Detection method of intraoperative awareness: a randomized comparative study.

BACKGROUND: : The incidence of intraoperative awareness varies in a wide range in the literature. The reasons for these different results include the questioning method used and the questioning time. The goal of this study is to compare the effectiveness of different questioning methods and times used in intraoperative awareness research for detecting the incidence. METHODS: We recruited patients between the ages of 18-70 years, with normal cognitive functions and able to speak after general anesthesia to the study. The patients were randomly divided into two groups. In Group 1 we applied the modified Brice questionnaire in the first 2 h and 24 h after surgery for investigating intraoperative awareness. In Group 2, 24 h after surgery, we asked about anesthesia satisfaction and patients' complaints, if any. RESULTS: There was no statistically significant difference between the groups in terms of age (p = 0.514).The proportion of women was significantly higher (p = 0.002), the duration of anesthesia was shorter, and the rate of narcotic analgesic use was higher in Group 2 (p < 0.001). The assessment in the first 2 h showed the frequency of awareness was statistically higher in Group 1 than in Group 2 (p = 0.016). In the postoperative 24-h assessment, we found no significant difference in the incidence of intraoperative awareness between the groups (p < 0.05). In Group 1, there was no statistically significant difference in terms of incidence of awareness according to evaluation time (p = 250). DISCUSSION: The incidence of intraoperative awareness in Group 1 was significantly higher than in Group 2 in the evaluation conducted in the first 2 h. There was no significant difference in the determination of intraoperative awareness between questioning times in group 1.

The relation between preoperative anxiety and awareness during anesthesia: an observational study / Relação entre ansiedade pré-operatória e consciência durante a anestesia: estudo observacional

Abstract Background: Anxiety is a state of worry caused by the anticipation of external or internal danger. Awareness During Anesthesia (ADA) is an unexpected memory recall during anesthesia. In this study, we aimed to determine the factors that affect preoperative anxiety and observe the incidence of ADA, as well as to determine the anxiety levels of these patients with a history of ADA. Methods: This study was planned to be prospective, observational, and cross-sectional. Patients in whom septoplasty was planned, who was admitted to the anesthesiology outpatients between March 2018 and September 2018, were ASA I-II, and aged 18-70 years were included in the study. The demographic characteristics of patients were recorded. The State-Trait Anxiety Inventory (STAI) was used to determine anxiety during a preoperative evaluation. The modified Brice awareness score was used simultaneously to determine previous ADA. Results: The anxiety scores of patients who were conscious during anesthesia were higher than other patients. The mean STAI score was 40.85 ± 14.8 in the 799 patients who met the inclusion criteria of this study. When the anxiety scores were compared, the scores were higher in females than in males (p < 0.05). The mean STAI score was found as 40.3 ± 13.8 in patients who dreamed during anesthesia. Conclusion: It is important to determine the anxiety levels of patients in the preoperative period to prevent the associated complications. Preoperative anxiety, besides preventing ADA, should be dealt with in a multidisciplinary manner. ADA should be carefully questioned while evaluating previous anesthesia experiences.

Resumo Justificativa: A ansiedade é um estado de preocupação causado pela expectativa de perigo externo ou interno. Consciência durante a anestesia (CDA) é a evocação imprevista da memória de eventos intranestésicos. O objetivo deste estudo foi determinar os fatores que afetam a ansiedade pré-operatória, a incidência de CDA e os níveis de ansiedade nos pacientes com antecedente de CDA. Método: O estudo foi planificado como prospectivo, observacional e transversal. Foram incluídos no estudo pacientes programados para septoplastia eletiva, admitidos ao ambulatório de anestesiologia entre Março de 2018 e Setembro de 2018, com classe funcional ASA I-II e faixa etária entre 18 e 70 anos. As características demográficas dos pacientes foram registradas. O Inventário de Ansiedade Traço-Estado (IDATE) foi utilizado para determinar a ansiedade durante a avaliação pré-operatória. Simultaneamente, o escore de consciência de Brice modificado foi usado para determinar CDA anterior. Resultados: Os escores de ansiedade dos pacientes que apresentaram CDA foram mais elevados do que de outros pacientes. A pontuação média do IDATE foi 40,85±14,8 nos 799 pacientes que obedeceram aos critérios de inclusão do estudo. Quando os escores de ansiedade foram comparados, foram maiores no sexo feminino do que no masculino (p < 0,05). O escore médio do IDATE encontrado foi 40,3±13,8 nos pacientes que relataram sonhos durante a anestesia. Conclusão: É importante determinar no pré-operatório os níveis de ansiedade dos pacientes para evitar as complicações associadas. Ansiedade pré-operatória e a prevenção de CDA devem ser tratadas com abordagem multiprofissional. A CDA deve ser cuidadosamente investigada, avaliando-se as experiências vividas pelo paciente em anestesias pregressas.

