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Biomedical subjects

T Meagher

Publications and source records attributed to T Meagher.

16 recordsLinked to original sources

The acquisition of tacit knowledge in medical education: learning by doing.

AIM: This study was designed to assess medical school teachers' tacit knowledge of basic pedagogic principles and to explore the specific character of the knowledge base. METHODS: We developed a 50-item, multiple-choice question test based on important pedagogic principles, and classified all questions as requiring either declarative or procedural knowledge. A total of 72 medical teachers representing 5 different groups of clinicians and educators agreed to sit the test. RESULTS: Teachers in all 5 groups performed well on the test of tacit pedagogic knowledge but those with advanced education degrees, or local recognition as experts, performed best. All test takers performed best on questions requiring procedural knowledge. CONCLUSION: Medical teachers possess tacit knowledge of basic pedagogic principles. Superior test performance on questions requiring procedural knowledge is consistent with their working in a clinical environment characterised by repeated procedural activities.

Education, Medical↗

Admiral Lord Nelson's death: known and unknown--a historical review of the anatomy.

STUDY DESIGN: Reviewing documents about Lord Admiral Nelson's wound inflicted at the Battle of Trafalgar and studying the collected data in connection with ballistics and human anatomy. OBJECTIVES: Attempting to find out the actual cause of death of Lord Nelson as soon as 4 h postinjury by a musket ball. SETTING: United Kingdom. METHODS: (1) Review of the original report of Mr W Beatty, Lord Nelson's surgeon, on his examination of His Lordship's wound. (2) Investigating the course of the musket ball in connection with an atlas of human anatomy. (3) Investigating the course of the musket ball on a cadaver by RP (one of the authors). (4) Reviewing modern medical literature. RESULTS: The report of Mr Beatty suggested that division of a large branch of the pulmonary artery was the cause of Lord Nelson's early death. Assuming the left pulmonary artery was injured, anatomical studies based on atlases and dissection on a cadaver failed to support a simple straight-line course of the musket ball that could have divided the artery and damage the spinal cord on its path forward. CONCLUSION: The question remains open as to how the musket ball following a relatively straight-line trajectory by entering the body at the acromion, could have divided the left pulmonary artery and damaged the spinal cord later in its course. The mechanism needs further investigation.

Blood Vessels↗

Managing errors in radiology: a working model.

AIM: To develop a practical mechanism for reviewing reporting discrepancies as addressed in the Royal College of Radiologists publication "To err is human. The case for review of reporting discrepancies". MATERIALS AND METHODS: A regular meeting was developed, and has evolved, within the department to review discrepancies. Standard forms were devised for submission of cases as well as recording and classification of discrepancies. This has resulted in availability of figures that can be audited annually. RESULTS: Eighty-one cases involving error were reviewed over a 12-month period. Seven further cases flagged as discrepancies were not identified on peer review. Twenty-four reports were amended subsequent to the meeting. Nineteen additional cases were brought to the meeting as illustrative of teaching points or for discussion. CONCLUSION: We have evolved a successful process of reviewing reporting errors, which enjoys the confidence and support of all clinical radiologists, and is perceived as a method of improving patient care through an increasing awareness of lapses in performance.

Clinical Competence↗

Clinical teachers' tacit knowledge of basic pedagogic principles.

Academic faculty members in medical schools rarely receive formal instruction in basic pedagogic principles; nevertheless many develop into competent teachers. Perhaps they acquire tacit knowledge of these principles with teaching experience. This study was designed to assess clinical teachers' tacit knowledge of basic pedagogic principles and concepts. The authors developed a multiple-choice question (MCQ) exam based on 20 pedagogic principles judged by a panel of education experts to be important for clinical teaching. Three groups of clinician-educators sat the test: (1) clinicians with advanced education training and experience; (2) internal medicine specialists; (3) surgical specialists. All four groups of clinicians-educators passed the test, indicating that they possess a reasonable tacit knowledge of basic pedagogic principles. Those with advanced education training performed much better than members of the other two groups while specialists and residents working in teaching hospitals outperformed specialists from non-teaching hospitals. It is possible that converting this tacit knowledge to explicit knowledge may improve individual teaching effectiveness.

Delphi Technique↗

Audit of a policy of magnetic resonance imaging with diffusion-weighted imaging as first-line neuroimaging for in-patients with clinically suspected acute stroke.

