The nurse knows that the adverse effects of a nonselective beta blocker are likely to be the most immediately life-threatening in which patient?

Choice A rationale

The patient's symptoms of shakiness, sweating, and anxiety are classic signs of hypoglycemia, a low blood glucose level. Giving them only a glass of water will not raise their blood glucose level and will not correct the underlying issue. The brain needs glucose to function, and without a rapid source, the patient could progress to more severe symptoms, including confusion, loss of consciousness, or seizures.

Choice B rationale

A carbohydrate-rich snack, such as a glass of juice or a few glucose tablets, provides a rapid source of glucose that can be quickly absorbed and utilized by the body. This action will promptly raise the patient's blood glucose level, reversing the hypoglycemic episode and alleviating the symptoms. This is the most effective and appropriate initial nursing action for a conscious patient experiencing hypoglycemia.

Choice C rationale

Exercising would further deplete the body's glucose stores, worsening the hypoglycemic state. Physical activity increases glucose utilization by muscles, which would lower the already deficient blood glucose level. This action would be dangerous and could cause the patient's condition to deteriorate rapidly, leading to a medical emergency. Exercise should only be encouraged after blood glucose has been stabilized.

Choice D rationale

A protein-rich snack takes longer to digest and convert into glucose, so it will not provide the rapid increase in blood sugar needed to treat an acute hypoglycemic event. While protein can help to stabilize blood glucose levels after they have been raised with a carbohydrate source, it is not the appropriate first-line treatment for a patient experiencing acute hypoglycemia.

Choice A rationale

While some beta-blockers have a minor effect on vasodilation, their primary purpose in a post-MI patient is not to dilate the coronary arteries. Beta-blockers reduce myocardial oxygen demand by decreasing heart rate, contractility, and blood pressure. Vasodilators, such as nitrates or calcium channel blockers, are the drugs of choice for dilating coronary arteries.

Choice B rationale

After an MI, circulating catecholamines (epinephrine and norepinephrine) can increase heart rate and contractility, which raises myocardial oxygen demand and can extend the size of the infarct. Metoprolol, a beta-blocker, competitively blocks these catecholamines at the beta-1 adrenergic receptors, thereby reducing heart rate and myocardial contractility. This action decreases oxygen consumption and prevents further cardiac damage.

Choice C rationale

Beta-blockers like metoprolol have a negative inotropic effect, meaning they decrease the force of myocardial contraction. A positive inotropic effect, which increases the force of contraction, is seen with drugs like digoxin or dopamine and would be counterproductive in a post-MI setting where the goal is to reduce the heart's workload.

Choice D rationale

While metoprolol does lower blood pressure as a secondary effect by decreasing heart rate and reducing cardiac output, its primary purpose in a post-MI patient is to reduce the workload of the heart and decrease myocardial oxygen demand. The reduction in blood pressure is a beneficial side effect, but it is not the main indication for its use in this context.