5th National Audit Project Research Articles

‘No volatile agent’ as a standard alarm on anaesthetic workstations

The 5th National Audit Project (NAP5) highlighted the various causes of accidental awareness under general anaesthesia (AAGA); six cases (8% of AAGA) occurred because the vaporiser was not turned on after induction or after arrival in theatre. The transfer process of a patient from the anaesthetic room to theatre can create distractions that increase the possibility of AAGA from task fixation errors. Such distractions may lead to errors of omission so that the maintenance volatile is not turned on 1. An informal poll that I undertook at the 21st Anaesthesia, Critical Care and Pain Forum in Portugal, October 2018, revealed that not turning on a vaporiser had happened at least once recently to nearly all of the 160 anaesthetists present. Modern anaesthetic workstations, like the Draeger Perseus (Draegerwerk AG, Lubeck, Germany), have an inhalational agent low level alarm if the MAC value is lower than pre-set, as well as an alarm for refilling an empty vaporiser, but do not have an alarm to alert the anaesthetist to the volatile agent not being present or the vaporiser not being switched on at the start of an anaesthetic. By comparison, it is unlikely that a no-fuel alarm in a motor car or an aeroplane would pass any safety standard if it failed to trigger before starting a journey. I suggest that newly manufactured (and retrofitted) anaesthetic machines should have an audible and visual alarm indicating non-commencement of volatile agent upon connection of a patient to the circuit, requiring manual de-activation once the vaporiser is turned on, or total intravenous anaesthesia (TIVA) started (Fig. 1). The NAP5 suggested incorporating the presence of volatile agent or continuous intravenous infusion into the anaesthetic component of WHO Checklist every time a patient is moved (the ‘D’ for drug in their ABCD aide memoir). Although this would represent an additional safeguard if adhered to, the WHO Checklist rarely takes place immediately after patient transfer and connection to the breathing circuit, and there may be a period of 10–20 min or more before any lack of anaesthetic administration is discovered, potentially leading to AAGA.

Monitoring of neuromuscular blockade during general anaesthesia

Accidental awareness under general anaesthesia (AAGA) is an uncommon but particularly distressing complication, with potentially long-lasting psychological consequences. Over 400 reported cases of AAGA were reported during the fifth National Audit Project, with a projected incidence of 1:136000 general anaesthetics. 1 However, 97% of reported cases of AAGA were associated with the use of neuromuscular blocking drugs (NMBDs), an incidence of 1:80001. Around one-fifth of these reported cases were at emergence with all patients experiencing residual neuromuscular blockade. Failure to use a peripheral nerve stimulator was seen as causal or at least contributory in half of these cases. The 2015 updated guidance from the Association of Anaesthetists of Great Britain and Ireland (AAGBI) 2 stated that a peripheral nerve stimulator must be used when a NMBD is given, as part of the minimum standards of monitoring during general anaesthesia.2 We aimed to explore the current use of NMBDs, nerve stimulators and reversal agents during general anaesthesia in a UK teaching hospital. A retrospective anaesthetic chart review of patients receiving surgery under general anaesthesia was undertaken at Leicester Royal Infirmary. Information collected included patient characteristics, NMBD used and timings, use of a nerve stimulator and reversal agent. Twenty nine patient anaesthetic charts post general anaesthetic and neuromuscular blockade drug have been reviewed to date. 11 male, mean age 50.8, 4 emergency procedures (14%) 25 elective procedures (86%), ASA 1-3. Atracurium was used in 62% of procedures and 87% of patients had a documented reversal agent administered. 14 charts (48%) had documented use of a peripheral nerve stimulator or neuromuscular monitoring peri-operatively. A Consultant Anaesthetist was present in all cases and trainees were also present in approximately half of the procedures. The documented use of neuromuscular monitoring showed no relationship with level of anaesthetist present. Neuromuscular blockade drugs are commonly used during general anaesthetic and increase the risk of accidental awareness under general anaesthesia. Although monitoring can reduce this risk, use has only been documented in 50% of cases by anaesthetists of varying experience. Data collection is ongoing and we plan to investigate any potential barriers or difficulties in our local hospital to using neuromuscular monitoring. 1.The Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland. Report and findings of the 5th National Audit Project, Accidental Awareness during General Anaesthesia in the United Kingdom and Ireland. 2014; Available from: http://www.nationalauditprojects.org.uk/NAP5home.2.The Association of Anaesthetists of Great Britain & Ireland. Recommendations for standards of monitoring during anaesthesia and recovery. 2015; Available from: http://www.aagbi.org/sites/default/files/Standards_of_monitoring_2015_0.pdf.

