Compromised tissue oxygenation during surgery may negatively influence patient outcome. Primary cause of insufficient tissue oxygenation is reduced cardiac output due to hypovolemia and/or reduced cardiac contractility. In cardiac surgery patients especially, postoperative pericardia effusion and/or tamponade may further compromise cardiac function. Today, hemodynamically instable patients are often monitored by means of pulmonal artery catheters or transpulmonary thermodilution. However, these methods only allow quantification of functional limitations. Underlying causes may be investigated by relatively recent technology through hemodynamically focussed transesophageal echocardiography (ClariTEE(R) ImaCor) that also provide the possibility of continuous monitoring. It has been reported that a training program consisting of six hours may enable physicians who are unexperienced in the field of echocardiography to apply this new method. Up to now, there is no evidence whether this methods is associated with improved postoperative outcome.

Therefore we hypothesize that continuous hemodynamically focussed transesophageal echocardiography positively influences patient outcome (primary hypothesis). Furthermore, its application may decrease hospital expenses (secondary hypothesis).

Inclusion Criteria:

• elective, cardiac surgery
• hemodynamic instability or placement of hTEE/PICCO (Pulse Contour Continuous Cardiac Output) /PAC (Pulmonary Arterial Catheter) within 12 hours of ICU admission

Exclusion Criteria:

• pregnant/breastfeeding women

Patients undergoing cardiac surgery followed by postoperative observation on an ICU of the anaesthesiology department of the Charité hospital