A patient with a history of coronary artery disease experiences chest pain while walking. After taking sublingual nitroglycerin, the patient’s chest pain increases, and they experience clammy skin and blurry vision.

They call 911 and you are the nurse attending to them in the emergency department. What is the most important nursing intervention to do first?

Choice A rationale
Administering Lasix (a diuretic) would not be the most immediate intervention for a patient experiencing increased chest pain after taking sublingual nitroglycerin. Lasix is used to treat fluid retention (edema) and swelling caused by congestive heart failure, liver disease, kidney disease, and other medical conditions. It works by causing the kidneys to get rid of unneeded water and salt from the body into the urine.
Choice B rationale
The most important nursing intervention for a patient experiencing increased chest pain after taking sublingual nitroglycerin would be to increase myocardial oxygenation. This can be achieved by administering supplemental oxygen and ensuring the patient is in a position that maximizes respiratory efficiency (such as semi-Fowler’s position). This intervention addresses the immediate life-threatening situation of myocardial ischemia.
Choice C rationale
Obtaining one hour of echocardiogram readings would not be the most immediate intervention for a patient experiencing increased chest pain after taking sublingual nitroglycerin. While an echocardiogram can provide valuable information about the structure and function of the heart, it is not the first step in managing acute chest pain. 
Choice D rationale
Decreasing the patient’s anxiety is an important aspect of care, but it is not the most immediate intervention for a patient experiencing increased chest pain after taking sublingual nitroglycerin. The priority is to address the physical cause of the chest pain.