Biomedical subjects
Publications and source records attributed to P Wilkinson.
This paper focuses on the management of change in the context of health care and looks specifically at methods of introducing a new model of nursing into a general Intensive Therapy Unit (ITU). Rationale for change is discussed, change theory is appraised and a strategy for implementation, management and evaluation of change is provided.
OBJECTIVE: To compare the circadian rhythm of myocardial ischaemia in patients with stable angina with that in patients in the early postinfarction period with particular emphasis on the role of the autonomic nervous system. PATIENTS: 44 patients with stable angina and ischaemia on treadmill testing (group A) were compared with 131 patients in the early postinfarction period (group B). All had 48 hour ambulatory Holter monitoring. SETTING: Coronary care unit and cardiology department of a district general hospital. DESIGN: Prospective, between group, comparative study. RESULTS: 337 ischaemic episodes occurred in 35 patients in group A and 370 ischaemic episodes occurred in 65 patients in group B. 34% of patients in group A had only silent episodes of ischaemia compared with 97% in group B (p < 0.0001). In group A ischaemic episodes showed a circadian rhythm that peaked during the daytime hours (p < 0.0001), but this was not seen in group B. Both the high (0.15-0.40 Hz) and low (0.04-0.15 Hz) frequency spectral components of heart rate variability showed a clear circadian rhythm (p < 0.0001); peak values occurred during the sleeping hours, although this pattern was less pronounced in group B. The ratio of low to high frequency variability (a measure of sympathovagal balance) showed a peak in daytime hours in group A (p < 0.002), but this was not seen in group B. CONCLUSION: In stable angina, myocardial ischaemia peaks during the day and is associated with a similar circadian rhythm of sympathovagal balance. In the early postinfarction period both the ischaemic and sympathovagal rhythms are severely diminished or lost altogether. Circadian changes in sympathovagal tone may explain, at least in part, the circadian rhythm of ambulatory myocardial ischaemia in patients with stable angina.
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OBJECTIVES: To evaluate the introduction to two health districts of an antenatal serum screening programme for Down's syndrome using the triple test-measurement of alpha fetoprotein, unconjugated oestriol, and human chorionic gonadotrophin concentrations in second trimester serum samples. METHODS: All women delivering at the main maternity units in both districts were eligible for the screening programme. A serum sample was taken between 15 and 22 weeks' gestation, confirmed by ultrasound scan. An estimated risk of 1 in 250 or greater was considered to be a screen positive result and further diagnostic tests were offered. As far as possible the outcome of all screened pregnancies was recorded, and babies with Down's syndrome born to women who declined serum screening were also identified. RESULTS: 6990 singleton pregnancies were screened over a two year period, representing an estimated uptake of 67% (6990/ 10,443). After a screen positive result 80% of women (168/211; 95% confidence interval 74.2 to 85.1%) opted for amniocentesis. The false positive rate was 2.9% (203/6979; 95% confidence interval 2.5 to 3.3%). The detection rate in the screened population was 73% (8/11). The estimated cost of identifying one Down's syndrome affected pregnancy was about 31,000 pounds. CONCLUSIONS: Successful introduction of the triple test to health districts where there is no established serum screening programme for neural tube defects is possible. The programme seems to be acceptable to most of those screened. Uptake of the programme is sufficient to make it more effective than a policy for Down's syndrome screening dependent on age only.
