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:

Amiodarone is an antiarrhythmic medication that is often used to treat ventricular tachycardia and ventricular fibrillation. However, it is not the first-line drug for Torsades de Pointes. In fact, amiodarone can actually worsen QT prolongation and increase the risk of Torsades de Pointes.

It's important to note that amiodarone has a long half-life and can accumulate in the body over time, further increasing the risk of QT prolongation.

Additionally, amiodarone can have several serious side effects, including pulmonary toxicity, thyroid dysfunction, and liver damage.

Choice B rationale:

Lidocaine is another antiarrhythmic medication that is sometimes used to treat ventricular arrhythmias. However, it is also not the first-line drug for Torsades de Pointes.

Lidocaine is less likely to worsen QT prolongation than amiodarone, but it can still have this effect in some patients.

Additionally, lidocaine has a short half-life and must be given as a continuous infusion, which can be challenging in a critical care setting.

Choice C rationale:

Atropine is a medication that is used to increase heart rate. It is not effective in treating Torsades de Pointes and is not indicated in this situation.

Atropine works by blocking the vagus nerve, which slows heart rate. In Torsades de Pointes, the heart rate is already very fast, so atropine would not be helpful.

Additionally, atropine can have several side effects, including dry mouth, blurred vision, and urinary retention.

Choice D rationale:

Magnesium sulfate is the first-line drug for treating Torsades de Pointes. It works by stabilizing the electrical activity of the heart and preventing further episodes of arrhythmia.

Magnesium sulfate is a relatively safe medication with few side effects. It can be given as an intravenous infusion or as an intramuscular injection.

Studies have shown that magnesium sulfate is effective in terminating Torsades de Pointes and preventing recurrences.

Choice A rationale:

Requesting an order for morphine sulfate IV 2 mg over 1-5 minutes would not be appropriate at this time for several reasons: The patient has already received a dose of 4 mg 15 minutes ago, and it has not been effective in relieving the chest pain.

The patient is showing signs of increased respiratory effort, which could be a sign of respiratory depression. Administering an additional dose of morphine could worsen the respiratory depression.

The patient's heart rate is 82 beats per minute, which is within the normal range.

The patient's blood pressure is 135/88 mm Hg, which is also within the normal range.

Choice C rationale:

Administering naloxone (Narcan) to counteract respiratory depression would not be appropriate at this time because the patient is not showing signs of severe respiratory depression. Naloxone is a medication that is used to reverse the effects of opioid overdose. It is typically only used in situations where the patient is experiencing life-threatening respiratory depression.

Choice D rationale:

Administering morphine sulfate IV 4 mg over 1-5 minutes would not be appropriate for the reasons listed above. It could worsen the patient's respiratory depression and potentially lead to other complications.

Choice B is the best answer because it is the most conservative and safest option. By withholding the next dose of morphine and informing the provider about the patient's symptoms, the nurse can ensure that the patient receives the appropriate care and that any potential complications are avoided.