Pediatric Anesthetic Techniques: Sedation for Procedures in and out of the Operating Room

Sedation for Procedures in and out of the Operating Room

Sedation is often requested for pediatric patients inside and outside the operating room for nonsur-gical procedures. Cooperation and motionlessness may be required for imaging studies, bronchoscopy, gastrointestinal endoscopy, cardiac catheterization, dressing changes, and minor procedures (eg, cast-ing and bone marrow aspiration). Requirements vary depending on the patient and the procedure, ranging from anxiolysis (minimal sedation), to conscious sedation (moderate sedation and analge-sia), to deep sedation/analgesia, and finally to gen-eral anesthesia. Anesthesiologists are usually held to the same standards when they provide moder-ate or deep sedation as when they provide general anesthesia. This includes preoperative preparation (eg, fasting), assessment, monitoring, and postop-erative care. Airway obstruction and hypoventila-tion are the most commonly encountered problems associated with moderate or deep sedation. With deep sedation and general anesthesia cardiovascular depression can also be a problem.

Table 42–3 includes doses of sedative-hypnotic drugs. One of the sedatives commonly used by non-anesthesia personnel in the past was chloral hydrate, 25–100 mg/kg orally or rectally. It has a slow onset of up to 60 min and a long half-life (8–11 h) that results in prolonged somnolence. Although it generally has little effect on ventilation, it can cause fatal airway obstruction in patients with sleep apnea. Overall, chloral hydrate is a poor choice given its propensity for producing cardiac arrhythmias when it is used in the larger doses needed for moderate sedation. Midazolam, 0.5 mg/kg orally or 0.1–0.15 mg/kg intravenously, is particularly useful because its effects can be readily reversed with flumazenil. Doses should be reduced whenever more than one agent is used because of the potential for synergistic respira-tory and cardiovascular depression.Propofol is by far the most useful sedative-hypnotic drug. Although the drug is not approved for sedation of pediatric ICU patients and is not approved for administration by anyone other than those trained in the administration of general anes-thesia, it can be dosed safely for most procedures at infusion rates up to 200 mcg/kg/min. In coun-tries other than the United States, propofol is often administered using the Diprifusor, a computer-controlled infusion pump that maintains a constant target site concentration. Supplemental oxygen and close monitoring of the airway, ventilation, and other vital signs are mandatory (as with other agents). An LMA is usually well tolerated at higher doses.