A nurse is giving a preoperative patient a dose of famotidine ( Pepcid). The patient asks why the nurse is giving this drug when the patient has no history of ulcers. What response by the nurse is best?

A serum potassium level of 3.2 mEq/L indicates hypokalemia, which is a potential complication of inhibiting aldosterone secretion and release. Aldosterone plays a key role in potassium regulation in the body by promoting potassium excretion in the kidneys. When aldosterone secretion is inhibited, potassium excretion decreases, leading to an accumulation of potassium in the bloodstream and resulting in hypokalemia. Symptoms of hypokalemia may include muscle weakness, cramping, irregular heartbeat, and fatigue.

B. Urine output of 1,200 mL in the last 2 hours:

This option does not directly relate to complications of inhibiting aldosterone secretion. A urine output of 1,200 mL in the last 2 hours indicates adequate urine production, which is generally a positive sign. However, in the context of inhibiting aldosterone secretion, the nurse would be more concerned about decreased urine output due to potential renal effects.

C. Blood osmolality of 250 mOsm/kg (250 mmol/kg):

Blood osmolality within the normal range (usually around 275-295 mOsm/kg) is not directly associated with complications of inhibiting aldosterone secretion. Blood osmolality reflects the concentration of solutes in the blood and is regulated by various factors, including water balance, electrolyte levels, and hormonal regulation. Inhibiting aldosterone secretion primarily affects electrolyte balance rather than blood osmolality.

D. Urine output of 25 mL/hr:

A urine output of 25 mL/hr is considered low and may indicate decreased renal perfusion or impaired kidney function. Inhibiting aldosterone secretion can affect renal function and urine output, leading to decreased urine production. Reduced urine output can contribute to fluid and electrolyte imbalances and may be a concern in patients with inhibited aldosterone secretion.

E. Serum potassium level of 5.4 mEq/L:

A serum potassium level of 5.4 mEq/L indicates hyperkalemia, which is another potential complication of inhibiting aldosterone secretion. Aldosterone helps regulate potassium levels by promoting potassium excretion in the kidneys. When aldosterone secretion is inhibited, potassium excretion decreases, leading to an accumulation of potassium in the bloodstream and resulting in hyperkalemia. Symptoms of hyperkalemia may include muscle weakness, irregular heartbeat, nausea, and numbness or tingling.

A. Diarrhea and vomiting for 36 hours:

Diarrhea and vomiting can lead to metabolic acidosis due to loss of bicarbonate and increased hydrogen ion concentration in the blood. However, the ABG values provided indicate respiratory alkalosis (high pH and low PaCO2), which is not consistent with metabolic acidosis caused by diarrhea and vomiting. Therefore, this choice does not correlate with the ABG values.

B. Chronic obstructive pulmonary disease (COPD):

COPD is a respiratory condition characterized by airflow limitation and increased airway resistance. It can lead to respiratory acidosis due to retention of carbon dioxide (PaCO2 levels would be elevated). The ABG values in the scenario show respiratory alkalosis (low PaCO2), which is the opposite of what would be expected in COPD. Therefore, this choice does not correlate with the ABG values provided.

C. Anxiety-induced hyperventilation:

Anxiety-induced hyperventilation is a common cause of respiratory alkalosis. During hyperventilation, there is excessive elimination of carbon dioxide (PaCO2 levels decrease), leading to an increase in pH (alkalosis). The ABG values in the scenario show a high pH (7.48) and low PaCO2 (28 mm Hg), consistent with respiratory alkalosis seen in hyperventilation due to anxiety.

D. Diabetic ketoacidosis and chronic obstructive pulmonary disease (COPD):

Diabetic ketoacidosis (DKA) is a metabolic condition characterized by hyperglycemia, ketosis, and metabolic acidosis (low pH and low bicarbonate levels). COPD, as mentioned earlier, can lead to respiratory acidosis due to retained carbon dioxide. Neither of these conditions correlates with the ABG values provided, which show respiratory alkalosis (high pH and low PaCO2). Therefore, this choice does not correlate with the ABG values.