Sedation in Children: Current Concepts
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Sedation in Children: Current Concepts Varsha Bhatt-Mehta, Pharm.D., and David A. Rosen, M.D. Sedation in children poses a great challenge, with the main concern one of safety. The importance of providing adequate sedation to children was realized only in the last decade and a half, and relevant data are severely lacking. Use of potent sedative agents is not without risk. Children are given sedative agents in a wide variety of settings by practitioners with different degrees of experience with the drugs and management of adverse effects. Controversial issues must be addressed in this area, and appropriate tools developed to measure sedation and individualize treatment based on the drugs’ pharmacokinetic and pharmacodynamic properties. (Pharmacotherapy 1998;18(4): 790-807) OUTLINE management, psychology, and pharmacology. A Pharmacologic Options multidimensional approach is optimal; however, Chloral Hydrate caregivers frequently resort to drug therapy Propofol because of inadequate time or resources. Benzodiazepines The literature on sedation in children is some- Ketamine what limited, and clinicians make considerable Barbiturates extrapolation from adult literature. However, not Narcotics only does the pharmacology of sedative agents Volatile Agents differ in children compared with adults, but the Other Agents time course of sedation differs. Adults usually Procedure-Directed Sedation require most pharmacologic intervention at the CT Scans and MRI beginning of an illness, whereas children tend to Ec hocardiogram need less at the beginning and more as they Dental Procedures recover. Oncology Procedures For any medical therapy, it is necessary to have Intensive Care Procedures an instrument that can detect problems and Endoscopy document treatment effectiveness. For sedation, Withdrawal of Sedative Agents developing such a tool is difficult since objective Summary data are not easily obtained. A number of scoring systems discriminate different levels of Children undergoing m dical car are sedation, but they have been slow to be accepted. confronted with unfamiliar environments that The Vancouver Sedative Recovery Scale, which is may be perceived as potentially threatening. To validated for the pediatric intensive care unit soothe their fears and anxieties, several (PICU) and postanesthesia recovery unit, rates approaches are available, such as behavioral 12 items in 3 categories-responsiveness, eye opening and function, and movements. The From the Department of Pharmacy Services, University of Michigan Medical Center, and the College of Pharmacy, score is between zero and 22, with higher University of Michigan, Ann Arbor, Michigan (Dr. Bhatt- numbers given to more awake patients.’ Mehta); and the Departments of Anesthesia and Pediatrics, The Neurobehavioral Assessment Scale (NAS) West Virginia University Health Sciences Center, rated behavioral function in adults (age 18-72 Morgantown, West Virginia (Dr. Rosen). Address reprint requests to Varsha Bhatt-Mehta, yrs) undergoing maxillofacial procedures and Pharm.D., F5203, 200 East Hospital Drive, Ann Arbor, MI was better than the Glasgow Coma Scale in 48109-0225. differentiating levels of sedation.’ The NAS rates SEDATION IN CHILDREN Bhatt-Mehta and Rosen 79 1 four areas: sedation and reduced alertness, and the complex condition of patients in whom disorientation, speech articulation defect, and such scales might be most useful. psychomotor retardation. The first three provided 97% of variance in scores; the Pharmacologic Options contribution of psychomotor retardation may be small and its evaluation unnecessary. A more Pharmacologic sedation should not be a objective device that does not require observed substitute for analgesics when a child is in pain, behavior analyzes the neural network to classify or for honest explanations about medical electroencephalographic patterns against the maneuvers and attempts at behavior modification. depth of midazolam sedation during long-term Distraction, relaxation techniques, and positive sedation in the intensive care unit (ICU).3 Even imagery can avoid sedation for many nonpainful though it successfully classified level of sedation procedures in which cooperation is necessary. in only 50-60% of patients, the authors These techniques achieved good cooperation in concluded that the scale compared with visual children as young as 7 years undergoing right classification alone. However, it is limited in that heart catheterization for bi~psies.~Using an age- it requires special equipment and expertise, and appropriate video tape as an alternative to is not easily performed at the bedside. sedative agents, 92% of children (mean age 18.6 We developed a sedation scoring system for mo) successfully underwent cardiac ultrasound our PICU (Figure 1). It has not been formally without ~edation.