AIM: To audit the feasibility and use of diffusion-weighted (DW) magnetic resonance imaging (MRI) as initial neuroimaging for in-patients with clinically suspected acute stroke. MATERIALS AND METHODS: In April 2000, MRI with DW and T2-weighted sequence was locally instituted as initial neuroimaging for patients with clinically suspected acute stroke. This retrospective study reviewed imaging performed for in-patients with suspected acute stroke over a 9-month period. Data were collected on image type, result and need for repeat imaging. RESULTS: During the study period, 124 patients had neuroimaging for suspected cerebrovascular accident, and 119 were MRI safe. Eighty-eight (73.9%) patients underwent DW MRI as first-line investigation. Five patients were not MRI safe and 31 had computed tomography (CT) as first-line imaging due to lack of available MRI capacity. Repeat neuroimaging was performed in 16 (12.9%) patients. Study times were comparable for both types of neuroimaging: a mean of 13 min for MRI and 11 min for CT. CONCLUSION: The audit standard was achieved in 88 (73.9%) patients. The use of DW MRI as a first-line investigation for patients with a clinical diagnosis of acute stroke is achievable in a district general hospital setting.

Decision Making↗

Abnormalities on diffusion weighted magnetic resonance imaging performed several weeks after a minor stroke or transient ischaemic attack.

OBJECTIVES: Diffusion weighted brain imaging (DWI) is used in acute stroke, and also shows an acute ischaemic lesion in most transient ischamic attack (TIA) patients scanned acutely. However, it may also be useful in identifying subacute ischaemic lesions in patients with minor stroke or TIA who present several weeks after symptom onset. This study investigated the sensitivity and the observer reproducibility of DWI in cerebral TIA and minor ischaemic stroke patients scanned more than two weeks after the last symptomatic event. METHODS: Consecutive patients underwent magnetic resonance imaging (T2, DWI, ADC). The presence of clinically appropriate lesions was assessed by two independent observers, and related to the type of presenting event, the NIH score, persistence of symptoms and signs, and the time since the presenting event. RESULTS: 101 patients (53 men) were scanned at a median time of 21 days (IQR=17-28) after symptom onset. Reproducibility of the assessment of DWI abnormalities was high: interobserver agreement =97% (kappa=0.94, p<0.0001); intraobserver agreement =94% (kappa=0.88, p<0.0001). DWI showed a clinically appropriate ischaemic lesion in 29 of 51 (57%) minor stroke patients, and in 7 of 50 (14%) TIA patients. The independent predictors of a positive DWI scan were presentation with minor stroke versus TIA (p=0.009) and increasing NIH score (p=0.009), but there was no difference between patients presenting 2-4 weeks compared with >4 weeks after symptom onset. In minor stroke patients, the presence of a clinically appropriate lesion was associated with persistent symptoms (63% versus 36%; p=0.12) and signs (64% versus 33%, p=0.06) at the time of scanning. CONCLUSIONS: DWI shows a clinically appropriate ischaemic lesion in more than half of minor stroke patients presenting more than two weeks after the symptomatic event, but only in a small proportion of patients with TIA. The persistence of lesions on DWI is closely related to markers of severity of the ischaemic event. These results justify larger studies of the clinical usefulness of DWI in subacute minor stroke.

Acute Disease↗

Low dose computed tomography in suspected acute renal colic.

AIM: To evaluate whether computed tomography (CT) of the renal tract in suspected renal colic using reduced exposure factors maintains diagnostic accuracy. METHODS: Prospective multi-centre cohort study. Patients with suspected renal colic were examined using computed tomography (CT) of the renal tract followed by intravenous urography (IVU) in four different centres with five different CT systems. RESULTS: Sixty-nine patients with suspected renal colic had CT of the renal tract followed by IVU. CT was performed with reduced exposure factors, giving a mean CT effective dose of 3.5 (range 2.8-4.5) mSv compared with 1.5 mSv for IVU. Ureteric calculi were detected in 43 patients: CT and IVU detected 40 (93%) ureteric calculi. CT identified other lesions causing symptoms in five patients and identified renal calculi in 24 patients. IVU identified renal calculi in six patients and made false positive diagnosis of renal calculi in seven patients. Mean examination time for CT was 5 minutes and for IVU was 80 minutes. CONCLUSION: CT examination at reduced exposure factors maintains the diagnostic accuracy recorded in other series.

Acute Disease↗

Red squirrels, Tamiasciurus hudsonicus, produce predator-class specific alarm calls

Red squirrels, can produce alarm calls when they detect a potential predator. Observations of natural interactions between red squirrels and large birds, and predator-presentation experiments in the field, showed that red squirrels produce acoustically different alarm calls in response to aerial danger (live birds and a model hawk flown towards them) versus danger approaching from the ground (dogs and humans). The alarm call produced in response to aerial danger is acoustically convergent on the 'seet' alarm call produced by many species of passerine birds in response to raptors. The squirrels' 'seet' alarm is a short, low-amplitude, high-frequency call. These characteristics make the call difficult to localize, and is in a frequency range that is poorly perceived by raptors. Red squirrels produce much louder, wide-bandwidth bark calls in response to terrestrial danger. This is the first demonstration of predator-class specific alarm calls of red squirrels. Copyright 1998 The Association for the Study of Animal Behaviour Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗

Can MRI of the knee affect arthroscopic practice? A prospective study of 58 patients.

