Accidental awareness during anesthesia in children.

This educational review explores the current understanding of accidental awareness during general anesthesia (AAGA) in children. Estimates of incidence in children vary between 1 in 135 (determined by direct questioning) and 1 in 51,500 (determined from spontaneous reporting). The lessons from the 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland show that the characteristics of spontaneous reports of AAGA are extremely variable and relate to the type of procedure and anesthetic technique rather than age group: approximately 50% of experiences were distressing; most lasted less than 5 min; neuromuscular blockade (NMB) combined with pain caused the most distress; most cases (approximately 70%) occur at induction or emergence. The value of depth of anesthesia monitoring in preventing AAGA is uncertain but is probably useful in patients having total intravenous anesthesia and NMB. Reports of AAGA by children should be received sympathetically and a generic protocol for managing distressed patients is presented.

5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: summary of main findings and risk factors.

We present the main findings of the 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia (AAGA). Incidences were estimated using reports of accidental awareness as the numerator, and a parallel national anaesthetic activity survey to provide denominator data. The incidence of certain/probable and possible accidental awareness cases was ~1:19,600 anaesthetics (95% confidence interval 1:16,700-23,450). However, there was considerable variation across subtypes of techniques or subspecialities. The incidence with neuromuscular block (NMB) was ~1:8200 (1:7030-9700), and without, it was ~1:135,900 (1:78,600-299,000). The cases of AAGA reported to NAP5 were overwhelmingly cases of unintended awareness during NMB. The incidence of accidental awareness during Caesarean section was ~1:670 (1:380-1300). Two-thirds (82, 66%) of cases of accidental awareness experiences arose in the dynamic phases of anaesthesia, namely induction of and emergence from anaesthesia. During induction of anaesthesia, contributory factors included: use of thiopental, rapid sequence induction, obesity, difficult airway management, NMB, and interruptions of anaesthetic delivery during movement from anaesthetic room to theatre. During emergence from anaesthesia, residual paralysis was perceived by patients as accidental awareness, and commonly related to a failure to ensure full return of motor capacity. One-third (43, 33%) of accidental awareness events arose during the maintenance phase of anaesthesia, mostly due to problems at induction or towards the end of anaesthesia. Factors increasing the risk of accidental awareness included: female sex, age (younger adults, but not children), obesity, anaesthetist seniority (junior trainees), previous awareness, out-of-hours operating, emergencies, type of surgery (obstetric, cardiac, thoracic), and use of NMB. The following factors were not risk factors for accidental awareness: ASA physical status, race, and use or omission of nitrous oxide. We recommend that an anaesthetic checklist, to be an integral part of the World Health Organization Safer Surgery checklist, is introduced as an aid to preventing accidental awareness. This paper is a shortened version describing the main findings from NAP5--the full report can be found at http://www.nationalauditprojects.org.uk/NAP5_home.

Anesthesia awareness: narrative review of psychological sequelae, treatment, and incidence.

Awareness during general anesthesia occurs when patients recall events or sensations during their surgeries, although the patients should have been unconscious at the time. Anesthesiologists are cognizant of this phenomenon, but few discussions occur outside the discipline. This narrative review summarizes the patient recollections, psychological sequelae, treatment and follow-up of psychological consequences, as well as incidence and etiology of awareness during general anesthesia. Recalled memories include noises, conversations, images, mental processes, feelings of pain and/or paralysis. Psychological consequences include anxiety, flashbacks, and posttraumatic stress disorder diagnosis. Limited discussion for therapeutic treatment after an anesthesia awareness experience exists. The incidence of anesthesia awareness ranges from 0.1 to 0.2% (e.g., 1-2/1000 patients). Increased recognition of awareness during general anesthesia within the psychological/counseling community, with additional research focusing on optimal therapeutic treatment, will improve the care of these patients.