What are the key management steps for Acute Coronary Syndrome (ACS) conditions in the prehospital setting for paramedics?

Paramedic Cheat Sheet for Acute Coronary Syndrome (ACS) Management

The immediate management of suspected ACS by paramedics should focus on rapid recognition, administration of key medications, and prompt transport to an appropriate facility for definitive care, as these actions significantly reduce mortality and improve outcomes. 1

Initial Assessment and Recognition

• Key symptoms to recognize:

  • Chest discomfort/pain (typically substernal, may radiate to arms/jaw)
  • Shortness of breath
  • Diaphoresis (sweating)
  • Nausea/vomiting
  • Lightheadedness
  • Note: Women, elderly, and diabetic patients may present with atypical symptoms 1

• Vital signs:

  • Monitor cardiac rhythm continuously
  • Check blood pressure, heart rate, respiratory rate, oxygen saturation
  • Be prepared for sudden cardiac arrest (VF/VT most common in early ACS) 1

Immediate Interventions (First 10 Minutes)

1. Obtain 12-lead ECG immediately (within 10 minutes of first contact)

   • Identify ST-segment elevation (STEMI) vs. non-ST elevation (NSTEMI/UA)
   • Transmit ECG to receiving hospital if possible
   • Provide early notification to hospital for STEMI 1

2. Administer medications:

   • Aspirin: 160-325 mg non-enteric, chewed (Class I, LOE B)

     • Contraindications: Allergy, active GI bleeding 1
     • Dispatch can instruct patients to take aspirin before EMS arrival 1

   • Oxygen: Only if SpO₂ <94% or signs of respiratory distress

     • Titrate to maintain SpO₂ ≥94% (Class I, LOE C) 1
     • Avoid routine oxygen in uncomplicated ACS

   • Nitroglycerin: Up to 3 doses (tablets/spray) at 3-5 minute intervals

     • Contraindications:
       • SBP <90 mmHg or 30 mmHg below baseline
       • Right ventricular infarction (perform right-sided ECG if inferior STEMI)
       • Use of PDE-5 inhibitors within 24-48 hours (Viagra, Cialis, etc.) 1

   • Morphine: For STEMI with chest pain unresponsive to nitrates (Class I, LOE C)

     • Use with caution in UA/NSTEMI (associated with increased mortality) 1

Transport Decision-Making

1. For STEMI patients:

   • If PCI is chosen reperfusion strategy and available within 90 minutes:

     • Transport directly to PCI-capable facility
     • Bypass closer hospitals if necessary when transport time <30 minutes 1

   • If PCI not available within 120 minutes:

     • Transport to nearest appropriate facility for fibrinolytic therapy 2

2. For high-risk NSTEMI/UA patients:

   • Transport to facility capable of cardiac catheterization within 24 hours 1, 3

3. For cardiogenic shock patients:

   • Transport to facility capable of rapid revascularization 1

Special Considerations

• Inferior wall MI: Perform right-sided ECG to rule out RV involvement; use nitrates with extreme caution if RV involved 1

• Prehospital fibrinolysis: Consider only in well-organized EMS systems with:

  • Physicians present or full-time paramedics with ECG transmission capability
  • Paramedic training in ECG interpretation
  • Medical direction with STEMI management experience
  • Continuous quality improvement program 1

• Risk stratification: Consider TIMI Risk Score factors:

  • Age ≥65 years
  • ≥3 CAD risk factors
  • Known coronary stenosis ≥50%
  • ST deviation ≥0.5mm
  • ≥2 anginal events in 24 hours
  • Aspirin use in past 7 days
  • Elevated cardiac markers 1

Documentation Essentials

• Time of symptom onset
• Medication administration times and doses
• ECG findings and times
• Vital sign trends
• Response to interventions
• Hospital pre-notification details

Common Pitfalls to Avoid

• Delaying ECG acquisition - obtain within first 10 minutes
• Missing atypical presentations in women, elderly, and diabetics
• Administering nitrates to patients with contraindications (RV infarction, hypotension)
• Routine oxygen administration to normoxic patients
• Failing to pre-notify receiving hospital for STEMI
• Administering aspirin to patients who have already taken it that day 4

Remember: Half of ACS deaths occur before reaching the hospital, with VF/VT being the most common precipitating rhythm. Early recognition, appropriate treatment, and rapid transport to definitive care are critical for improving survival 1.