EMT Basic Certification Complete Practice Exam 2026

A systolic blood pressure below 90 mmHg is a critical contraindication for the administration of nitroglycerin. Nitroglycerin is a vasodilator that relaxes and widens blood vessels, which can significantly lower blood pressure. When a patient already has a low systolic blood pressure (below 90 mmHg), administering nitroglycerin can lead to dangerously low blood pressure levels, increasing the risk of shock and further complications. Therefore, ensuring that the patient's blood pressure is within a safe range before giving nitroglycerin is essential to avoid adverse effects.

The other options do not represent immediate contraindications for nitroglycerin administration. While having a fever, a history of migraines, or recent surgery may warrant caution or further assessment, they do not pose the same immediate risk of critical hypotension that a low systolic blood pressure does. Thus, it is crucial to prioritize blood pressure assessment when considering the use of nitroglycerin.