Pulse Contour Analysis and Tissue Oxymetry in Changing Vascular Tone

The purpose of this study is to compare changes of minimally invasive arterial pulse contour cardiac output with changes of intermittent and continuous thermodilution cardiac output by pulmonary artery catheter in hemodynamic unstable patients with rapid changing vascular tone (changing dosage of vasoactive drugs or inotropics, or volume challenge). Simultaneously, global parameters of oxygen delivery and consumption will be compared with regional flow parameters and tissue oxymetry (near infrared spectrometry and laser-Doppler). While continuous thermodilution cardiac output is used for patient management, pulse contour cardiac output, intermittent thermodilution cardiac output and tissue oxymetry is only used for monitoring.

Arterial pulse contour cardiac output, Changing vascular tone, Tissue Oxymetry, Prediction of Fluid Responsiveness

Vigileo TM / Flotrac TM (Minimally invasive cardiac output system consisting of arterial line sensor and cardiac output monitor)

Attachment of the arterial line sensor and pulse contour cardiac output monitor to the arterial line of the patient.

Either a volume challenge (using colloids or crystalloids) or a change in the dosage of of vasoactive drugs or inotropics, or a combination of them, as proposed by the treating physician.

Tissue oxymetry continuously measured with near infrared spectrometry and laser Doppler during the whole study period.

Prediction of fluid responsiveness with minimally invasive arterial pulse contour analysis in hemodynamic unstable patients.

Comparison of global parameters of oxygen delivery and consumption with local parameters of flow and tissue oxymetry during changes of vascular tone.

Inclusion Criteria: Indication for invasive hemodynamic monitoring with pulmonary artery catheter and arterial catheter Hemodynamic instability (need for vasoactive drugs, inotropics or volume). Exclusion Criteria: Age < 18. Patient with contraindications for the placement of arterial cannula. Patient with history or clinical findings of aortic valve regurgitation. Atrial fibrillation. Patient being treated with an intra-aortic balloon pump. Limitation of therapy due to bad prognosis