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.

Unsettled Weather and the End for Thiopental? Obstetric General Anesthesia After the NAP5 and MBRRACE-UK Reports

(Anaesthesia. 2015;70:375–379) This editorial summarizes major findings from the 5th National Audit Project (NAP5) investigation of accidental awareness under general anesthesia and the 2014 Mothers and Babies: Reducing Risk through Audit and Confidential Enquiries (MBRRACE-UK) report, focusing on maternal mortality associated with anesthesia.

How deep is your love: Awareness monitoring during general anesthesia

The 5th National Audit Project (NAP5) has established that the incidence of accidental awareness during general anaesthesia is about 1 in 15414 general anesthesia. In total, about two-thirds of accidental awareness during general anaesthesia happened during the so-called 'dynamic' phase of anesthesia. The stages of consciousness are often very short and that implies that the used monitoring must be able to detect even a short phase of consciousness. Administration of neuromuscular blockators makes monitoring of consciousness difficult, therefore currently the most reliable methods of monitoring are: IFT, BIS monitoring and maintenance of ETAG > 0.7 MAC. Certainly, none of these methods can be used independently from the experienced anesthesiologists and clinical methods for assessing accidental awareness during general anaesthesia.

An observational study of the 'isolated forearm technique' in unparalysed, spontaneously breathing patients.

The isolated forearm technique enables a patient, otherwise paralysed by neuromuscular blockade, to communicate by movement if wakeful during surgery. The positive response rate to verbal command is high (~32%). The 5th National Audit Project recommended that this monitoring technique should become more widely taught and considered, so this study was designed to assess its utility as a standard of care in unparalysed patients. A positive response rate as high as in the paralysed would justify local adoption. Therefore, 100 consecutive patients undergoing urology surgery were given verbal commands to move at two-minute intervals from induction of anaesthesia (fentanyl and propofol) to full emergence and extubation of the supraglottic airway. Anaesthesia was maintained with isoflurane in oxygen/nitrous oxide. Although 24 patients moved during surgery (and therefore needed additional anaesthetic), none moved to verbal command. Even at extubation, when patients moved to expel the airway, there was no response to command until after wakening. These results suggest that in contrast to its use in paralysed patients, the isolated forearm technique does not yield useful information about the patient's state of wakefulness in the unparalysed. Another interpretation is that unparalysed patients are less prone to wakefulness than the paralysed.

The State of UK Anaesthesia

Background Details of current UK anaesthetic practice are unknown and were needed for interpretation of reports of accidental awareness during general anaesthesia (GA) within the 5th National Audit Project. Methods We surveyed NHS anaesthetic activity to determine numbers of patients managed by anaesthetists and details of ‘who, when, what, and where': activity included GA, local anaesthesia, sedation, or patients managed awake. Anaesthetists in NHS hospitals collected data on all patients for 2 days. Scaling enabled estimation of annual activity. Results Hospital response rate was 100% with 20 400 returns. The median return rate within departments was 98% (inter-quartile range 0.95–1). Annual numbers (% of total) of general anaesthetics, sedation, and awake cases were 2 766 600 (76.9%), 308 800 (8.6%), and 523 100 (14.5%), respectively. A consultant or career grade anaesthetist was present in more than 87% of cases. Emergency cases accounted for 23.1% of workload, 75% of which were undertaken out of hours. Specialties with the largest workload were orthopaedics/trauma (22.1%), general surgery (16.1%), and gynaecology (9.6%): 6.2% of cases were non-surgical. The survey data describe: who anaesthetized patients according to time of day, urgency, and ASA grade; when anaesthesia took place by day and by weekday; the distribution of patient types, techniques, and monitoring; where patients were anaesthetized. Nine patients out of 15 460 receiving GA died intraoperatively. Conclusions Anaesthesia in the UK is currently predominantly a consultant-delivered service. The low mortality rate supports the safety of UK anaesthetic care. The survey data should be valuable for planning and monitoring anaesthesia services.

