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Biomedical subjects

A J Lloyd

Publications and source records attributed to A J Lloyd.

At least 19 recordsLinked to original sources

Impairment of sustained attention after major gynaecological surgery.

BACKGROUND AND OBJECTIVES: The sustained attention to response task (SART) test is a sensitive indicator of deficits in sustained attention and is simple to perform. Sustained attention is impaired for a short period after minor surgery under general anaesthesia but the magnitude and duration of this effect after major surgery is unknown. We used the SART test to investigate deficits in sustained attention in patients undergoing major surgery under general anaesthesia. METHODS: The SART test was completed before surgery and at 24, 48 and 72 h postoperatively by 20 ASA I-II female patients (mean age 48.6 yr) undergoing total abdominal hysterectomy under general anaesthesia. It was also completed by 20 age-matched female controls at similar time intervals to evaluate the effect of repeated test performance. RESULTS: There was a significant (P < 0.05) interaction between the groups in number of errors made (a measure of sustained attention deficit). The number of errors decreased in control subjects on repeated performance of the SART test but remained unchanged in patients undergoing total abdominal hysterectomy. The differences between groups remained significant after 72 h (P < 0.05). Patients' overall response times slowed significantly at 24-48 h (P < 0.05), but this recovered by 72 h after surgery. In contrast, overall response times in the control group tended to accelerate on repeated performance of the SART. CONCLUSIONS: The results of this study suggest that 72 h following major surgery patients have deficits in sustained attention compared with controls. Control subjects demonstrated a marked learning effect on repeated test performance compared with patients.

Anesthesia Recovery Period↗

Using the Sustained Attention to Response Test to detect cognitive dysfunction after day case surgery.

BACKGROUND AND OBJECTIVE: Cognitive dysfunction has been reported after general anaesthesia, but its assessment is time consuming and difficult to evaluate. This pilot study assessed the feasibility of using the Sustained Attention to Response Test to assess 35 ASA I-II adults (mean age 31.6 yr) undergoing day case surgery under general anaesthesia, and 25 ASA I-II adults (mean age 47.8 yr) undergoing day case surgery under local anaesthesia. METHODS: The Sustained Attention to Response Test was performed before surgery and repeated 2 h after surgery. RESULTS: When patients repeated the test after surgery under local anaesthesia, the number of incorrect responses increased, but reaction times decreased (P < 0.05). Following general anaesthesia, the number of incorrect responses increased (P < 0.05), but reaction times remained unchanged. CONCLUSIONS: The Sustained Attention to Response Test is simple to administer and may be a useful tool when comparing different anaesthetic techniques and their effects on postoperative deficits in sustained attention.

Adult↗

Dementia with Lewy bodies and AD are not associated with occipital lobe atrophy on MRI.

Dementia with Lewy bodies (DLB) is associated with occipital changes in blood flow and metabolism, but structural changes in this region have not previously been assessed. The authors performed volumetric MRI measurement of the occipital lobe blind to the diagnosis in 23 subjects with DLB, 25 with AD, and 24 age-matched control subjects. There were no significant differences between groups in occipital lobe volume. The authors conclude gross structural changes in the occipital lobe do not occur in patients with mild to moderate DLB or AD.

Aged↗

Dimeric pig heart succinate-coenzyme A transferase uses only one subunit to support catalysis.

Pig heart succinate-coenzyme A transferase (succinyl-coenzyme A: 3-oxoacid coenzyme A transferase; E. C. 2.8.3.5.), a dimeric enzyme purified by affinity chromatography on Procion Blue MX-2G Sepharose, reacts with acetoacetyl-coenzyme A to form a covalent enzyme-coenzyme A thiolester intermediate in which the active site glutamate (E344) of both subunits each forms thiolester links with coenzyme A. Reaction of this dimeric enzyme-coenzyme A species with sodium borohydride leads to inactivation of the enzyme and reduction of the thiolester on both subunits to the corresponding enzyme alcohol, as judged by electrospray mass spectrometry. Reaction of the dimeric enzyme-coenzyme A intermediate with either succinate or acetoacetate, however, results in only one-half of the coenzyme A being transferred to the acceptor carboxylate to form either succinyl-coenzyme A or acetoacetyl-coenzyme A. Reaction of this latter enzyme species with borohydride caused no loss of enzyme activity despite the reduction of the remaining half of the enzyme-coenzyme A thiolester to the enzyme alcohol. That this catalytic asymmetry existed between subunits within the same enzyme dimer was demonstrated by showing that the enzyme species, created by successive reaction with acetoacetyl-coenzyme A and succinate, bound to Blue MX-2G Sepharose through the remaining available active site and could be eluted as a single chromatographic species by succinyl-coenzyme A. It is concluded that while both of the subunits of the succinate-coenzyme A transferase dimer are able to form enzyme-coenzyme A thiolester intermediates, only one subunit is competent to transfer the coenzyme A moiety to a carboxylic acid acceptor to form the new acyl-coenzyme A product. The possible structural basis for this catalytic asymmetry and its mechanistic implications are discussed.

