A patient is taking a beta 1-adrenergic drug to improve the stroke volume of the heart. The nurse caring for this patient knows that this drug acts by increasing:

Choice A reason: Uncompensated respiratory alkalosis requires low PaCO2 (<35 mm Hg) and high pH (>7.45). Here, PaCO2 is 48 mm Hg (high) and HCO3- is 29 mEq/L (high), indicating a metabolic cause with respiratory compensation, making this choice incorrect.

Choice B reason: Partially compensated respiratory alkalosis involves low PaCO2 and high HCO3- with high pH. With PaCO2 at 48 mm Hg (high) and HCO3- at 29 mEq/L, the alkalosis is metabolic, with elevated PaCO2 as compensation, making this choice incorrect.

Choice C reason: pH 7.48 (alkalotic), PaCO2 48 mm Hg (high), and HCO3- 29 mEq/L (high) indicate metabolic alkalosis (high HCO3-), with elevated PaCO2 showing partial respiratory compensation (hypoventilation to retain CO2). This matches partially compensated metabolic alkalosis, making it the correct choice.

Choice D reason: Uncompensated metabolic alkalosis requires high pH and high HCO3- with normal PaCO2. Here, PaCO2 is 48 mm Hg (high), indicating respiratory compensation, not an uncompensated state. This makes the condition partially compensated, so this choice is less accurate than C.

Choice A reason: Normal BP is below 120/80 mm Hg. These readings, with diastolic consistently above 90 mm Hg, indicate hypertension, not normal BP, so this is incorrect.

Choice B reason: Isolated systolic hypertension involves systolic BP ≥130 mm Hg with diastolic <80 mm Hg. High diastolic readings rule this out, so this is incorrect for the pattern.

Choice C reason: BP readings above 130/80 mm Hg, especially with diastolic ≥90 mm Hg, classify as hypertension (Stage 2). This matches the patient’s pattern, making it the correct category.

Choice D reason: Prehypertension is 120–129/<80 mm Hg. These readings exceed this with high diastolic values, indicating hypertension, so this is incorrect for the BP pattern.