Lack of consistent reference devices

The purpose of this study is to retrospectively evaluate the hemodynamic response to goal directed fluid therapy fluid during open abdominal surgery where goal directed fluid therapy is a standard of care after establishing a pre-incision baseline response to fluids.

Electronic and annotated observation data to support an algorithm library

Inclusion Criteria:

1. Adults ≥18 years booked for an open abdominal procedure
2. American Society of Anaesthesiologists (ASA) Physical Status 1 - 3
3. Expected duration of surgical procedure to be ≥ 2 hours
4. Standard of care monitoring to include cardiac output

Exclusion Criteria:

1. Open chest surgical procedure expected
2. Cardiac arrhythmia such as atrial fibrillation.
3. Right Ventricular Failure
4. Aortic regurgitation

Data collected for new algorithm development

Self hemodynamic baseline before surgical incision.

Two weeks. Consent in pre-op clinic to end of surgical procedure

Reference devices did not agree so trial terminated.