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Biomedical subjects

J Rawles

Publications and source records attributed to J Rawles.

At least 37 records · Page 2Linked to original sources
PubMed1994

Attitudes of general practitioners to prehospital thrombolysis.

OBJECTIVE: To investigate reasons for general practitioners not giving thrombolytic treatment to eligible patients with acute myocardial infarction. DESIGN: Postal questionnaires were sent to 424 general practitioners. SUBJECTS: 97 general practitioners who had taken part in the Grampian region early anistreplase trial, 185 whose practices in Scotland were at least 24 km from a district general hospital, and 142 who had attended postgraduate conferences at which thrombolysis had been discussed; 87, 158, and 125 respectively responded. MAIN OUTCOME MEASURES: Answers to questions about readiness to use thrombolytic treatment. RESULTS: Response rate was 87% (370/424). Almost all respondents (350) were convinced of benefits of thrombolysis for acute myocardial infarction, and 277 were convinced that there were additional benefits from its administration in the community at first opportunity. Most doctors working 16 km or more from hospital thought that giving treatment at home would appreciably save time (200/274). Most doctors agreed that they could make time to give thrombolytic treatment (278), and would be willing to record an electrocardiogram (284), and would be able to interpret it (280). Sixty four respondents (17%) reported using thrombolytic treatment in previous year. Among non-users, 150 (49%) were unwilling to use thrombolytic treatment without further training. While many non-users (210 (69%)) were willing to use thrombolytic treatment without encouragement from Department of Health, 184 (60%) were unwilling to use it unless encouraged to do so by their local cardiologist. CONCLUSIONS: The need to become better informed about thrombolysis and lack of encouragement from local cardiologists were important factors preventing wider use of thrombolytic treatment in the community by general practitioners.

Attitude of Health Personnel↗
PubMed1994

Halving of mortality at 1 year by domiciliary thrombolysis in the Grampian Region Early Anistreplase Trial (GREAT).

OBJECTIVES: Our aim was to determine the time saved by administration of thrombolytic therapy at home rather than in the hospital and to assess whether earlier thrombolysis resulted in decreased mortality from acute myocardial infarction. BACKGROUND: There is much theoretic, experimental and trial evidence to indicate that in acute myocardial infarction the earlier that thrombolytic therapy is given, the greater its efficacy. However, the clinical importance of this time effect is uncertain. METHODS: In a randomized double-blind parallel-group clinical trial, 311 patients with suspected acute myocardial infarction seen by their general practitioners within 4 h of symptom onset were given intravenous anistreplase (30 U) either at home or later, after arrival in the hospital. RESULTS: Anistreplase was given at home or in the hospital at median times of 101 and 240 min, respectively, after symptom onset. The median time saved by domiciliary thrombolysis was 130 min. By the end of 1 year after trial entry, 17 (10.4%) of 163 patients given anistreplase at home died compared with 32 (21.6%) of 148 in those allotted anistreplase in the hospital (relative reduction 52%, 95% confidence interval 14% to 89%, p = 0.007). CONCLUSIONS: In this trial the time saved by domiciliary thrombolysis by primary care physicians was > 2 h. It is likely that a similar time saving would be achieved if prehospital thrombolysis were to become established practice. Prehospital thrombolysis resulted in a halving of the mortality rate from acute myocardial infarction.

Adult↗
PubMed1994

Electrocardiographic evidence of reperfusion occurring before hospital admission. A Grampian Region Early Anistreplase Trial (GREAT) sub-study.

The benefits of thrombolysis are believed to be related to the speed of reperfusion of the infarct-related artery. In this sub-study, evidence for the occurrence of reperfusion before admission to hospital has been sought. In a randomized double-blind controlled trial, 311 patients with suspected acute myocardial infarction were given anistreplase 30 units i.v., either at home at a median 101 min (early group, n = 163), or in hospital at a median 240 min after symptom onset (large group, n = 148). Paired electrocardiograms recorded at home and on admission to hospital were available for study in 143 and 137 patients in early and late groups. Reduction in ST elevation between home and hospital electrocardiograms of > 25% in a single lead was taken as evidence of reperfusion. Patients with significant ST elevation in either electrocardiogram comprised the sub-study groups, and numbered 63/143 (44%) and 68/137 (50%) in early and late groups respectively. A reduction of > 25% in the single lead demonstrating greatest ST elevation on the presenting electrocardiogram was observed in 37/63 (59%) and 23/68 (34%) patients in the early and late sub-study groups (difference 25%, 95% confidence interval 8% to 42%, P = 0.003). It was found that domiciliary thrombolysis was associated with electrocardiographic evidence of an increased rate of reperfusion occurring before admission to hospital. Evidence of reperfusion occurring pre-hospital, whether spontaneous or following thrombolytic therapy, was associated with a better outcome.

