The client is experiencing sinus bradycardia with hypotension and dizziness.
Which medication will the nurse administer?

Choice A rationale

Magnesium sulfate administration is scientifically indicated because the patient's magnesium level is 0.2 mEq/L, which is significantly lower than the normal range of 1.5 to 2.5 mEq/L. Hypomagnesemia increases myocardial irritability and can directly precipitate premature ventricular contractions or torsades de pointes. Providing 2 grams intravenously helps stabilize the cardiac membrane potential by restoring the necessary cofactor for the sodium potassium adenosine triphosphatase pump, which maintains the appropriate intracellular and extracellular electrolyte gradients.

Choice B rationale

Increasing oxygen to 6 L/min is appropriate because the patient's SpO2 is currently 92 percent, which is at the lower limit of acceptable for a patient three days post anterior wall myocardial infarction. Normal SpO2 should ideally be ≥ 94 percent in cardiac patients to ensure adequate myocardial oxygenation. Increasing the fraction of inspired oxygen helps reduce the workload of the heart and may decrease the frequency of ectopy caused by localized areas of myocardial hypoxia.

Choice C rationale

Administering 40 mEq of potassium chloride is inappropriate for this specific patient because her potassium level is 4.4 mEq/L, which falls perfectly within the normal physiological range of 3.5 to 5.0 mEq/L. Over-supplementing potassium when the serum level is already optimal carries a significant risk of inducing hyperkalemia. Excessive potassium can lead to lethal arrhythmias, such as ventricular fibrillation or asystole, by disrupting the resting membrane potential and interfering with cardiac repolarization.

Choice D rationale

Lidocaine 100 mg IV push is a standard pharmacological intervention for a patient experiencing frequent or multifocal premature ventricular contractions following an acute myocardial infarction. Lidocaine is a Class IB antiarrhythmic that works by blocking fast voltage-gated sodium channels, particularly in ischemic tissues. This action shortens the action potential duration and raises the fibrillation threshold, thereby suppressing ventricular ectopy and preventing the progression to more dangerous rhythms like ventricular tachycardia or ventricular fibrillation.

Choice A rationale

An oncology nurse is highly skilled in maintaining sterile techniques and performing complex dressing changes, which are common in cancer care. A patient with partial-thickness burns requiring a dressing change matches the float nurse's existing competency level. This assignment allows the nurse to provide safe, effective care without requiring specialized burn-unit training in hemodynamic resuscitation or graft-specific monitoring, ensuring the patient's wound environment remains protected and the risk of infection is minimized.

Choice B rationale

Discharge teaching for a burn patient involves highly specific knowledge regarding nutrition for hypermetabolic states and specialized wound care for skin grafts. An oncology nurse may not be familiar with the unique caloric requirements (often 4000-5000 calories daily) or the specific appearance of healing grafts versus oncology-related skin breakdown. This task is better suited for a permanent burn unit RN who understands the long-term recovery trajectory and specific complications of thermal injuries.

Choice C rationale

A new admission with burns covering 30 percent of the body surface area is in the critical emergent phase of burn care. This stage requires intensive fluid resuscitation calculations, usually following the Parkland formula, and frequent monitoring of urine output (target 0.5 to 1 mL/kg/hr). The oncology float nurse likely lacks the specialized training required to manage the rapid shifts in capillary permeability and the severe systemic inflammatory response seen in major thermal trauma.

Choice D rationale

Positioning hand splints for a patient with full-thickness burns requires specialized knowledge of occupational therapy goals and the prevention of contractures. Full-thickness burns involve the destruction of the epidermis and dermis, often requiring precise immobilization to maintain function. An oncology nurse would not typically have experience with burn-specific splinting protocols or the assessment of graft adherence under those splints, making this an inappropriate assignment for a nurse floating from a different specialty.