Evaluation of Transcranial Doppler Vasoconstrictor Vasoreactivity During General Anesthesia in Hypertensive Patients

Study Overview
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Brief Summary
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During a general anesthesia, people over 65 years old and hypertensive, have a modification of the vasoreactivity and their cerebral blood flow under vasoconstrictor such as norepinephrine or phenylephrine. We study the variation of the average velocity of the average cerebral artery under vasoconstrictor and during a modification of End Tidal CO2 (EtCO2) by transcranial Doppler.

Detailed Description
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General anesthesia induces a sympathetic block frequently leading to hypotension, especially in elderly and hypertensive patients. Currently, Phenylephrine (PE) and Norepinephrine (NE) are commonly used in clinical practice to address this arterial pressure drop. Their cardiovascular effects are not exactly the same, even though they both increase mean blood pressure. Maintenance of mean arterial pressure is not the only hemodynamic goal during general anesthesia in the elderly. Cognitive disorders have been demonstrated during post-anesthetic awakening. Cerebral hemodynamics is assessed by analyzing the speed of blood flow in the middle cerebral artery using transcranial Doppler (DTC). It measures the systolic and diastolic speed as well as the pulsatility index, which are predictive factors for lowering cerebral blood flow.

Official Title
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Evaluation of Transcranial Doppler Vasoconstrictor Vasoreactivity During General Anesthesia in Hypertensive Patients

Conditions
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Hypertensive Disease, Elderly, Vasopressors, General Anesthesia

Intervention / Treatment
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* Other: Transcranial Doppler (DTC)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: older over 65 years high blood pressure disease need general anesthesia need vasopressors : norepinephrine or phenylephrine temporal window of transcranial doppler is viable Exclusion Criteria: Acute, valvular, rhythmic or ischemic cardiovascular pathology severe arthritis (stage 3) Intra-cranial pathology Significant carotid stenosis (> 40%) or carotid endarterectomy Cervical surgery Taking a premedication that can modify cerebral vasoreactivity Insulin-dependent diabetes for more than 10 years Person under judicial protection Opposition to data processing

Ages Eligible for Study
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Minimum Age: 65 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients under vasoconstrictor<br>Patients older than 65 years old and hypertensive, requiring vasoconstrictor (phenylephrine or Neosynephrine) during general anesthesia. | Other: Transcranial Doppler (DTC)<br>* Evaluation of Vasoconstrictor Vasoreactivity with Transcranial Doppler<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Variation of the velocity of the middle cerebral artery with vasoconstrictors and during a modification of EtCO2. | Measurements from transcranial doppler velocity of the middle cerebral artery | 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Variation of cardiac output with vasoconstrictors and during modification of EtCO2. | Measurements from non invasive device (ClearSight System) of the cardiac output. The ClearSight system quickly connects to the patient by wrapping an inflatable cuff around the finger. Then the system presents cardiac output clearly and simply on the monitor. | 48 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cerebral vasoreactivity, transcranial doppler, hypertensive disease, elderly, vasopressors, general anesthesia