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Biomedical subjects

G Fletcher

Publications and source records attributed to G Fletcher.

At least 19 recordsLinked to original sources
PubMed2004

Patient maintained sedation for colonoscopy using a target controlled infusion of propofol.

In this study, we evaluated safety and recovery using a patient maintained, target controlled infusion of propofol for sedation in 20 patients undergoing colonoscopy. Using a handset with a two-minute lockout interval, patients could make 0.2 micro g.ml(-1) increments to an initial target plasma concentration of 1 micro g.ml(-1) up to a maximum 4.5 micro g.ml(-1). Four patients became oversedated but required no airway or circulatory interventions. Subjects had a significant reduction in mean (SD) heart rate: 78.7 (15) vs. 69.8 (13.5) (p < 0.001) and in systolic blood pressure 121.1 (13.2) mmHg vs. 96.5 (8.6) mmHg (p < 0.001). Choice reaction time testing 15 min after colonoscopy showed a significant median (IQR [range]) rise of 162 (- 16, 383.3 [-199-859]) ms (p < 0.05). Six patients had faster reaction times postcolonoscopy. All patients denied unpleasant recall and were satisfied with the system. Although oversedation was a problem in this model, we conclude that patient maintained propofol sedation could be possible for colonoscopy.

Adult↗
PubMed2003

Anaesthetists' attitudes to teamwork and safety.

A questionnaire survey was conducted with 222 anaesthetists from 11 Scottish hospitals to measure their attitudes towards human and organisational factors that can have an impact on effective team performance and consequently on patient safety. A customised version of the Operating Room Management Attitude Questionnaire (ORMAQ) was used. This measures attitudes to leadership, communication, teamwork, stress and fatigue, work values, human error and organisational climate. The respondents generally demonstrated positive attitudes towards the interpersonal aspects of their work, such as team behaviours and they recognised the importance of communication skills, such as assertiveness. However, the results suggest that some anaesthetists do not fully appreciate the debilitating effects of stress and fatigue on performance. Their responses were comparable with (and slightly more favourable than) those reported in previous ORMAQ surveys of anaesthetists and surgeons in other countries.

Anesthesia↗
PubMed2003

Clinical effects of air filters in homes of asthmatic adults sensitized and exposed to pet allergens.

BACKGROUND: Despite medical advice, many pet-allergic asthma sufferers refuse to remove the pet to which they are sensitized from their home. OBJECTIVE: We aimed to assess the clinical effects of air cleaners in the homes of adult asthma patients sensitized and exposed to cats and/or dogs. METHODS: We performed a randomized, parallel-group study of 30 asthmatic adults sensitized to and sharing a home with cats or dogs. The effects of placing air cleaners in the living room and bedroom for 12 months and using high efficiency particulate air filter vacuum cleaners (active group) were compared with using these vacuum cleaners alone (control group). Measures of airway responsiveness, treatment requirement, lung function, peak flow, reservoir and airborne allergen were recorded before, during and after the interventions. A beneficial clinical response was assessed in terms of a 'combined asthma outcome'. This was defined as a two or more doubling dose improvement in bronchial hyper-reactivity to histamine and/or a reduction in treatment requirement of at least one step change on the British Thoracic Society guidelines for asthma treatment. RESULTS: A beneficial clinical response was observed in 10/15 subjects in the active group compared with 3/15 in the control group after 12 months intervention (P = 0.01). No significant differences between the active and control groups were detected for changes in measures of lung function, reservoir pet allergen and airborne pet allergen during the study. CONCLUSION: Whilst the study design has not allowed complete exclusion of a placebo effect, we believe that this pragmatic study of adult asthmatic patients sensitized and exposed to pets resulted in a small, but significant improvement in combined asthma outcome.

Adult↗
PubMed2003

Anaesthetists' Non-Technical Skills (ANTS): evaluation of a behavioural marker system.

