Pre-Hospital Management of Acute Myocardial Infarction A. W. Murphy, R. Power, K. Ungruh, G. Bury
Department of General Practice Professional Unit, University College, Dublin. Abstract Two-hundred and eleven Irish GPs responded to a questionnaire survey of their experience and management of acute myocardial infarction (MI) and their attitudes to the use ofthrombolytic therapy. Three-quarters of the respondents felt they dealt with three or more MIs per year; most felt that the'majority of MIs were initially seen by a GP. Diagnosis is based on clinical findings; only 11% i'outinely take an ECG. Management is largely nriented to relief of pain but intravenous narcotics are only used by a minority. Hospital referral for suspected acute MI was the preferred choice for almost all GPs in a variety of patlent-care scenarios, ttome care for MI was chosen only for a minority of elderly patients when some hours had elapsed since the onset of symptoms. Definitive guidelines on the pre-hospital use ofthrombolysis are not yet available. However, eighty per cent of respondents in this study feel that thrombolysis is beneficial and many feel that it has value in the pre-hospital situation. Respondents identified educational, organisational and financial problems to be overcome before this could happen. Introduction Ischaemic Heart Disease is the single most important cause of death in the Western world, accounting for over 10,000 deaths a year. in Ireland alone1. The treatment of acute myocardial infarction (MI) has recently undergone a revolution with the advent of thrombolysis. It is now accepted that the earlier thrombolysis is initiated, the greater the likelihood of successful reperfusion, limitation of infarct size and reduction of both early and late mortality23. In the GISSI study, for example, streptokinase treatment within the first three hours was associated with the greatest improvement in mortality2. Clinical trials have clearly demonstraed a pattern of diminishing returns with increasing delays2"5, However the median time between the onset of symptoms and admission to a hospital bed is generally four to six hours, with patient delay constituting the largest componenP .7. To reduce these crucial delays, the definitive role of the general practitioner in the early diagnosis+.9, management '0.'' and possible initiation of pre-hospital thrombolysis12"1+is currently undergoing reappraisal. A great deal of information on pre-hospital thrombolytic therapy will be provided by the RCGP Manchester Research Unit from its prospective multi-observer study of GP administered thrombolysis and this may help to resolve some of these issuest~. The application of these findings must however take into account the unique primary care environment and the individual experiences and attitudes of general practitioners. This study was undertaken to examine these issues by establishing the views of Irish general practitioners about the pre-hospital care of patients with suspected myocardial infarction and their attitudes towards thrombolytic therapy.
stamped addressed envelope was enclosed. Five hundred members of the Irish College of General Practitioners were randomly selected; the membership of the ICGP includes about 90% of all Irish GPs. The survey involved twenty eight questions in several sections. The first dealt with personal and practice characteristics, the second with GP's experience and usual management of MI, the third with referral practices for MI in a variety of circumstances and the final section dealt with attitudes to the use of thrombolytic therapy in a pre-hospitai setting. The third section which presented the respondents with theoretical situations was similar to models previously used by Pell t~and Mason 16. Each involved a patient with clinical indications of an acute MI, who was haemodynamicaUy stable and had good social support. Respondents were asked to make referral decisions for patients of different ages and different elapsed times since the onset of symptoms. In describing their usual management, respondents were asked to indicate their use of certain procedures along a five point scale ranging from "never use" to "always use". A number of questions were incompletely answered, giving slightly different numbers of respondents to different questions. The total numbers of respondents therefore varies slightly between different Tables. Results Five hundred questionnaires were distributed. A total of 211 (42%) valid replies was received. Tables I to V show the age, sex and practice characteristics of respondents. Eighty-six (41%) had received vocational training in general practice, 76 (36%) had obtained the MRCGP and 19 (9%) practices were part of vocational training schemes for general practice. Table V1 shows that almost one half of the GPs surveyed (47%), estimated that on average three to six Mls occur per year in their practices; a further 53 GPs (25%) consid-
Methods The study used a postal questionnaire in a six page catalogue type format. An explanatory cover letter and
593
IJ.M.S. October, 1992
