Closed-loop Vasopressor Infusion Using Continuous Noninvasive Blood Pressure Monitoring

Study Overview
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Brief Summary
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Intraoperative hypotension and blood pressure variability are associated with postoperative complications in surgical patients. The investigators have developed a closed-loop vasopressor (CLV) controller that titrates norepinephrine to correct hypotension. After having tested the system in a small cohort series of patients undergoing major surgeries, the investigators aimed to test the feasibility of the CLV controller guided noninvasively and continuously with the ClearSight system (Edwards Lifesciences, USA) in three high risk patients undergoing renal transplant surgery

Detailed Description
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Intraoperative hypotension is frequent in patients undergoing surgery and can negatively impact organ perfusion. The investigators have developed a closed-loop vasopressor (CLV) controller to more efficiently correct hypotension. The investigators tested it extensively in preclinical studies and recently demonstrated its feasibility and excellent performance metrics in a short series of high-risk patients undergoing major surgical procedures. In these studies, the controller was linked to a minimally-invasive advanced hemodynamic monitoring device utilizing an arterial line which then controlled a vasopressor infusion. However, the vast majority of patients who undergo surgery do not require an arterial line but should still benefit from rapid corrections of hypotensive episodes that are less rapidly detected via an intermittent non-invasive blood pressure cuff. Fortunately, completely noninvasive technology now allows us to continuously monitor blood pressure and therefore extend the use of our closed-loop vasopressor system to patients in whom an arterial catheter would not typically be placed. Patients undergoing renal transplant surgeries are the ideal patient population. The investigators aimed to test the feasibility of guiding our CLV controller with a continuous noninvasive blood pressure monitoring device (ClearSight system, Edwards Lifesciences, Irvine, CA, USA) in three patients (case series)

Official Title
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Feasibility of Computer-assisted Vasopressor Infusion Using Continuous Noninvasive Blood Pressure Monitoring in High-risk Patients Undergoing Renal Transplant Surgery

Conditions
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Hemodynamic (MAP) Stability

Intervention / Treatment
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* Device: Closed-loop system


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult high risk patients undergoing renal transplant surgery Patients equipped with a clearsight advanced hemodynamic monitoring system Exclusion Criteria: Atrial fibrillation No consent obtained from the patient. Ejection fraction < 30%

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 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
Intervention Model: Single Group Assignment
Interventional Model Description: Single prospective pilot study
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Closed-loop group<br>The MAP of the patient will be managed by the CLV system to avoid hypotension. The MAP target selected in the closed-loop system will be the patient's MAP target ( same target as patient's MAP value preoperatively). Then the closed-loop system will have to adjust norepinephrine infusion rate to keep that MAP value within 10% of patient's target. | Device: Closed-loop system<br>* the CLV system will correct hypotension by automated adjustment of norepinephrine.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of case time in hypotension | % of case time without hypotension. MAP of at least 5mmHg below the chosen CLV target | during surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of active treatment time spent in a hypertensive state | Percentage of active treatment time spent in a hypertensive state, defined as a MAP >5mmHg above the chosen target MAP with an active norepinephrine infusion | during surgery | 
| Amount of vasopressor used | Amount of vasopressor administered to the patient | during surgery | 
| Incidence of acute kidney injury | Incidence of acute kidney injury defined with the KDIGO classification | 30 days postsurgery |