Unexpected Increase in Arterial to End-Tidal CO<sub>2</sub> Gradient in a Child Undergoing Embolization of MAPCAs

Abstract

A 17-month-old infant with multiple aorto-pulmonary collateral arteries (MAPCAs) and pulmonary hypertension presented for diagnostic catheterization. On the day of the procedure, the infant was asymptomatic with oxygen saturation in the 90's on 1.0 L/min O 2 nasal cannula. His parents denied any recent illness. During the procedure, one coil was inadvertently embolized into the right lung resulting in markedly increased pulmonary artery pressures.The Pa-etCO 2 gradient increased to 25 mmHg from a baseline of 2 mmHg.Therapy was initiated to reduce the PaCO 2 . The patient could not be weaned from mechanical ventilation due to elevated PA pressures.