Emergence delirium: Children
Basic, Clinical Sciences: Anesthesia Procedures, Methods, and Techniques
Emergence delirium (ED) —a state of confusion, agitation, and restlessness—is seen with arousal from volatile agents at the completion of delivery of an anesthetic, and is a potentially dangerous phenomenon which has been associated with loss of central or peripheral access, self-extubation, and both patient and provider injury. Classically described in pre-school aged patients after the use of Sevoflurane or Desflurane, it has also been seen with patients with high anxiety or other psychiatric impairments in about 3.7% of the adult population (2). Risk factors for ED include male gender, duration of anesthesia, post-operative pain, perioperative anxiety, and the use of a volatile anesthetics versus TIVA (1,2). No correlations have been seen with either ASA status or geriatric age (2). The phenomenon most commonly occurs with arousal though has been reported as much as 45 minutes after emergence from anesthesia (1).
The exact cause of emergence delirium has not been elucidated, though pain, speed of emergence, and the graduated awakening of the neural circuitry have been hypothesized in synergistic models. Though increased use of intraoperative analgesic medications are associated with a decrease in ED, many patients have reported no pain upon returning to baseline status from their delirium (1). Nonetheless, post-operative pain in PACU remains correlated with ED in a significant portion of the literature (2). The speed of emergence is hypothesized as a cause because the phenomenon was noted with increasing frequency with the rise of the rapidly cleared volatile agents (Sevoflurane and Desflurane). However, the mechanism has not been determined, as rapid emergence from IV anesthetics such as Propofol has actually been shown to be protective against the phenomenon (2). The thalamo-cortical sedation with Propofol versus alterations in resting state and dynamic state states of mind with cortico-thalamic connectivity are thought to be causes for this differentiation (1).
Prevention and treatment of ED involves addressing some of the risk factors such as perioperative anxiety, pain, and smoothening emergence with other medications. Preoperative use of Midazolam has provided mixed results for reducing the incidence of ED. The use of clonidine with melatonin has decreased the incidence of ED comparatively. As mentioned, treatment of pain with analgesics including preoperative Gabapentin, Fentanyl (1-2 mcg/kg). Near the end of surgery, Propofol 1 mg/kg has shown to smooth emergence with significant improvement also with Dexemedetomine (0.3 mg/kg) though both can result in slightly longer PACU stays(1). Parents of children with ED should be informed as it has also been correlated with maladaptive behaviors post-operatively including sleep disturbances and enuresis.