6 months of age, it can be given intravenously at a dosage of 1 to 3 mg/kg and titrated every 3 to 5 minutes to a maximum dosage of 100 mg, or intramuscularly at a dosage of 2 to 6 mg/kg to a maximum dosage of 100 mg.

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May 14, 2017 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Pediatric Sedation and Analgesia

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