Estimation of Pulmonary Artery Occlusion Pressure Using Doppler Echocardiography in Mechanically Ventilated Patients.

Objectives: Evaluation of left atrial pressure is frequently required for mechanically ventilated critically ill patients. The objective of the present study was to evaluate the 2016 American Society of Echocardiography and the European Association of Cardiovascular Imaging guidelines for assessment of the pulmonary artery occlusion pressure (a frequent surrogate of left atrial pressure) in this population.

Design: A pooled analysis of three prospective cohorts of patients simultaneously assessed with a pulmonary artery catheter and echocardiography.

Settings: Medical-surgical intensive care department of two university hospitals in France.

Patients: Mechanically ventilated critically ill patients.

Interventions: None.

Measurements And Main Results: Of 98 included patients (males: 67%; mean ± SD age: 59 ± 16; and mean Simplified Acute Physiology Score 2: 54 ± 20), 53 (54%) experienced septic shock. Using the 2016 American Society of Echocardiography and the European Association of Cardiovascular Imaging guidelines, the predicted pulmonary artery occlusion pressure was indeterminate in 48 of the 98 patients (49%). Of the 24 patients with an elevated predicted left atrial pressure (grade II/III diastolic dysfunction), only 17 (71%) had a pulmonary artery occlusion pressure greater than or equal to 18 mm Hg. Similarly, 20 of the 26 patients (77%) with a normal predicted left atrial pressure (grade I diastolic dysfunction) had a measured pulmonary artery occlusion pressure less than 18 mm Hg. The sensitivity and specificity of American Society of Echocardiography and the European Association of Cardiovascular Imaging guidelines for predicting elevated pulmonary artery occlusion pressure were both 74%. The agreement between echocardiography and the pulmonary artery catheter was moderate (Cohen's Kappa, 0.48; 95% CI, 0.39-0.70). In a proposed alternative algorithm, the best echocardiographic predictors of a normal pulmonary artery occlusion pressure were a lateral e'-wave greater than 8 (for a left ventricular ejection fraction ≥ 45%) or an E/A ratio less than or equal to 1.5 (for a left ventricular ejection fraction < 45%).

Conclusions: The American Society of Echocardiography and the European Association of Cardiovascular Imaging guidelines do not accurately assess pulmonary artery occlusion pressure in ventilated critically ill patients. Simple Doppler measurements gave a similar level of diagnostic performance with less uncertainly.