Mechanical ventilation strategy following Glenn and Fontan surgeries: On going challenge!

The Glenn and Fontan operations put the pulmonary and systemic circulations in series. It has been shown that positive pressure ventilation (PPV) decreases pulmonary blood flow (PBF) and cardiac output (CO), and negative pressure ventilation (NPV) significantly improves PBF and CO. If early extubation is not achievable, the postoperative ventilator management strategy should aim at promoting PBF and CO by lowering pulmonary vascular resistance (PVR) and intrathoracic pressure. Multiple ventilator strategies have been evaluated to optimize this physiology, including high frequency ventilation, hyperventilation post Glenn, hypoventilation post Glenn with buffered pH, and the use of inhaled nitric oxide as an adjunct therapy for mechanical ventilation. In this review, the results of these studies will be reviewed and discussed.