End-inspiratory occlusion maneuver during transesophageal echocardiography for patent foramen ovale detection in intensive care unit patients

Objective: Mechanically ventilated patients in the intensive care unit cannot cooperate to perform the Valsalva maneuver during echocardiography for detection of patent foramen ovale. We evaluated the effectiveness of the end-inspiratory occlusion maneuver to enhance detection of patent foramen ovale in this patient population. Design: Prospective interventional study. Setting: The 40-bed intensive care unit of a university hospital. Patients and participants: Twenty five sedated and mechanically ventilated intensive care unit patients referred by their attending physician for bedside transesophageal echocardiography and agitated saline contrast study for detection of patent foramen ovale. Intervention: Agitated saline contrast study with end-inspiratory occlusion maneuver. Measurements and results: All patients underwent a complete transesophageal echocardiographic study without any complications. Reduction in right atrial cross-sectional area (from 15.80 +/- 6.08 cm(2) to 12.40 +/- 4.63 cm(2); p < 0.001) and interatrial septum deviation during the maneuver were recorded in all patients. Microbubbles imaged in the left atrium within three cardiac cycles after injection of agitated saline diagnosed patent foramen ovale in three patients. When end-inspiratory occlusion maneuver was added, patent foramen ovale was diagnosed in seven patients (McNemar chi(2) = 9.33, p = 0.0023). Conclusions: The end-inspiratory occlusion maneuver enhances the sensitivity of transesophageal echocardiography with agitated saline contrast study for diagnosing intermittent patent foramen ovale in critically ill mechanically ventilated patients.