The effects of age and alcohol intoxication on simulated driving performance, awareness and self-restraint.
(9/1787)
AIMS: To investigate whether, compared with middle-aged men (aged 30-50), older men (age > or =60) (i) perform more poorly on a driving simulator and (ii) are more sensitive to the effects of ethanol in terms of blood alcohol concentration (BAC) and driving performance, but more aware of their driving difficulties, and therefore exercise better driving judgement. METHODS: 14 Healthy middle-aged men (mean age 36 years) were compared with 14 healthy older men (mean age 69 years) on an interactive driving simulator, while sober and while legally intoxicated (BAC >80 mg/dl). RESULTS: Older age was associated with poorer driving performance on the simulator. While sober, older men exhibited more improper braking, slower driving, greater speed variability, fewer appropriate full stops and more crashes, and spent more time executing left turns (across oncoming traffic); all values < or =0.02. BACs > or =80 mg/dl were associated with impaired driving, with more inappropriate braking, fewer appropriate full stops and more time executing left turns (all values > or =0.02) and trends towards more speed variability, more low speed collisions and more wrong turns (values <0.1). However, similar ethanol consumption did not produce higher peak BAC or more driving impairments in older drivers. While there were no differences between age groups in terms of awareness of intoxication or driving difficulties, older men were unwilling to drive while legally intoxicated because of fear of physical injury, whereas middle-aged men were more likely to avoid driving when intoxicated due to fear of legal ramifications. CONCLUSION: While both age and legal intoxication affected driving performance, older men were no more sensitive to ethanol in terms of peak BACs, driving performance or awareness/judgement than middle-aged men. (+info)
Sedation depends on the level of sensory block induced by spinal anaesthesia.
(10/1787)
We have investigated the relationship between the extent of spinal block and occurrence of sedation. In a first series of 43 patients, the distribution of sedation score (measured on the Ramsey scale) was related to the extent of spinal block (pinprick). In a second series of 33 patients, the relationship between sedation score and spinal block persisted after injection of midazolam 1 mg. This study confirmed that high spinal block was associated with increased sedation. (+info)
Emotional status after right vs. left temporal lobectomy.
(11/1787)
Nineteen temporal lobectomy patients with epilepsy were evaluated (11 right and 8 left) with a brief questionnaire that addressed: (1) General Happiness; (2) Depression; (3) Anxiety; (4) Impulse Control; and (5) Socialization. The patients with left temporal lobectomy reported increases in depression and decreases in socialization compared with the right temporal lobectomy patients after surgery. Furthermore although the right temporal lobectomy patients reported increases in general happiness, no changes in general happiness were reported by the left temporal lobectomy patients. The present study supported the idea that an increased negative affect is associated with left rather than right temporal lobectomy. This is consistent with a model of negative emotional valence when the right hemisphere dominates awareness. (+info)
Barriers to guideline adherence. Based on a presentation by Michael Cabana, MD.
(12/1787)
Successful implementation of the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-VI) should improve quality of care by decreasing inappropriate variation and by disseminating new advances to everyday practice. A key component of this process is physician adherence to JNC-VI guidelines. However several reports in the literature show a discrepancy between hypertension guidelines and actual practice. The factors that influence physician behavior change and optimal use of practice guidelines are poorly understood. A combined model that uses the Awareness-to-Adherence Model and Social Cognitive Theory identifies five sequential steps that lead to adherence to a guideline--awareness, agreement, self-efficacy, outcome expectancy, and presence of a cueing mechanism. Barriers to implementation may occur at any of these steps and can be identified with this model. Programs can then be designed to overcome specific barriers. By conceptualizing the underlying issues in physician adherence, the combined model should be useful to guideline developers, practice directors, and health services researchers. (+info)
Interactions of prefrontal cortex in relation to awareness in sensory learning.
(13/1787)
In an associative learning paradigm, human subjects could be divided based on whether they were aware that one tone predicted a visual event and another did not. Only aware subjects acquired a differential behavioral response to the tones. Regional cerebral blood flow in left prefrontal cortex showed learning-related changes only in aware subjects. Left prefrontal cortex also showed changes in functional connectivity with contralateral prefrontal cortex, sensory association cortices, and cerebellum. Several of the interacting areas correlated with aware subjects' behavior. These results suggest cerebral processes underlying awareness are mediated through interactions of large-scale neurocognitive systems. (+info)
Blood glucose awareness training and epinephrine responses to hypoglycemia during intensive treatment in type 1 diabetes.
