What do blood gas results of pH 7.07, PCO2 62 torr, and PO2 45 torr indicate in a 28-week gestation neonate receiving 40% oxygen?

The correct choice reflects an understanding of the underlying principles of acid-base balance and gas exchange. A pH of 7.07 indicates significant acidemia, as normal arterial blood pH ranges from 7.35 to 7.45. The elevated PCO2 of 62 torr suggests a primary respiratory component, as this value is well above the normal range of 35-45 torr, indicating CO2 retention. Elevated CO2 typically results in respiratory acidosis, which is characterized by decreased pH alongside increased PCO2 due to inadequate ventilation.

The PO2 level of 45 torr indicates hypoxemia, which is not uncommon in a preterm neonate, especially one of 28 weeks gestation, who may have underdeveloped lungs and decreased capacity for gas exchange.

Considering these findings together, the results clearly indicate non-compensated respiratory acidosis due to the high CO2 level and low pH, with the presence of hypoxemia. This diagnosis correctly emphasizes the primary disturbance in respiratory function leading to acid-base imbalance in the context of premature neonates. Other options would misinterpret these blood gas results or incorrectly imply the presence of metabolic disturbances, rather than focusing on the respiratory acidosis evidenced by the CO2 and