Closed-loop Control of Vasopressor Administration in Cardiac Surgery

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 in three high risk patients undergoing cardiac surgery

Detailed Description
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The investigators have recently developed an automated closed-loop vasopressor (CLV) controller to better titrate vasopressor (e.g:norepinephrine) to maintain MAP within a narrow range (±5mmHg of the chosen target). The investigators published engineering, animal studies and recently described the feasibility of titration of norepinephrine in 20 patients undergoing major noncardiac procedures. This initial cohort human study showed the controller was able to keep patients within ± 5 mmHg of a target pressure for more than 90% of management time. Cardiac surgery represents unique challenges in MAP management as the manipulation of the heart itself, the use of cardiopulmonary bypass (CPB) and cardioplegia, and the pre-existing cardiac disease all increase the difficulty in maintaining a steady MAP throughout the surgical period. In this case series the investigators describe three cardiac surgical procedures managed with the CLV system (one coronary artery bypass graft (CABG) procedure done under CPB; one robotic minimally invasive direct coronary artery bypass (MIDCAB) procedure (through a mini-thoracotomy), and one off-pump CABG) in order to assess its feasibility, efficiency and behavior in three high-risk patients before starting a randomized controlled trial.

Official Title
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Closed-loop Control of Vasopressor Administration in High-Risk Patients Undergoing Cardiac Surgery: A Case Series

Conditions
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Hemodynamic MAP Stability

Intervention / Treatment
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* Device: closed-loop system for vasopressor administration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult high risk patients undergoing cardiac surgery (robotic, off-pump and on pump cardiac surgery) Exclusion Criteria: Atrial fibrillation

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: Other
Intervention Model: Single Group Assignment
Interventional Model Description: Closed-loop system to titrate vasopressor
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Closed-loop<br>Closed-loop system to titrate vasopressor during surgery | Device: closed-loop system for vasopressor administration<br>* closed-loop system for vasopressor administration<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| percentage of time spent during surgery in hypotension | percentage of time spent during surgery in hypotension defined as a MAP below 65 mmHg. | during surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| time in target during surgery | time with a MAP within 5 mmHg of the chosen target | during surgery | 
| 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 |