FIELD REFERENCE
Full criteria & treatment guidance
Key cautions & base contact
- Hold aspirin for allergy, anticoagulant/antiplatelet use, or direct midline mid-back pain raising concern for dissection.
- Do not give nitroglycerin after sildenafil, vardenafil, or tadalafil within 24 hours. Avoid IO in potential CVRC patients because of possible thrombolysis-related bleeding.
Recognize & assess
- Suspect an anginal equivalent with unexplained diaphoresis, sudden weakness, dyspnea, anxiety, or atypical chest discomfort. Heartburn-like, pleuritic, or musculoskeletal-sounding pain does not exclude cardiac disease.
- Monitor rhythm and obtain a 12-lead as soon as practical before leaving the scene. A normal/non-STEMI tracing does not rule out acute MI.
Initial treatment
- If no contraindication applies, give four 81 mg aspirin tablets (324 mg) or one 325 mg tablet to chew.
- When room-air SpO₂ is below 95%, provide mask oxygen or nasal cannula at 6 L/min as tolerated.
- For discomfort, give nitroglycerin 0.4 mg SL if systolic BP is above 100; repeat about every 3 minutes, up to 3 EMS doses while BP stays above 100. Prior self-doses are not included in that EMS count.
Persistent pain or nausea
- If 3 nitroglycerin doses fail or nitroglycerin cannot be given, give morphine 5 mg (or 4 mg carpuject) IV, or fentanyl 50 mcg IV. Either may repeat once after about 3 minutes; hold if systolic BP is below 90.
- For nausea/vomiting without known or suspected pregnancy: ondansetron 8 mg ODT or 4 mg IV, with one IV repeat after about 3 minutes if needed.
Destination & reassessment
- Suspected/identified acute MI requires base contact for a CVRC with an available catheterization lab. Otherwise provide ALS escort to an appropriate ERC.
- Reassess pain, BP, breathing, rhythm, and treatment response. If a patient with a performed 12-lead requests AMA, contact base before leaving the scene.
Assess the whole patient — possible ACS
- Consider suspected cardiac ischemia from the complete presentation: onset and course, discomfort location/radiation, exertional context, known heart disease and medications, associated symptoms, skin signs, breathing, perfusion and vital-sign trends. Ask what is different from the patient’s usual symptoms.
- OCEMS anginal equivalents include unexplained sweating/diaphoresis, sudden weakness, dyspnea, anxiety or a vague feeling of panic. Cardiac illness can present with heartburn-like, pleuritic or musculoskeletal-sounding discomfort.
- Pain reproduced by palpation or movement can suggest a chest-wall source, but that feature alone does not establish a noncardiac diagnosis or rule out ACS. Continue the indicated assessment and early 12-lead; a normal/non-STEMI tracing does not exclude acute MI or serious angina.
- When adult/adolescent ACS or an anginal equivalent is reasonably suspected, use SO-C-015 and its aspirin exclusions. Do not dismiss a cardiac cause from one reassuring feature or give aspirin automatically for every chest-pain complaint. This is an educational assessment reminder, not a field rule-out tool.
OCEMS SO-C-015 — exact indication, exclusions and assessment guidance
UNDERSTAND THE CARE
Why an ACS assessment is more than a chest-pain description
The clinical picture combines symptoms, their onset, risk context, perfusion and ECG findings. The local order recognizes anginal equivalents and atypical descriptions. A reproducible or heartburn-like discomfort may suggest an alternative explanation but cannot, by itself, finish the cardiac assessment. A normal or non-STEMI tracing also does not exclude acute MI.
Applying the guidance
Connect each medication decision to its own eligibility conditions. Record medication already taken, the pressure before repeat nitroglycerin and the response to treatment. When the tracing or clinical picture raises concern for acute MI, communicate the findings and coordinate the receiving cardiovascular center’s availability. Repeat assessment when symptoms or physiology change.
Putting it together
Teaching example: a patient describes indigestion with sweating and weakness. The assessment should retain the possible anginal-equivalent pathway and early ECG rather than relying on the patient’s label for the discomfort.
Diagram text & teaching checkpoints
- Presentation
- Symptoms, onset and anginal equivalents.
- ECG
- Acquire, assess and transmit when indicated.
- Treatment checks
- Allergy, medications, pressure and exclusions.
- Reassessment
- Symptoms, ECG evolution and destination.
Sources for this explanation
Original OCMedic teaching synthesis of the references below. Educational expansion updated ; this is not a new independent clinical-review date. Source-specific dates and limitations remain in the full guidance.