Reassessment of the Accuracy of Cardiac Doppler Pulmonary Artery Pressure Measurements in Ventilated ICU Patients: A Simultaneous Doppler-Catheterization Study
Résumé
Objectives: Doppler echocardiography is a well-recognized technique for the noninvasive evaluation of pulmonary artery pressure; however, little information is available concerning patients receiving mechanical ventilation. Furthermore, recent studies have debatable results regarding the relevance of this technique to assess pulmonary artery pressure. The aim of our study was to reassess the accuracy of Doppler echocardiography to evaluate pulmonary artery pressure and to predict pulmonary hypertension. Design: Prospective observational study. Setting: Amiens ICU, France. Patients. ICU patients receiving mechanical ventilation. Interventions: In 40 patients, we simultaneously recorded Doppler echocardiography variables (including tricuspid regurgitation and pulmonary regurgitation) and invasive central venous pressure, systolic pulmonary artery pressure, diastolic pulmonary artery pressure, and mean pulmonary artery pressure. Measurements and Main Results: Systolic pulmonary artery pressure assessed from the tricuspid regurgitation derived maximal pressure gradient added to the central venous pressure demon-strated the best correlation with the invasive systolic pulmonary artery pressure (r = 0.87) with a small bias (-3 mm Hg) and a precision of 9 mm Hg. A Doppler echocardiography systolic pulmonary artery pressure greater than 39 mm Hg predicted pulmonary hypertension (mean pulmonary artery pressure >= 25 mm Hg) with 100% sensitivity and specificity. Tricuspid regurgitation maximal velocity greater than 2.82 m/s as well as tricuspid regurgitation pressure gradient greater than 32 mm Hg predicted the presence of pulmonary hypertension. Pulmonary regurgitation was recorded in 10 patients (25%). No correlation was found between pulmonary regurgitation velocities and either mean pulmonary artery pressure or diastolic pulmonary artery pressure. Pulmonary acceleration time less than 57 ms and isovolumic relaxation time less than 40 ms respectively predicted pulmonary hypertension 100% of the time and had a 100% negative predictive value. Conclusions: Tricuspid regurgitation maximal velocity pressure gradient added to invasive central venous pressure accurately estimates systolic pulmonary artery pressure and mean pulmonary artery pressure in ICU patients receiving mechanical ventilation and may predict pulmonary hypertension.