[Intraoperative diagnosis--measuring heart time volume and assessment of shunts]

Intraoperative measurement of hemodynamics provides objective data supporting improvement of surgical and anaesthesiological treatment. Several methods including the thermodilution method, application of ultrasonic flow meters, use of the computed pressure gradient technique, application of transoesophageal color flow mapping and other cardiovascular applications of ultrasound are discussed with respect to their benefits and limitations in a clinical routine environment in cardiac surgery. According to our experiences the application of intraoperative transoesophageal doppler echocardiography and use of electromagnetic flow measurements are today the methods of choice. However, methodological limitations have to be regarded and additional intraoperative and clinical data are necessary whenever semiquantitative measurements of ultrasound techniques are used as basis for intraoperative judgement on the hemodynamic situation.