Transesophageal echocardiographic assessment of right heart hemodynamics during high-frequency jet ventilation

Study Objective: To evaluate right ventricular dimensions and function by e chocardiography in anesthetized patients during superimposed high-frequency jet ventilation (HFJV). Design: Prospective clinical study. Setting: University hospital operating room. Patients: 20 ASA physical status I patients undergoing elective minor otorh inolaryngological surgery, and undergoing conventional mechanical ventilati on with subsequent superimposed HFJV. Interventions: Two-dimensional transesophageal echocardiography with a 5-MH z multiplane transducer to determine right ventricular dimensions and funct ion from a mid-esophageal view. Insertion of a radial artery catheter for m onitoring blood pressure and blood gases. Measurements and Main Results: Heart rate, mean arterial blood pressure, an d right ventricular and end-diastolic and end-systolic volumes determined b y echocardiography, stroke volume, and ejection fraction. Measurements were performed after 10 minutes of subsequent superimposed HFJV at similar peak and positive end-expiratory airway pressures. Right ventricular systolic a nd diastolic volumes, stroke volume, and ejection fraction did not reveal s tatistical significant differences after transition to HFJV. Interventricul ar septum did not show any abnormalities in motion. In contrast, interartri al septum demonstrated momentary mid-systolic bows toward the left atrium i n 9 of 17 patients (53%) during conventional ventilation, but in 15 of 17 p atients (88%) during jet ventilation. Heart rate and mean arterial blood pr essure remained unchanged, but arterial oxygen tension values were higher a nd arterial carbon dioxide tension values lower during HFJV. Conclusion: Transesophageal echocardiographic evaluation of right heart hem odynamics did not show any significant difference after transition of venti lation to superimposed HFJV applying similar airway pressures. Furthermore, superimposed HFJV was safe and effective, it improved oxygenation, and it faciliated carbon dioxide elimination. (C) 1999 by Elsevier Science Inc.