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

Study Overview
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Brief Summary
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The Nexfin monitoring system offers a complete non-invasive approach to a continuously estimation of blood pressure, CI and PPV by means of finger-cuff based pulse contour analysis. Several clinical investigations have proven reliability and interchangeability of the Nexfin technology yielding acceptable results especially regarding the trending abilities. At present there is no evidence available, whether a early goal directed hemodynamic optimization protocol based on a completely non-invasive monitoring technology is able to reduce postoperative complication. Therefore, the aim of this single-center study is to compare the clinical outcome and postoperative complications of patients undergoing major colorectal surgery treated with standard of care or with a GDT protocol based on the Nexfin technology.

Detailed Description
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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.

Conditions
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Perioperative/Postoperative Complications, C.Surgical Procedure; Digestive System

Intervention / Treatment
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* Drug: Dobutamine


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Study group (SG)<br>Before induction of anaesthesia: Arterial line Nexfin Monitoring System Measurement of cardiac index (CI), pulse pressure variation (PPV) and mean arterial pressure (MAP) Baseline blood samples. Induction of anaesthesia Study Group: PPV ≤10%, 500 ml of crystalloids/colloids as long as CI was ≥2.5 l/min/m² Maintenance of CI ≥2.5 l/min/m² and MAP ≥65 mmHg by using dobutamine (10 µg/kg/min) and norepinephrine (0.03 µg/kg/min). | Drug: Dobutamine<br>* If PPV ≤10%, volume substitution of 500 ml of crystalloids and/or colloids as long as CI was ≥2.5 l/min/m². Maintenance of CI ≥2.5 l/min/m² and MAP ≥65 mmHg was achieved by using dobutamine (10 µg/kg/min) and norepinephrine (0.03 µg/kg/min).<br>* Other names: crystalloids/colloids;|
| No Intervention: Control group (CG)<br>MAP ≥65 mmHg CVP ≤12 mmHg Haemoglobin level ≥8 g/dl. Maintenance of MAP ≥65 mmHg by using crystalloids/colloids, bolus injection of theodrenaline/cafedrine or continuous infusion of norepinephrine (0.03 µg/kg/min) according to clinical evaluation. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative complications |  | 28 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Length of hospital stay (LOS) |  | 28 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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haemodynamic optimization, cardiac index, non-invasive, pulse pressure variation