Emergence from anesthesia: a winding way back.

none.

Quality and Quantity of Memories in Patients Who Undergo Awake Brain Tumor Resection.

BACKGROUND: Awake craniotomy is performed with increasing frequency for brain tumor surgery in eloquent areas; however, little is known about patients' memories of this procedure. Here we retrospectively analyzed the quality and quantity of memories in a series of patients treated following a standardized protocol. METHODS: We treated 61 consecutive patients within 3 years, 48 of whom were alive when the study was performed. Each of these patients received a questionnaire eliciting information about their perioperative memories and perceptions. The perioperative process was broken down into steps, and for each step the patient was to judge the quantity (nothing-everything) and quality (very negative-very positive) of his or her memories. RESULTS: Thirty-six of the 48 patients completed the questionnaire (75%). The quantity of memories was quite incomplete, even for intraoperative moments when patients were awake and cooperative. On average, the quality of memories was neutral or positive. A higher quantity of memories was associated with a higher quality of memories. The most commonly reported sources of discomfort were placement of the Mayfield clamp, followed by laying on the operating room table with movement restriction, and irritation by the urinary catheter in situ. CONCLUSIONS: Awake craniotomy can be performed following our protocol in such a way that it is experienced as (very) comfortable. However, there are moments of discomfort, which can be managed by the team. Extensive preoperative preparation may be considered a crucial part of the procedure. Less amnesia seems to improve patient satisfaction. The results of this study can help guide protocol optimization, expectation management, and information for future patients.

Effects of different methods of general anesthesia on intraoperative awareness in surgical patients.

The purpose of the study was to investigate the effects of total intravenous anesthesia (TIVA) and combined of intravenous and inhaled anesthesia (CIIA) on intraoperative awareness in surgical patients.A total of 678 patients were recruited in the CIIA group, while TIVA group included 566 patients. The clinical characteristics and the occurrence of intraoperative awareness were compared between the groups. Mini-Mental State Examination, Generalized Anxiety Disorder 7, and Patient Health Questionnaire 9 tests were performed to estimate cognitive and psychological functions of the patients. In addition, logistic regression analysis was applied to identify the risk factors for intraoperative awareness in surgical patients.In CIIA group, 3 patients (0.44%) were confirmed with intraoperative awareness, while 11 patients (1.94%) in TIVA group underwent intraoperative awareness. The occurrence rate of intraoperative awareness was significantly higher in VITA group than that in the CIIA group (P = .029). Awareness classification demonstrated that intraoperative awareness mainly included auditory, tactile, and pain perceptions. Moreover, 4 patients showed distress after operation. Patients with intraoperative awareness exhibited poor performance in cognitive and psychological tests (P < .001 for all). Logistic regression analysis demonstrated that CIIA (odds ratio [OR] = 0.198, 95% confidence interval [CI] = 0.047-0.827), age (OR = 0.951, 95% CI = 0.908-0.997), midazolam application (OR = 0.158, 95% CI = 0.034-0.736), awareness history (OR = 10.131, 95% CI = 2.206-45.517), and duration of surgery (OR = 1.016, 95% CI = 1.001-1.032) were significantly associated with intraoperative awareness.Intraoperative awareness can significantly influence the cognitive and psychological functions of surgical patients. CIIA and midazolam application may lower the risk of intraoperative awareness.

