Numerous drug regimens are used with children to produce conscious sedation, and no consensus exists on the optimum method. They should produce a medically controlled state of depressed consciousness that (1) allows protective reflexes to be maintained, (2) retains the patient's ability to maintain a patent airway independently and continuously, and (3) permits appropriate response by the patient to physical stimulation or verbal command (e.g., 'Open your eyes") (Cote, 1994). Unconscious sedation occurs when the child can no longer respond to commands and is typically induced with propofol (Diprivan) or ketamine.
Drugs used to induce conscious sedation should achieve five goals (American Academy of Pediatrics, 1992): (1) to guard the patients safety and welfare; (2) to minimize physical discomfort or pain; (3) to minimize negative psychologic responses to treatment by providing analgesia, and to maximize the potential for amnesia; (4) to control behavior; and (5) to return the patient to a state in which safe discharge, as determined by recognized criteria, is possible. Administration should also be "atraumatic" by using oral, topical, or existing IV routes. Several analgesic/sedation options, such as fentanyl, meperidine, morphine, midazolam, or diazepam, are available although none is ideal. However, one of the best choices is fentanyl and midazolam because they have a quick onset and a short duration of action. Both can be given IV or orally. A commercially available oral form of midazolam, Versed Syrup, has recently been FDA approved. See also Oral Midazolam (Versed) Syrup Approved for Pediatric Conscious Sedation.
The oral transmucosal preparation, Fentanyl Oralet, provides an effective and atraumatic form of conscious sedation, especially in children without preexisting IV access. It consists of a confection or candy lozenge on a plastic holder that is available in 200-, 300-, and 400-mg strengths. The recommended dose is 5 to 15 mcg/kg of body weight; children who weigh over 40 kg may need the higher dosage. It is not recommended for children who weigh less than 15 kg. The peak effect occurs in 20 to 30 minutes from the start of administration if the drug is sucked, not chewed and swallowed. If the lozenge is chewed, the drug is less effective because the liver metabolizes part of it before the drug enters the bloodstream. However, swallowing the drug rapidly does not increase the risk of respiratory depression during the first 15 to 30 minutes, the period of greatest risk for decreased respiration.
The drug combination of meperidine (Pethidine, Demerol), promethazine (Phenergan), and chlorpromazine (Thorazine) is no longer recommended. Major disadvantages of DPT include the following:
To emphasize its risks, the Acute Pain Management Guideline Panel (1992) of the Agency for Health Care Policy and Research (AHCPR) includes the following in its Clinical Practice Guideline: "Exercise caution when using the mixture of meperidine (Demerol), promethazine (Phenergan), and chlorpromazine (Thorazine), also known as DPT. DPT given intramuscularly commonly has been used for painful procedures. The efficacy of this mixture is poor when compared with alternative approaches, and it has been associated with a high frequency of adverse effects (Nahata, Clotz, and Krogg, 1985). It is not recommended for general use and should be used only in exceptional circumstances." These guidelines are available by calling 800-358-9295 or from the website www.ahcpr.gov. See also Notes on Meperidine.
For clinicians to use alternate drug regimens, it is essential that they know the appropriate dosages and timing of the administration. For example: Fentanyl, I to 2 mcg/kg (0.001 to 0.002 mg/kg) IV 3 minutes before procedure; Morphine sulfate, 0.05 to 0.10 mg/kg IV over I to 2 minutes given 5 minutes before procedure; Meperidine, 0.5 to 1.0 mg/kg IV over I to 2 minutes given 2 to 5 minutes before procedure or 1.5 mg/kg orally 45 to 60 minutes before procedure; Midazolam (Versed), 0.05 mg/kg IV 3 minutes before procedure, or 0.25 to 0.5 mg/kg maximum dose of 20 mg. (children 6 months to less than 6 years of age and less cooperartive children may require a higher dose of up to 1 mg/kg), orally 20 minutes before procedure. If a painful procedure is performed, midazolam should be combined with an analgesic to treat the pain, not just induce amnesia of the event, which may not be permanent. For sedation alone, other agents include Pentobarbital (Nembutal), I to 3 mg/kg IV boluses to maximum of 100 mg until asleep (Merrick and others, 1991)or chloral hydrate, 50 to 75 mg/kg, to maximum of 100 mg/kg or 2.5 gm, orally or rectally 60 minutes before procedure. A common problem is the administration of an insufficient initial dose of chloral hydrate with subsequent doses that lead to an excessively sedated child.
