Sedation during electroencephalography (EEG) is often necessary to avoid using restraints, to reduce unnecessary anxiety, to minimize muscle and movement artifact, and to accommodate an adequate sleep EEG. In most children, conscious sedation can be completed without complications, although it may pose an increased risk in children with airway difficulties. Olson and colleagues conducted a retrospective review to determine the incidence of adverse effects occurring in children who received sedation during EEG.

An evaluation of all 2,855 children who had EEGs during a four-year period revealed that conscious sedation was attempted during EEG in 513 of these cases. The type of sedation administered, dosage, and duration of sedation were recorded, as were complications occurring during the procedure.

Of the 513 children who received a sedative during EEG, 91 percent (n = 469) of the procedures were completed without difficulty. Nine percent (n = 44) of them were incomplete (including 29 children who had a diagnosis of developmental delay or autism). A repeat dose of sedative medication was administered to 29 percent (n = 147) of patients. The two most commonly used sedatives were chloral hydrate and chloral hydrate plus hydroxyzine. The use of an agent other than chloral hydrate usually came about because previous attempts at sedation with chloral hydrate had failed. Oxygen desaturation occurred in only three children; each of them had risk factors—large tongue, recent tonsillectomy, or adenoidectomy—for airway compromise. Mean time to sedation was 38 minutes, with sedation averaging around 30 minutes.

The authors conclude that sedation is safe and effective in children undergoing EEG. They note that sedative drugs such as benzodiazepines, barbiturates, deep sedation, and anesthesia may increase the amount of faster background EEG readings and interfere with interpretation. Chloral hydrate causes minimal change to background EEG activity. Some children require a second dose of the chloral hydrate and, in most cases, physicians should not hesitate to provide a second dose.