Emergency Medical Technician (EMT) Practice Test

When is nitroglycerin not advised to be administered?

1. if the systolic blood pressure is less than 90

2. if the systolic blood pressure is less than 100

3. if the systolic blood pressure is more than 120

4. if the systolic blood pressure is more than 140

The correct answer is: if the systolic blood pressure is less than 100

Nitroglycerin is a medication commonly used to relieve chest pain associated with conditions like angina or myocardial infarction (heart attack). It works by dilating blood vessels, thus reducing the workload on the heart and improving blood flow. The use of nitroglycerin is contraindicated when a patient's systolic blood pressure is below a certain threshold. If the systolic blood pressure is less than 90, administering nitroglycerin could result in severe hypotension, which can be dangerous for the patient. This is because nitroglycerin can cause a significant drop in blood pressure through its vasodilatory effects. Therefore, it is critical to monitor blood pressure carefully and avoid administering nitroglycerin if systolic blood pressure falls below the safe limit. In clinical practice, a threshold of 100 mmHg is sometimes considered the lower limit for administering nitroglycerin, aiming to prevent adverse effects related to excessive blood pressure lowering. However, the absolute cutoff is generally recognized at 90 mmHg. This threshold is critical in ensuring patient safety while managing conditions requiring nitroglycerin.