5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: patient experiences, human factors, sedation, consent, and medicolegal issues

The 5th National Audit Project (NAP5) of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland into accidental awareness during general anaesthesia (AAGA) yielded data related to psychological aspects from the patient, and the anaesthetist, perspectives; patients' experiences ranged from isolated auditory or tactile sensations to complete awareness. A striking finding was that 75% of experiences were for <5 min, yet 51% of patients [95% confidence interval (CI) 43-60%] experienced distress and 41% (95% CI 33-50%) suffered longer term adverse effect. Distress and longer term harm occurred across the full range of experiences but were particularly likely when the patient experienced paralysis (with or without pain). The patient's interpretation of what is happening at the time of the awareness seemed central to later impact; explanation and reassurance during suspected AAGA or at the time of report seemed beneficial. Quality of care before the event was judged good in 26%, poor in 39%, and mixed in 31%. Three-quarters of cases of AAGA (75%) were judged preventable. In 12%, AAGA care was judged good and the episode not preventable. The contributory and human factors in the genesis of the majority of cases of AAGA included medication, patient, and education/training. The findings have implications for national guidance, institutional organization, and individual practice. The incidence of 'accidental awareness' during sedation (~1:15,000) was similar to that during general anaesthesia (~1:19,000). The project raises significant issues about information giving and consent for both sedation and anaesthesia. We propose a novel approach to describing sedation from the patient's perspective which could be used in communication and consent. Eight (6%) of the patients had resorted to legal action (12, 11%, to formal complaint) at the time of reporting. NAP5 methodology provides a standardized template that might usefully inform the investigation of claims or serious incidents related to AAGA.

5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: protocol, methods, and analysis of data

Accidental awareness during general anaesthesia (AAGA) with recall is a potentially distressing complication of general anaesthesia that can lead to psychological harm. The 5th National Audit Project (NAP5) was designed to investigate the reported incidence, predisposing factors, causality, and impact of accidental awareness. A nationwide network of local co-ordinators across all the UK and Irish public hospitals reported all new patient reports of accidental awareness to a central database, using a system of monthly anonymized reporting over a calendar year. The database collected the details of the reported event, anaesthetic and surgical technique, and any sequelae. These reports were categorized into main types by a multidisciplinary panel, using a formalized process of analysis. The main categories of accidental awareness were: certain or probable; possible; during sedation; on or from the intensive care unit; could not be determined; unlikely; drug errors; and statement only. The degree of evidence to support the categorization was also defined for each report. Patient experience and sequelae were categorized using current tools or modifications of such. The NAP5 methodology may be used to assess new reports of AAGA in a standardized manner, especially for the development of an ongoing database of case reporting. This paper is a shortened version describing the protocols, methods, and data analysis from NAP5--the full report can be found at http://www.nationalauditprojects.org.uk/NAP5_home.

