During a reassessment of a neonate on CPAP, what action should a respiratory therapist take if the arterial blood gas shows significant acidosis?

Initiating mechanical ventilation is the correct approach when a neonate on CPAP shows significant acidosis in their arterial blood gas results. This situation often indicates that the infant is unable to properly ventilate, which may be due to various factors such as respiratory distress, inadequate alveolar ventilation, or an inability to maintain proper respiratory rates and depths. When acidosis is present, particularly if it is severe, it suggests that the carbon dioxide levels are elevated, leading to respiratory acidosis, and the current CPAP support is insufficient to correct this imbalance.

Mechanical ventilation can provide controlled breaths and improved gas exchange, allowing for a more effective means of managing ventilation and correcting the acid-base balance. This intervention is crucial in preventing further respiratory compromise or other complications.

In contrast, the other options do not adequately address the problem of significant acidosis. Increasing CPAP pressure may not sufficiently enhance ventilation; administering additional oxygen could improve oxygen saturation but not directly address the acidosis; and switching to a different oxygen delivery system would likely also be ineffective without improving the underlying ventilation issue.