Cardiopulmonary consequences of congenital diaphragmatic hernia.

The cardiopulmonary consequences of CDH can be devastating, and despite intensive research the pathophysiologic makeup of this condition is not fully understood. It seems likely that its overall prognosis is related to the size of the pulmonary vascular bed and its capacity to accept the cardiac output at birth. The ability of the lungs to perform this task is impaired by a surfactant deficiency and by pulmonary vessels that respond excessively to normal stimuli of vasoconstriction. Understanding the mechanisms through which these pathophysiological abnormalities are occurring should provide us with therapeutic insights into how we may recruit all the available alveoli in these lungs, prevent ventilation-induced lung injury, optimize pulmonary blood flow, and maximize cardiac output without causing right or left heart compromise. Failure to achieve all or any of these goals can feed back and exacerbate the underlying pathophysiological condition.