Uh-oh, some CO2 has gone missing

Abstract

In this issue of the Journal, Koth and colleagues 1 analyzed dead space ventilation fraction (Vd/Vt) in a cohort of 265 patients shortly after collateral unifocalization and report an association between increased Vd/Vt (>20%) and prolonged mechanical ventilation. The report is noteworthy-it describes an underappreciated aspect of physiology in a large cohort of patients with tetralogy of Fallot with pulmonary atresia treated at a center that is well-known for excellent outcomes with this group of patients. The authors' general message appeals to intuition-unifocalization may be associated with alveolar collapse, reperfusion injury, underperfused segments, capillary leak, interstitial edema, etc-all contributing to increased dead space and pulmonary morbidity.