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Use of Inhaled Nitric Oxide To Reverse Flow through a Patent Foramen Ovale during Pulmonary Embolism
- Philippe Estagnasie, MD;
- Genevieve Le Bourdelles, MD;
- Laurence Mier, MD;
- Francois Coste, MD; and
- Didier Dreyfuss, MD
- From Hopital Louis Mourier, Colombes, France. Requests for Reprints: Didier Dreyfuss, MD, Service de Reanimation Medicale, Hopital Louis Mourier, 92700 Colombes et Faculte Xavier Bichat, 75018 Paris, France.
The presence of a patent foramen ovale during pulmonary embolism may promote right-to-left shunting when right atrial pressure exceeds that in the left atrium. This may cause severe hypoxemia and paradoxical embolism [1]. The diagnosis of this complication has benefited from contrast transesophageal echocardiography [2]. Invasive procedures, such as transcatheter or surgical closure, are usually required [3] but may not be easily done in unstable patients. Reversing the right-to-left atrial pressure gradient may promote closure of the patent foramen ovale. We report an example of this reversal using inhaled nitric oxide, a potent pulmonary vasodilator [4-7].
Case Report
A 74-year-old woman was admitted to our intensive care unit with deep coma and acute respiratory failure requiring mechanical ventilation. A complete right bundle-branch block was seen on the electrocardiogram. Despite clear lung fields on the chest radiograph, the pulmonary angiographic results showed a massive embolism (the Miller index [8], 23/34). A continuous intravenous infusion of heparin was immediately started. A cerebral computed tomographic scan showed several cerebral infarctions in the vertebrobasilar system. A patent foramen ovale was suspected, and transesophageal echocardiography using an Aloka SSD-870 device Aloka, Tokyo, Japan with a 5-MHz monoplane probe showed an atrial septal aneurysm (Figure 1, top left). A right-to-left shunt …