Anistreplase↗
PubMed1993

Earliest electrocardiographic evidence of myocardial infarction: implications for thrombolytic treatment. The GREAT Group.

OBJECTIVES: To determine the incidence of the earliest electrocardiographic changes in patients with suspected myocardial infarction and their sensitivity and specificity for predicting the final diagnosis of acute myocardial infarction. DESIGN: Retrospective study of paired electrocardiograms recorded at home and on admission to hospital. SETTING: 29 rural practices in Grampian and teaching hospitals in Aberdeen. PATIENTS: 137 patients participating in the early anistreplase trial in the Grampian region, who received placebo at home and for whom paired electrocardiograms were available. MAIN OUTCOME MEASURES: Classified electrocardiographic abnormalities and diagnosis at discharge. RESULTS: Electrocardiograms were recorded immediately before injection of placebo at home and anistreplase in hospital at median times of 110 and 240 minutes after the onset of symptoms. Definite or probable myocardial infarction was later confirmed in 93 (68%) patients. Of these, 66 (71%) had the same findings on both electrocardiograms of either ST elevation, bundle branch block, or a non-specific abnormality, while 27 (29%) showed a major change of classification between home and hospital recordings; 21 (23%) had ST elevation or bundle branch block on only one of the paired recordings. Although ST elevation was the commonest abnormality in the 93 patients with myocardial infarction, in only 51 was it recorded at home (sensitivity 55%) and in 49 on admission (sensitivity 53%). Of 57 patients with ST elevation at home, six did not have infarction (specificity 86%), while of 51 with ST elevation on admission, two did not have infarction (specificity 95%). CONCLUSIONS: Elevation of the ST segment is a transient electrocardiographic abnormality that has high specificity but low sensitivity for predicting the diagnosis of acute myocardial infarction; it is an unsatisfactory precondition for giving thrombolytic treatment to patients with suspected acute myocardial infarction.

Anistreplase↗
PubMed1993

Measurement of cardiac output with the Quantascope, a novel Doppler device: comparison with thermodilution.

The Quantascope is a novel non-imaging echo-Doppler device designed to measure cardiac output. We have compared this device with thermodilution. Twenty-five patients with suspected coronary artery disease undergoing diagnostic coronary arteriography simultaneously had cardiac output measured with the Quantascope and with thermodilution. Doppler systematically underestimated cardiac output, when compared with thermodilution, by a mean (SD) of 0.9 (1.5) l.min-1 (P < 0.01). The cardiac output derived by the Doppler technique did not correlate with that derived by thermodilution (r = 0.36, P = NS). Compared with the currently accepted reference technique of thermodilution, we found measurement of cardiac output by the Quantascope to be inaccurate: this contradicts previous reports.

Aged↗
PubMed1993

Loss of quality adjusted days as a trial endpoint: effect of early thrombolytic treatment in suspected myocardial infarction. Grampion Region Early Anistreplase Trial (GREAT).

