1. Unique Identifier 90210191
Author
McCleane GJ; Cooper R
Institution Altnagelvin Hospital,
Londonderry, Northern Ireland.
Title The nature of pre-operative
anxiety.
Source Anaesthesia 1990 Feb;45(2): p153-5
ISSN
0003-2409
Abstract
In a study of 247 patients who had general anaesthesia for dental procedures, the incidence of individual anxieties was noted using a questionnaire completed by the patient. The most common anxieties related to the period before transfer to the operating theatre, intra-operative awareness and postoperative pain. These anxieties were present in over half the patients questioned. The follow-up questionnaire was completed by 207 patients in order to indicate which anxieties they would expect to have if they needed anaesthesia in the future. All anxieties were less frequent than found before operation.
2. Unique
Identifier 99215860
Author Domino KB; Posner KL;
Caplan RA; Cheney FW
Institution Department of Anesthesiology,
University of Washington School of Medicine, and the Virginia Mason Medical Center,
Seattle 98195, USA. kdomino@u.washington.edu.
Title Awareness
during anesthesia: a closed claims analysis.
Source Anesthesiology
1999 Apr;90(4): p1053-61
ISSN 0003-3022
Abstract
BACKGROUND: Awareness during general anesthesia is a frightening experience, which may result in serious emotional injury and post-traumatic stress disorder. We performed an in-depth analysis of cases from the database of the American Society of Anesthesiologists Closed Claims Project to explore the contribution of intraoperative awareness to professional liability in anesthesia.
METHODS: The database of the Closed Claims Project is composed of closed US malpractice claims that have been collected in a standardized manner. All claims for intraoperative awareness were reviewed by the reviewers to identify patterns of causation and standard of care. Logistic regression analysis was used to identify independent patient and anesthetic factors associated with claims for recall during general anesthesia compared to other general anesthesia malpractice claims.
RESULTS: Awareness claims accounted for 79 (1.9%) of 4,183 claims in the database, including 18 claims for awake paralysis, i.e., the inadvertent paralysis of an awake patient, and 61 claims for recall during general anesthesia, ie., recall of events while receiving general anesthesia. The majority of awareness claims involved women (77%), younger than 60 yr of age (89%), American Society of Anesthesiologists physical class I-II (68%), who underwent elective surgery (87%). Most (94%) claims for awake paralysis represented substandard care involving errors in labeling and administration, whereas care was substandard in only 43% of the claims for recall during general anesthesia (P < 0.001). Claims for recall during general anesthesia were more likely to involve women (odds ratio [OR] = 3.08, 95% confidence interval [CI] = 1.58, 6.06) and anesthetic techniques using intraoperative opioids (OR = 2.12, 95% CI = 1.20, 3.74), intraoperative muscle relaxants (OR = 2.28, 95% CI = 1.22, 4.25), and no volatile anesthetic (OR = 3.20, 95% CI = 1.88, 5.46). CONCLUSIONS: Deficiencies in labeling and vigilance were common causes for awake paralysis. Claims for recall during general anesthesia were more likely in women and with nitrous-narcotic-relaxant techniques.
3. Unique Identifier
93370661
Author Moerman N; Bonke B; Oosting J
Institution
Department of Anesthesiology, Academic Medical Center, University of
Amsterdam, The Netherlands.
Title Awareness and recall during
general anesthesia. Facts and feelings.
Source Anesthesiology
1993 Sep;79(3): p454-64
ISSN 0003-3022
Abstract
BACKGROUND: Experiences of awareness and recall during general anesthesia can be most distressing for patients. To obtain relevant information, the authors systematically interviewed patients in whom awareness during surgery had occurred, and questioned them about their experiences. METHODS: Twenty-six patients, referred by colleagues, described the facts and feelings they had experienced during the period of awareness, and whether these had had any consequences. Available anesthetic records were independently judged by three experienced anesthesiologists for relevant parameters. RESULTS: Auditory perception and the sensation of paralysis were most frequently mentioned, followed by the sensation of pain. Patients' feelings were mostly related to anxiety, panic, powerlessness, and helplessness. Eighteen patients (70%) experienced unpleasant aftereffects, including sleep disturbances, dreams and nightmares, and flashbacks and anxiety during the day. Only nine patients (35%) had informed their anesthesiologists about what had taken place. Twelve anesthetic records were assessed. In three, the occurrence of awareness had been indicated, while, in a fourth, it was noted that an amnesic drug had been given at a moment of increased blood pressure. Experienced anesthesiologists were unable to reliably distinguish awareness cases from matched controls when judging the records. CONCLUSIONS: Details recalled from the period of awareness correspond with data from the literature. The anesthesiologist's role in discussing, and dealing with, traumatic experiences related to anesthesia may be of great importance. The hand-written anesthetic record is of limited value in retrospectively explaining why awareness and recall have occurred.
