From the Guidelines
For a patient experiencing chest pain in the clinic before EMS transfer, administer 162-324 mg of non-enteric coated aspirin (acetylsalicylic acid) as soon as possible, as recommended by the 2024 American Heart Association and American Red Cross guidelines for first aid 1. The patient should chew the tablets rather than swallow them whole to facilitate rapid absorption. This typically means giving either two 81 mg baby aspirin tablets or one regular 324 mg tablet. Aspirin works by irreversibly inhibiting platelet aggregation, which helps prevent further clot formation in the coronary arteries if the chest pain is due to acute coronary syndrome. This immediate intervention can significantly reduce mortality in patients experiencing a myocardial infarction, as supported by a 2020 systematic review that found early administration of aspirin to adults with nontraumatic chest pain was associated with reduced mortality 1. The non-enteric coated formulation and chewing method allow for faster absorption through the oral mucosa and more rapid onset of antiplatelet effects. Aspirin should be given regardless of whether the patient reports already taking daily aspirin, unless there is a clear contraindication such as true aspirin allergy, active gastrointestinal bleeding, or a bleeding disorder. Some key points to consider when administering aspirin include:
- The dose of 162-324 mg is recommended for patients with suspected myocardial infarction 1
- Non-enteric coated aspirin is preferred for faster absorption 1
- Chewing the tablets facilitates rapid absorption 1
- Aspirin should be given promptly, unless contraindicated 1
From the Research
Aspirin Administration for Chest Pain
- The ideal dose of aspirin for a patient experiencing chest pain in the clinic before Emergency Medical Services (EMS) transfer is not explicitly stated in the provided studies.
- However, the studies suggest that aspirin should be administered as soon as possible to patients with suspected cardiac ischemia, as early administration is associated with increased survival 2.
- The American Heart Association recommends that aspirin be administered to patients with suspected acute coronary syndrome, including those with chest pain, as soon as possible, ideally within 24 hours of symptom onset.
Considerations for Aspirin Administration
- Before administering aspirin, it is essential to consider the patient's medical history, including any contraindications to aspirin use, such as bleeding disorders or allergy to aspirin 3, 4.
- The studies also highlight the importance of paramedics and prehospital personnel being aware of the benefits and potential risks of aspirin administration in the prehospital setting 5, 6.
- Aspirin is rarely associated with adverse events when administered by prehospital personnel for presumed coronary syndromes 3.
Prehospital Aspirin Administration
- The studies suggest that prehospital aspirin administration is not always optimal, with some patients not receiving aspirin due to various reasons, including the paramedic's belief that the chest pain is not of cardiac nature or the patient's previous use of aspirin 5, 4.
- Early administration of aspirin, ideally within two hours of symptom onset, is associated with improved survival outcomes 2.