Acyl Coenzyme A↗

Depression in late life, cognitive decline and white matter pathology in two clinico-pathologically investigated cases.

CASE REPORTS: We report two cases of late life depression who became progressively more resistant to treatment, developed cognitive impairment, and began to exhibit neurological abnormalities and evidence of vascular disease. A discussion of the clinical features of the cases is accompanied by reports of neuropathology and neuroimaging findings. Extensive white matter lesions were present on computed tomography in both patients, and basal ganglia infarcts were seen in one. Neuropathology revealed evidence of cerebral atrophy, demyelination and white matter lesions in addition to cerebrovascular and generalised vascular disease. Neither patient exhibited Alzheimer pathology outwith the norm for their age. We believe this to be the first report of neuropathological findings in depression with white matter changes. LITERATURE REVIEW: The pathological basis of white matter lesions and their relationship to depression, its age of onset and clinical features is addressed in relation to the cases described. Pathological investigation of white matter lesions has not previously been carried out in depression and hypotheses regarding their nature in this illness are based on extrapolation from research in a variety of other disorders. The association of depression with vascular risk factors is considered, as is the relationship between depression and cognitive deficits. There is a need for further investigation in this area.

Age of Onset↗

Patients' thromboembolic potential between bilateral carotid endarterectomies remains stable over time.

OBJECTIVES: There is limited understanding of the reasons underlying post-CEA carotid thrombosis. Clinicians have often implicated operative technique, such as patch type or shunting, however the evidence for this is limited. We have studied whether it is the patients themselves who are prothrombotic, by studying the rates of emboli detection in patients undergoing bilateral CEAs at separate time points. MATERIALS AND METHODS: Sixteen patients (3 women) underwent CEA during the study period, all of whom were taking aspirin. CEA was performed in a standardised manner throughout the study. All patients were monitored for 3 h postoperatively using a 2 MHz fixed head probe. RESULTS: Those patients who had no emboli detected on TCD after the first operation, had a mean of 2.5 emboli after the second operation. Patients with emboli after the first operation had a mean of 41.3 emboli after the second CEA (MWU test, p=0.02). The dose of aspirin administered did not affect emboli rates. Correlation of the number of emboli detected after the first CEA with the second CEA gave a significant correlation ( p=0.038). CONCLUSIONS: There appear to be factors relating to the patient that places some individuals at an increased risk of thrombotic stroke. Further elucidation of these factors may enable more effective, targeted therapy to be applied in the prevention of arterial thrombosis.

Aspirin↗

The extent of patients' understanding of the risk of treatments.

The scientific understanding of how people perceive and code risks and then use this information in decision making has progressed greatly in the last 20 years. There is considerable evidence that people employ simplifying heuristics in judgement and decision making. These heuristics may lead to bias in how people interpret information. However, much of our understanding of risk perception is based on laboratory studies. It is much less clear whether risk perception in the real world (as in the case of medical treatments) exhibits the same patterns and biases. This paper reviews the published literature on risk perception in patients who face substantial treatment risks. It examines how accurate patients' perception of risk is, what factors affect the perception of risk, and several possible explanations for why patients' risk perception is not always accurate.

Bias↗

Kawasaki disease: is it caused by an infectious agent?

Kawasaki disease (KD) is an acute systemic febrile illness of unknown aetiology, predominantly affecting children under five years of age. Initially described in 1967 by Tomisaku Kawasaki, it is now the most common cause of acquired heart disease in children in the developed world. Although normally self-limiting, KD is associated with a range of complications, the most important of which is the development of life-threatening coronary artery abnormalities. Here, we examine the evidence supporting the concept that KD is caused by an infectious agent. Various infectious agents--including bacterial, viral and Rickettsial organisms--have been implicated as potential causes, as have certain immunological agents such as bacterial toxin-mediated superantigens, allergens such as anionic detergents and house-dust mites, and some chemicals (including heavy metals). Following extensive research, however, no links between any of these individual agents and the disease have been established irrefutably. Despite this, most of the epidemiological and immunological evidence currently available indicates that the causative agent is most likely to be infectious in nature; and additional evidence highlights the likelihood that development of KD is multifactorial in nature, requiring certain genetic and immunological factors, and possibly a vector.

