A nurse is caring for a client who has just experienced a 90-second tonic-clonic seizure. The arterial blood gas values are pH 6.88, PaO2 50 mmHg PaCO2 60 mmHg, and HCO3 22mEq/L. Which action should the nurse take first?

Rationale: A. Sodium bicarbonate may be used to correct acidosis, but oxygenation must be addressed first to prevent further deterioration. B. The first priority is to improve oxygenation. Administering oxygen by mask or nasal cannula is the most immediate and effective way to increase PaO₂ and support respiratory function. C. A paper bag is used for respiratory alkalosis, not acidosis—it would worsen hypoxemia. D. Glucose and insulin are used for hyperkalemia, which is not the current priority.