Rhythm Strip

A client comes to the emergency department (ED) complaining of a "racing heart and nervousness." The client's blood pressure is 106/60. The cardiac monitor displays the rhythm below. Which nursing action should be performed first?

A. Maintain the infusion because the client had a cardiac arrest: While epinephrine is essential during cardiac arrest, continuing a high-dose infusion post-resuscitation without reassessment may lead to complications like tachycardia, hypertension, and increased myocardial oxygen demand.

B. Continue to monitor the client's rhythm closely: Ongoing monitoring is important, but it is a passive intervention. The heart rate of 120 bpm may reflect excessive adrenergic stimulation from epinephrine, and further action is needed to prevent deterioration.

C. Suggest that the client's medication be changed to norepinephrine: Norepinephrine is another vasopressor that has less of a beta-1 adrenergic effect compared to epinephrine. It is primarily used for hypotension and septic shock, not as a direct substitute for epinephrine post-cardiac arrest. Changing to another vasopressor without indication is not the best initial step.

D. Ask the physician if the dose can be decreased: A heart rate of 120 bpm may indicate that the epinephrine dose is too high, causing sympathetic overstimulation. Prolonged or excessive tachycardia increases myocardial oxygen demand, which can be detrimental, especially in a post-arrest heart. Decreasing the dose can help prevent arrhythmias or myocardial ischemia, making this the most appropriate and proactive action.

A. Hypermagnesemia: Hypermagnesemia (high magnesium levels) can cause bradycardia, hypotension, and prolonged PR and QRS intervals. While it can affect cardiac rhythm, it's less commonly associated with PVCs. The client's magnesium level of 2.5 mg/dL is within the normal range (1.5-2.5 mg/dL).

B. Hypocalcemia: While the calcium level of 8.0 mg/dL is slightly low (normal: ~8.5–10.5 mg/dL), mild hypocalcemia is less commonly associated with PVCs compared to hypokalemia. It can affect cardiac contractility but is not the most likely cause of these arrhythmias.

C. Hypokalemia: The potassium level is 2.8 mEq/L, which is significantly below normal (normal: 3.5–5.0 mEq/L). Potassium is a crucial electrolyte for maintaining normal cardiac electrical activity. Hypokalemia increases myocardial excitability and can lead to various cardiac dysrhythmias and a known cause of ventricular irritability, including multifocal PVCs, and increases the risk of life-threatening arrhythmias in clients with cardiac or metabolic conditions.

D. Hyperglycemia: The glucose level of 200 mg/dL is elevated but not severely high. While it reflects poor glycemic control, it is not directly linked to the occurrence of PVCs. Electrolyte imbalances, particularly low potassium, are more arrhythmogenic.