Bacterial Infections↗

Comparison of cognitive function and quality of life after endovascular or conventional aortic aneurysm repair.

INTRODUCTION: The long-term effects of endovascular aortic aneurysm repair on cognitive function and quality of life are not known. METHODS: The cognitive function and quality of life of 82 patients undergoing aortic aneurysm repair (34 endovascular and 48 conventional procedures) were assessed before and 6 months after operation. Cognitive function was quantified using a battery of psychometric tests. Quality of life was assessed with the Medical Outcomes Short Form 36 (SF-36) questionnaire. RESULTS: Data at 6 months were available for 78 per cent of patients. As a group the patients showed a significant decline on one cognitive function test (visual search) and on two domains of the SF-36 (physical function and vitality) when they were reassessed. There were no significant differences between patients undergoing endovascular or conventional aneurysm repair after 6 months in cognitive function or quality of life. CONCLUSION: Endovascular aneurysm surgery had a similar impact on health-related quality of life and cognitive function compared with conventional aneurysm repair. Patients in both groups demonstrated a significant decline in cognitive function.

Aged↗

Transcranial Doppler-directed Dextran-40 therapy is a cost-effective method of preventing carotid thrombosis after carotid endarterectomy.

OBJECTIVES: perioperative stroke reduces the clinical effectiveness of carotid endarterectomy (CEA). Postoperative thrombotic stroke may be reduced in incidence by the use of transcranial Doppler-directed Dextran-40 therapy. This programme requires the purchase of additional equipment and employment of more staff. This study examined whether this additional financial outlay was cost-effective in terms of saving expenditure by preventing postoperative thrombotic stroke. MATERIALS AND METHODS: data was collected prospectively on a series of 600 consecutive CEAs. The costs of the monitoring programme were analysed over 1- and 5-year periods. Formulae were derived allowing other units to calculate whether this technique will be cost-effective for them. RESULTS: after the introduction of TCD monitoring the postoperative thrombotic stroke rate fell from 2.7% to 0% (8 strokes prevented). Our local unit cost for the treatment of stroke was 25,702 pounds. After allowing for the additional costs of the monitoring programme, we calculate that postoperative TCD has saved 171,393 pounds. CONCLUSIONS: postoperative TCD monitoring is a clinically effective and also cost-effective method of reducing the stroke rate associated with CEA. For units performing more than 50 CEAs per year who experience occasional postoperative carotid thrombosis, its introduction should be considered.

Aged↗

The use of aromatherapy in intrapartum midwifery practice an observational study.

The authors report the process and results of an evaluation of a midwifery aromatherapy service for mothers in labour: This study of 8058 mothers in childbirth, is the largest research initiative in the use of aromatherapy within a health-care setting. The study involved a wide range of participants, from mothers who experienced a low risk, spontaneous labour and birth, to those whose labour was induced, and those who had vaginal operative delivery and Caesarean section. The study-took place over a period of 8 years, which enabled a more challenging test of the effect of aromatherapy on intrapartum midwifery practice and outcomes. In the study a total of 10 essential oils were used, plus a carrier oil, which were administered to the participants via skin absorption and inhalation. The study found little direct evidence that the practice of aromatherapy per se reduces the need for pain relief during labour, or the incidence of operative delivery. But a key finding of this study suggests that two essential oils, clary sage and chamomile are effective in alleviating pain. The evidence from this study suggests that aromatherapy can be effective in reducing maternal anxiety, fear and/or pain during labour. The use of aromatherapy appeared to facilitate a further reduction in the use of systemic opioids in the study centre, from 6% in 1990 to 0.4% in 1997 (per woman). Aromatherapy is an inexpensive care option. In 1997 when 1592 mothers used aromatherapy, the total cost was 769.17 Pounds. The study reports a minimal incidence of associated symptoms. Out of 8058 mothers, 1% (100) recorded an associated symptom. These were mild in nature. The successful model of integrated practice that this aromatherapy study presents, offers a useful example for other units to consider.

Adult↗

An investigation into the use of aromatherapy in intrapartum midwifery practice.

