Awareness during emergence from anesthesia: Features and future research directions

Table 1 Features of awareness during emergence

Features
Incidence	About 20% of all awareness with recall episodes[7]
Clinical features	Distress especially due to sense of paralysis
Causes and mechanisms	Inappropriate anesthesiological management:
	1 Anesthesia plan is lightened too early
	2 Lack of use, or misuse, of neuromuscular monitoring
	3 Awake extubation
	Butyrylcholinesterase deficiency (in case of succinylcholine and mivacurium use)
	Human error (e.g., dose calculation) or devices malfunctioning
Predisposing factors	Resistance to anesthetics genetically determined
	Drug induction by alcohol, tobacco or centrally acting drugs
Assessment	When awareness is suspected at the emergence, patients should be assessed before the postanesthesia care unit discharge, after 1-3 d, and after 7-14 d using a structured interview
Psychological sequelae	Frequent and of variable entity depending on the distress, duration, and type of event
Management	Multidisciplinary approach and specialized interventions by properly trained personnel (psychiatrist / psychologist). It is mandatory to accept the patient's report as truthful, to characterize it and to carry out a root case analysis with all the medical personnel, and not, involved in the operating theatre

Table 2 Prophylactic strategies for prevention of awareness in the awakening phase

Preoperative phase

Identification of patients at risk and correction of modifiable risk factors

Careful information of patients at risk such as those who have experienced awareness

Check of anesthesia devices and instruments

Intraoperative management

Use of neuromuscular monitoring (quantitative > qualitative)

Maintenance of an adequate anesthesia state until complete recovery of the neuromuscular block

Careful dose adjustment of neuromuscular blocking drugs

Careful management of the reversal (train of four at least 4)

Avoid, if possible, extubation with a fully conscious patient

Use of brain monitoring devices (especially in high-risk patients)

Set threshold alarms of devices following the manufacturer’s specifications

Maintain professionalism in the theatre