We made a prospective study of 58 patients with suspected internal derangement of the knee. They were examined by magnetic resonance imaging using 3-D gradient echo intermediate-weighted studies before having an arthroscopy. The preoperative clinical assessment was found to have a diagnostic sensitivity of 77% and a specificity of 43%, compared with 100% and 63% respectively for magnetic resonance imaging. Comparison of magnetic resonance imaging and arthroscopy confirmed the accuracy of magnetic resonance imaging in the diagnosis of internal derangement but the results for articular cartilage lesions were much less good, with a sensitivity of only 18% but a specificity of 100%. Acceptance of the magnetic resonance imaging findings could have resulted in a 29% reduction in the number of arthroscopies without missing any significant meniscal lesion.

Adolescent↗

The bedside assessment of splenic enlargement.

STUDY OBJECTIVE: To evaluate the clinical assessment of splenic enlargement using specific bedside maneuvers including Traube's space percussion, the splenic percussion sign, Middleton's maneuver, supine palpation, and right lateral decubitus palpation. DESIGN: Quasi-experimental prospective study of cases and controls selected according to the results of abdominal ultrasonographic examinations. SETTING: Selected inpatients of a tertiary care hospital. MAIN RESULTS: Comparing the areas under the receiver operating characteristic curves for each bedside maneuver demonstrated that Traube's space percussion and palpation were significant discriminators (p less than 0.001) of splenic enlargement with respective areas of 0.70 +/- 0.04 and 0.76 +/- 0.04. No one palpation maneuver was superior to another, and right lateral decubitus palpation was not useful when performed after supine palpation. The splenic percussion sign (sensitivity 79%, specificity 46%) was no better than Traube's space percussion (sensitivity 62% and specificity 72%) in assessing splenic enlargement. The palpation maneuvers appeared more sensitive and more specific than Traube's space percussion. Palpation was a significant clinical discriminator when performed on patients who exhibited percussion dullness of Traube's space (area = 0.87 +/- 0.04, p less than 0.0001) but was of little value among those without percussion dullness (area = 0.55 +/- 0.08). Also, palpation was significantly more accurate when performed on lean patients versus obese patients (areas = 0.83 +/- 0.04 versus 0.65 +/- 0.08, p less than 0.05). When a positive bedside examination was defined as positive palpation and positive percussion (concordant-positive), the combined test sensitivity and specificity were 46% and 97% respectively. CONCLUSIONS: The optimal clinical assessment of splenic enlargement includes the percussion of Traube's space. If Traube's space is dull, palpation of the spleen is warranted. This assessment is most accurate in lean patients.

Adult↗

The role of abdominal and transrectal ultrasound and cytology in the detection of recurrent bladder tumours.

Transrectal and transabdominal ultrasound combined with cytology were compared with conventional cystoscopy as a mean of detecting recurrences of bladder tumours. One hundred and twenty-five patients underwent combination ultrasound in the outpatient department 1 week before cystoscopy. Combination ultrasound identified 90% of recurrent tumours and tumour identification with the results of ultrasound and cytology combined was 93%. The false positive rate was 2%. The ultrasonographer would have referred 97% of patients with recurrent tumour for cystoscopy. Combination ultrasound and cytology may be a satisfactory alternative to check cystoscopy in certain categories of bladder tumours.

Adult↗

Splenic enlargement and Traube's space: how useful is percussion?

PURPOSE: The utility of Traube's space percussion in the bedside assessment of splenic enlargement was evaluated. The influence of meals and obesity on this sign were also assessed, because both are believed to interfere with the results of abdominal percussion. PATIENTS AND METHODS: The inpatient population of a tertiary care hospital was studied where cases and controls were selected according to the results of abdominal ultrasonographic examinations. RESULTS: Traube's space percussion exhibited a sensitivity of 0.62 (95% confidence interval [CI], 0.51 to 0.71) and a specificity of 0.72 (95% CI, 0.65 to 0.80) when classifying tympanitic examinations as negative. False-positive examinations were reduced by assessing patients more than two hours after mealtime. Obese patients were a source of false-negative examinations. CONCLUSION: Traube's space percussion compares favorably with other commonly used clinical maneuvers and diagnostic tests. When performed alone in a selected patient population, it adds useful clinical information but is not sufficiently sensitive or specific to obviate the need for further diagnostic testing.

Adult↗

Detection of recurrent bladder tumours by transrectal and abdominal ultrasound compared with cystoscopy.

Transrectal and transabdominal ultrasound was used to detect the recurrence of bladder tumours and compared with conventional cystoscopy. Forty patients with a previous history of bladder tumour were examined by these methods; 50% had a recurrence. Transabdominal and transrectal ultrasound together identified 95% of recurrences; 1 tumour (diameter 1 mm) was missed. The false positive rate was 5% and these areas, identified wrongly by ultrasound as tumour, were shown to be scars on cystoscopy. Combination ultrasound may be used as an alternative to check cystoscopy in certain categories of bladder tumour.

Abdomen↗