The State of UK anaesthesia: a survey of National Health Service activity in 2013

Details of current UK anaesthetic practice are unknown and were needed for interpretation of reports of accidental awareness during general anaesthesia (GA) within the 5th National Audit Project. We surveyed NHS anaesthetic activity to determine numbers of patients managed by anaesthetists and details of 'who, when, what, and where': activity included GA, local anaesthesia, sedation, or patients managed awake. Anaesthetists in NHS hospitals collected data on all patients for 2 days. Scaling enabled estimation of annual activity. Hospital response rate was 100% with 20,400 returns. The median return rate within departments was 98% (inter-quartile range 0.95-1). Annual numbers (% of total) of general anaesthetics, sedation, and awake cases were 2,766,600 (76.9%), 308,800 (8.6%), and 523,100 (14.5%), respectively. A consultant or career grade anaesthetist was present in more than 87% of cases. Emergency cases accounted for 23.1% of workload, 75% of which were undertaken out of hours. Specialties with the largest workload were orthopaedics/trauma (22.1%), general surgery (16.1%), and gynaecology (9.6%): 6.2% of cases were non-surgical. The survey data describe: who anaesthetized patients according to time of day, urgency, and ASA grade; when anaesthesia took place by day and by weekday; the distribution of patient types, techniques, and monitoring; where patients were anaesthetized. Nine patients out of 15 460 receiving GA died intraoperatively. Anaesthesia in the UK is currently predominantly a consultant-delivered service. The low mortality rate supports the safety of UK anaesthetic care. The survey data should be valuable for planning and monitoring anaesthesia services.

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.

The 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 on accidental awareness during general anaesthesia. 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 ~1:19600 anaesthetics (95% CI 1:16700-23450). However, there was considerable variation across subtypes of techniques or subspecialties. The incidence with neuromuscular blockade was ~1:8200 (1:7030-9700), and without it was ~1:135900 (1:78600-299000). The cases of accidental awareness during general anaesthesia reported to 5th National Audit Project were overwhelmingly cases of unintended awareness during neuromuscular blockade. 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; neuromuscular blockade; 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, most 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 neuromuscular blockade. 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 5th National Audit Project - the full report can be found at http://www.nationalauditprojects.org.uk/NAP5_home#pt.

The 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: protocol, methods and analysis of data.

Accidental awareness during general anaesthesia with recall is a potentially distressing complication of general anaesthesia that can lead to psychological harm. The 5th National Audit Project was designed to investigate the reported incidence, predisposing factors, causality and impact of accidental awareness. A nationwide network of local co-ordinators across all UK and Irish public hospitals reported all new patient reports of accidental awareness to a central database, using a system of monthly anonymised reporting over a calendar year. The database collected the details of the reported event, anaesthetic and surgical technique, and any sequelae. These reports were categorised into main types by a multidisciplinary panel, using a formalised process of analysis. The main categories of accidental awareness were: certain or probable; possible; during sedation; on or from the intensive care unit; could not be determined; unlikely; drug errors; and statement only. The degree of evidence to support the categorisation was also defined for each report. Patient experience and sequelae were categorised using current tools or modifications of such. The 5th National Audit Project methodology may be used to assess new reports of accidental awareness during general anaesthesia in a standardised manner, especially for the development of an ongoing database of case reporting. This paper is a shortened version describing the protocols, methods and data analysis from 5th National Audit Project - the full report can be found at http://www.nationalauditprojects.org.uk/NAP5_home#pt.

The 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: patient experiences, human factors, sedation, consent and medicolegal issues.

