Rivers et al. laid the foundation for modern hemodynamic and fluid management by establishing goal directed therapy (GDT) for the treatment of sepsis using fluid and inotropic and vasoactive agents. There have been many subsequent protocols to improve outcome in the operating room or in the ICU. These are mainly passive decision support systems. Active clinical decision support systems using fluid and pharmacologic agents to improve intraoperative hemodynamics are not really found.

The investigators developed an active clinical decision support system based on an institutional GDT-protocol using fluid, vasopressors and inotropes using the LiDCOrapid device.

The goal of the study was to check the feasibility of an active clinical decision support system to optimize hemodynamics during high risk vascular surgery based on the principles of GDT implementing fluid, vasopressors and inotropes.

Inclusion Criteria:

• elective major vascular surgery such as peripheral arterial surgery and open abdominal aortic surgery except for carotid artery surgery

Exclusion Criteria:

• patients under 18 years of age
• absence of cardiac sinus rhythm at induction of anesthesia