STUDY OBJECTIVES: (1) To measure the quality of life and the loss of quality adjusted days (QADS) after suspected acute myocardial infarction in patients who received thrombolytic treatment either at home or in hospital. (2) To compare the loss of QADS as a trial endpoint with the conventional endpoints of mortality and Q-wave infarction. DESIGN: Randomised double blind parallel group trial of anistreplase (30 U given intravenously) and placebo given either at home or in hospital. SETTING: Rural practices in Grampian admitting patients to teaching hospitals in Aberdeen. PATIENTS: A total of 311 patients with suspected acute myocardial infarction and no contraindications to thrombolytic treatment seen at home within four hours of the onset of symptoms. MEASUREMENTS AND MAIN RESULTS: Loss of quality adjusted days (QADS) in the first 100 days after suspected myocardial infarction (365 QADS = 1 QALY) was the main outcome measure. Compared with later administration in hospital, anistreplase at home resulted in a relative reduction of mortality of 49% (95% confidence interval 3.95%, 2p = 0.04), and a relative reduction of 26% in the proportion of survivors with infarction who had Q-waves (95% CI 7.44%, 2p = 0.007). During the 100 day follow up, the median loss of QADS was 25 for all patients. This loss was significantly greater in those who died than in survivors (65 v 18, 2p < 0.001), and in survivors with infarction than in survivors without infarction (26 v 13, 2p < 0.01). However, there was no significant difference in loss of QADS in those with infarction with or without Q-waves (29 v 21, NS), and the median loss of QADS was not significantly different in those who had thrombolytic treatment at home or in hospital (median difference 0, 95% CI -5, +4 QADS). CONCLUSIONS: Loss of QADS had two serious limitations as an outcome measure: it was less sensitive than mortality and it failed to reflect physiological benefit. Palliative treatment with no physiological effect would have resulted in a greater gain in QADS (or QALYs) than did early thrombolytic treatment. Extreme caution is required in accepting a gain in QALYs as a valid outcome measure for health care.

Anistreplase↗
PubMed1992

Quality of life in the first 100 days after suspected acute myocardial infarction--a suitable trial endpoint?

STUDY OBJECTIVE: The aim was to determine the loss of quality of life following admission to hospital with suspected myocardial infarction. DESIGN: The study involved a cohort of admissions, with interview and follow up for 100 days. Main outcome measures were the quality of life prior to admission and at each stage of convalescence, estimated using the Rosser-Kind matrix: the calculated number of quality adjusted days during a 100 d follow up period. SETTING: The study took place in a teaching hospital in Scotland. PATIENTS: 206 patients were admitted with suspected acute myocardial infarction. Infarction was confirmed in 160 (Q wave infarcts 100, non-Q-wave infarcts 60), and unconfirmed in 46. MAIN RESULTS: The quality of life scores before the suspected heart attack were similar for patients whose final diagnosis was Q wave infarction, non-Q-wave infarction, or non-infarction. Of the 160 patients with confirmed infarction, only 54 (34%) had regained their previous quality of life scores at the end of 100 days, compared with 26 of 46 (57%) patients with unconfirmed infarction (p < 0.01). The mean numbers of quality adjusted days lost to patients with Q wave infarction, non-Q-wave infarction, and non-infarction were 17.0, 12.4, and 5.9 respectively (infarction v non-infarction, p < 0.0001). Measurements of both quantity and quality of life contributed to these results. CONCLUSIONS: The number of quality adjusted days lost after acute myocardial infarction is a practicable measurement that is relevant to patients' lives. It might be suitable as an outcome measure for clinical trials of thrombolytic therapy.

Adult↗
PubMed1992

General practitioners and emergency treatment for patients with suspected myocardial infarction: last chance for excellence?

Pre-hospital coronary care usually consists of a medically staffed coronary care ambulance going into the community from a hospital base, as pioneered in Northern Ireland. In today's medicopolitical and economic climate, this model is not viable in mainland United Kingdom. Current proposals seem to favour a 'scoop and run' policy for heart attack victims, that utilizes the ambulance service but bypasses the general practitioner. Since the majority of telephone calls from people with suspected myocardial infarction are directed to general practitioners, a preferable alternative would be a 'stay and stabilize' strategy that uses the existing referral pattern and builds on general practitioners' medical education and skills. The role of the general practitioner in the management of patients with suspected myocardial infarction is discussed.

Ambulances↗
PubMed1991

Comparison of four different Doppler instruments used to measure linear and volumetric cardiac output: a study of reproducibility and agreement.

