A 2-week-old infant on pressure control ventilation needs a decrease in PaCO2. What should the specialist increase?

To decrease the PaCO2 in an infant on pressure control ventilation, increasing the respiratory rate is a key strategy. The primary purpose of increasing the respiratory rate is to enhance the overall minute ventilation, which can help facilitate the removal of carbon dioxide from the bloodstream.

In the context of ventilation, PaCO2 levels are influenced by the balance between the amount of carbon dioxide produced by the body and the amount removed via ventilation. By increasing the number of breaths the infant receives per minute, more fresh gas is introduced, and more carbon dioxide is expelled, leading to a reduction in PaCO2 levels.

While other strategies like increasing tidal volume or adjusting inspiratory time and flow can impact ventilation, they may not be effective in this specific clinical scenario. Tidal volume impacts the volume delivered with each breath, but in pressure control ventilation, this is already constrained by the pressure settings. Inspiratory time and flow adjustments primarily affect the delivery characteristics of the breath but would not directly optimize the ventilation rate in the same way as increasing the respiratory rate does. Thus, to achieve the desired change in PaCO2, increasing the respiratory rate is the most effective approach in this situation.