(14/1787)
OBJECTIVE: To determine the effect of blood glucose awareness training (BGAT) on epinephrine and symptom responses to hypoglycemia in patients with type 1 diabetes enrolled in an intensive diabetes treatment (IDT) program. RESEARCH DESIGN AND METHODS: A total of 47 subjects with uncomplicated diabetes (duration 9 +/- 3 years: HbA1c 9.0 +/- 1.2%; reference range 4-6%) enrolled in a 4-month outpatient IDT program were randomized to classes in BGAT (n = 25) (BGAT group) or cholesterol awareness (n = 22) (control group). Subjects underwent stepped hypoglycemic clamp studies before and at completion of IDT. Plasma glucose was lowered from 6.7 mmol/l (baseline) to 4.4, 3.9, 3.3, 2.8, and 2.2 mmol/l over 190 min. Symptoms, counterregulatory hormones, and ability of the subject to estimate their glucose level were assessed at each plateau. At home, subjects used a handheld computer to first estimate and then measure and record blood glucose levels for 70 trials over a 4-week period immediately before IDT and again immediately following the educational intervention. RESULTS: HbA1c decreased in both BGAT group (9.1 +/- 1.4 to 7.9 +/- 1.1%; P < 0.001) and control group (9.0 +/- 1.1 to 7.8 +/- 0.8%; P < 0.001) (NS between groups). Frequency of hypoglycemia (< 3.9 mmol/l) increased in both groups, from 0.45 +/- 0.06 to 0.69 +/- 0.07 episodes per day (P < 0.001) in the BGAT group and from 0.50 +/- 0.08 to 0.68 +/- 0.06 episodes per day (P < 0.05) in the control group NS between groups). Epinephrine responses after IDT were greater in the BGAT group (repeated measure analysis of variance [ANOVA], F = 3.5, P < 0.05). A separate analysis of subjects n = 26) most at risk for hypoglycemia (HbA1c after IDT < 7.8% or an HbA1c improvement of > 2 percentage points) showed that frequency of hypoglycemia increased in both the groups: from 0.50 +/- 0.09 to 0.80 +/- 0.11 episodes per day (P < 0.01) in the BGAT group (n = 14) and from 0.43 +/- 0.11 to 0.75 +/- 0.07 episodes per day (P < 0.05) in the control group (n = 12) (NS between groups). However, the epinephrine response in control subjects decreased with IDT while the response in the BGAT subjects was preserved (repeated measure ANOVA, F = 4.4, P < 0.02). CONCLUSIONS: BGAT is a useful intervention to decrease blunting of counterregulatory responses associated with improved glycemic control and may modify the severity of hypoglycemia associated with improved glycemic control in type 1 diabetes. (+info)
Differential pupillary constriction and awareness in the absence of striate cortex.
(15/1787)
The fact that the pupil constricts differentially to visual stimuli in the absence of changes in light energy makes it a valuable tool for studying normal function as well as residual capacity in hemianopic subjects. When pupillometrically effective stimuli such as equiluminant gratings or coloured patches with an abrupt onset and offset are presented to the 'blind' hemifield, a hemianopic subject with damage largely restricted to striate cortex (V1) sometimes reports being 'aware' of the transient onset/offset, although without 'seeing' as such. The question addressed here is whether the pupil still responds in the condition of blindsight in its strict sense--i.e. discriminative capacity in the absence of acknowledged awareness--when stimuli are deliberately designed to eliminate awareness. This was accomplished by making stimulus onset and offset slow and gradual. The results with a well-studied hemianope, G.Y., demonstrate that there is still a pupillary constriction to isoluminant achromatic gratings and red-coloured stimuli, although reduced in size, in the absence of acknowledged awareness. (+info)
Distribution of rest days in 12 hour shift systems: impacts on health, wellbeing, and on shift alertness.
(16/1787)
OBJECTIVES: To investigate of the effects of distribution of rest days in 12 hour shift systems. Although several studies have examined the effects of compressing work schedules by comparing 8 and 12 hour shift systems, there is little published research examining the various forms of 12 hour shift system. METHODS: An abridged version of the standard shiftwork index which included retrospective alertness ratings was completed by a large sample of industrial shiftworkers. The respondents worked 12 hour shift systems that either did or did not incorporate breaks of > 24 hours between the blocks of day and night shifts. For the purposes of the analysis, each of these two groups were further subdivided into those who started their morning shift at 0600 and those who started at 0700. RESULTS: Systems which incorporated rest days between the day and night shifts were associated with slightly higher levels of on shift alertness, slightly lower levels of chronic fatigue, along with longer sleep durations when working night shifts and between rest days. Early changeovers were associated with shorter night sleeps between successive day shifts, but longer and less disturbed day sleeps between night shifts. These effects of changeover time were broadly in agreement with previous research findings. CONCLUSIONS: The distribution of rest days in 12 hour shift systems had only limited effects on the outcome measures, although the few modest differences that were found favoured systems which incorporated rest days between the day and night shifts. It is conceded that the design of the study may have obscured some subtle differences between the shift systems. Nevertheless, it is concluded that the impact of distribution of rest days seems to be minor relative to previously found effects of other features of shift systems--for example, shift duration. (+info)