The Utility of Tissue Doppler Imaging for the Noninvasive Determination of Left Ventricular Filling Pressures in Patients With Septic Shock

Abstract

Pulmonary artery wedge pressure (PAWP) is an important indicator of volume status in septic patients. Although it requires invasive pulmonary artery catheterization (PAC), a noninvasive method to assess PAWP would be clinically useful in this select patient population. Diastolic indices using transthoracic echocardiography (TTE) may provide an accurate estimate of PAWP. To determine whether echocardiographic Doppler assessment is accurate in estimating PAWP in patients with septic shock. A retrospective chart review was performed of 320 patients admitted with a diagnosis of septic shock from 2007-2008. Of the total patient population, 40 patients fulfilled the inclusion criteria, having undergone both TTE and PAC within 4 hours. Spectral Doppler indices including peak early (E) and late (A) transmitral velocities, E/A ratio, and E-wave deceleration time were measured. Tissue Doppler indices including S', E' and A' velocities were determined. Pulmonary artery wedge pressure values measured invasively were compared to the dimensionless index of E/E' in each patient. The mean age was 68 +/- 12 years with 28 males (70%). On echo assessment, 28% of patients had evidence of mild left ventricular diastolic dysfunction while 17% of patients had moderate diastolic dysfunction. Pulmonary artery wedge pressures ranged from 7 to 31 mm Hg with a mean of 18 +/- 5 mm Hg. The mean E/E' was 11 +/- 8. Linear regression analysis between PAWP and E/E7apos; demonstrated a strong correlation (r = .84, P < .05). Tissue Doppler indices using TTE is a feasible and strong predictor of PAWP in patients with septic shock.