A nurse is reviewing the medical records of four clients who have an acid-base imbalance. The nurse should recognize that which of the following clients is at risk for respiratory alkalosis?

The correct answer is Choice C.

Choice A rationale: Thiazide diuretics cause potassium and chloride loss, leading to metabolic alkalosis, not respiratory alkalosis. Hypokalemia decreases hydrogen ion excretion, increasing bicarbonate levels. Metabolic alkalosis is characterized by pH >7.45 and HCO₃⁻ >26 mEq/L rather than decreased PaCO₂.

Choice B rationale: Vomiting leads to metabolic alkalosis due to gastric acid loss. Hydrogen ion depletion increases bicarbonate concentration, shifting pH above normal. Arterial blood gases typically show increased HCO₃⁻ (>26 mEq/L) with a compensatory increase in PaCO₂ (>45 mmHg), not respiratory alkalosis.

Choice C rationale: Salicylate intoxication initially induces hyperventilation, reducing PaCO₂ levels below 35 mmHg and increasing pH above 7.45, leading to respiratory alkalosis. As toxicity progresses, metabolic acidosis may develop due to lactic acid accumulation, but early stages primarily present with respiratory alkalosis.

Choice D rationale: Hypoventilation leads to CO₂ retention, increasing PaCO₂ above 45 mmHg, forming carbonic acid (H₂CO₃) and causing respiratory acidosis. Blood gases show pH <7.35 with elevated PaCO₂, not respiratory alkalosis, which is caused by excessive CO₂ elimination through hyperventilation.

Choice A rationale:

A client with placenta previa and a hematocrit of 36% should be monitored closely due to the risk of bleeding, but it is not an immediate priority compared to the client with hyperemesis gravidarum and a low sodium level.

Choice B rationale:

Hyperemesis gravidarum is a severe form of morning sickness characterized by excessive vomiting, leading to dehydration and electrolyte imbalances. A sodium level of 110 mEq/L is dangerously low and requires immediate attention to correct the electrolyte disturbance and prevent further complications.

Choice C rationale:

A client with diabetes mellitus and an HbA1c of 5.8% is within a normal range, indicating good glycemic control. This client's condition can be managed on an outpatient basis and does not require urgent assessment compared to the others.

Choice D rationale:

A client with preeclampsia and a creatinine level of 1.1 mg/dL should be closely monitored, but it is not the priority over the client with hyperemesis gravidarum and severe electrolyte imbalance.