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OBJECTIVE: To record prognosis and determinants of outcome in patients with acute myocardial infarction since thrombolysis was introduced. DESIGN: Observational study. SETTING: London district general hospital. PATIENTS: 608 consecutive patients admitted to the coronary care unit with acute myocardial infarction between 1 January 1988 and 31 December 1991. MAIN OUTCOME MEASURE: All cause mortality, non-fatal ischaemic events (myocardial infarction, unstable angina), and revascularisation. RESULTS: Of the 608 patients, 89 (14.6%) died in hospital. 507 [corrected] patients were followed up after discharge from hospital. Mortality (95% confidence interval) at 30 days, one year, and three years was 16.0% (13.4% to 19.2%), 21.7% (18.6% to 25.2%), and 29.4% (25.3% to 33.9%) respectively. Event free survival (survival without a non-fatal ischaemic event) was 80.4% (77.0% to 83.4%) at 30 days, 66.8% (62.8% to 70.5%) at one year, and 56.1% (51.3% to 60.6%) at three years. Survival in patients treated with thrombolysis was considerably higher than in those not given thrombolysis (three year survival: 76.7% v 54.3%), although the incidence of non-fatal ischaemic events was the same in the two groups. Multivariate determinants of six month survival were left ventricular failure, treatment with thrombolysis and aspirin, smoking history, bundle branch block, and age. For patients who survived six months, age was the only factor related to long term survival. CONCLUSIONS: Although patients treated by thrombolysis had a relatively good prognosis, long term mortality and the incidence of non-fatal recurrent ischaemic events remained high. Effective strategies for the identification and treatment of high risk patients need to be reassessed.
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Aztreonam is a monobactam exhibiting an antibacterial spectrum similar to that of the aminoglycosides, with activity against aerobic gram-negative bacilli, and is the only related drug that may be given to patients hypersensitive to beta-lactams. The pharmacokinetics of aztreonam were compared in two groups of healthy volunteers. The young group comprised 10 adults between the ages of 18 and 30 years, and the elderly group included 10 adults older than 65 years of age. The two groups each received two doses (1 and 2 g) aztreonam, separated by 1 week. Although the mean peak serum concentrations of aztreonam for the two groups were similar, there were differences in other pharmacokinetic parameters. For example, for the 2-g dose the mean half-life (1.8 +/- .51 versus 3.1 +/- .9 hour), and area under the curve (AUC) (294.42 +/- 64.08 versus 469.01 +/- 144.02 micrograms x hour/mL per 1.73 m2) were less for the younger group compared with the elderly group. The mean total body clearance of aztreonam was greater for the younger than the elderly group. The results were similar to the pharmacokinetic parameters derived from the 1-g dose. These results mirror the lower creatinine clearances and higher serum creatinine levels found in the elderly group. The data suggest that lower doses of aztreonam given at less frequent intervals may be appropriate in the elderly population.
413 women were included in the study: 100 who had had a normal delivery and 313 who had participated in a randomised controlled comparison of forceps or ventouse delivery. The study comprised a questionnaire and assessment at 24-48 hours after delivery and a questionnaire in the second year after delivery. There was significantly more morbidity in the women in the instrumental delivery group compared to women in the normal delivery group at both the early assessment and long-term follow-up.
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OBJECTIVE: To determine the circadian and seasonal variations in the incidence of acute myocardial infarction and the influence of environmental temperature. PATIENTS: 633 consecutive patients with acute myocardial infarction admitted to a coronary care unit over four years. SETTING: Coronary care unit in a district general hospital. DESIGN: An observational study. RESULTS: The onset of acute myocardial infarction had a circadian rhythm with a peak in the second quarter of the day. A seasonal variation was also found with a significant winter peak. There was, however, an excess of infarctions on colder days in both winter and summer indicating that the effect of environmental temperature on the onset of acute myocardial infarction is independent of the time of year. CONCLUSION: Acute myocardial infarction is more common in winter and more common on colder days, independent of season. Environmental temperature may play an important part in the pathogenesis of acute myocardial infarction.
