Successful weaning from mechanical ventilation after abdominal lipectomy and omentectomy in an obese patient with multiple rib fractures.

men ovale with major shunt and moderately dilated right ventricle. Inhaled NO was started. This immediately improved oxygenation (Pao2=Fio2 78 mm Hg) and the thermodilution curve (Fig. 1B) despite persistent and unchanged norepinephrine dose of 1 mg kg min 1 and same ventilatory settings. NO was titrated to 20 ppm. Twelve hours later norepinephrine was reduced to 0.3 mg kg min 1 and NO was reduced to 3 ppm as the double hump had completely disappeared (Fig. 1C). In the next 48 h norepinephrine and NO were discontinued and the trachea was successfully extubated 1 week later. Norepinephrine can cause a significant increase in pulmonary artery pressures in ARDS and sepsis. In this case, pulmonary pressures apparently were sufficient to cause right-to-left intracardiac shunt through a patent foramen ovale. The shunt presented as profound hypoxia exacerbated by increasing norepinephrine and the double hump on the transpulmonary thermodilution curve, suggested a short pass of the indicator. Besides reducing ventilation–perfusion mismatch, 4 inhaled NO can also improve oxygenation by resolving intracardiac shunt. 6 Here, the shunt was likely triggered by the high dose of norepinephrine as reduction allowed weaning from NO. This quick improvement was unlikely to be regression of ARDS. In patients with ARDS and worsening hypoxemia receiving high dose norepinephrine, right-to-left shunt should be suspected. Visual analysis of the transpulmonary thermodilution curve may suggest the diagnosis. Therapy with NO should be considered. The effect can be assessed by the shape of the thermodilution curve.