Anesthesia management by residents does not alter the incidence of recall of tracheal extubation: a teaching hospital-based propensity score analysis / A administração de anestesia por residentes não altera a incidência de memória da extubação traqueal: uma análise de pontuação de propensão baseada no ensino hospitalar

Abstract Background and objectives: The memory of emergence from anesthesia is recognized as one type of anesthesia awareness. Apart from planed awake extubation, unintentional recall of tracheal extubation is thought to be the results of inadequate anesthesia management; therefore, the incidence can be related with the experience of anesthetists. To assess whether the incidence of recall of tracheal extubation is related to anesthetists' experience, we compared the incidence of recall of tracheal extubation between patients managed by anesthesia residents or by experienced anesthetists. Methods: This is a retrospective review of an institutional registry containing 21,606 general anesthesia cases and was conducted with the board of ethical review approval. All resident tracheal extubations were performed under anesthetists' supervision. To avoid channeling bias, propensity score analysis was used to generate a set of matched cases (resident managements) and controls (anesthetist managements), yielding 3,475 matched patient pairs. The incidence of recall of tracheal extubation was compared as primary outcomes. Results: In the unmatched population, there was no difference in the incidences of recall of tracheal extubation between resident management and anesthetist management (6.5% vs. 7.1%, p = 0.275). After propensity score matching, there was still no difference in incidences of recall of tracheal extubation (7.1% vs. 7.0%, p = 0.853). Conclusion: In conclusion, when supervised by an anesthetist, resident extubations are no more likely to result in recall than anesthetist extubations.

Resumo Justificativa e objetivos: A recordação da emergência da anestesia é reconhecida como um dos tipos de memória da anestesia. Excluindo a extubação planejada com o paciente acordado, acredita-se que a memória não intencional durante a extubação traqueal seja o resultado de manejo inadequado da anestesia; portanto, a incidência pode estar relacionada com a experiência dos anestesistas. Para avaliar se a incidência de memória durante a extubação traqueal está relacionada com a experiência dos anestesistas, comparamos a incidência de memória durante a extubação traqueal entre pacientes tratados por residentes de anestesia ou por anestesistas experientes. Métodos: Estudo retrospectivo de revisão de um registo institucional com 21.606 casos de anestesia geral, conduzido com a aprovação do Comitê de Ética. Todas as extubações traqueais foram feitas por residentes sob a supervisão de anestesistas. Para evitar o viés de canalização, a análise do índice de propensão foi usada para gerar um grupo de casos pareados (manejo por residentes) e de controles (manejo por anestesistas), obtiveram-se 3.475 pares combinados de pacientes. A incidência de memória durante a extubação traqueal foi comparada com os desfechos primários. Resultados: Na população não pareada, não houve diferença na incidência de memória durante a extubação traqueal entre o manejo feito por residentes e anestesistas (6,5% vs. 7,1%, p = 0,275). Mesmo após parear os escores de propensão, não observamos diferença na incidência de memória durante a extubação traqueal (7,1% vs. 7,0%, p = 0,853). Conclusão: Em conclusão, quando supervisionadas por um anestesista, as extubações feitas por residentes não são mais propensas a resultar em memória do que as extubações feitas por anestesistas.

[Waking up during general anaesthesia]. / Wakker worden tijdens de narcose.

Awareness with recall is defined as 'both conscious experience and memory of events during surgery'. Perceptions of sound, pain or paralysis and assimilation of these in the memory can lead to post-traumatic stress disorder. Prospective studies report an incidence of 0.1-1%. Risk factors include those circumstances that result in under-dosing of anaesthetic agents relative to the patient's specific requirement. A lack of reliable monitoring of depth of anaesthesia is a result of our limited knowledge of the effect of anaesthetics on consciousness and memory. No additional benefit has been shown for the use of bispectral index (BIS) monitoring compared with measuring the expired concentration of an inhaled anaesthetic agent. High-risk patients undergoing total intravenous anaesthesia may benefit from BIS for monitoring depth of anaesthesia. Further scientific investigation of the neurological processes involved in awareness with recall is required in order to develop novel monitoring techniques.

