The Incidence of Awareness During Anesthesia: A Multicenter United States Study

Duke University, Durham, North Carolina, United States
Anesthesia & Analgesia (Impact Factor: 3.47). 10/2004; 99(3):833-9, table of contents. DOI: 10.1213/01.ANE.0000130261.90896.6C
Source: PubMed


Awareness with recall after general anesthesia is an infrequent, but well described, phenomenon that may result in posttraumatic stress disorder. There are no recent data on the incidence of this complication in the United States. We, therefore, undertook a prospective study to determine the incidence of awareness with recall during general anesthesia in the United States. This is a prospective, nonrandomized descriptive cohort study that was conducted at seven academic medical centers in the United States. Patients scheduled for surgery under general anesthesia were interviewed in the postoperative recovery room and at least a week after anesthesia and surgery by using a structured interview. Data from 19,575 patients are presented. A total of 25 awareness cases were identified (0.13% incidence). These occurred at a rate of 1-2 cases per 1000 patients at each site. Awareness was associated with increased ASA physical status (odds ratio, 2.41; 95% confidence interval, 1.04-5.60 for ASA status III-V compared with ASA status I-II). Age and sex did not influence the incidence of awareness. There were 46 additional cases (0.24%) of possible awareness and 1183 cases (6.04%) of possible intraoperative dreaming. The incidence of awareness during general anesthesia with recall in the United States is comparable to that described in other countries. Assuming that approximately 20 million anesthetics are administered in the United States annually, we can expect approximately 26,000 cases to occur each year.

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Available from: Karen Domino, Apr 08, 2014
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    • "There were an additional 46 cases (0.23%) of " possible awareness " and 1,183 cases of " intraoperative dreaming, " which corresponded to 6.04% (Sebel et al., 2004, 836). With respect to the group of 25 patients who had awareness with recall after general anesthesia, almost half described auditory perceptions, and being unable to move or breathe; other descriptions of awareness included anxiety/stress, pain, sensation of the endotracheal tube, and feeling surgery without pain (Sebel et al., 2004, 836). 21. "
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    ABSTRACT: Patients who are imminently dying sometimes experience symptoms refractory to traditional palliative interventions, and in rare cases, continuous sedation is offered. Samuel H. LiPuma, in a recent article in this Journal, argues that continuous sedation until death is equivalent to physician-assisted suicide/euthanasia based on a higher brain neocortical definition of death. We contest his position that continuous sedation involves killing and offer four objections to the equivalency thesis. First, sedation practices are proportional in a way that physician-assisted suicide/euthanasia is not. Second, continuous sedation may not entirely abolish consciousness. Third, LiPuma's particular version of higher brain neocortical death relies on an implausibly weak construal of irreversibility-a position that is especially problematic in the case of continuous sedation. Finally, we explain why continuous sedation until death is not functionally equivalent to neocortical death and, hence, physician-assisted suicide/euthanasia. Concluding remarks review the differences between these two end-of-life practices. © The Author 2015. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail:
    Journal of Medicine and Philosophy 08/2015; 40(5). DOI:10.1093/jmp/jhv018 · 0.79 Impact Factor
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    • "Molaee-Ardekani et al. showed that phase of modulation related to various delta subbands as very slow, slow, fast, narrow, cumulative slow 1, and cumulative slow 2 deltas with alpha waves had different correlations with depth of anesthesia, and finally they implied that a fast delta subband was the best choice among various delta subbands to correlate with brain activities, and their phase difference changes with DOA [9]. By considering about 0.2% incidence of awareness and its complications in the united states of America (USA) and multiplying this incidence rate by 22 million anesthesia cases annually in the USA [20], we can find out the magnitude of the problem. Finding solution to this problem can be a great motivation to do of this study. "
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    ABSTRACT: Awareness during general anesthesia for its serious psychological effects on patients and some juristically problems for anesthetists has been an important challenge during past decades. Monitoring depth of anesthesia is a fundamental solution to this problem. The induction of anesthesia alters frequency and mean of amplitudes of the electroencephalogram (EEG), and its phase couplings. We analyzed EEG changes for phase coupling between delta and alpha subbands using a new algorithm for depth of general anesthesia measurement based on complex wavelet transform (CWT) in patients anesthetized by Propofol. Entropy and histogram of modulated signals were calculated by taking bispectral index (BIS) values as reference. Entropies corresponding to different BIS intervals using Mann-Whitney U test showed that they had different continuous distributions. The results demonstrated that there is a phase coupling between 3 and 4 Hz in delta and 8-9 Hz in alpha subbands and these changes are shown better at the channel T 7 of EEG. Moreover, when BIS values increase, the entropy value of modulated signal also increases and vice versa. In addition, measuring phase coupling between delta and alpha subbands of EEG signals through continuous CWT analysis reveals the depth of anesthesia level. As a result, awareness during anesthesia can be prevented.
    Computational and Mathematical Methods in Medicine 09/2014; 2014:354739. DOI:10.1155/2014/354739 · 0.77 Impact Factor
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    • "Recalling the events in surgical time has been observed in 1.2 to 2.7% of cases [27] while recalling the sounds and images in surgical time of the present study was observed in 9.4% and 6.3% of control group respectively, but not in the study group. "
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    ABSTRACT: Statement of the Problem: Premedication is expedient in reducing the psychological trauma from recalling the unpleasant pre-anesthetic phases, hence, inducing a trouble-free anesthesia. Purpose: This study aimed to determine the effectiveness of oral midazolam in co-operation of the subjects before general anesthesia and in recalling the pre-anesthetic phases, performed on children candidate for dental treatment under general anesthesia. Materials and Method: In this prospective clinical trial study, 62 healthy non-cooperative children, candidate for dental treatment under general anesthesia, were randomly divided into study and control groups. The children received 20ml orange juice, 20 minutes before starting the anesthesia. The juice of the test group contained 0.5mg/kg of midazolam and that of the control group included no medication. The induction and the maintenance process of anesthesia were similar in both groups. The manner of subjects when separated from parents, their cooperation during intravenous catheterization, and recalling the pre-anesthetic events were recorded. Data were analyzed by adopting chi-square and Mann-Whitney tests. Results: Most of the children in the test group had a comfortable separation from parents, restful IV catheterization and 90% of the subjects did not recall the pre-anesthetic events. Conclusion: Under the circumstances of this study, it could be concluded that 0.5mg/kg oral midazolam premedication is effective for comfortable separation of children from parents and restful IV catheterization and also forgetting the pre-anesthetic events.
    09/2014; 15(3):123-8.
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