A client on mechanical ventilation has pH 7.26, PaCO2 68 mm Hg, PaO2 92 mm Hg. What action should the nurse take?

• A. Increase the rate of ventilation
• B. Decrease the rate of ventilation
• C. Elevate the head of the bed 30 degrees
• D. Administer a bronchodilator

Answer: (A)

This situation shows respiratory acidosis from hypoventilation. The client has a low pH (7.26) with a high PaCO2 (68 mm Hg), which means CO2 is accumulating because ventilation isn’t clearing it adequately. Oxygenation is acceptable (PaO2 92), so the immediate issue is removing CO2, not increasing oxygen delivery. The way to lower PaCO2 and raise the pH is to boost alveolar ventilation, which on the ventilator means increasing the ventilator rate (and potentially tidal volume, as clinically appropriate) to increase minute ventilation. Elevating the head of the bed won’t correct the CO2 retention, and a bronchodilator would only help if bronchospasm were contributing to obstruction. So increasing the ventilator rate is the appropriate action to correct the acidemia caused by hypercapnia.