The nurse observes a short period of asystole on the cardiac monitor that resolves spontaneously immediately after administering adenosine IV to a patient who was experiencing paroxysmal supraventricular tachycardia. Which initial action is the most appropriate for the nurse?

Correct Answer: D

Rationale: Adenosine is used to treat paroxysmal supraventricular tachycardia (PSVT) by temporarily blocking AV node conduction, which can cause a brief period of asystole. This is an expected effect and typically resolves spontaneously. The nurse should closely monitor the patient and the cardiac monitor for the return of a normal rhythm. Calling a code (A), preparing epinephrine and atropine (B), or initiating CPR (C) is unnecessary unless the asystole persists or the patient becomes unstable.

Correct Answer: C

Rationale: Penicillin is a type of antibiotic that works by disrupting the synthesis of the bacterial cell wall. Bacterial cells have a cell wall that provides structural support and protection. The cell wall is composed of peptidoglycan, a complex molecule that gives the cell wall its strength. Penicillin interferes with the formation of peptidoglycan by inhibiting the enzyme transpeptidase, which is essential for cross-linking the peptidoglycan strands. As a result, bacterial cells become more susceptible to osmotic pressure and eventually burst, leading to their death. This mechanism of action is particularly effective against rapidly growing bacterial cells because they are actively synthesizing new cell wall components to keep up with their growth. Thus, penicillin's primary effectiveness against rapidly growing cells is primarily due to its disruption of cell wall synthesis.

Correct Answer: B

Rationale: Ibutilide (Corvert) is a medication commonly used to treat atrial fibrillation, a type of irregular heart rhythm that originates in the heart's upper chambers (atria). It works by restoring normal heart rhythm in patients with atrial fibrillation. Therefore, the nurse notes the use of ibutilide in the patient's medication orders, indicating that the patient has atrial fibrillation.

Correct Answer: C

Rationale: One life-threatening side effect of lithium therapy is the risk of seizures. While seizures are a rare side effect, they can occur, especially at higher doses or in patients with a history of seizure disorders. It is important to monitor for any signs of seizures in patients taking lithium and to promptly address any potential neurological symptoms.

Correct Answer: A

Rationale: Metformin belongs to the class of medications known as biguanides. Biguanides work primarily by decreasing glucose production in the liver and increasing insulin sensitivity in peripheral tissues, such as muscles. They also help improve glucose uptake and utilization by cells, leading to better control of blood sugar levels. Metformin is commonly used to treat type 2 diabetes mellitus and can also be used in the management of polycystic ovary syndrome (PCOS).