OBJECTIVES: To evaluate the role of Holter ST monitoring for identifying patients at risk of recurrent ischaemic events after acute myocardial infarction treated by thrombolysis. BACKGROUND: The natural history of myocardial infarction has changed with the introduction of thrombolytic treatment. There is now a lower mortality but a higher incidence of recurrent thrombotic events (reinfarction, unstable angina). Preliminary evidence indicates that Holter ST monitoring may be of prognostic value in patients with acute myocardial infarction, but there are limited data available in patients treated by thrombolysis. METHODS: Prospective observational study of 256 consecutive patients who presented with acute myocardial infarction treated by thrombolysis. All underwent 48 hour Holter ST monitoring early after thrombolysis (mean 83, range 48-180 hours) and were followed up for eight (range three to 12) months. RESULTS: Recurrent ischaemic events occurred in 45 patients (fatal reinfarction 17, non-fatal reinfarction 12, unstable angina 16). Also four patients died as a result of progressive heart failure, and a further 15 patients required revascularisation. Analysis of the Holter data showed that 32% of patients had at least one episode of isolated ST depression (> or = 0.1 mV) and 41% either ST depression or elevation (> or = 0.2 mV). Ischaemic episodes were silent in 95% of cases. Event free survival analysis showed a significant association between Holter findings and recurrent ischaemic events (ST depression: p = 0.009; ST depression or elevation: p = 0.002). The association remained significant when the end point was restricted to fatal or non-fatal reinfarction (ST depression: p = 0.005; ST depression or elevation p = 0.001), the period of greatest risk for patients with an abnormal recording occurred early after investigation. An abnormal Holter recording identified patients at risk of early (within 30 days) reinfarction with 79% sensitivity and 60% specificity. Although positive predictive accuracy was low (11%), a normal Holter recording was associated with 98% negative predictive accuracy. CONCLUSIONS: In patients treated by thrombolysis, ST change on Holter monitoring may be useful for identifying patients at increased risk of recurrent ischaemic events, and in particular early reinfarction.
OBJECTIVES: To evaluate the role of a treadmill stress test for identifying patients at risk of recurrent ischaemic events after acute myocardial infarction treated by thrombolysis. BACKGROUND: The natural history of myocardial infarction has changed with the introduction of thrombolytic treatment; there is a lower mortality but a higher incidence of recurrent thrombotic events (reinfarction, unstable angina). The treadmill stress continues to be recommended for risk stratification after acute myocardial infarction even though its value has never been formally reassessed in the thrombolytic era. METHODS: Prospective observational study in which 256 consecutive patients who presented with acute myocardial infarction treated by thrombolysis underwent an early treadmill stress test and were followed up for 10 (range 6-12) months. RESULTS: Recurrent ischaemic events occurred in 41 patients (unstable angina 15, reinfarction 21, death five) and a further 21 required revascularisation. Both ST depression at a low workload and low exercise tolerance (< 7 metabolic equivalents of the task (METS) were predictive of recurrent events, with respective hazard ratios of 1.93 (95% confidence interval (95% CI) 1.17-3.20; p < 0.01)) and 1.67 (95% CI 1.0-2.78; p < 0.05). These variables identified 50% and 70% of patients who subsequently sustained a recurrent ischaemic event, but the corresponding values for positive predictive accuracy were only 26% and 21%. Thus they are of limited value as a screening measure for identifying patients likely to benefit from invasive investigation and revascularisation. None of the other variables (ST elevation, haemodynamic responses, ventricular extrasystoles, angina) was significantly associated with recurrent ischaemic events. CONCLUSIONS: The treadmill stress test is of limited value for identifying patients at risk of recurrent ischaemic events after acute myocardial infarction treated by thrombolysis.
This article focuses on the potentially dichotomous relationship of caring for critically ill patients in a high technology environment. Does technology enhance or hinder the quality of patient care delivered by nurses in such an environment? The discussion within this article is initially at a societal level before focusing at an interpersonal level within a specific care setting. The author argues for finding a balance between high technology and humanity within the intensive care environment by highlighting the psychological impact that this may have on patients, relatives and nurses. Guidance as to how a balance may be achieved is also provided. Technology is an explicit theme within the text, whilst the concept of power that technology holds is discussed in an implicit manner.