4. Unique
Identifier 20166542
Author Sandin RH; Enlund G;
Samuelsson P; Lennmarken C
Institution Department of Anaesthesia
and Intensive Care, Lanssjukhuset, Kalmar, Sweden. rolfs@ltkalmar.se.
Title Awareness during anaesthesia: a prospective case study
[see comments]
Source Lancet 2000 Feb 26;355(9205): p707-11
ISSN 0140-6736
Abstract
BACKGROUND: Patients who are given general anaesthesia are not guaranteed to remain unconscious during surgery. Knowledge about the effectiveness of current protective measures is scarce, as is our understanding of patients' responses to this complication. We did a prospective case study to assess conscious awareness during anaesthesia.
METHODS: 11785 patients who had undergone general anaesthesia were interviewed for awareness on three occasions: before they left the post-anaesthesia care unit, and 1-3 days and 7-14 days after the operation.
FINDINGS: We identified 18 cases of awareness and one case of inadvertent muscle blockade that had occurred before unconsciousness. Incidence of awareness was 0.18% in cases in which neuromuscular blocking drugs were used, and 0.10% in the absence of such drugs. 17 cases of awareness were identified at the final interview, but no more than 11 would have been detected if an interview had been done only when the patients left the post-anaesthesia care unit. Four non-paralysed patients recalled intraoperative events, but none had anxiety during wakefulness or had delayed neurotic symptoms. This finding contrasts with anaesthesia with muscle relaxants, during which 11 of 14 patients had pain, anxiety, or delayed neurotic symptoms. After repeated discussion and information, the delayed neurotic symptoms resolved within 3 weeks in all patients. Analysis of individual cases suggests that a reduced incidence of recall of intraoperative events would not be achieved by monitoring of end-tidal anaesthetic gas concentration or by more frequent use of benzodiazepines. INTERPRETATION: The inability to prevent awareness by conventional measures may advocate monitoring of cerebral activity by neurophysiological techniques. However, the sensitivity of such techniques is not known, and in the light of our findings, at least 861 patients would need to be monitored to avoid one patient from suffering due to awareness during relaxant anaesthesia.
5. Unique Identifier 98244702
Author Ranta
SO; Laurila R; Saario J; Ali-Melkkila T; Hynynen M
Institution Department
of Anaesthesia, Children's Hospital, Helsinki University Central Hospital, Finland.
seppo.ranta@huch.fi.
Title Awareness with recall during general
anesthesia: incidence and risk factors [see comments]
Source Anesth
Analg 1998 May;86(5): p1084-9
ISSN 0003-2999
Abstract
We studied the associated factors and incidence of awareness during general anesthesia and the nature of subsequent psychiatric disorders. Patients older than 12 yr undergoing surgery under general anesthesia in a secondary care hospital during 1 yr were included in the study. The doses of anesthetics were calculated for the patients with and without awareness. There were 4818 operations under general anesthesia; 2612 (54%) patients were interviewed. Ten (0.4% of those interviewed) patients were found to have undisputed awareness, and there were nine (0.3%) patients with possible awareness. The doses of isoflurane (P < 0.01) and propofol (P < 0.05) were smaller in patients with awareness. Five patients with awareness underwent a psychiatric evaluation. One patient experienced sleep disturbances afterward, but the other four patients did not have any after effects. In conclusion, awareness is a rare complication of general anesthesia associated with small doses of anesthetics. Implications: In an interview of 2612 patients after general anesthesia, 10 (0.4%) patients with awareness and 9 (0.3%) patients with possible awareness were found. A predisposing factor was small doses of the principal anesthetic. In a psychiatric interview, a large proportion of the patients with awareness were found to have suffered from depression in the past.
6. Unique Identifier
94168273
Author Cobcroft MD; Forsdick C
Title
Awareness under anaesthesia: the patients' point of view.
Source
Anaesth Intensive Care 1993 Dec;21(6): p837-43
ISSN 0310-057X
Abstract
The collective experience of 187 patients who suffered awareness during general anaesthesia is presented. This has been collated from letters solicited in September 1992 by a women's magazine widely distributed throughout Australia and New Zealand. The responses cover anaesthetics given during a period from the 1950s to the present. The findings show a disturbing symptomatology ranging over all modalities of sensation and of postoperative psychological and psychiatric disturbances. The letters also reveal that in most cases understanding of awareness and its proper management by medical personnel was poor or totally lacking.
