Clinical trials

All patients undergoing an implantation of a durable left ventricular assist device and monitored by pulmonary artery catheter showing no adverse events after surgery are included in the study and ventilated for 15 minutes using extra thoracic negative pressure ventilation and usual intrathoracic positive pressure ventilation. Hemodynamics changes between both ventilation modes, especially focussing on right ventricular function and measured by a pulmonary artery catheter, are compared.

A comparison of cardiac performance determined by stroke-volume-index measured by different mechanisms in patients during and after cardiac surgery: 1. Pulmonary artery catheter 2. Flo Trac 3. Argos Monitor Investigations will be done in theater and on ICU in ventilated and spontaneously breathing patients.

Patients receives induction of general anesthesia for interventional tricuspidal clipping and standard monitoring for this procedure including arterial and central venous line and transesophageal ultrasound. A cuirass for extrathoracal negative pressure ventilation is placed onto the chest but not switched on. During usual positive pressure ventilation a ventilatory, a hemodynamic and a 3D full volume ultrasounddataset of the right and left ventricle is recorded and severity of tricuspidal regurgitation examined. Afterwards negative pressure ventilation is started and positive pressure ventilation reduced as far as possible without reduction of tidal volumes. The same dataset of ventilation, hemodynamics and ultrasound is collected again during negative pressure ventilation. Afterwards the cuirass gets removed, study finished and everything proceeds as during standard procedure.