The use of sedating drugs for procedures has serious associated risks, such as hypoventilation, apnea, airway obstruction, and cardiopulmonary impairment. The American Academy of Pediatrics (1992) has guidelines for the safe administration of conscious sedation. These guidelines include provision of emergency equipment, such as a positive-pressure oxygen delivery system, airway management and breathing equipment, and an emergency cart. The patient's level of consciousness and responsiveness, heart rate, blood pressure, respiratory rate, and oxygen saturation (via pulse oximetry) must be monitored during the procedure by an individual present for this purpose only.
Conscious sedation can sometimes be avoided with topical anesthetics, such EMLA, a eutectic mixture of lidocaine 2.5% and prilocaine 2.5%. One study found that using EMLA to alleviate pain associated with the injection of lidocaine during arthrocentesis eliminated the need for conscious sedation using oral midazolam (Versed). The use of EMLA also decreased length of stay and overall costs (Kerr and Jarvis, 1996). EMLA is now available as a "peel and stick" anesthetic disk that is very easily applied by parents at home before a procedure is scheduled. The disk or a thick layer of cream is applied under an occlusive transparent dressing for at least one hour or more before procedures that involve a skin puncture or painful stimulus, such as laser treatment (Koren, 1993; Sherwood, 1993; Taddio and others, 1994; Uhari, 1993). For deeper pain, such as IM injections, the application time should be extended up to 2 1/2 hours. Children with darker skin may require longer application times. For venous cannulation, at least two sites should be anesthetized to provide an alternative area if needed. The duration of anesthesia is up to 4 hours. See also Guidelines for using EMLA.
Another topical preparation is Numby Stuff, which uses iontopheresis (low voltage current) to enhance penetration of a mixture of lidocaine 2% with epinephrine 1:1000,000 through intact skin (Ashburn and others, 1997). Depending on the voltage setting, the medicated electrode provides anesthesia to the site to a depth of 10 mm in 8 to 20 minutes. The application requires an iontopheresis machine, two electrodes, and the anesthetic, lontocaine. The child feels a tingling sensation in either electrode, which may be uncomfortable to some youngsters.
The intradermal route is often used to inject a local anesthetic, typically lidocaine (Xylocaine), into the skin to reduce the pain from a lumbar puncture, bone marrow aspiration, suturing, or venous or arterial access. One problem with the use of lidocaine is the stinging and burning that initially occur. However, buffering the lidocaine (BL) with 8.4% sodium bicarbonate in a ratio of 9:1 respectively reduces the stinging sensation (McKay, Morris, and Mushlin, 1987; Orlinsky and others, 1992). For venipuncture or port access, inject 0.1 ml or less BL intradermally directly over intended puncture site; anesthesia occurs almost immediately. If the lidocaine vial (e.g., 20 ml lidocaine with 2 ml sodium bicarbonate) is buffered, the solution is stable for 7 days unrefrigerated or 14 days refrigerated. Warming the lidocaine to 37'C (98.6'F) may also accomplish the same effect (Davidson and Boom, 1992). Using a 30-gauge needle for infiltration further reduces the puncture pain. See also Use of Buffered Xylocaine for Venipuncture.
A final comment is the importance of using conscious or unconscious sedation for the first procedure. In a study of 21 children who fentanyl Oralet for painful procedures such as bone marrow aspiration, lumbar puncture, or both, those who were medicated for the first procedure rated the pain significantly lower than those who had initially received a placebo and later were given the analgesic. This pattern was seen in children under 8 years of age, suggesting that inadequate analgesia for initial procedures in young children may diminish the effect of adequate analgesia in subsequent procedures (Weisman, Bernstein, and Schechter, 1998).
Fortunately, more aggressive management of painful procedures is becoming the norm, rather than the exception. Nurses must be children's advocates in those situations where appropriate control of procedure pain is not practiced. Parent education regarding the options of conscious sedation, unconscious sedation, and local anesthetics is essential in their providing atraumatic care to their children.
See also Bibliography: Conscious Sedation.
Ashburn MA and others: Iontophoretic administration of 2% lidocaine HCI and 1:100,000 epinephrine in humans, Clin J Pain 13:22-26, 1997.
Kerr KL and Jarvis JN: Cost-effectiveness of EMLA vs oral midazolam for analgesia during pediatric arthocentesis. Poster presentation at Sixth Annual Meeting of the Society of Pediatric Nurses National Conference, Chicago, IL, April 24 and 25, 1996.
Weisman SJ, Bernstein B, and Schechter NL: Consequences of inadequate analgesia during painful procedures in children, Arch Pediatr Adolesc Med 152:147-149, 1998.
March 15, 2002
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