The aim of this study was to describe a scoring system for high resolution computed tomographic (HRCT) scans analogous to the International Labour Office (ILO) scoring system for plain chest radiographs in patients with asbestos related disease. Interstitial fibrosis, pleural disease, and emphysema were scored, the reproducibility and the interobserver agreement using this scoring system were examined, and the extent of the various types of disease was correlated with measurements of lung function. Sixty asbestos workers (five women and 55 men) mean age 59 (range 34-78) were studied. The lungs were divided into upper, middle, and lower thirds. An HRCT score for the extent of pleural disease and pulmonary disease in each third was recorded in a way analogous to the International Labour Office (ILO) method of scoring pleural and parenchymal disease on chest radiographs. A CT score for the extent of emphysema was also recorded. Pleural disease and interstitial fibrosis on the plain chest radiographs were assessed according to the ILO scoring system. A chest radiographic score for emphysema analogous to that used for HRCT was also recorded. Two independent readers assigned HRCT scores that differed by two categories or less in 96%, 92%, and 85% compared with 90%, 78%, and 79% of cases for chest radiographs for fibrosis, emphysema, and pleural disease respectively. There was better intraobserver repeatability for the HRCT scores than for the chest radiograph scores for all disorders. Multiple regression analysis showed that scores for interstitial fibrosis, emphysema, and pleural disease on chest radiographs and HRCT correlated to a similar degree with impairment of lung function.
BACKGROUND: Notification of tuberculosis is essential for local contact tracing and for assessing the national incidence of tuberculosis. The accuracy of notification figures is uncertain. This study examined the notification rates of all patients diagnosed as having tuberculosis at two hospitals in the East End of London over five years. METHODS: In a retrospective survey of all patients aged 16 years or more presenting with tuberculosis to the London Chest Hospital or the Royal London Hospital from 1 January 1985 to 31 December 1989, cases of tuberculosis were identified from microbiology and histology records, statutory notifications, necropsy reports, coroners' records, hospital activity data, and death certificates. Clinical data were obtained from case notes and notification was determined from the local authority notification lists. RESULTS: Six hundred and nine adult patients with tuberculosis were identified. Notes were available for 580 cases (95%), of which 426 (73%) had been notified. The proportion of cases notified varied according to the specialty of the clinician in charge of the patient at diagnosis. Patients with a past history of tuberculosis and those who died within one year were less likely to have had their tuberculosis notified. Age, race, and lack of microbial or histological confirmation of diagnosis did not influence the proportion of cases notified. One hundred and eighty five patients had smear positive sputum, but 25 of these cases (14%) were not notified. Eighty five patients who had presented with pulmonary tuberculosis did not have their disease notified; 20 (24%) had smear positive sputum. CONCLUSIONS: Many cases of tuberculosis are not notified (27%). Fourteen per cent of all sputum smear positive cases of tuberculosis were not notified, and these patients are a considerable public health risk. The true incidence of tuberculosis in the area studied is at least one third higher than current notification figures suggest.
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A total of 25 patients (5 groups of 5) were given single i.v. doses of 5, 10, 20, 40 and 60 mg MDL 72,222 (a 5-HT3 receptor antagonist) at 15 minutes before the commencement of a 24-h cisplatin infusion (total dose, 120-200 mg) to determine the efficacy and safety of the former in the prevention of nausea and vomiting associated with such chemotherapy. All patients completed the study. The time to onset of vomiting was significantly correlated with dose. All patients vomited following doses of 5 and 10 mg (range, 1-6 episodes), with onset being noted at 5-8 h. At the 20-mg level, only one episode of vomiting was observed in 3/5 patients, with onset being observed at 18-22 h. Following doses of 40 and 60 mg, 3/10 patients did not vomit; in the remaining patients the number of episodes ranged from 1 to 6, but a significant increase occurred in the time to onset of symptoms. At the higher doses, nausea tended to be milder in nature both at onset and at the time of maximal severity. A similar dose-effect trend was seen in the time to onset of the maximal severity of nausea. The time to and requirement for escape medication was similarly extended at doses of greater than or equal to 20 mg MDL 72,222. Pain at the injection site in one patient was the only unwanted effect associated with MDL 72,222. The results suggest that the i.v. injection of 20 mg MDL 72,222 should be further explored in the control of nausea and vomiting associated with cisplatin administration.