A patient who is intubated develops sinus bradycardia. Which medication will the nurse anticipate administering to treat this symptom?

A. Hypernatremia: Hydrochlorothiazide promotes sodium excretion, so high sodium levels are unlikely. The medication tends to lower sodium, making hypernatremia an uncommon concern in this combination therapy.

B. Hypokalemia: Hydrochlorothiazide increases renal potassium excretion, which can lower serum potassium levels. Low potassium enhances the risk of digoxin toxicity, including arrhythmias, making close monitoring essential. This electrolyte imbalance is the most significant concern with this drug combination.

C. Hypocalcemia: Thiazide diuretics like hydrochlorothiazide actually decrease calcium excretion, so low calcium levels are not expected. Monitoring calcium is not a primary concern for this patient.

D. Hypermagnesemia: Hydrochlorothiazide increases magnesium excretion, but high magnesium levels are unlikely. Hypermagnesemia is not a common side effect of this therapy and is not a priority for monitoring in this scenario.

A. Complete Blood Count: A CBC evaluates red and white blood cells and platelets, which are not direct indicators of kidney function. While anemia can develop in chronic kidney disease, CBC changes are secondary and do not provide immediate information about renal clearance.

B. Creatinine: Serum creatinine is a primary marker of kidney function because it reflects the kidneys’ ability to filter waste products. Elevated levels indicate impaired glomerular filtration rate (GFR) and help guide medication dosing and fluid management in older adults.

C. Serum Sodium and Potassium: Electrolytes can be affected by kidney impairment, but changes often occur after kidney function declines significantly. While important to monitor for complications such as hyperkalemia or hyponatremia, these values are not as sensitive as creatinine for detecting early decreases in renal function.

D. Serum Albumin: Albumin measures protein status and nutritional health rather than kidney filtration ability. Low levels may be seen in nephrotic syndrome but are not a reliable indicator of general kidney function.