[Anxieties of patients before anesthesia - what information can the family physician provide?]. / Ängste der Patienten vor einer Anästhesie - welche Informationen kann der Hausarzt geben?

Patients' fears of anesthesia mostly focus on a possibly inadequate anesthetic effect, on postoperative wound pain and/or nausea and vomiting (PONV). Concerning the possibility of an inadequate anesthetic effect, patients usually express two different kinds of fears: first, that they might stay conscious during surgery («Awareness¼) without it being noticed, and second that they might not wake up again after the operation or that they might sustain neurological damages or deficits after the anesthesia. Last but not least patients are afraid they might suffer from substantial pain after waking up from the anesthesia. In this article we take a closer look at these aspects and discuss ways and possibilities of handling them, suggesting useful approaches for the general practitioner when talking these issues through with his patients prior to an operation.

Les craintes des malades avant une anesthésie ont trait principalement à un effet anesthésiant insuffisant en cours de l'intervention ainsi que de la survenue d'une douleur ou de nausées et de vomissements dans la période post-opératoire. En ce qui concerne la crainte d'un effet anesthésiant insuffisant, elle comporte deux aspects: d'une part la crainte de devenir conscient pendant l'opération sans que cela se remarque et d'autre part de ne pas se réveiller après l'opération ou de développer des atteintes ou es déficits neurologiques. Finalement il y a aussi une crainte non négligeable concernant l'existence d'une douleur en post-opératoire. Dans ce travail sont discutées en détail les craintes potentiellement engendrées lors de la planification d'une anesthésie. Est proposée également une approche utile de discuter de ces craintes entre la malade et le médecin généraliste en préparation de l'intervention.

Psychological sequelae of surgery in a prospective cohort of patients from three intraoperative awareness prevention trials.

BACKGROUND: Elective surgery can have long-term psychological sequelae, especially for patients who experience intraoperative awareness. However, risk factors, other than awareness, for symptoms of posttraumatic stress disorder (PTSD) after surgery are poorly defined, and practical screening methods have not been applied to a broad population of surgical patients. METHODS: The Psychological Sequelae of Surgery study was a prospective cohort study of patients previously enrolled in the United States and Canada in 3 trials for the prevention of intraoperative awareness. The 68 patients who experienced definite or possible awareness were matched with 418 patients who denied awareness based on age, sex, surgery type, and awareness risk. Participants completed the PTSD Checklist-Specific (PCL-S) and/or a modified Mini-International Neuropsychiatric Interview telephone assessment to identify symptoms of PTSD and symptom complexes consistent with a PTSD diagnosis. We then used structural equation modeling to produce a composite PTSD score and examined potential risk factors. RESULTS: One hundred forty patients were unreachable; of those contacted, 303 (88%) participated a median of 2 years postoperatively. Forty-four of the 219 patients (20.1%) who completed the PCL-S exceeded the civilian screening cutoff score for PTSD symptoms resulting from their surgery (15 of 35 [43%] with awareness and 29 of 184 [16%] without). Nineteen patients (8.7%; 5 of 35 [14%] with awareness and 14 of 184 [7.6%] without) both exceeded the cutoff and endorsed a breadth of symptoms consistent with the Diagnostic and Statistical Manual Fourth Edition diagnosis of PTSD attributable to their surgery. Factors independently associated with PTSD symptoms were poor social support, previous PTSD symptoms, previous mental health treatment, dissociation related to surgery, perceiving that one's life was threatened during surgery, and intraoperative awareness (all P ≤ 0.017). Perioperative dissociation was identified as a potential mediator for perioperative PTSD symptoms. CONCLUSIONS: Events in the perioperative period can precipitate psychological symptoms consistent with subsyndromal and syndromal PTSD. We not only confirmed the high rate of postoperative PTSD in awareness patients but also identified a significant rate in matched nonawareness controls. Screening surgical patients, especially those with potentially mediating risk factors such as intraoperative awareness or perioperative dissociation, for postoperative PTSD symptoms with the PCL-S is practical and could promote early referral, evaluation, and treatment.

