The accuracy of transoesophageal echocardiography in estimating pulmonary capillary wedge pressure in anaesthetised patients

The objective of this study was to identify whether pulmonary capillary wedge pressure can be estimated in anaesthetised patients receiving mechanical ventilation, using transoesophageal echocardiography. A retrospective validation study investigated a 10-patient cohort with variable haemodynamic conditions, and a 102-patient series in which a single measurement was made during stable haemodynamic conditions. Concurrent echocardiographic Doppler and pulmonary artery catheter wedge pressure measurements were performed. In the 10-patient cohort, the systolic fraction of Doppler measurements in the pulmonary vein (r = -0.32, p = 0.035) and the E/A ratio (r = 0.56, p = 0.0009) were correlated with the wedge pressure. In all cases, the limits of agreement exceeded 10 mmHg, and sensitivity or specificity for detecting wedge pressure ≥ 15 mmHg was poor. This study demonstrates proof of concept that using transoesophageal echocardiography for estimating the pulmonary artery wedge pressure may not be sufficiently accurate for clinical use.