Implementation of Computer-Assisted Intraoperative Goal-Directed Fluid Therapy

Implementation of Computer-Assisted Intraoperative Goal-Directed Fluid Therapy in Major Abdominal Surgery: A Before and After Study

The aim of this study is to compare the implementation of computer-assisted goal directed fluid therapy (GDFT) to standard of care fluid therapy in major abdominal surgery.

Fluid therapy is one of the main tools used in anesthesiology to maintain adequate hemodynamic stability. Goal-directed fluid therapy (GDFT) based on cardiac output and/or dynamic parameters of fluid responsiveness (e.g. pulse pressure variation) has been shown to decrease post-operative complications. The main inconvenience of protocol based therapy is its technical complexity which requires considerable time, attention, and vigilance. GDFT assisted by a closed-loop system, when compared to manual GDFT, is associated with a longer preload independent state and could increase clinician adherence to protocol. To this day no study has compared closed-loop assisted GDFT to standard of care.

Goal:

This study compares the results of the study entitled "Crystalloids or Colloids for Goal directed Fluid Therapy With Closed-loop Assistance in Major Surgery" (NCT02312999) to a standard of care group (started retrospectively before the first included patient of the above study) where fluid therapy is based only on static variables (e.g. arterial pressure, heart rate, central venous pressure (CVP), and urine output.) These groups consisted of the same population undergoing the same types of surgery.

Hypothesis:

A protocolized approach using computer-assisted GDFT when compared to standard of care is associated with less fluid administration and less blood transfusions.

Inclusion Criteria:

• Adult patients (over the age of 18) undergoing elective major abdominal surgery that is expected to take longer than 3 hours and requiring general anesthesia.

Exclusion Criteria:

• Patients under 18 years of age
• Patients not undergoing surgery, requiring anesthesia, or cardiac output monitoring
• Patients with arrhythmia and/or atrial fibrillation
• Patients who are allergic to HES (hydroxyethyl starch)
• Patients with renal insufficiency (serum creatinine of >2 mg/ml) or hepatic dysfunction (liver enzymes >1.5)
• Patients who has coagulation disorders (values higher than 1.5x normal values)
• Patients without the capacity to give written informed consent or refusal of consent
• Pregnancy at time of enrollment.