The 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland into accidental awareness during general anaesthesia yielded data related to psychological aspects from the patient, and the anaesthetist, perspectives; patients' experiences ranged from isolated auditory or tactile sensations to complete awareness. A striking finding was that 75% of experiences were for <5min, yet 51% of patients (95% CI 43-60%) experienced distress and 41% (95% CI 33-50%) suffered longer-term adverse effect. Distress and longer-term harm occurred across the full range of experiences but were particularly likely when the patient experienced paralysis (with or without pain). The patient's interpretation of what is happening at the time of the awareness seemed central to later impact; explanation and reassurance during suspected accidental awareness during general anaesthesia or at the time of report seemed beneficial. Quality of care before the event was judged good in 26%, poor in 39% and mixed in 31%. Three quarters of cases of accidental awareness during general anaesthesia (75%) were judged preventable. In 12% of cases of accidental awareness during general anaesthesia, care was judged good and the episode not preventable. The contributory and human factors in the genesis of the majority of cases of accidental awareness during general anaesthesia included medication, patient and education/training. The findings have implications for national guidance, institutional organisation and individual practice. The incidence of 'accidental awareness' during sedation (~1:15000) was similar to that during general anaesthesia (~1:19000). The project raises significant issues about information giving and consent for both sedation and anaesthesia. We propose a novel approach to describing sedation from the patient's perspective which could be used in communication and consent. Eight (6%) of the patients had resorted to legal action (12, 11%, to formal complaint) at the time of reporting. The 5th National Audit Project methodology provides a standardised template that might usefully inform the investigation of claims or serious incidents related to accidental awareness during general anaesthesia.

A national survey (NAP5-Ireland baseline) to estimate an annual incidence of accidental awareness during general anaesthesia in Ireland.

As part of the 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland concerning accidental awareness during general anaesthesia, we issued a questionnaire to every consultant anaesthetist in each of 46 public hospitals in Ireland, represented by 41 local co-ordinators. The survey ascertained the number of new cases of accidental awareness becoming known to them for patients under their care or supervision for a calendar year, as well as their career experience. Consultants from all hospitals responded, with an individual response rate of 87% (299 anaesthetists). There were eight new cases of accidental awareness that became known to consultants in 2011; an estimated incidence of 1:23 366. Two out of the eight cases (25%) occurred at or after induction of anaesthesia, but before surgery; four cases (50%) occurred during surgery; and two cases (25%) occurred after surgery was complete, but before full emergence. Four cases were associated with pain or distress (50%), one after an experience at induction and three after experiences during surgery. There were no formal complaints or legal actions that arose in 2011 related to awareness. Depth of anaesthesia monitoring was reported to be available in 33 (80%) departments, and was used by 184 consultants (62%), 18 (6%) routinely. None of the 46 hospitals had a policy to prevent or manage awareness. Similar to the results of a larger survey in the UK, the disparity between the incidence of awareness as known to anaesthetists and that reported in trials warrants explanation. Compared with UK practice, there appears to be greater use of depth of anaesthesia monitoring in Ireland, although this is still infrequent.

Who operates when, where and on whom? A survey of anaesthetic‐surgical activity in Ireland as denominator of NAP5

The second phase of the 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland, concerning accidental awareness during general anaesthesia, consisted of a survey of anaesthetic activity in Ireland. A network of consultant anaesthetists co-ordinated data collection from the anaesthetic departments of 46 public and 20 independent hospitals over seven days. Data on patients' characteristics, anaesthetic techniques, staffing, and admission and discharge arrangements were collected on all cases for which anaesthetic care (general, regional or local anaesthesia, sedation or monitored anaesthesia care) was provided. A total of 8049 cases were reported during the survey, giving an annual estimate of 426 600 cases for which anaesthetic care is provided. General anaesthesia constituted 5621 (70%), regional anaesthesia 1404 (17%), local anaesthesia 290 (4%), sedation 618 (8%) and monitored anaesthesia care 116 (1%) of the total number of cases. This survey provides unique data regarding anaesthesia services in public and independent hospitals in Ireland.

