Tight Closed-loop Systolic Arterial Pressure Control

Study Overview
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Brief Summary
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The purpose of this case series is to evaluate the performance of a novel closed-loop (automated) vasopressor administration system that delivers norepinephrine using feedback from standard operating room hemodynamic monitoring (EV1000 monitoring device, Edwards Lifesciences, Irvine, USA).

Detailed Description
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In this case series, the investigators will report the percentage of case time in hypotension (defined as systolic arterial pressure (SAP) < 117mmHg). The target mean arterial pressure (MAP) will be set at a SAP of 130mmHg in all patients. Definition of Hypotension is target SAP - 10% (130mmHg - 13 mmHg = 117 mmHg). We will use the same SAP target in all patients even if we used a modified definition of hypotension from the study of Futier and colleagues ( JAMA 2017). We won't use a individualized SAP for each patient but the same SAP target in all patients. The investigators want to demonstrate that the closed-loop system can prevent hypotension at this specific set point. The Investigators have shown the system works well based on a target MAP but not yet using a target of SAP. The investigators will test the system in a pilot study of 13 patients undergoing High-risk abdominal surgery which require the placement of a arterial catheter, the optimization of fluid therapy and a tight SAP control. Participants will receive standard patient care in that in no way will their anesthetic or surgical procedure will be altered as part of the study, with the exception of vasopressor administration ( automatically delivery instead of manually adjustments) Fluids will be given as goal directed fluid therapy in order to maintain stroke volume variation below 13% (hospital guidelines).

Official Title
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Tight Systolic Arterial Pressure Control Using a Closed-loop System for Vasopressor Infusion in Patients Undergoing High-risk Abdominal Surgery: A Proof-of-Concept Study

Conditions
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Cardiovascular Diseases

Intervention / Treatment
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* Device: Closed-loop vasopressor


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients (age of >17) Elective high-risk abdominal surgery Patients with an arterial line and in whom a goal directed fluid therapy protocol is applied manually (administration of fluid bolus to maintain a stroke volume variation < 13%) Exclusion Criteria: Atrial Fibrillation Pregnancy Subjects without the capacity to give informed consent

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 (12 patients)
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Closed-loop<br>Closed-loop administration of norepinephrine | Device: Closed-loop vasopressor<br>* The system will adjust the norepineprhine infusion rate based on a target SAP of 130 mmHg in 20 patients<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 (SAP <117 mmHg) | The primary outcome will be the percentage of case time in predefined SAP target (SAP of 130 mmHg -10 % = 117 mmHg) | At postoperative day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amount of vasopressors received | Amount of vasopressors received (norepinephrine) | At postoperative day 1 | 
| Number of vasopressors infusion rate modifications | Number of vasopressors infusion rate modifications | At postoperative day 1 | 
| Percentage of case time with a MAP < 65 mmHg | Percentage of case time with a MAP < 65 mmHg | At postoperative day 1 |