Survey of general practitioners' prehospital management of suspected acute myocardial infarctionBMJ 1994; 309 doi: https://doi.org/10.1136/bmj.309.6951.375 (Published 06 August 1994) Cite this as: BMJ 1994;309:375
- A Round,
- A J Marshall
- Correspondence to: Dr Round.
- Accepted 7 July 1994
The effectiveness of thrombolysis in acute myocardial infarction is greater the shorter the time between onset of symptoms and administration of thrombolysis.1 Recent guidelines for the British Heart Foundation suggest that thrombolysis should be given within 90 minutes.2 Debate continues, however, about the best way to give thrombolysis and about the role of general practitioners.3,4 We studied general practitioners' knowledge of and attitudes and behaviour towards patients with suspected acute myocardial infarction and considered the relevance of our findings to the development of district policies.
Subjects, methods, and results
Between June and August 1992 we sent a questionnaire to all general practitioners (n=205) who refer patients to Plymouth's coronary care unit, where all hospital thrombolysis for myocardial infarction in Plymouth district is given. The district is clearly divided into rural and urban areas, with 143 urban and 62 rural general practitioners and longer times for travelling to hospital from the rural areas. We asked about the doctors' knowledge of thrombolysis; attitudes to aspirin; administration of thrombolysis and use of electrocardiography; and behaviour with respect to patients with suspected acute myocardial infarction.
During the same period we reviewed the records of all patients admitted to the coronary care unit who were given thrombolysis (n=149). We determined the total number of patients admitted with a final diagnosis of myocardial infarction (n=222) from the hospital computer system. We recorded details of prehospital electrocardiography, administration of thrombolysis and aspirin, and delay between symptoms and use of thrombolysis. For geographical reasons, no other coronary care unit is available for over 95% of the district's population so the patients admitted accurately reflect general practitioners' behaviour.
In all, 180 (88%) general practitioners completed the questionnaire (88% of urban and 87% of rural doctors). Knowledge of thrombolysis was reasonable, with 148 (82%) respondents giving the correct answer to one or more of three questions. Most general practitioners (98 (54%)), however, did not consider that giving thrombolysis was part of their job (table); 80 of the 98 respondents gave more than one reason, but the two most common reasons (each given by 60 (61%) respondents) were diagnostic uncertainty and practical difficulties. With respect to electrocardiography in patients with acute chest pain, respondents did not consider it useful (72(40%)), were neutral (41 (23%)), or considered it worthwhile (67 (37%)). Aspirin was valued, however, with 160 (89%) respondents stating that they gave aspirin routinely.
Examination of the records showed that thrombolysis was given by only one (1%) general practitioner (once); prehospital electrocardiography was performed on 16 (11%) occasions; and aspirin was given on 43 (29%) occasions. The difference between this finding on aspirin and the stated routine practice of 89% (in the questionnaire) is significant (P<0.001, 95% confidence interval 51% to 69%).
In all, 142 records had complete information about delay between onset of symptoms and administration of thrombolysis. Surprisingly, no significant correlation existed between urban or rural residence and delay: median delay was 5.1 hours and 4.5 hours respectively.
This survey suggests that general practitioners, although well informed about managing suspected acute myocardial infarction, do not wish to give thrombolysis themselves and do not often give aspirin or perform electrocardiography. Only 67% of patients admitted with acute myocardial infarction, however, were given thrombolysis, although these patients were probably those in whom general practitioners believed myocardial infarction was most likely and who were therefore admitted to the coronary care unit.
These findings are relevant in formulating district policies for maximum benefit from thrombolysis. Although the delay between onset of symptoms and administration of thrombolysis is reduced when thrombolysis is given before a patient is admitted - by 60 minutes on average,4 perhaps more if given by a general practitioner5 - a considerable change in general practitioners' attitude and behaviour is needed if they are to give thrombolysis routinely. Doctors in primary and secondary care must work together in this field as in others.