Question

A 9-year-old girl is receiving mechanical ventilation with an adult circuit with the following arterial blood gases values: pH 7.30, PaCO₂ 53 mm Hg, PaO2 78 mm Hg, HCO₃⁻ 25 mEq/L, BE +1 mEq/L. Based on these values, what should the respiratory therapist do?

1) decrease the rate.
2) change the circuit.
3) increase the rate.
4) reduce 50 ml mechanical deadspace.

Answer 1

Based on the provided arterial blood gas values, the correct action for the respiratory therapist would be to increase the rate of mechanical ventilation to address the respiratory acidosis indicated by the low pH and elevated PaCO₂.

Step-by-step explanation:

The arterial blood gas values provided for the 9-year-old girl show a pH of 7.30 (acidosis), PaCO₂ of 53 mm Hg (elevated), PaO2 of 78 mm Hg (normal), HCO₃⁻ of 25 mEq/L (normal), and BE of +1 mEq/L (slight base excess). Considering the normal pH range is 7.35-7.45, a pH of 7.30 indicates acidosis. Since the PaCO₂ is elevated, this suggests a respiratory cause of the acidosis.

The respiratory therapist should focus on correcting the respiratory acidosis. In such a case, increasing the respiratory rate is often the appropriate intervention to help decrease the PaCO₂ level by exhaling more CO₂, potentially bringing the pH back towards the normal range. Therefore, the correct action based on the provided values would be to 'increase the rate' of the mechanical ventilation.

Changing the circuit or decreasing the rate would not be advisable as these actions might not adequately address the underlying respiratory acidosis. Reducing mechanical deadspace may be considered if issues with deadspace ventilation are suspected, but it does not seem to be the primary concern given the current blood gas values.