Atropine Effects in Anaesthesia With Sufentanil vs. Remifentanil

Study Overview
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Brief Summary
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Induction of general anaesthesia with a combination of opiates and hypnotics often induces vasodilation resulting in several haemodynamic effects such as a decrease in blood pressure (MAP), heart rate (HR) and cardiac output (CO). This haemodynamic suppression may jeopardize tissue oxygenation, particularly cerebral oxygenation. Previous research of the investigators group has revealed that atropine has an exceptionally beneficial effect on the determinants of tissue oxygen delivery as well as on tissue oxygenation. The investigators have demonstrated a significant and clinically relevant increase in CO and cerebral tissue oxygenation (SctO2) for a desired increase in MAP. This is in steep contrast with the more usual clinical practice of administrating classical vasoactive medication such as phenylephrine or norepinephrine, since the two latter have an even negative effect on CO and SctO2. In previous research the investigators used standardized target controlled propofol/remifentanil infusions for induction and maintenance of anaesthesia. It is known that remifentanil has more intense haemodynamic side-effects compared to other opiates such as fentanyl, sufentanil or alfentanil. This raises the question whether the beneficial effect of atropine is restricted to propofol/remifentanil anaesthesia, or if this is equally valid during anaesthesia of propofol combined with other opiates such as sufentanil. Patients undergoing off-pump coronary artery bypass grafting (CABG) require a long and deep general anaesthesia, which is usually performed with the combination of drugs as mentioned above. Because these patients often experience severe haemodynamic fluctuations they need to be closely monitored.

Official Title
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Comparison of the Effects of Atropine on Haemodynamics and Tissue Oxygenation in Anaesthesia With Propofol and Sufentanil Versus Propofol and Remifentanil

Conditions
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Haemodynamic Fluctuations During Off-pump CABG.

Intervention / Treatment
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* Drug: Remifentanil
* Drug: Sufentanil


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 18 years and older. Elective CABG surgery performed off-pump. Written informed consent to participate in this study. Patient and surgical procedure appropriate for treatment with either sufentanil or remifentanil. Exclusion Criteria: Refusal to participate in this study. Age: younger than 18 years. Pregnant. BMI > 35 kg/m2. Patients in which atropine is contra-indicated. Patients in which sufentanil or remifentanil at the proposed doses are contra-indicated. Urgent or emergency surgery.

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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Remifentanil<br>Anaesthesia with remifentanil/propofol | Drug: Remifentanil<br>* Anaesthesia with remifentanil/propofol.<br>|
| Active Comparator: Sufentanil<br>Anaesthesia with sufentanil/propofol | Drug: Sufentanil<br>* Anaesthesia with sufentanil/propofol<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CO |  | During anaesthesia | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| MAP |  | During anaesthesia | 
| Tissue oxygen saturation |  | During anaesthesia | 
| CO | CO obtained by different devices/methods (i.e. the Vigileo device and TEE) | During anaesthesia |