[Impedance cardiography following cardiac surgery].

For checking the possibility of using impedance cardiography in intensive care, 10 patients were examined before and up to 2 days after cardiac surgery with extracorporeal circulation. The comparison of stroke volumes examined by thermodilution with those calculated from impedance cardiography showed a good correlation (r = 0.933). The cardiac output measured by impedance cardiography was reduced to 77% of the initial preoperative value. It increased again to 94% on the second postoperative day. HEATHER-index and dZ/dt are well suited for supervision and quantitative treatment control in the postoperative period. The thoracic impedance was diminished more than 20% after extracorporeal circulation and did not yet reach the preoperative value on the second day. The continuous measurement of the thoracic impedance proved to be particularly helpful for assessing the pulmonary hydration and for controlling the fluid balance.