Non-invasive Early Goal Directed Therapy in Colorectal Surgery: a Feasibility Study

The Nexfin™ monitoring system is able to provide continuous beat-to-beat stroke volume index (SVI), stroke volume variation (SVV), pulse pressure variation (PPV), cardiac index (CI) and arterial pressure by using an inflatable finger cuff. This system consists of a frequency dependent transfer function for calculation of brachial artery pressure from the finger artery pressure.

Major surgery bares the risk of concealed hypoperfusion and therefore possible mismatch in oxygen delivery and oxygen demand. It must be noted, that the "basic" perioperative monitoring, i.e. electrocardiogram, oxygen saturation and non-invasive or invasive blood pressure measurements is not able to accurately detect hypovolemia and ongoing organ hypoperfusion. Perioperatively, patients undergoing major abdominal surgery are prone to high risk of hemodynamic instabilities and consequently relevant changes in oxygen delivery, associated with an increase in postoperative complications and length of stay in hospital. Over the last years several studies focused on early goal directed hemodynamic therapy (GDT) with strong proof for the feasibility of such algorithms and the improvement in patient's outcome with respect to certain clinical scenarios.However, there is still a debate regarding an individualized GDT approach, based on pre-procedural defined individualized hemodynamic goals yielded by an advanced haemodynamic monitoring technology. We do have to distinguish which monitoring system, invasive to non-invasive, matches the kind of estimated risk at what time best.

Inclusion criteria

• Major abdominal procedures
• Estimated duration ≥120 minutes
• High transfusion probability
• Anticipated blood loss ≥1000 ml

Exclusion criteria

• Patients less than 18 years old
• ASA I or IV classification
• Heart rhythm disorders
• Advanced peripheral artery occlusive disease
• Arteriovenous shunts concerning upper extremities
• Laparoscopic abdominal procedures