A nurse is performing a nonstress test on a client who is at 35 weeks of gestation and has diabetes mellitus. The test reveals no accelerations of fetal heart rate for 20 min. Which of the following actions should the nurse take?

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:
Levothyroxine is not a medication used to treat gestational diabetes mellitus. Levothyroxine is a synthetic thyroid hormone used to treat hypothyroidism, which is a different medical condition.

Choice B rationale:
Nifedipine is a calcium channel blocker primarily used to manage hypertension and angina. It is not indicated for the treatment of gestational diabetes mellitus.

Choice C rationale:
Chlorpromazine is an antipsychotic medication used to treat conditions like schizophrenia and bipolar disorder. It has no role in the treatment of gestational diabetes mellitus.

Choice D rationale:
Glyburide is the correct medication to expect for administering to a client with gestational diabetes mellitus. Glyburide is an oral antidiabetic agent that helps lower blood glucose levels by increasing insulin secretion from the pancreas. It is often used when dietary and lifestyle modifications are not sufficient in managing gestational diabetes. However, it is essential to follow healthcare provider guidelines and closely monitor the client's blood glucose levels while on this medication. In some cases, insulin may be required if glyburide alone is inadequate in controlling blood sugar levels.