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.

Anaesthesia, amnesia and harm.

Anaesthesia causes unconsciousness by suppressing neural mechanisms mediating arousal and awareness. It also causes amnesia by disrupting mechanisms of memory consolidation. Some patients under general anaesthesia unexpectedly become aware during surgery and form a traumatic memory of their experience. After describing the neural underpinning of phenomenal consciousness and memory, I examine the respects in which patients who experience anaesthesia awareness can be harmed by it. In cases where awareness is detected intraoperatively, I consider whether an anaesthetist would be justified in administering a drug to prevent a memory of the experience, as well as reasons for and against preoperatively informing patients of the possibility of awareness. In cases where awareness is reported postoperatively, I consider reasons for taking a drug to erase a memory of awareness against reasons for retaining the memory. A decision to take or decline such a drug would be informed by the potential harm of these memories and the potential benefits and risks of drugs intended to erase them.

Antiseptic phobia in a patient experiencing anesthesia awareness during cleft palate repair surgery: a case report.

Specific phobia is an excessive and irrational fear often triggered by a stressor. Among different types of phobias arising in medical settings, we could not find any case reported for exclusively antiseptic fluids without any medical-surgical intervention. The term "anesthesia awareness" (AA) signifies the specific surgical period of time when an individual, in spite of being under intended general anesthesia, remains aware of the sensory stimuli and the memories of which also remain available for his subsequent explicit recall in the future. According to the "American Society of Anesthesiologists Practice Advisory", it is explicit recall during general anesthesia. Its hallmark is the presence of awareness of the events going on during the surgical procedure while being under a general anesthesia. AA is a distressing condition with immediate and long-term consequences. In spite of an estimated prevalence of 0.1%-0.2% of all the surgeries, our knowledge about this condition is limited. The most commonly reported consequences of AA are acute painful flashbacks of surgical events along with the emotional turmoil and a sense of helplessness followed later by posttraumatic stress disorder. Here, we report a unique case of occurrence of "antiseptic-phobia" in a patient following the experience of anesthesia awareness during cleft palate repair surgery.

Improved patient awareness and satisfaction using procedure specific consent forms in carpal tunnel decompression surgery.

Carpal tunnel decompression (CTD) is a common procedure amenable to procedure specific consent forms (PSCFs). These may help better inform patients and so increase patient satisfaction with the consent process. We assessed the use of a PSCF for CTD. The PSCF mentions eight complications of carpal tunnel surgery and alternative non-operative treatments. Two groups of 40 patients each were compared prospectively. Patients in one group were issued with a PSCF prior to admission whereas those in the other group were not. After standard pre-operative consent, patients were interviewed prior to surgery and assessed for their awareness of complications and alternative treatment options. The patients who received a PSCF showed greater awareness of different complications and alternative treatments and reported greater satisfaction with the consent process. We conclude that using PSCFs is a very useful and inexpensive adjunct to improve patient awareness and satisfaction with the consent process.

Postoperative recovery with bispectral index versus anesthetic concentration-guided protocols.

