Repeat the test because of obvious laboratory error
a.A
b.B
c.C
d.D
Explanation:
The data on row A indicate severe acidemia and severe hypoxia with a marked respiratory acidosis and metabolic acidosis. These are manifestations of severe ventilatory failure, probably accompanied by circulatory failure or cardiac arrest. This mandates the most aggressive therapy, including assisted ventilation with administration of high oxygen levels. Other measures to restore circulation and improve the acidemia are also indicated.
The results of row C show metabolic alkalosis. The high PCO2 and low PO2 result from compensatory hypoventilation. This can all be secondary to excessive body potassium losses from diuretics.
The results in row B indicate respiratory acidosis with metabolic compensation, indicating chronic upper airway obstruction. A common cause of chronic hypoventilation in children is hypertrophied tonsils and adenoids, which may be an indication for tonsillectomy or adenoidectomy (or both).
The blood gases of row D are impossible in a patient breathing room air. The PCO2 cannot go up without the PO2 dropping roughly proportionately. An increase in PCO2 of 20 mm Hg, from 40 to 60 mm Hg, should therefore produce a fall in PO2 from 90 to 70 mm Hg. The test should be repeated after the blood gas equipment has been checked and recalibrated.