North Trent Critical Care Network

Background: 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. Objective: To determine whether echocardiographic Doppler assessment is accurate in estimating PAWP in patients with septic shock.

Methods:
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.

Results:
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).

Conclusion:
Tissue Doppler indices using TTE is a feasible and strong predictor of PAWP in patients with septic shock.

Authors: Mousavi, N., Czarnecki, A., Ahmadie, R., Tielan Fang, , Kumar, K., Lytwyn, M., Kumar, A., Jassal, D. S.

Read More: Journal of Intensive Care Medicine current issue