594 Murphy et al. ered the figure to be between seven and 10 MIs per year. More than two thirds of GPs felt that at least 75% of these patients were seen initially by GPs (Table VII). Usual management of suspected MI: Eighty three GPs (40%) never have access to an ECG machine whilst 84 (41%) have twenty four access; the remainder have limited access only. One hundred and forty eight GPs (75%) never or almost never take an ECG in suspected MIs whereas 21 (11%) always or almost always do so. One hundred and fifteen GP~s'(60%) never or almost never give aspirin to a patient ,~vith suspected MI; 62 (32%) always or almost alw.'iys do. Ninety five (48.7%) always or almost always give a narcotic via the intramuscular route; 49 (26.8%) always or almost always use the iatravenous route for analgesia. Eighty five (43%) never or almost never give sublingual nitrate, whereas 71 (27%) always or amost always administer the drug. There was no association found between the doctors age or a background of Vocational training and suggested management. Referral decisions in theoretical scenarios: Table VII1 shows the numbers of GPs who, in cases of suspected MI, would opt for home treatment of suspected MI. Equivalent UK figures are from Pell in Scotland~~ Home treatment is increasingly preferred by Irish GPs when the patient is older and ~ e elapsed time from onset of symptoms longer. There is no correlation between GPs reported usual treatTABLE I Age and sex respondents (n=211) Male 25-34 years 35~14 years 45 -54 years 55-64years >65years
7 (3.3%) 20 (9.5%) 6 (2.8%) 1 (0.5%) 1 (0.5%)
Number of respondents
Urban
Rural
Mixed
66 (31.3%)
51 (24.2%)
94 (44.55)
1
2
3
4
5
115 55 30 7 3 (54.8%) (26.2%) (14.3%) (3.3%) (IA%) TABLE IV Post-graduate qualifications
Number
Vocational training 86 (40.7%)
MICGP 167 (79.1%)
30-69 mlns 1-2 hours
>2 hours
143 (68%)
53 (25.2%) 11 (5.2%)
3 (1.4%)
TABLE VI Estimated annual incidence of MI per GP (n=207) Average number of MIs per year 0-2 3-6 7-10 11-15 >15
Frequency 31 (15.0%) 98 (47.3%) 53 (25.6%) 12 (5.8%) 13 (6.3%)
TABLE VII Percentage of MIs seen initially by GPs (207) % seen by GP before referral to hospital
Frequency 18 (8.7%) t7 (8.2%) 36 (17.4%) 69 (33.3%) 67 (32.4%)
Department of General Practice Professional Unit, University College, Dublin. Abstract Two-hundred and eleven Irish GPs responded to a questionnaire survey of their experience and management of acute myocardial infarction (MI) and their attitudes to the use ofthrombolytic therapy. Three-quarters of the respondents felt they dealt with three or more MIs per year; most felt that the'majority of MIs were initially seen by a GP. Diagnosis is based on clinical findings; only 11% i'outinely take an ECG. Management is largely nriented to relief of pain but intravenous narcotics are only used by a minority. Hospital referral for suspected acute MI was the preferred choice for almost all GPs in a variety of patlent-care scenarios, ttome care for MI was chosen only for a minority of elderly patients when some hours had elapsed since the onset of symptoms. Definitive guidelines on the pre-hospital use ofthrombolysis are not yet available. However, eighty per cent of respondents in this study feel that thrombolysis is beneficial and many feel that it has value in the pre-hospital situation. Respondents identified educational, organisational and financial problems to be overcome before this could happen. Introduction Ischaemic Heart Disease is the single most important cause of death in the Western world, accounting for over 10,000 deaths a year. in Ireland alone1. The treatment of acute myocardial infarction (MI) has recently undergone a revolution with the advent of thrombolysis. It is now accepted that the earlier thrombolysis is initiated, the greater the likelihood of successful reperfusion, limitation of infarct size and reduction of both early and late mortality23. In the GISSI study, for example, streptokinase treatment within the first three hours was associated with the greatest improvement in mortality2. Clinical trials have clearly demonstraed a pattern of diminishing returns with increasing delays2"5, However the median time between the onset of symptoms and admission to a hospital bed is generally four to six hours, with patient delay constituting the largest componenP .7. To reduce these crucial delays, the definitive role of the general practitioner in the early diagnosis+.9, management '0.'' and possible initiation of pre-hospital thrombolysis12"1+is currently undergoing reappraisal. A great deal of information on pre-hospital thrombolytic therapy will be provided by the RCGP Manchester Research Unit from its prospective multi-observer study of GP administered thrombolysis and this may help to resolve some of these issuest~. The application of these findings must however take into account the unique primary care environment and the individual experiences and attitudes of general practitioners. This study was undertaken to examine these issues by establishing the views of Irish general practitioners about the pre-hospital care of patients with suspected myocardial infarction and their attitudes towards thrombolytic therapy.
