Final answer:
Beta blockers would be given in the emergency of a myocardial infarction (heart attack) because they help reduce the heart's oxygen demand and workload by slowing down the heart rate and allowing blood vessels to dilate.
Step-by-step explanation:
A beta blocker would be administered in which emergency? The correct answer is B) Myocardial infarction. Beta blockers are a class of medication that are commonly used to treat cardiovascular diseases. They function by blocking the beta receptors associated with vasoconstriction and cardioacceleration. This action helps to reduce high blood pressure, prevent heart attacks, and decrease the heart's workload.
When a myocardial infarction, or heart attack, occurs, part of the heart muscle is deprived of oxygen due to a blocked blood vessel. Beta blockers can improve cardiac function in this compromised system by slowing down the heart rate and allowing blood vessels to dilate. This reduces the oxygen demand on the heart and helps to minimize the extent of the heart damage. Common types of beta blockers include metoprolol, which specifically blocks the B1-receptor, and propranolol, which blocks beta receptors nonspecifically.
It is essential to note that beta blockers are not used in emergencies such as acute asthma attacks, opioid overdoses, or diabetic ketoacidosis, as they may worsen the conditions or have no therapeutic effect in such cases.