What should be done for chest pain if nitrates (nitroglycerin) are not available or not taken?

Management of Chest Pain When Nitrates Are Not Available or Not Taken

If nitrates are unavailable or not taken, immediately activate emergency medical services (EMS) by calling 9-1-1 and transport the patient to an emergency department for urgent evaluation, as chest pain requires rapid assessment regardless of medication availability. 1

Immediate Actions Without Nitrates

Call 9-1-1 Immediately If:

• Chest discomfort/pain is unimproved or worsening after 5 minutes from onset 1
• Patient has no previously prescribed nitroglycerin available 1
• Symptoms include radiation to arm(s), back, neck, jaw, or epigastrium; shortness of breath; weakness; diaphoresis; nausea; or lightheadedness 1

Pre-Hospital Management by EMS:

• Aspirin administration: EMS providers should administer 162-325 mg of non-enteric-coated aspirin (chewed) unless contraindicated or already taken 1
• Oxygen therapy: Administer supplemental oxygen only if arterial oxygen saturation is <90%, respiratory distress, or other high-risk features of hypoxemia are present 1
• Cardiac monitoring: Place patient on continuous cardiac monitoring with defibrillator nearby 1
• 12-lead ECG: Obtain and transmit ECG to receiving hospital if available 1

Alternative Pharmacologic Management in Hospital Setting

Beta-Blockers (First-Line Alternative):

• Oral beta-blockers should be initiated within the first 24 hours in the absence of heart failure, low-output state, risk for cardiogenic shock, or other contraindications 1
• Intravenous beta-blockers may be considered for severe hypertension or tachyarrhythmias in patients without contraindications 1

Calcium Channel Blockers:

• Nondihydropyridine calcium channel blockers (verapamil or diltiazem) are recommended for recurrent ischemia when beta-blockers are contraindicated, unsuccessful, or cause unacceptable side effects 1
• Administer in the absence of left ventricular dysfunction, increased risk for cardiogenic shock, PR interval >0.24 seconds, or second- or third-degree atrioventricular block without a pacemaker 1
• Immediate-release nifedipine is contraindicated in the absence of a beta-blocker 1

Analgesic Therapy:

• Intravenous morphine sulfate may be reasonable for continued ischemic chest pain despite maximally tolerated anti-ischemic medications 1
• Morphine is the preferred analgesic for patients with STEMI 1

Critical Contraindications and Pitfalls

Do NOT Administer NSAIDs:

• Nonsteroidal anti-inflammatory drugs (except aspirin) should not be initiated and should be discontinued during hospitalization for acute coronary syndromes due to increased risk of mortality, reinfarction, hypertension, heart failure, and myocardial rupture 1

Aspirin Considerations in Special Populations:

• In elderly patients (≥65 years) already on anticoagulation (such as apixaban), adding aspirin is inappropriate due to substantially increased bleeding risk 2
• For patients not on anticoagulation, aspirin 162-325 mg (non-enteric-coated, chewed) should be given as soon as possible unless contraindicated by known allergy or active gastrointestinal hemorrhage 1

Hospital Evaluation Protocol

Within 10 Minutes of Arrival:

• Obtain and interpret 12-lead ECG to evaluate for STEMI or other ischemic changes 1, 2, 3
• If STEMI is present, decision regarding fibrinolytic therapy or primary PCI should be made within the next 10 minutes 1

Serial Monitoring:

• Observe patients with symptoms consistent with ACS without objective evidence of myocardial ischemia in a chest pain unit or telemetry unit 1
• Obtain serial ECGs and cardiac troponin at 3- to 6-hour intervals 1
• Troponin elevations are useful for short- and long-term prognosis 1

Key Clinical Pearls

The absence of nitroglycerin should never delay emergency evaluation. The diagnostic and prognostic value of nitroglycerin response is limited, and its unavailability does not preclude the need for urgent assessment 2. The priority is rapid transport to a facility capable of ECG interpretation, biomarker determination, and definitive cardiac care 1. Alternative anti-ischemic therapies (beta-blockers, calcium channel blockers) can be initiated in the hospital setting once contraindications are excluded 1.