A nurse is assessing a client who is 6 hr postpartum and has endometritis. Which of the following findings should the nurse expect?

Choice A rationale:

Determining gestational age in the first trimester is a common and important use of ultrasound. It helps confirm the estimated due date and monitor the fetus's growth and development.

Choice B rationale:

Performing a biophysical profile in the first trimester is not a common use of ultrasound. Biophysical profiles are usually performed in the second or third trimester to assess fetal well-being.

Choice C rationale:

Observing placental maturity in the first trimester is not a standard use of ultrasound. Placental maturity is typically assessed later in pregnancy, especially in the third trimester.

Choice D rationale:

Detecting intrauterine growth restriction in the first trimester is not a primary use of ultrasound. Intrauterine growth restriction is more commonly assessed in the later stages of pregnancy when fetal growth is a concern.

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.