Which arterial blood gas reading indicates uncompensated respiratory acidosis in a premature infant?

Uncompensated respiratory acidosis is characterized by a decreased pH, an increased pCO2, and normal or only slightly altered bicarbonate (HCO3) levels, as the body has not yet begun to compensate for the acidotic state.

In this case, the correct reading indicates a pH of 7.22, which is below the normal range of approximately 7.35-7.45, indicating acidosis. The pCO2 is 70, which is significantly elevated; normal pCO2 levels range from about 35-45 mmHg. This elevation in carbon dioxide suggests a respiratory cause for the acidosis, likely due to inadequate ventilation or respiratory failure. The HCO3 level is 28, which is within a range that indicates the bicarbonate has not yet altered significantly, consistent with the lack of compensation.

Understanding these parameters helps in clinically identifying respiratory acidosis in a premature infant, highlighting the importance of monitoring these blood gas levels for effective assessment and management of respiratory function.