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Biomedical subjects

B Bonke

Publications and source records attributed to B Bonke.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Implicit memory in patients with Alzheimer disease: a concise review].

Experimental psychologists have made a distinction between explicit and implicit memory tasks. In contrast to explicit tasks implicit ones do not refer to conscious recollection of a previous learning episode. Implicit memory is revealed by a change in task performance which can be attributed to previous learning. Amnesic patients, by definition, perform poorly on explicit memory tasks, but exhibit normal performance on certain implicit tasks. In recent years, investigators have studied the implicit memory capabilities of patients with Alzheimer's disease. The present article aims to give an overview of the performance of Alzheimer patients on four tasks of implicit memory. Compared with normal elderly persons, patients with Alzheimer's disease seem to demonstrate impaired performance on conceptual, but not on perceptual implicit memory tasks. This dissociation could yield important information about the neurological systems subserving implicit memory processes. Some suggestions for future research into implicit memory in Alzheimer patients are given.

Aged↗
PubMed1993

Implicit memory for stimuli presented during anaesthesia: role of anaesthetic cocktail and memory test.

Recently, investigators have used so-called implicit memory tests to investigate 'hearing' during general anaesthesia. Some of them were able to demonstrate auditory perception in anaesthetized patients, but others have failed to find any evidence for intraoperative stimulus registration. We argue that differences in anaesthetic cocktails and memory tests can explain why some researchers have produced positive results, supportive of information-processing under anaesthesia, and others have not. It appears that stimulus registration can occur during surgery, regardless of anaesthetic technique. However, processing of complex information may only be possible during nitrous oxide anaesthesia.

Acoustic Stimulation↗
PubMed1993

Awareness and recall during general anesthesia. Facts and feelings.

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.

Adult↗
PubMed1993

Implicit memory during balanced anaesthesia. Lack of evidence.

The effect of the number of presentations on implicit memory for words was studied in anaesthetised patients. During standardised, balanced anaesthesia, 81 surgical patients were presented with less common specimens of familiar word categories. For each of three word categories the number of word presentations varied between the patients (0 (control), 5, or 30 presentations). Postoperatively, repetition priming was tested by asking patients to generate exemplars for each of the word categories. No implicit memory for the words presented during anaesthesia was found and consequently no effect of number of word presentations could be demonstrated. It is suggested that this finding, which contradicts previous results, may be caused by the relatively low familiarity of the words used.

Adult↗
PubMed1993

Implicit learning during enflurane anaesthesia in spontaneously breathing patients?

Forty-one patients breathing spontaneously during enflurane anesthesia were presented (via headphones) either with statements about common facts of some years ago, or new verbal associations, i.e. names of fictitious people. Postoperatively, there were no differences between the two groups in the responses to questions about the common facts or attribution of fame to the fictitious people. This finding suggests that unconscious learning and activation may not occur during enflurane anaesthesia without neuromuscular block.

Adult↗
PubMed1993

Patient-controlled analgesia (PCA) leads to more postoperative pain relief, but also to more fatigue and less vigour.

This investigation evaluated patient-controlled analgesia (PCA) for subjective well-being and mood in the postoperative period in comparison with the intramuscular (im) administration of morphine given on demand. Patients scheduled for elective upper abdominal surgery were assigned at random to either PCA (n = 17) or im morphine (n = 14). The PCA group experienced significantly more pain relief and consumed more morphine than those who received im morphine. The PCA patients suffered from more fatigue and showed less vigour than the im group. Neither preoperative trait anxiety nor locus of control was associated with postoperative pain in either of the groups.

Adult↗
PubMed1993

Clinical note on the use of denial in patients undergoing surgery for breast cancer.

44 patients awaiting surgery for breast cancer completed the Hospital Anxiety and Depression Scale. Thirteen patients had anxiety scores within the normal range, and five of them even scored extremely low in anxiety. These five and possibly all 13 patients were probably using denial as a defense against the stress of major surgery.

Adaptation, Psychological↗
PubMed1993

Effect of different therapeutic suggestions presented during anaesthesia on post-operative course.

A double-blind, randomized study was conducted to examine the effect of different types of therapeutic suggestions, administered during general anaesthesia, on post-operative course. Eighty-two patients undergoing cholecystectomy were intra-operatively exposed to either affirmative and non-affirmative suggestions, affirmative or non-affirmative suggestions separately, or some irrelevant text. Patients who had received both affirmative and non-affirmative suggestions spent less time in hospital than patients in the other three groups. No significant differences were demonstrated for subjective well-being measured on the third and sixth days.

Anesthesia, General↗
PubMed1992

Unconscious learning during anaesthesia.