OBJECTIVE: The principal aim of the study was to examine the contribution of aromatherapy to the promotion of maternal comfort during labor and as a tool to improve the quality of midwifery care. DESIGN: Evaluative study. SETTING: Delivery suite in a large British teaching hospital with approximately 6,500 deliveries per annum. SUBJECTS: A total of 8,058 mothers were evaluated between 1990 and 1998. INTERVENTIONS: Women were offered aromatherapy to relieve anxiety, pain, nausea and/or vomiting or to strengthen contractions. Routine data collected on the use of aromatherapy over the period were analyzed. Data from the unit audit were used to provide a comparison group of mothers not given aromatherapy (n = 15,799) from the study center. OUTCOME MEASURES: Outcome measures include mothers' ratings of effectiveness, outcomes of labor, use of pharmacologic pain relief, uptake of intravenous oxytocin, reported associated symptoms, and annual costs. RESULTS: The use of aromatherapy during childbirth was an increasingly popular care option with mothers and midwives. More than 50% of mothers rated it as helpful, and only 14% found it unhelpful. The use of aromatherapy was not confined to low-risk mothers. Sixty percent of the sample were primigravidae, and 32% overall had had their labor induced. The administration of aromatherapy in childbirth did appear to reduce the need for additional pain relief in a proportion of mothers. More than 8% of primigravidae and 18% of multigravidae used no conventional pain relief during labor after using essential oils. During the years of the study, the use of pethidine in the study center declined from 6% to 0.2% of women. The study also showed that aromatherapy may have the potential to augment labor contractions for women in dysfunctional labour. A very low number of associated adverse symptoms were reported (1%). CONCLUSION: This study represents a successful example of the integration of a complementary therapy into mainstream midwifery practice and forms a basis for future research.

Anxiety↗

Applied medical informatics and computing skills of students, residents, and faculty.

BACKGROUND AND OBJECTIVES: Little is known regarding the applied medical informatics and computing skills of family practice residents and faculty, yet such information is critical when planning a medical informatics curriculum. We conducted a survey at our institution to collect this information. METHODS: An applied medical informatics and computing skills survey was administered to 93 first-year medical students, 42 family practice residents, and 14 family medicine faculty. Responses were compared between groups before and after stratification by age and gender. RESULTS: A total of 92% of students, 100% of residents, and 79% of faculty responded. Faculty had the highest rate of computer ownership (91%), followed by students (86%) and family practice residents (79%). Students and interns had the highest overall confidence using computers, followed by faculty and then senior residents. Faculty, students, and junior residents were significantly more confident than senior residents in their ability to perform several specific tasks, such as conducting a MEDLINE search. Residents perceived lack of money and time as barriers to improving their skills. CONCLUSIONS: Current senior residents may require remedial training to graduate with the computer skills specified in curricular guidelines. While upcoming medical students and interns will demand more advanced training, faculty may not have the skills to provide it.

Adult↗

Comprehension of prosody in Parkinson's disease.

The evidence for a receptive prosodic loss in Parkinson's disease (PD) has remained inconclusive since the first reports in the early 1980s (Scott, Caird and Williams, 1984). The present study examined three aspects of comprehension in 11 PD patients and a group of age matched controls. Experiment 1 found no evidence of deficits in phonological discrimination or lexical access in the PD patients. Experiment 2 found that one patient (EA) was significantly impaired on a test of lexical stress discrimination. Experiment 3 examined the discrimination, comprehension and identification of utterance prosody. This experiment found that overall the PD patients were significantly impaired at the identification of utterance prosody. Patient TB was significantly worse than controls on the identification and comprehension of utterance prosody. The study has shown that PD patients can exhibit impairments in the comprehension of prosody and lexical stress. The evidence suggests that only some patients are impaired and the pattern of deficits can differ significantly.

Aged↗

Randomized study of carotid angioplasty and stenting versus carotid endarterectomy: a stopped trial.

BACKGROUND: Carotid angioplasty (CA) has been suggested to be a safer and more cost-effective alternative to carotid endarterectomy (CEA) in the management of symptomatic severe internal carotid artery (ICA) disease. METHODS: The study was conducted as a prospective consecutive randomized trial of CEA versus CA for symptomatic severe ICA disease in a university teaching hospital. All patients were assessed before and after surgery by a neurologist. The study consisted of 23 patients with focal carotid territory symptoms and severe ICA stenosis (> 70%) who were randomized to either CEA or CA. However, only 17 had received their allocated treatment before trial suspension. CEA with patching or CA with stenting were used as interventions. The main outcome measures were death or disabling or nondisabling stroke within 30 days. RESULTS: All 10 CEA operations proceeded without complication, but 5 of the 7 patients who underwent CA had a stroke (P=.0034), 3 of which were disabling at 30 days. CONCLUSIONS: After referral, the Data Monitoring Committee invoked the stopping rule and the trial was suspended. The investigators and the Ethics Committee subsequently concluded that the trial could not be restarted--even in an amended format-primarily because of problems with informed consent. We review many of the ethical dilemmas encountered in the performance of this study. If future trials do suggest a selected role for CA, it is essential that both the inclusion and the exclusion criteria are fully documented.

Aged↗