BACKGROUND: Use of the bispectral index (BIS) monitor has been suggested to decrease excessive anesthetic drug administration, leading to improved recovery from general anesthesia. The purpose of this substudy of the B-Unaware and BAG-RECALL trials was to assess whether a BIS-based anesthetic protocol was superior to an end-tidal anesthetic concentration-based protocol in decreasing recovery time and postoperative complications. METHODS: Patients at high risk for awareness were randomized to either BIS-guided or end-tidal anesthetic concentration-guided general anesthesia in the original trials. Outcomes included time to postanesthesia care unit discharge readiness, time to achieve a postoperative Aldrete score of 9-10, intensive care unit length of stay, postoperative nausea and vomiting, and severe postoperative pain. Univariate Cox regression and chi-square tests were used for statistical analyses. RESULTS: The BIS cohort was not superior in time to postanesthesia care unit discharge readiness (hazard ratio, 1.0; 95% CI, 1.0-1.1; n = 2,949), time to achieve an Aldrete score of 9-10 (hazard ratio, 1.2; 95% CI, 1.0-1.4; n = 706), intensive care unit length of stay (hazard ratio, 1.0; 95% CI, 0.9-1.1; n = 2,074), incidence of postoperative nausea and vomiting (absolute risk reduction, -0.5%; 95% CI, -5.8 to 4.8%; n = 789), or incidence of severe postoperative pain (absolute risk reduction, 4.4%; 95% CI, -2.3 to 11.1%; n = 759). CONCLUSIONS: In patients at high risk for awareness, the BIS-guided protocol is not superior to an anesthetic concentration-guided protocol in time needed for postoperative recovery or in the incidences of common postoperative complications.

Case report: Volitional delay of self-reported outcomes: insights from a case of intraoperative awareness with explicit recall.

Intraoperative awareness with explicit recall (AWR) is a self-reported outcome of interest in clinical practice, quality assurance initiatives, and clinical trials. Combining structured postoperative interviews with a preoperative description of AWR is assumed to ensure prompt patient disclosure. We describe a volitionally delayed reporting of AWR because of the perceived unimportance of nondistressing awareness experiences, despite preoperative education and 2 postoperative interviews. This delay had implications for a major randomized controlled trial on AWR. Volitionally delayed self-reported outcomes may affect statistical comparisons in clinical trials and quality assurance initiatives, and delay the treatment of subsequent sequelae in clinical practice. This limitation should be considered, even when using structured outcome assessment and preoperative education.

Psychological impact of unexpected explicit recall of events occurring during surgery performed under sedation, regional anaesthesia, and general anaesthesia: data from the Anesthesia Awareness Registry.

BACKGROUND: Anaesthetic awareness is a recognized complication of general anaesthesia (GA) and is associated with post-traumatic stress disorder (PTSD). Although complete amnesia for intraprocedural events during sedation and regional anaesthesia (RA) may occur, explicit recall is expected by anaesthesia providers. Consequently, the possibility that there could be psychological consequences associated with unexpected explicit recall of events during sedation and RA has not been investigated. This study investigated the psychological sequelae of unexpected explicit recall of events during sedation/RA that was reported to the Anesthesia Awareness Registry. METHODS: The Registry recruited subjects who self-identified as having had anaesthetic awareness. Inclusion criteria were a patient-reported awareness experience in 1990 or later and availability of medical records. The sensations experienced by the subjects during their procedure and the acute and persistent psychological sequelae attributed to this explicit recall were assessed for patients receiving sedation/RA and those receiving GA. RESULTS: Among the patients fulfilling the inclusion criteria, medical record review identified 27 sedation/RA and 50 GA cases. Most patients experienced distress (78% of sedation/RA vs 94% of GA). Approximately 40% of patients with sedation/RA had persistent psychological sequelae, similar to GA patients. Some sedation/RA patients reported an adverse impact on their job performance (15%), family relationships (11%), and friendships (11%), and 15% reported being diagnosed with PTSD. CONCLUSIONS: Patients who self-reported to the Registry unexpected explicit recall of events during sedation/RA experienced distress and persistent psychological sequelae comparable with those who had reported anaesthetic awareness during GA. Further study is warranted to determine if patients reporting distress with explicit recall after sedation/RA require psychiatric follow-up.

Awareness during general anaesthesia--implications of explicit intraoperative recall.