BACKGROUND: Non-technical skills are critical for good anaesthetic practice but are not addressed explicitly in normal training. Realization of the need to train and assess these skills is growing, but these activities must be based on properly developed skills frameworks and validated measurement tools. A prototype behavioural marker system was developed using human factors research techniques. The aim of this study was to conduct an experimental evaluation to establish its basic psychometric properties and usability. METHOD: The Anaesthetists' Non-Technical Skills (ANTS) system prototype comprises four skill categories (task management, team working, situation awareness, and decision making) divided into 15 elements, each with example behaviours. To investigate its experimental validity, reliably and usability, 50 consultant anaesthetists were trained to use the ANTS system. They were asked to rate the behaviour of a target anaesthetist using the prototype system in eight videos of simulated anaesthetic scenarios. Data were collected from the ratings forms and an evaluation questionnaire. RESULTS: The results showed that the system is complete, and that the skills are observable and can be rated with acceptable levels of agreement and accuracy. The internal consistency of the system appeared sound, and responses regarding usability were very positive. CONCLUSIONS: The findings of the evaluation indicated that the ANTS system has a satisfactory level of validity, reliability and usability in an experimental setting, provided users receive adequate training. It is now ready to be tested in real training environments, so that full guidelines can be developed for its integration into the anaesthetic curriculum.

Adult↗
PubMed2000

A controlled trial of cardiac rehabilitation in the home setting using electrocardiographic and voice transtelephonic monitoring.

OBJECTIVE: The goal of this study was to compare the effectiveness of home-based, transtelephonically monitored cardiac rehabilitation with standard, on-site, supervised cardiac rehabilitation. BACKGROUND: Participation in cardiac rehabilitation has been demonstrated to increase exercise capacity, decrease cardiovascular symptoms, improve psychosocial status, and decrease total and cardiovascular mortality rates in patients with coronary heart disease. Because of multiple factors, national overall participation is only at 15% of eligible patients. METHODS: Effects of a 3-month home-based, transtelephonically monitored rehabilitation program (n = 83 patients) with simultaneous voice and electrocardiographic transmission to a centrally located nurse coordinator were compared with effects of a standard on-site rehabilitation program (n = 50 patients). The study design was a multicenter, controlled trial. Primary outcome variables were peak aerobic capacity and quality of life, as measured by the Health Status Questionnaire. RESULTS: Patients in the home-based monitoring program increased peak aerobic capacity to a similar degree as patients who exercised on site (18% vs 23%). Quality of life domains of physical functioning, social functioning, physical role limitations, emotional role limitations, bodily pain, and energy/fatigue improved similarly in both groups. There were no circulatory arrests or other major exercise-related medical events in either group. A total of 3100 hours of home exercise were transtelephonically monitored. CONCLUSIONS: Patients with coronary heart disease can effectively participate in home-based, monitored cardiac rehabilitation, with exercise and quality of life improvements comparable to those demonstrated at on-site programs.

Age Factors↗
PubMed1999

Liver-specific and seasonal expression of transgenic Atlantic salmon harboring the winter flounder antifreeze protein gene.

We have analyzed the inheritance and expression of a line of transgenic salmon harboring the antifreeze protein gene from the winter flounder. The genomic clone 2A-7 coding for a major liver-type antifreeze protein gene (wflAFP-6) was integrated into the salmon genome. From a transgenic founder (#1469), an F3 generation was produced. In this study, southern blot analysis showed that only one copy of the antifreeze protein transgene was integrated into a unique site in F3 transgenic fish. The integration site was cloned and characterized. Northern analysis indicated that the antifreeze protein mRNA was only expressed in the liver and showed seasonal variation. All of the F3 offspring contained similar levels of the antifreeze protein precursor protein in the sera and the sera of these offspring showed a characteristic hexagonal ice crystal pattern indicating the presence of antifreeze activity. In addition, the antifreeze protein precursor protein level was found to vary with the season, being highest in the month of November and lowest in May. This study had demonstrated a tissue-specific and stable expression of the antifreeze protein transgene in the F3 generation of the transgenic salmon 1469 line.

Animals↗
PubMed1998

Reliability of linear alveolar bone loss measurements of mandibular posterior teeth from digitized bitewing radiographs.

Observer reliability in performing linear measurements between the cementoenamel junction and alveolar crest was determined for mandibular posterior teeth from digitized clinical bitewing radiographs acquired during recall examinations. 6 measurements (corresponding to traditional probing measurements) were made per tooth by 3 observers. Mesial and distal measurements made to the most coronal aspects of the alveolar crest were the most reliable and least biased. As was anticipated, intra-observer reliability was better than inter-observer reliability although the 3 observers of our study were able to detect a significant mean change (0.1 mm, p<0.0001) in alveolar bone height over a 1-year period for 10 patients. For our most reliable and unbiased measurements (mesial measurements to the alveolar crest), a change of 0.54 mm (90th percentile) would be required to indicate change at a site from one time to the next. Based on the reliability of our digital radiographic measurements, with the alpha error rate set at 0.05 and beta at 0.20, a difference in alveolar bone height of 0.3 mm could be detected with a patient sample size of between 13 (best case) and 54 (worst case).

