What are the diagnostic questions and treatment options for Emergency Medical Services (EMS) personnel to manage a patient presenting with chest pain, specifically acute coronary syndrome (ACS)?

From the Guidelines

For EMS treating chest pain, immediately assess the patient's vital signs, oxygen saturation, and obtain a 12-lead ECG to identify potential cardiac causes, as recommended by the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain 1. This approach is crucial in reducing morbidity, mortality, and improving quality of life for patients with chest pain. The following steps should be taken:

• Administer oxygen if saturation is below 94%
• Establish IV access
• Provide aspirin (325mg chewed) for suspected cardiac chest pain unless contraindicated, as supported by the 2012 ACCF/AHA focused update incorporated into the ACCF/AHA 2007 guidelines for the management of patients with unstable angina/non-ST-elevation myocardial infarction 1
• Nitroglycerin (0.4mg sublingual, repeated every 5 minutes for up to 3 doses) can be given if systolic blood pressure is above 90mmHg and there's no recent phosphodiesterase inhibitor use
• For severe pain, consider morphine (2-4mg IV) titrated carefully Some key points to consider:
• Continuous cardiac monitoring is essential throughout transport
• Ask focused questions about pain characteristics (onset, quality, radiation, severity), associated symptoms (shortness of breath, nausea, diaphoresis), cardiac risk factors, and medication history
• These interventions aim to reduce cardiac workload, improve myocardial oxygen supply, prevent clot formation, and relieve pain while the patient is transported to definitive care
• Rapid assessment and treatment are critical as chest pain may indicate life-threatening conditions requiring prompt intervention, as emphasized by the 2011 ACCF/AHA focused update incorporated into the ACC/aha 2007 guidelines for the management of patients with unstable angina/non-ST-elevation myocardial infarction 1. The importance of early recognition and treatment of chest pain is also highlighted by the ACR Appropriateness Criteria for chest pain-possible acute coronary syndrome, which notes that noninvasive imaging may be indicated for risk stratification and clinical management in both low-risk and intermediate-risk patients 1. Overall, the goal of EMS treatment for chest pain is to quickly and accurately identify potential cardiac causes and provide appropriate interventions to reduce morbidity, mortality, and improve quality of life.

From the FDA Drug Label

DOSAGE & ADMINISTRATION Myocardial Infarction Early Treatment During the early phase of definite or suspected acute myocardial infarction, initiate treatment with metoprolol tartrate as soon as possible after the patient’s arrival in the hospital. Such treatment should be initiated in a coronary care or similar unit immediately after the patient’s hemodynamic condition has stabilized Begin treatment in this early phase with the intravenous administration of three bolus injections of 5 mg of metoprolol tartrate injection each; give the injections at approximately 2-minute intervals. During the intravenous administration of metoprolol tartrate injection, monitor blood pressure, heart rate, and electrocardiogram

For Emergency Medical Services (EMS) treatment of chest pain suspected to be a myocardial infarction, the recommended treatment is to initiate metoprolol tartrate as soon as possible after the patient's arrival in the hospital, in a coronary care unit.

• The treatment should be started with three bolus injections of 5 mg of metoprolol tartrate injection, given at approximately 2-minute intervals.
• Monitoring of blood pressure, heart rate, and electrocardiogram should be done during the intravenous administration of metoprolol tartrate injection 2. The initial dose in the EMS setting is not explicitly stated, but in a hospital setting, treatment is initiated as soon as possible. Key considerations for EMS personnel include:
• Rapid transportation to a hospital with a coronary care unit
• Monitoring of the patient's condition during transport
• Communication with hospital staff to ensure prompt initiation of treatment upon arrival 2.

From the Research

EMS Treatment for Chest Pain

• The administration of aspirin to patients with chest pain is crucial in the prehospital setting, as it can help reduce the risk of acute coronary syndromes (ACSs) 3.
• However, studies have shown that prehospital providers do not always administer aspirin to patients with chest pain, with reasons including the belief that the chest pain is not cardiac in nature, the patient having already taken aspirin, or the provider being a basic-level emergency medical technician (EMT)-Basic 3.
• In patients with coronary artery disease, antiplatelet therapy, including aspirin, is essential for reducing the risk of cardiovascular events and death 4.
• The antiplatelet effect of aspirin can be affected by various factors, including genetic factors, pharmacological interactions, smoking, diabetes mellitus, and increased platelet turnover 4.

Questions to Ask Patients with Chest Pain

• What is the nature and severity of the chest pain?
• Has the patient taken any medications, including aspirin, prior to the onset of chest pain?
• Does the patient have a history of coronary artery disease or other cardiovascular conditions?
• Are there any contraindications to the administration of aspirin or other antiplatelet medications?

Treatment Options for Chest Pain

• Aspirin administration for patients with suspected ACSs 3, 4.
• Dual antiplatelet therapy for patients undergoing percutaneous coronary intervention (PCI) 5, 6.
• Anticoagulation therapy for patients with atrial fibrillation or other conditions that increase the risk of thrombosis 5.
• Aspirin desensitization for patients with aspirin hypersensitivity 6.