7. Unique Identifier
96399401
Author Schwender D; Daunderer M; Klasing S; Mulzer
S; Finsterer U; Peter K
Institution Institut fur Anasthesiologie
der Ludwig-Maximilians-Universitat Munchen.
Title [Monitoring
intraoperative awareness. Vegetative signs, isolated forearm technique, electroencephalogram,
and acute evoked potentials]
Vernacular Title [Monitoring
intraoperativer Wachzustande. Vegetative Zeichen, isolierte Unterarmtechnik, Elektroenzephalogramm
und akustisch evozierte Potentiale.]
Source Anaesthesist
1996 Aug;45(8): p708-21
ISSN 0003-2417
Abstract
Several methods have been developed to quantify central anaesthetic effects and monitor awareness during general anaesthesia. The most important of these are the PRST score, calculated from changes in blood pressure, heart rate, sweating, and tear production, the isolated forearm technique, where the patient is allowed to move during surgery, the processed electroencephalogram (EEG) and the derived parameters median frequency (MF) and spectral-edge frequency (SEF), and mid-latency auditory evoked potentials (MLAEP). In clinical practice, the application of individual doses of anaesthetics is generally guided by autonomic vegetative clinical signs such as changes in blood pressure, heart rate, sweating, and tear production, quantified as the PRST score. Unfortunately, these parameters are not very reliable with regard to predicting the suppression of consciousness and awareness, especially when high-dose opioids are used in patients with cardiovascular medications and a variety of accompanying diseases. The PRST score probably indicates mainly the autonomic responses to painful stimuli, and seems to be useful in guiding the individual use of analgesics. The isolated forearm technique is a useful test of the patient's responsiveness during general anaesthesia, and thus an instrument for investigating the incidence of awareness during different anaesthetic regimens and when muscle relaxants are employed. A disadvantage is that it can only be used for 20 to 30 min because of pressure-induced nerve blocks or lesions. It can not be employed when long-term relaxation is necessary and consciousness and awareness are to be monitored continuously. The processed EEG and the derived parameters MF and SEF are important scientific tools to quantify central effects of many anaesthetics and opioid analgesics that allow the development of pharmacodynamic-pharmacokinetic models of anaesthetic action. MF has proven to be useful in monitoring closed-loop feedback of intravenous drug administration. Unfortunately, until now there have been no clinical studies that document the usefulness of MF or SEF with regard to predicting intraoperative arousal or awareness. To the contrary, some experimental data failed to predict imminent arousal and response to surgical incision or verbal commands by MF or SEF. Therefore, the EEG seems to be of limited value for monitoring awareness, consciousness, or memory formation during anaesthesia. MLAEP are suppressed in a dose-dependent fashion by many general anaesthetics and correlate with wakefulness, awareness, and explicit and implicit memory during anaesthesia and seem to be a promising method of monitoring awareness during anaesthesia. Nevertheless, future studies will have to determine threshold values for the different MLAEP parameters for intraoperative awareness and explicit and implicit recall of intraoperatively presented information for the different commonly used anaesthetics. Only then will it be possible to determine the usefulness of the method in clinical practice.
8. Unique Identifier 97267860
Author Ranta
S; Ranta V; Aromaa U
Institution Department of Anaesthesia,
Helsinki University Central Hospital, Finland.
Title The
claims of compensation for awareness with recall during general anaesthesia in
Finland [see comments]
Source Acta Anaesthesiol Scand 1997
Mar;41(3): p356-9
ISSN 0001-5172
Abstract
BACKGROUND: Awareness during anaesthesia has been estimated to occur in 0.2%-0.4% of patients undergoing general surgery. In Finland, according to the Patient Injury Act, compensation is paid for an injury caused by medical treatment. We have analysed the claims for compensation involving awareness under anaesthesia filed between May, 1987 and December, 1993.
METHODS: Original claims, hospital notes, and expert advisor's comments as well as the comments of the anaesthesiologist in charge of the anaesthesia, and decisions of the Patient Injury Association, were reviewed.
RESULTS: A total of 23363 claims of patient injury were made during the study period. Of these, 391 considered anaesthetic treatments, and there were four cases of awareness with recall. CONCLUSION:
Claims of compensation for awareness during anaesthesia were surprisingly few, possible reasons of which are discussed. Compensations paid were low in comparison with some other countries.
![[Return to article]](../../../images/backbutton.gif){kind=small}