<qa>  What is the effect of Natrecor?This study seeks to demonstrate that Natrecor nesiritide is safe and effective and has a favorable hemodynamic profile in lung transplant recipients that will allow for the avoidance of inhaled nitric oxide iNO use. It is estimated that the use of nesiritide will decrease the otherwise historically mandated use of iNO by 50, as compared to the necessity of iNO use by matched historical controls. 