Alveolar Bone Loss↗
PubMed1997

When to start cholesterol-lowering therapy in patients with coronary heart disease. A statement for healthcare professionals from the American Heart Association Task Force on Risk Reduction.

At present a large number of patients with atherosclerotic disease are not receiving aggressive cholesterol-lowering therapy. Consequently they are being deprived of a cost-effective, risk-reducing treatment. Every physician who treats patients with clinical atherosclerotic disease should become fully informed about the results of cholesterol-lowering trials in patients at high risk. All physicians who care for high-risk patients should take responsibility for cholesterol management, including primary care physicians and cardiovascular specialists. Highly effective and generally safe drugs for cholesterol lowering are available. The benefits of therapy for reducing recurrent CHD and prolonging life are considerable. There is no justification for unduly delaying institution of therapy for the majority of patients. The many advantages of nonpharmaceutical therapy call for its use in almost all patients, but drug treatment should not be postponed if the target for LDL cholesterol lowering (< or = 100 mg/dL) is unlikely to be achieved in the near term by a nonpharmaceutical approach alone. The view that patients with CHD or other forms of atherosclerotic disease do not receive substantial clinical benefits from aggressive cholesterol-lowering therapy is no longer warranted. Intensive cholesterol reduction, initiated immediately, has the potential to significantly reduce both morbidity and mortality. Cholesterol-lowering therapy thus should become a routine part of clinical management to reduce risk of future coronary events and to prolong life in patients with CHD or other forms of atherosclerotic disease.

Anticholesteremic Agents↗
PubMed1997

A comparison of the response of storage phosphor and film radiography to small variations in X-ray exposure.

OBJECTIVES: To determine the response to small repeated variations in X-ray exposure of storage phosphor (SP) plates compared with Ektaspeed Plus dental film. METHODS: Exposure of SP plates and Ektaspeed Plus dental film was varied within a small range [8.62 microC kg-1 to 9.03 microC kg-1, (5%)]. Radiographs were digitized and SP plates read with a laser-based scanner. Nested analysis of variance, analysis of covariance, and regression analysis were used to test the relationship between exposure and the resulting signal. RESULTS: The relationship between exposure and signal for digital images of film radiographs was not significant whereas the corresponding relationship for SP images was highly significant (P < 0.001, R2 = 0.44). CONCLUSIONS: Over the narrow range of X-ray exposures studied there was a significant direct linear relationship between exposure and digital gray-scale values for SP images but not for digital images of Ektaspeed Plus films.

Analysis of Variance↗
PubMed1995

The special study module: a novel approach to undergraduate teaching in occupational medicine.

Difficulties in teaching occupational medicine to undergraduates stem from the reduced availability of teaching time and the perception of the specialty. Recent changes in the General Medical Council curricular framework have permitted the development of a special study module (options course) in occupational medicine, in which a small number of motivated undergraduates elected to participate and which was adequately resourced. This course laid particular emphasis on changing students' attitudes towards the specialty, self-learning techniques, problem-solving and other skills such as workplace assessment. The objectives, content and teaching methods of the course are described, as is a preliminary evaluation. It is suggested that other medical schools should adopt and refine this approach in order to improve the quality of undergraduate training in at least a proportion of the output of medical schools.

Education, Medical, Undergraduate↗
PubMed1993

Cryogenic protection of oocytes with antifreeze proteins.

Proteins belonging to a family of compounds known as "antifreeze proteins" interact with oocytes and protect the oolemma from damage at cryogenic temperatures. Experiments were performed with pig oocytes rapidly cooled to cryogenic temperatures in vitrifying solutions with and without antifreeze proteins. Four different types of antifreeze polypeptides and glycoproteins were tested. The integrity of the oolemma was examined with Fluorescein Diacetate (FDA) staining and morphological examinations. Results show that the pig oocyte oolemma is a primary site of injury during exposure to low temperatures and that all the different proteins have a similar ability to interact with and protect the oolemma. Our results may be important in developing solutions for long-term preservation of oocytes at cryogenic temperatures (cryopreservation).

Animals↗