Forty-three surgical patients were, during general anaesthesia, presented (via headphones) with either statements about common facts of some years ago (group A), or new verbal associations, i.e. the names of fictitious, nonfamous people (group B). None had any recall of intra-operative events. In a postoperative test of indirect memory, patients in group A answered more questions about the 'common facts' correctly than those in group B (p < 0.005), which reflects the activation of pre-existing knowledge. Furthermore, patients in group B designated more 'nonfamous names' as famous (thus falsely attributing fame) than patients in group A (p < 0.001), which demonstrates that information-processing during anaesthesia can also take place as unconscious learning.

Adolescent↗
PubMed1992

Implicit memory tested in children during inhalation anaesthesia.

Memory for stimuli presented during inhalation anaesthesia was tested in 80 children undergoing eye surgery. Two groups were exposed, in a random double-blind study, to repeated neutral phrases including either the colour orange or green. A postoperative colouring task was used as a test of implicit memory to detect any preference for the colour named under anaesthesia. No colour preference attributable to implicit memory could be demonstrated. One patient had a distinct preference for the named colour. No patient remembered any intra-operative events.

Anesthesia, Inhalation↗
PubMed1992

Pre-operative anxiety variables as possible predictors of post-operative stay in hospital.

The extent to which measures of pre-operative anxiety predict post-operative hospital stay, over and above what is predicted by biographical, medical status and post-operative anxiety variables, was examined in 81 cholecystectomy patients. Hierarchical multiple regression analysis revealed that patients who were older, had lower health status and suffered from wound infection, had a longer post-operative hospital stay than others. None of the pre-operative anxiety measures had a significant incremental value in the prediction of the post-operative hospital stay.

Anxiety↗
PubMed1991

Failure to demonstrate unconscious perception during balanced anaesthesia by postoperative motor response.

Eighty patients undergoing a standardized balanced anaesthesia were randomly assigned to either a suggestion group (N = 38) or a control group (N = 42), in a double-blind design. Anaesthesia was maintained with nitrous oxide, enflurane and fentanyl. Patients in the suggestion group were played seaside sounds, interrupted by statements of the importance of touching the ear during a postoperative visit, by means of a prerecorded audiotape and headphones. Tapes containing these suggestions were played from 30 min after the first incision, for a duration of 15 min. Patients in the control group were only played seaside sounds. There were no significant differences between the groups in either the number of patients touching their ears postoperatively or the number and duration of ear touches.

Adult↗
PubMed1991

Preoperative anxiety and motives for surgery.

Preoperative anxiety was assessed in 20 patients undergoing surgery for esthetic reasons and 20 other surgical patients. Patients with plastic surgery reported significantly less anxiety than patients with general surgery, as measured by the State-Trait Anxiety Inventory.

Adult↗
PubMed1990

Shortening the State-Trait Anxiety Inventory.

Questionnaires that are used in studies with severely patients should be as short as possible. Abridged versions of existing inventories are very practical in these instances. The answers of 444 subjects in three samples (cancer patients, medical students, surgical patients) were used to investigate the possibility of constructing short and reliable versions of the scales of the State and Trait Anxiety Inventory. A stepwise regression procedure showed the possibility to reliably predict the total score of the unabridged versions by means of weighted sums of eight items for each scale. Omission of weights did not lead to substantial loss of information. Cronbach's alpha of the State-scale decreased from 0.93 to about 0.85 for different combinations of items and from 0.91 to about 0.82 for combinations of eight items of the Trait-scale. The relationship between both scales was only slightly modified by the shortening procedure.

Adolescent↗
PubMed1989

Detection of lacunar infarction in brain CT-scans: no evidence of bias from accompanying patient information.

Interobserver agreement in assessing brain CT-scans is, in general, high. The extent, however, to which such agreement is caused by bias through knowledge of other clinical details remains uncertain. The hypothesis that observers are somehow prejudiced before assessing ambiguous CT-scans in this particular situation was tested. Sixteen neurologists and 16 radiologists volunteered to interpret two ambiguous brain CT-scans, with regard to the presence or absence of a lacunar infarct in the region of the internal capsule. The scans were accompanied by "patient" information that was or was not suggestive of a stroke. These scans were camouflaged by a variety of other scans, to be assessed in the same way, to mask the purpose of the study. It was assumed that the observers, in their assessments of the scans, would somehow let their ratings of the likelihood of a lacunar infarction in or near the internal capsule be subject to the accompanying information. Results showed lower ratings produced by neurologists (i.e., less likelihood of an infarction) than by radiologists in the majority of all assessments, but no bias by the accompanying information.

Cerebral Infarction↗