Intravascular volume monitoring and extravascular lung water in septic patients with pulmonary edema

Abstract

Objective: To evaluate whether different indicators using for guiding volume expansion are valuable tools to assess edematous lung injury in patients with septic shock. Design and setting: Prospective observational clinical study in a university intensive care unit. Patients: Sixteen consecutive mechanically ventilated patients developing septic shock with evidence of pulmonary edema on chest radiograph and severe hypoxemia (PaO2/FIO2<250 mmHg). Measurements and results: A pulmonary artery catheter was used for the measurement of cardiac index (CI), central venous pressure (CVP), and pulmonary artery occlusion pressure (PAOP). A fiberoptic catheter was placed in the descending aorta. Measurements of extravascular lung water index (EVLWI), intrathoracic blood volume index (ITBVI), and total end-diastolic volume index (TEDVI) were obtained using the thermal dye dilution technique. Measurements were taken just after placement of catheters and 24 h later. Fluid balance was also estimated within the first 24 h. TEDVI and ITBVI were significantly correlated with EVLWI, but not CVP and PAOP. Analysis of 24-h changes showed that the changes in TEDVI and in ITBVI reflected the change in EVLWI, whereas PAOP, CVP, and fluid balance did not. Conclusions: Volume variables (TEDVI, ITBVI) are more useful indicators than pressure variables (CVP, PAOP) for assessment of EVLWI in septic patients with pulmonary edema.