IMPACT: Vasopressor Impact on Brain Circulation, Organ Blood Flow and Tissue Oxygenation During Anesthesia
Study Details
Study Description
Brief Summary
The optimal vasopressor for ensuring organ blood flow and tissue oxygen delivery during surgery remains undetermined. This study aim to compare the effects of noradrenaline vs. phenylephrine infusion on blood flow and oxygen delivery to the brain and various other organs in anesthetized neurosurgical patients.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
| Phase 2/Phase 3 |
Detailed Description
The brain and other blood flow sensitive organs are vulnerable to hypotension during neurosurgery. As a countermeasure, vasopressor agents are often administered to increase blood pressure. The ultimate goal of the vasopressor is to secure perfusion of vital organs and fulfill their metabolic demand. However, the optimal vasopressor for ensuring organ blood flow and tissue oxygen delivery during surgery remains undetermined.The aim of this study is to compare the effects of noradrenaline vs. phenylephrine infusion on blood flow and oxygen consumption in the brain and various other organs in anesthetized neurosurgical patients.
The project constitutes a clinical randomized study involving 40 patients diagnosed with brain tumors. The study is conducted on the same day as their scheduled brain tumor surgery. The study is designed as a randomized, double-blinded clinical trial, with two distinct groups: Group 1 receives phenylephrine, while Group 2 receives noradrenaline.
PET exams of blood flow and oxygen consumption in brain and organs are performed using a PET scanner with a wide field of view. The wide field of view allow for simultaneous multiorgan blood flow and oxygen consumption measurements.
Four positron emission tomography (PET) examinations are performed prior to the surgical procedure. The first PET examination (PET 1) is performed in the awake patient. The patient is then anesthetized, and the PET exam is repeated (PET 2). Vasopressor infusion is initiated and PET exams are repeated after a 10 % (PET3) and 20% (PET4) increase in mean arterial blood pressure (MABP) relative to pre-treatment level(as measured during anesthesia). Surgery is performed immediately after the PET examinations.
The blinded vasopressor infusion is initiated after PET 2 and terminated after the surgical procedure. Invasive blood pressure, cardiac output (CO),depth of anesthesia (bispectral index) and brain tissue oxygen saturation(near infrared spectroscopy) are continuously measured.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Noradrenaline Noradrenaline |
Drug: Noradrenalin
Infusion of noradrenaline during anesthesia and surgery
Other Names:
|
| Active Comparator: Phenylephrine Phenylephrine |
Drug: Phenylephrine
Infusion of phenylephrine during anesthesia and surgery
Other Names:
|
Outcome Measures
Primary Outcome Measures
- Cerebral blood flow [Up to 3 hours (measured on the day of surgery prior to the surgical procedure)]
Blood flow measured in milliliters per minute through selected regions of the brain as determined by Positron Emission Tomography
Secondary Outcome Measures
- Cerebral metabolic rate of oxygen [Up to 4 hours (measured on the day of surgery prior to the surgical procedure)]
Cerebral oxygen consumption in selected regions of the brain as determined by Positron Emission Tomography
- Blood flow through body organs in milliliters per minute as determined by Positron Emission Tomography [Up to 4 hours (measured on the day of surgery prior to the surgical procedure)]
Blood flow in various body organs supplied by the systemic circulation
- Blood pumped out by the heart per minute (cardiac output) [Up to one day]
Cardiac output as determined by Positron Emission Tomography and/or by beat-to-beat determination by analysis of the arterial blood pressure waveform
- Ischemic lesions [Up to 3 days]
Ischemic lesions possibly associated with vasopressor use as detected on the postoperative MRI examination
- Cerebral tissue oxygen saturation [Up to one day]
Cerebral tissue oxygen saturation as measured with near infrared spectroscopy (NIRS)
- Bispectral Index (BIS) [Up to one day]
Depth of anesthesia as measured by BIS
- Organ metabolic rate of Oxygen [Up to 3 hours (measured on the day of surgery prior to the surgical procedure)]
Oxygen consumption in various organs as measured by Positron Emission Tomography
Eligibility Criteria
Criteria
Inclusion Criteria:
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Clinical diagnosis of supratentorial malignant or non-malignant brain tumors. Preferably 3 cm or larger( measured as the largest diameter in any plane on MRI).
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Scheduled for elective supratentorial craniotomy.
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Patients aged between 18 and 75 years.
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American Society of Anesthesiologists status 1-3
Exclusion Criteria:
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History of allergy or intolerance to one of the study medications.
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Active treatment with monoamine oxidase inhibitors.
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An American Society of Anesthesiologists (ASA)physical status IV-VI.
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Pregnancy or breastfeeding.
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Inability to provide written informed consent -
Contacts and Locations
Locations
No locations specified.Sponsors and Collaborators
- University of Aarhus
Investigators
None specified.Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- IMPACT study