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Biomedical subjects

K T Evans

Publications and source records attributed to K T Evans.

At least 37 records · Page 2Linked to original sources
PubMed1986

Multicentre trial of four strategies to reduce use of a radiological test.

The Royal College of Radiologists' guidelines on the use of pre-operative chest X-rays were implemented for 1 year in four hospitals in England and Wales. The strategies adopted were: (1) the appointment of a utilisation review committee; (2) getting feedback on use to consultants; (3) the introduction of a new chest X-ray request form; or (4) the concurrent reviewing of chest X-ray requests by the radiology department. The lowest level of use (8.5 pre-operative chest X-rays per 100 elective operations) was achieved with the utilisation review committee after it displayed the guidelines in surgical wards. Information feedback produced a consistent reduction from 29.4 to 13.3 X-rays per 100 operations. Both the new request form and concurrent review had a moderate and intermittent effect. No change in practice occurred in a control hospital.

England↗
PubMed1986

Effect of volume of water taken with diazepam tablets on absorption.

Thirty-three patients received either 10 ml (group A) or 50 ml (group B) of water with diazepam tablets as premedication while in the supine position. Plasma diazepam concentrations were measured, a delay in the attainment of the peak plasma concentration being taken as an indication of delayed absorption and oesophageal hold-up. There was no difference between the two groups, although in an important minority (16.7% (group A) and 20% (group B], absorption was delayed to beyond 60 min. There was a wide scatter of plasma diazepam concentrations in both groups. Dysphagia during swallowing did not appear to delay absorption.

Absorption↗
PubMed1986

Forensic radiology.

Like any branch of medicine, radiology has an interface with the law. This has two main facets: first the technical applications of radiology to forensic problems and secondly the legal aspects of radiological practice.

Age Factors↗
PubMed1985

Can we afford screening for neural tube defects? The South Wales experience.

Clinical and financial gains and losses accruing from five different options for screening for open neural tube defects were estimated, based principally on the results of detailed monitoring of inputs and outcomes and of process costs in the South Wales Anencephaly and Spina Bifida Study. As well as estimating the overall clinical costs of a screening service it was shown that if the prevalence, including terminations, of open neural tube defects is between 1.25 and five per 1000 births the financial cost of avoiding the birth of a seriously handicapped child who would survive for more than 24 hours is in the range 9000 pounds- 54000 pounds depending on the option adopted and the prevalence of the condition in the target population. Prevalence is the biggest determinant of cost. The data should provide a basis for assessment and discussion of resource priorities in the National Health Service.

Anencephaly↗
PubMed1985

Should women at high risk of neural tube defect have an amniocentesis?

As part of an investigation into the practical problems of a maternal serum alphafetoprotein (AFP) neural tube defect (NTD) screening programme carried out in Mid Glamorgan, South Wales, between 1977 and 1979, obstetricians were recommended to refer women with high risk pregnancies directly for counselling, high resolution ultrasonography, and amniocentesis without first carrying out serum screening. Out of 15 687 pregnant women one-third attended too late to be screened. A total of 637 was classed as high risk, mostly at greater risk than 1 in 50 because of a previously affected pregnancy or an affected close relative. Compliance with recommended procedure was relatively low as many were screened. There were 10 pregnancies with a recurrence of NTD, of which one was not tested at all, two were not detected (one closed meningocele and one closed iniencephalic), and seven were detected and the pregnancies terminated. All the latter, as well as the iniencephalic, would have been detected from a serum AFP determination and a high resolution ultrasound scan alone. It is concluded that these investigations are sufficient for high risk pregnancies and that amniocentesis is not really cost effective or necessary unless either of these investigations is abnormal. As numbers in this study were small it is suggested that these conclusions should be tested in a larger study.

Amniocentesis↗
PubMed1984

Ultrasonic appearances associated with prostatic inflammation: a preliminary study.

Per-rectal ultrasonography was performed on 40 patients in whom a diagnosis of prostatitis had been made on the basis of symptoms and signs of prostatic inflammation confirmed by bacteriology, microscopy or pH changes of expressed prostatic secretion. Certain ultrasonic features were present in all patients to a variable degree. A change in volume and weight of the prostate could be an indicator of treatment response.

Adolescent↗
PubMed1983

Diagnostic effectiveness of ultrasound in detection of neural tube defect. The South Wales experience of 2509 scans (1977-1982) in high-risk mothers.