stamped addressed envelope was enclosed. Five hundred members of the Irish College of General Practitioners were randomly selected; the membership of the ICGP includes about 90% of all Irish GPs. The survey involved twenty eight questions in several sections. The first dealt with personal and practice characteristics, the second with GP's experience and usual management of MI, the third with referral practices for MI in a variety of circumstances and the final section dealt with attitudes to the use of thrombolytic therapy in a pre-hospitai setting. The third section which presented the respondents with theoretical situations was similar to models previously used by Pell t~and Mason 16. Each involved a patient with clinical indications of an acute MI, who was haemodynamicaUy stable and had good social support. Respondents were asked to make referral decisions for patients of different ages and different elapsed times since the onset of symptoms. In describing their usual management, respondents were asked to indicate their use of certain procedures along a five point scale ranging from "never use" to "always use". A number of questions were incompletely answered, giving slightly different numbers of respondents to different questions. The total numbers of respondents therefore varies slightly between different Tables. Results Five hundred questionnaires were distributed. A total of 211 (42%) valid replies was received. Tables I to V show the age, sex and practice characteristics of respondents. Eighty-six (41%) had received vocational training in general practice, 76 (36%) had obtained the MRCGP and 19 (9%) practices were part of vocational training schemes for general practice. Table V1 shows that almost one half of the GPs surveyed (47%), estimated that on average three to six Mls occur per year in their practices; a further 53 GPs (25%) consid-
Methods The study used a postal questionnaire in a six page catalogue type format. An explanatory cover letter and
593
IJ.M.S. October, 1992
594 Murphy et al. ered the figure to be between seven and 10 MIs per year. More than two thirds of GPs felt that at least 75% of these patients were seen initially by GPs (Table VII). Usual management of suspected MI: Eighty three GPs (40%) never have access to an ECG machine whilst 84 (41%) have twenty four access; the remainder have limited access only. One hundred and forty eight GPs (75%) never or almost never take an ECG in suspected MIs whereas 21 (11%) always or almost always do so. One hundred and fifteen GP~s'(60%) never or almost never give aspirin to a patient ,~vith suspected MI; 62 (32%) always or almost alw.'iys do. Ninety five (48.7%) always or almost always give a narcotic via the intramuscular route; 49 (26.8%) always or almost always use the iatravenous route for analgesia. Eighty five (43%) never or almost never give sublingual nitrate, whereas 71 (27%) always or amost always administer the drug. There was no association found between the doctors age or a background of Vocational training and suggested management. Referral decisions in theoretical scenarios: Table VII1 shows the numbers of GPs who, in cases of suspected MI, would opt for home treatment of suspected MI. Equivalent UK figures are from Pell in Scotland~~ Home treatment is increasingly preferred by Irish GPs when the patient is older and ~ e elapsed time from onset of symptoms longer. There is no correlation between GPs reported usual treatTABLE I Age and sex respondents (n=211) Male 25-34 years 35~14 years 45 -54 years 55-64years >65years
7 (3.3%) 20 (9.5%) 6 (2.8%) 1 (0.5%) 1 (0.5%)
Number of respondents
Urban
Rural
Mixed
66 (31.3%)
51 (24.2%)
94 (44.55)
1
2
3
4
5
115 55 30 7 3 (54.8%) (26.2%) (14.3%) (3.3%) (IA%) TABLE IV Post-graduate qualifications
Number
Vocational training 86 (40.7%)
MICGP 167 (79.1%)
30-69 mlns 1-2 hours
>2 hours
143 (68%)
53 (25.2%) 11 (5.2%)
3 (1.4%)
TABLE VI Estimated annual incidence of MI per GP (n=207) Average number of MIs per year 0-2 3-6 7-10 11-15 >15
Frequency 31 (15.0%) 98 (47.3%) 53 (25.6%) 12 (5.8%) 13 (6.3%)
TABLE VII Percentage of MIs seen initially by GPs (207) % seen by GP before referral to hospital
Frequency 18 (8.7%) t7 (8.2%) 36 (17.4%) 69 (33.3%) 67 (32.4%)
