Neonatal Nurse Practitioner Practice Exam 2026 – Complete Prep Resource

The arterial blood gas results demonstrate a low pH of 7.23, indicating acidosis. The elevated PCO₂ of 49 mm Hg suggests hypoventilation or respiratory depression, leading to an accumulation of carbon dioxide, which is characteristic of respiratory acidosis. The low HCO₃ of 19 mEq/L indicates a metabolic compensation attempt but is also reflective of the acid-base status in this case.

In the context of the clinical presentation, where the neonate exhibits labored breathing, retractions, and grunting, the combination of respiratory distress and the blood gas values leads to the conclusion of mixed acidosis. This means there is both a respiratory component (evidenced by the elevated PCO₂ and low pH) and a metabolic component (indicated by the low HCO₃) contributing to the overall acidotic state.

Understanding mixed acidosis in this scenario is essential, as it highlights that not only is the respiratory system contributing to the acidosis, but there is also a metabolic response that is exacerbating the condition. This knowledge is key for formulating an appropriate management plan for the neonate.