A patient with angina has been given 0.4 mg of nitroglycerin SL and reports continued chest pain 5 minutes later.
The nurse assesses a heart rate of 84 beats per minute and a blood pressure of 88/68 mm Hg. What action should the nurse take next?

Choice A rationale:

Dopamine is a catecholamine that acts on both alpha- and beta-adrenergic receptors. It has inotropic (increases heart contractility), chronotropic (increases heart rate), and vasopressor (constricts blood vessels) effects.

It was previously used as a first-line agent for cardiogenic shock, but it has fallen out of favor due to concerns about its potential to increase heart rate and arrhythmias, which can worsen myocardial oxygen demand and ischemia.

Additionally, dopamine's effects on renal blood flow can be unpredictable, and it may not be as effective as norepinephrine in increasing blood pressure in patients with severe shock.

Choice B rationale:

Norepinephrine is a potent alpha-adrenergic agonist that causes vasoconstriction, leading to an increase in blood pressure. It has minimal beta-adrenergic effects, so it does not significantly increase heart rate.

Norepinephrine is the preferred first-line vasopressor for cardiogenic shock because it effectively raises blood pressure without significantly increasing heart rate or myocardial oxygen demand.

It also has beneficial effects on renal blood flow and may improve organ perfusion.

Choice C rationale:

Epinephrine is a potent alpha- and beta-adrenergic agonist. It has strong inotropic, chronotropic, and vasopressor effects.

It can be used in cardiogenic shock, but it is typically reserved for patients who do not respond adequately to norepinephrine or who have severe bradycardia.

Epinephrine's potent beta-adrenergic effects can increase heart rate and myocardial oxygen demand, which can be detrimental in patients with cardiogenic shock.

Choice D rationale:

Vasopressin (Pitressin) is a hormone that acts on V1 receptors in vascular smooth muscle to cause vasoconstriction. It is not a first-line agent for cardiogenic shock, but it can be used as an adjunct to norepinephrine in patients who are refractory to other vasopressors.

Vasopressin may be particularly useful in patients with septic shock, as it has been shown to improve outcomes in this population.

Choice A rationale:
NPH insulin is an intermediate-acting insulin that typically peaks 6-12 hours after administration.
Given that the insulin was administered at 1700 (5:00 PM), the peak action would be expected to occur between 2100 (9:00 PM) and 0500 (5:00 AM).
This time frame aligns with the known pharmacokinetics of NPH insulin.
It's crucial for nurses to be aware of the peak action times of different insulin types to effectively manage blood glucose levels and adjust insulin doses accordingly.
Choice B rationale:
Incorrect. NPH insulin does have a peak action, as explained above.
It's important to understand that even intermediate-acting insulins have a period of peak activity when they exert their strongest glucose-lowering effect.
Choice C rationale:

Incorrect. This time frame is too early to represent the peak action of NPH insulin. The peak action typically occurs later, between 6-12 hours after administration.
Choice D rationale:
Incorrect. This time point is too specific to accurately represent the peak action of NPH insulin.
The peak action can vary within the 6-12 hour window, depending on individual factors and injection site.