Final answer:
The blood gas results indicate respiratory alkalosis. Among the options provided, nausea is associated with alkalosis, and the patient may also experience lightheadedness.
Step-by-step explanation:
The arterial blood gas results showing a pH of 7.50 and a PCO₂ of 30 mmHg indicate a condition known as respiratory alkalosis. The patient's pH is above the normal arterial blood pH range of 7.35 to 7.45, and the PCO₂ is below the normal range, suggesting a decrease in blood levels of CO₂, typically linked to hyperventilation. Respiratory alkalosis can lead to certain clinical manifestations, such as cognitive impairment which can progress to unconsciousness, tingling or numbness in the extremities, muscle twitching and spasm, and nausea and vomiting. Among the options provided, (C) Nausea is a clinical manifestation associated with alkalosis, while (D) Lightheadedness, another symptom of respiratory alkalosis, might also be present but is not explicitly listed as a commonly identified manifestation.