Anaesthesia awareness (AA) is postoperative recall of events experienced under general anaesthesia. Most frequently patients remember an auditory perception, the feeling of motor function lost, pain, helplessness, anxiety, panic, impending death. The prevalence of awareness in nonobstetric and noncardiac surgical cases is 0.1%-0.2%. The prevalence is higher in cardiac surgery, obstetric and major trauma cases. According to the results of many studies light anaesthesia is the most common cause of the AA. Posttraumatic stress disorder appears in 33%-56% of patients who experienced awareness during general anaesthesia. Extreme awareness experiences are very uncommon, but traumatic and can have lasting effects on patients. Several brain-function monitors based on the processed electroencephalogram or evoked potentials have been developed to assess anaesthetic depth. Measures to prevent awareness include avoidance of light anesthesia, gaining more knowledge about patient anaesthetic requirements and development of methods to detect consciousness during anesthesia.

Awareness during anesthesia: the results of a questionnaire survey in Japan.

PURPOSE: We planned a survey to evaluate the current incidence and risk factors of intraoperative awareness. METHODS: A questionnaire survey was conducted via the Internet. The survey was designed to obtain information regarding cases involving intraoperative awareness in 2008. RESULTS: A total of 172 anesthesiologists answered the survey. The total number of reported anesthetic cases was 85,156. Twenty-four cases of definite or possible awareness were reported by 21 anesthesiologists, of which 14 were cases of definite awareness and ten of possible awareness. The incidence of awareness, including possible awareness, was 0.028%. Propofol was used in 21 cases, sevoflurane in two, and a high dose of fentanyl in one. Bispectral index (BIS) monitoring was used in seven cases (29%). Sixteen patients (67%) were <50 years old, six (26%) were men, and 17 (74%) were women. As the type of surgery, three cases (13%) involved gynecological surgeries and seven (30%) involved cervicofacial surgeries. During surgery, the memory at postural change was preserved in two cases. CONCLUSION: The most surprising finding of this study is that total intravenous anesthesia (TIVA) was used in 21 of the 24 (88%) cases of definite and possible awareness. Although the incidence of intraoperative awareness was compatible with the previous studies, meticulous care should be taken when anesthesia is performed by TIVA for high-risk patients. The results of this survey should be verified, as well as further continuous survey and prospective study, because this study was performed by an anonymous questionnaire survey conducted over only 1-year period.

Patient perception of combined awake brain tumor surgery and intraoperative 1.5-T magnetic resonance imaging: the Kiel experience.

OBJECTIVE: To assess patients' perspective of combined awake craniotomy and intraoperative magnetic resonance imaging (MRI) in a prospective study. METHODS: We evaluated 25 consecutive patients prospectively. Qualitative and quantitative results were obtained by a psychologist via a structured interview 5 +/- 2 days postoperatively, supplemented by preoperative and postoperative assessment of the patients' mood with the Hospital Anxiety and Depression Scale, as well as parts of a structured clinical interview during the postoperative assessment. RESULTS: Satisfaction with the experience was high in almost all cases. Only 1 patient recalled experiencing considerable discomfort during the operation. About one-third (39%) of our sample described minor to moderate difficulties; the remaining were entirely satisfied. CONCLUSION: Although the combination of awake craniotomy and intraoperative MRI is demanding, it was both tolerable and reasonable for the patients. Our data confirm that intraoperative MRI appears to have no additional significant impact on the subjective patient perception, although it does prolong the procedure.

[Anesthesia awareness]. / Awareness, consecuencias de una experiencia estresante.

Anesthesia awareness, or "unintended intra-operative awareness" occurs during general anesthesia, on the operating table, when a patient has not had enough general anesthetic or analgesic to prevent consciousness or waking up during surgery. According to international studies its global incidence ranges from 0.1 to 0.2%. Its impact on people can be as severe as other traumatic experiences such as natural disasters, violent fights or sexual abuse. The prevalence of symptoms compatible with post traumatic stress disorder can be as high as 50%, after experiencing the awareness phenomenon. This paper reviews the main issues of the awareness phenomenon.