Extravascular lung water in patients with septic shock during a fluid regimen guided by cardiac index.

BACKGROUND: To elucidate whether patients with a septic shock develop pulmonary edema in a treatment protocol in which volume loading is guided by its effect on the cardiac output, rather than by preset values of pulmonary artery wedge pressure (PAWP).

METHODS: 15 consecutive patients with the diagnosis of septic shock were studied in a prospective observational study. Cardiac output, PAWP and extravascular lung water index (EVLWI) were determined at regular intervals during the first 24 h of treatment. Fluid challenges were given if MAP was <80 mm Hg and/or CI was <4.5 l/min/m(2), and PAWP was <16 mm Hg. Further fluid challenges were only given if the preceding fluid challenge resulted in an increase in CI of more than 10% and PAWP was still <16 mm Hg.

RESULTS: EVLWI was slightly above normal (10.4+/-1.2 ml/kg) and did not change during the treatment protocol. One third of the patients had an initial PAWP>16 mmHg. In these patients, EVLWI was significantly higher than in patients with an initial PAWP <16 mm Hg (14.1+/-1.1 ml/kg versus 10.0+/-0.9 ml/kg, P=0.026). No significant correlation was found between PAWP and EVLWI.

CONCLUSION: In this study, patients with septic shock did not develop pulmonary edema during the first 24 h of treatment, when their fluid regimen was guided by the effects on cardiac output.