~Certainly, when nonpharma- validated, but in practice it proved useful. A cologic modalities fail, sedatives are appropriate. practical problem with validating tools such as General guidelines for sedation such as those those intended for the ICU is concomitant set forth by the American Academy of Pediatrics administration of analgesic agents that act as should be adhered to when the drugs are confounders and prevent a true evaluation of the delivered by a nonanesthesiologist.6 These efficacy of the sedative agent. Classic, validated guidelines were developed due to increased use analgesic scales have little or no application to of sedatives during invasive diagnostic, assessment of sedation, although many have tried radiologic, and minor surgical procedures to use them for this purpose. When conscious performed in children outside the operating sedation is necessary for procedures such as room. They were issued with the understanding echocardiography and computed tomographic that regardless of the intended level of sedation (CT) scans, a simpler tool may be more or route of administration, sedation represents a appropriate. A modified version of this scale is continuum from a loss of protective reflexes, currently being used at one author’s institution to through a light level of sedation, to obtundation. monitor sedation for short procedures. The guidelines clearly define the extent of Thus, although many scoring systems are physiologic monitoring during various degrees of available to measure depth of sedation, an ideal sedation, defined as follows: does not exist. Development of such an ideal 1. Conscious sedation, a medically controlled system is hampered by many factors, including state of depressed consciousness that allows difficulty eliminating subjectivity from assessment the patient’s protective reflexes to be 0 1 2 3 4 5 a b C Coma Aslaep Drowsy Calm Awake Wild -40% Baseline 110% Eyes closed Eyes closed Eyes open Eyes open. Alert Anxious -40% Baseline 110% No motion Rare spon. Moves < 0-5 Moves 4-18 Active, moves Excess . -40% Baseline 110% motion timeslmin. timedmin. >lo timed motion. small midsize large min. No head No head No head Minimal Slow head Tosses head motion motion. motion. Moves head motion. motion. from side to No arm or leg Minimal arm arms or legs. Moves arms. Moves arms side. motion. No or leg motion. Eyes open or legs. and legs. Thrashes arms reaction to No reaction with mild Moves on Easy to and legs. stimulus to mild stimulus. command. control No control of stimulus. movements. movements. I Figure 1. West Virginia University PICU sedation scoring system. -- ._ . ____ 792 PHARMACOTHERAPY -7Volume ’ 18, Number 4, 1998 maintained, maintains a patent airway examinations, 7% experienced side effects, with independently and continuously, and vomiting being the most common (4.3%).’ The permits appropriate responses by the patient frequencies of hyperactivity and respiratory to physical stimulation or verbal command symptoms were less than 2%. 2. Deep sedation, a medically controlled state The success rate for sedation is usually around of consciousness or unconsciousness from 86% for healthy children, whereas in those with which the patient may not be easily aroused; neurologic disorders it tends to be 10wer.~In this it may be accompanied by partial or complete study of 50 children, 43 were successfully loss of protective reflexes, including inability sedated with a mean chloral hydrate dose of 58 to maintain a patent airway independently mg/kg (range 25-81mgkg). Seven patients who and respond purposefully to physical did not respond to the initial dose had neurologic stimulation or verbal command abnormalities including intraventricular 3. General anesthesia, a medically controlled hemorrhage, cerebral palsy, brain tumors, and state of unconsciousness accompanied by seizure disorder. Failure to respond ranged from loss of protective reflexes, including inability being awake during procedures to requiring to maintain a patent airway independently additional doses of chloral hydrate or a different and respond purposefully to physical agent (unspecified) intramuscularly and stimulation or verbal command. rescheduling procedures. I Recommended physiologic monitoring for Because chloral hydrate does not increase conscious sedation covers baseline vital signs, intraocular pressure, it was recommended in pulse oximetry or equivalent continuously children with normal or glaucomatous eyes who during the procedure, intermittent respirations require ocular pressure measurements. lo The and blood pressure, continuous heart rate, and suggested dose is 100 mg/kg for the first 10 kg airway patency. After the procedure, the child body weight, and