Values of stroke distance obtained from 25 subjects with the obsolete Transcutaneous Aortovelograph were compared with those from two commercially available Doppler ultrasound devices, the Doptek Decoder, and the Doppler unit of the Interspec-XL Ultrasound System. Also studied was the Quantascope, an ultrasound device designed to measure stroke volume. In the aortic arch, reproducibility was 4.8% with the Transcutaneous Aortovelograph, 9.1% with the Doptek Decoder, 17.2% with the Interspec, and 23.6% with the Quantascope. In the ascending aorta, reproducibility was worse, being 13.4% for the Doptek, 23.0% for the Interspec, and 28.1% for the Quantascope. There was close agreement between the absolute values of stroke distance obtained with the Transcutaneous Aortovelograph and the Interspec, but lower values were obtained by the Doptek Decoder. There is a need for an updated instrument dedicated to the measurement of stroke distance in the aortic arch.

Adolescent↗
PubMed1991

A comparison of the chronic effects of oral xamoterol and enalapril on blood pressure and renal function in mild to moderate heart failure.

1. We compared the effects, after 3 weeks oral therapy, of xamoterol 200 mg twice daily and enalapril 2.5, 5 or 10 mg twice daily on home and clinic blood pressure, glomerular filtration rate (GFR) and renal plasma flow, stroke and minute distances, linear resistance and on plasma renin activity in 19 patients with mild to moderate heart failure in a single-blind randomised crossover study. 2. Enalapril reduced mean home blood pressure by 17/7 mm Hg compared with xamoterol (P less than 0.0001) and by 19/7 mm Hg compared with placebo. Compared with placebo xamoterol had no effect. Enalapril reduced predose blood pressure, compared with xamoterol, on average by 15/5 mm Hg (P = 0.02 systolic, 0.09 diastolic) and by 20/7 mm Hg compared with placebo. At 4 h post-dose the mean differences were: xamoterol-enalapril 13/10 mm Hg (P = 0.01 systolic, 0.0007 diastolic) and placebo-enalapril 23/9 mm Hg. 3. Stroke and minute distances were marginally less 4 h following xamoterol than following enalapril: mean (s.e. mean) values were 9.4 (0.7) vs 10.4 (0.8) cm (P = 0.23) and 699 (51.7) vs 767 (62.1) cm (P = 0.04) respectively. Linear resistance was reduced by enalapril, from the placebo value of 13.2 (1.2) to 11.0 (0.9) mm Hg m-1 and marginally increased by xamoterol, to 14.2 (1.2) mm Hg m-1, the difference between active treatments being statistically significant (P = 0.03). 4. Renal plasma flow, GFR and filtration fraction were not influenced by enalapril or xamoterol therapy. There were no significant correlations between glomerular filtration rate and either blood pressure or stroke distance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1990

The QALY argument: a physician's and a philosopher's view.

The arguments used by Gavin Mooney in his scornful response to Castigating QALYs, are examined. In spite of the rhetoric there is a broad measure of agreement about the deficiencies of QALYs as a means of distributing scarce resources. The main area of conflict is that John Rawles favours compaigning for more resources while Gavin Mooney, constrained by his remit as a health economist, favours acceptance of the present level of funding and better methods of distributing resources.

Attitude of Health Personnel↗
PubMed1990

The management of suspected myocardial infarction by Scottish general practitioners with access to community hospital beds.

General practitioners working in 20 community hospitals in Scotland participated in a survey of the management of myocardial infarction. During one year they suspected acute myocardial infarction in 451 patients. Of these patients, 278 (62%) were admitted to a community hospital, 125 (28%) to a district general hospital and 48 (11%) were kept at home. The main reasons given for admission to a community hospital were for monitoring and investigation, while the main reasons for admission to a district hospital rather than a community hospital were the relative youth of the patient and the severity of the illness. Acute myocardial infarction was confirmed in 323 (72%) cases, but in 26 (6%) cases the final diagnosis was other than ischaemic heart disease. Patients with acute myocardial infarction who entered a community hospital did so a median of two hours 25 minutes after the onset of symptoms. Among 18 patients admitted to a community hospital in whom resuscitation was attempted after cardiac arrest four (22%) were subsequently discharged from hospital. The mortality rate from acute myocardial infarction in the community studied was 171/418 (41%), of whom 95 died suddenly before coming under medical care. It is concluded that in rural areas of Scotland an acceptable standard of care for patients with acute myocardial infarction, including the administration of thrombolytic therapy, could be provided rapidly by general practitioners working in community hospitals.

Adult↗