2509 pregnant women were investigated between April 1, 1977, and March 31, 1980 (study 1), and April 1, 1980, and March 31, 1983 (study 2), to assess the effectiveness of diagnostic ultrasound in the diagnosis of neural tube defect (NTD) in women judged to be at high risk of NTD on the basis of raised serum alpha-fetoprotein or family history, or of other congenital malformation. The detection rate (sensitivity) for anencephaly was 100% in both studies. The detection rate for open spina bifida (OSB) improved from 33% in study 1 to 80% in study 2, specificity rose from 96% to 99%, the false-positive rate dropped from 57% to 9%, and the false-negative rate fell from 1% to 0.3%. Diagnostic ultrasound is likely to be conducted with greater vigilance and subjected to greater scrutiny than routine ultrasound because the patients have already been selected as being at high risk, the operators are more experienced, and their apparatus is likely to be more refined than that used for routine ultrasound. It is unlikely that the effectiveness levels for detection of OSB of 80% observed in this study could be sustained if diagnostic ultrasound were to be offered to all pregnant women. Consideration will need to be given to the question of whether an improved OSB detection rate will be worth the additional cost incurred in providing diagnostic ultrasound for every pregnant woman.

Anencephaly↗
PubMed1983

The efficacy of a serum screening service for neural-tube defects: the South Wales experience.

Serum-alpha-fetoprotein (AFP) levels were measured in more than 15 000 pregnant women in an investigation designed to examine the operational issues entailed in a large-scale population screening programme for antenatal detection of neural-tube defects. The proportion of open neural-tube defects (ONTD) terminated as a result of serum screening was 56.1% (66.6% for anencephaly and 40.7% for open spina bifida). The principle causes of poor efficacy were: failure of pregnant women to undergo screening (18.2% of ONTD were not screened); failure of the screening test to detect ONTD (20.4% of those screened were below the 90th centile); decisions against termination of detected ONTD (14% of ONTD detected by serum AFP were not terminated). Given present practices and knowledge it is doubtful whether overall efficacy levels above 65% for open spina bifida can be achieved under normal service conditions. The establishment of a regional or national screening programme on grounds of clinical efficacy alone may be premature. The decision would seem to hinge principally around a careful consideration of the economic issues.

Anencephaly↗
PubMed1983

Diagnostic value of "bread-barium" swallow in patients with esophageal symptoms.

The value of a "bread-barium" swallow for diagnosis of disordered esophageal motility was examined in 53 patients, 20 of whom complained of dysphagia, 20 retrosternal chest pain, and 13 heartburn; a further 19 subjects served as controls. Esophageal manometry in the patients with dysphagia and chest pain revealed major abnormalities in 14 compared with the bread-barium swallow which showed changes consistent with esophageal spasm in 20. The standard barium swallow examination revealed major abnormalities in only five of these patients. The bread-barium examination is simple, complements the routine barium swallow, and is of value in patients with symptoms suggesting disturbed motility. It does not replace conventional studies for the diagnosis of esophageal motility disorders.

Barium Sulfate↗
PubMed1983

Renal papillary necrosis in haemophilia and christmas disease.

Haematuria is common in haemophilia and Christmas disease. A variety of radiological abnormalities in the urinary tract has been described in the literature, the commonest being hydronephrosis and obstructive uropathy. The findings in 26 cases seen in this centre were reported by Beck and Evans in 1972; although urinary-tract obstruction was relatively common, it was noted that signs suggestive of renal papillary necrosis (RPN) were present in some cases. In the present study, 20 of these patients were reinvestigated up to 10 years after the original radiological studies; a total number of 46 past and present intravenous urograms were examined. There was evidence of RPN in 11 of the 20 patients, and in five of these the signs had changed over the intervening period. The relevance of these findings is discussed; none of the patients showed evidence of renal failure. It is suggested that episodes of urinary-tract obstruction could be related to papillary sloughing, in some cases, rather than clot obstruction or obstruction due to retroperitoneal bleeding.

Adult↗
PubMed1980

Antenatal attendance and screening for neural tube defects.

An analysis of factors influencing the time of booking at seven hospital antenatal clinics in one Health Authority Area showed that only 52.5 per cent of patients booked before 16 weeks gestation and 78.9 per cent before 19 weeks gestation. The principle reasons for late booking were delay in the patient seeking medical advice and delay in referral to hospital by the general practitioner (GP) after pregnancy was confirmed. Possibilities for improving early attendance and hence implementing an effective screening programme for the detection of neural tube defects are discussed.

Appointments and Schedules↗
PubMed1979

Precision in estimating gestational age and its influence on sensitivity of alphafetoprotein screening.

The interpretation of maternal serum alpha-fetoprotein (AFP) concentrations in relation to fetal neural tube defects depends on accurate assessment of the gestational age. In a quadruple-blind study three antenatal methods of assessment--namely, menstrual dates, clinical examination, and ultrasound scanning--were correlated with postnatal assessment using the Dubowitz scoring system. The best agreement to +/- 1 week was obtained using menstrual dates and ultrasound in combination, such agreement being found in 91 (77%) of the 118 women studied. Since serum AFP concentrations vary with gestational age, precise gestational dating is necessary. In many cases, particularly in women who are unsure of their dates or have irregular menstrual cycles, ultrasound examination is needed to supplement clinical findings.

Clinical Trials as Topic↗