Final answer:
The nurse can interpret these results as metabolic acidosis in the infant, with evidence of respiratory compensation.
Step-by-step explanation:
The nurse can interpret these results as indicating metabolic acidosis in the infant. A pH value of 7.32 is lower than the normal range of 7.35-7.45, indicating acidosis. The PaCO₂ value of 40, which falls within the normal range of 35-48 mm Hg, suggests that the respiratory system is compensating for the acidosis. The HCO₃ value of 21, which is lower than the normal range of 22-29 mM, further supports the diagnosis of metabolic acidosis.