A National Survey of Anaesthetists (NAP5 Baseline) to Estimate an Annual Incidence of Accidental Awareness During General Anaesthesia in the UK

As part of the 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland concerning accidental awareness during general anaesthesia, we issued a questionnaire to every consultant and staff and associate specialist anaesthetist in the UK. The survey was designed to ascertain the number of new cases of accidental awareness that became known to them, for patients under their direct or supervised care, for a calendar year, and also to estimate how many cases they had experienced during their careers. The survey also asked about use of monitoring designed to measure the depth of anaesthesia. All local co-ordinators responsible for each of 329 hospitals (organised into 265 'centres') in the UK responded, as did 7125 anaesthetists (82%). There were 153 new cases of accidental awareness notified to respondents in 2011, an estimated incidence of 1:15 414, lower than the 1-2:1000 previously reported in prospective clinical trials. Almost half the cases (72, 47%) occurred at or after induction of anaesthesia but before surgery, with 46 (30%) occurring during surgery and 35 (23%) after surgery before full recovery. Awareness during surgery appeared to lead more frequently to pain or distress than at induction and emergence (62% vs 28% and 23%, respectively). Depth of anaesthesia monitors were available in 164 centres (62%), but routinely used by only 132 (1.8%) of anaesthetists. The disparity between the incidence of awareness as notified to anaesthetists and that reported in trials warrants further examination and explanation.

Isolated forearm – or isolated brain? Interpreting responses during anaesthesia – or ‘dysanaesthesia’

Isolated forearm – or isolated brain? Interpreting responses during anaesthesia – or ‘dysanaesthesia’

A national survey of anaesthetists (NAP5 Baseline) to estimate an annual incidence of accidental awareness during general anaesthesia in the UK

As part of the 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland concerning accidental awareness during general anaesthesia, we issued a questionnaire to every consultant and staff and associate specialist anaesthetist in the UK. The survey was designed to ascertain the number of new cases of accidental awareness that became known to them, for patients under their direct or supervised care, for a calendar year, and also to estimate how many cases they had experienced during their careers. The survey also asked about use of monitoring designed to measure the depth of anaesthesia. All local co-ordinators responsible for each of 329 hospitals (organised into 265 'centres') in the UK responded, as did 7125 anaesthetists (82%). There were 153 new cases of accidental awareness notified to respondents in 2011, an estimated incidence of 1:15 414, lower than the 1-2:1000 previously reported in prospective clinical trials. Almost half the cases (72, 47%) occurred at or after induction of anaesthesia but before surgery, with 46 (30%) occurring during surgery and 35 (23%) after surgery before full recovery. Awareness during surgery appeared to lead more frequently to pain or distress than at induction and emergence (62% vs 28% and 23%, respectively). Depth of anaesthesia monitors were available in 164 centres (62%), but routinely used by only 132 (1.8%) of anaesthetists. The disparity between the incidence of awareness as notified to anaesthetists and that reported in trials warrants further examination and explanation.

A national survey of anaesthetists (NAP5 Baseline) to estimate an annual incidence of accidental awareness during general anaesthesia in the UK

As part of the 5th National Audit Project of the Royal College of Anaesthetists and the Association of Anaesthetists of Great Britain and Ireland concerning accidental awareness during general anaesthesia, we issued a questionnaire to every consultant and staff and associate specialist anaesthetist in the UK. The survey was designed to ascertain the number of new cases of accidental awareness that became known to them, for patients under their direct or supervised care, for a calendar year, and also to estimate how many cases they had experienced during their careers. The survey also asked about use of monitoring designed to measure the depth of anaesthesia. All local co-ordinators responsible for each of 329 hospitals (organised into 265 'centres') in the UK responded, as did 7125 anaesthetists (82%). There were 153 new cases of accidental awareness notified to respondents in 2011, an estimated incidence of 1:15 414, lower than the 1-2:1000 previously reported in prospective clinical trials. Almost half the cases (72, 47%) occurred at or after induction of anaesthesia but before surgery, with 46 (30%) occurring during surgery and 35 (23%) after surgery before full recovery. Awareness during surgery appeared to lead more frequently to pain or distress than at induction and emergence (62% vs 28% and 23%, respectively). Depth of anaesthesia monitors were available in 164 centres (62%), but routinely used by only 132 (1.8%) of anaesthetists. The disparity between the incidence of awareness as notified to anaesthetists and that reported in trials warrants further examination and explanation.