Published in:
01-03-2007 | Original
Assessing pulmonary permeability by transpulmonary thermodilution allows differentiation of hydrostatic pulmonary edema from ALI/ARDS
Published in: Intensive Care Medicine | Issue 3/2007
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Objective
To test whether assessing pulmonary permeability by transpulmonary thermodilution enables to differentiate increased permeability pulmonary edema (ALI/ARDS) from hydrostatic pulmonary edema.
Design
Retrospective review of cases.
Setting
A 24-bed medical intensive care unit of a university hospital.
Patients
Forty-eight critically ill patients ventilated for acute respiratory failure with bilateral infiltrates on chest radiograph, a PaO2/FiO2 ratio < 300 mmHg and extravascular lung water indexed for body weight ≥ 12 ml/kg.
Intervention
We assessed pulmonary permeability by two indexes obtained from transpulmonary thermodilution: extravascular lung water/pulmonary blood volume (PVPI) and the ratio of extravascular lung water index over global end-diastolic volume index. The cause of pulmonary edema was determined a posteriori by three experts, taking into account medical history, clinical features, echocardiographic left ventricular function, chest radiography findings, B-type natriuretic peptide serum concentration and the time-course of these findings with therapy. Experts were blind for pulmonary permeability indexes and for global end-diastolic volume.
Measurements and results
ALI/ARDS was diagnosed in 36 cases. The PVPI was 4.7 ± 1.8 and 2.1 ± 0.5 in patients with ALI/ARDS and hydrostatic pulmonary edema, respectively (p < 0.05). The extravascular lung water index/global end-diastolic volume index ratio was 3.0 × 10−2 ± 1.2 × 10−2 and 1.4 × 10−2 ± 0.4 × 10−2 in patients with ALI/ARDS and with hydrostatic pulmonary edema, respectively (p < 0.05). A PVPI ≥ 3 and an extravascular lung water index/global end-diastolic index ratio ≥ 1.8 × 10−2 allowed the diagnosis of ALI/ARDS with a sensitivity of 85% and specificity of 100%.
Conclusion
These results suggest that indexes of pulmonary permeability provided by transpulmonary thermodilution may be useful for determining the mechanism of pulmonary edema in the critically ill.