IRB-HSR# 14296 The Use of the Intrathoracic Pressure Regulator (ITPR) to Improve Systemic Blood Pressure in Patient Undergoing CABG Surgery

August 9, 2011 updated by: University of Virginia

Briefly, after the induction of anesthesia and the placement of TEE, hemodynamic variables (pulmonary and systemic blood pressure, central and pulmonary venous pressure, cardiac output, calculated SVR, etc.) will be collected. In addition, left ventricular performance (including estimates of LVEDV, LVESV, EF, FAC, etc.) will be assessed using TEE. Once these baseline data are recorded, the ITPR will be inserted in the anesthesia circuit and activated to provide -9 mmHg ETP. After the ITPR has been active for at least two minutes, the same hemodynamic and TEE data obtained above will be gathered. After the data is recorded, the ITPR will be disconnected and no further interventions will be made. In addition to the hemodynamic and echocardiographic data described above, an arterial blood gas will be obtained from the pre-existing radial artery catheter during the on- and off- states.

Finally, the TEE examination will be recorded on videotape or DVD. A second echocardiographer, blinded to patient and ITPR status will review each echocardiogram and assess left ventricular performance. In addition to the data derived at the time of testing, the second echocardiographer will assess, if possible, changes in EF using Simpson's method of disks is used to calculate the LV volume.

This is a proof of concept/feasibility study designed to test the primary hypothesis that use of the ITPR will result in increased systemic blood pressure and cardiac output in patients undergoing CABG surgery. The effect of the ITPR on other secondary indicators of cardiac performance will also be examined. These include but are not limited to left ventricular end diastolic volume (LVEDV), ejection fraction (EF), left ventricular end systolic volume (LVESV), and fractional area change (FAC) as assessed by echocardiography, pulmonary artery pressure, and calculated systemic vascular resistance (SVR).

Study Overview

Status

Completed

Intervention / Treatment

Detailed Description

The ITPR is an FDA-approved device intended to increase circulation and blood pressure in hypovolemic and cardiogenic shock. The device is inserted within a standard respiratory circuit between the patient and the ventilator. It functions by decreasing intrathoracic pressure during the expiratory phase to subatmospheric levels after each positive pressure ventilation. The decrease in intrathoracic pressure creates a vacuum within the thorax relative to the rest of the body thereby enhancing blood return to the heart and consequently increasing cardiac output and blood pressure. Activation of the device is also accompanied by a decrease in SVR. The end result is a device that simultaneously improves cardiac output by increasing LVEDP/LVEDV and decreasing SVR while increasing coronary perfusion pressure by increasing blood pressure and decreasing LVESP/LVESV.1-8

Study Type

Interventional

Enrollment (Actual)

20

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Virginia
      • Charlottesville, Virginia, United States, 22908
        • University of Virginia Health System

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 1. patients presenting for elective CABG with planned intraoperative TEE 2. age 18 years of age and older 3. informed consent has been obtained

Exclusion Criteria:

  • 1. Patients with planned valve surgery (valve or CABG + valve) 2. patients with a contraindication to transesophageal echocardiography (TEE); including patients with extensive esophageal or gastric disease. Relative contraindications include esophageal varices, Barrett's esophagus, Zenker's diverticulum, and postradiation therapy of the esophageal area.

    3. patients requiring IABP or VAD pre-operatively 4. emergent CABG 5. pneumothorax 6. hemothorax 7. uncontrolled bleeding 8. uncontrolled hypertension defined as SBP > 180 mmHg at the time of surgery

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: HEALTH_SERVICES_RESEARCH
  • Allocation: NON_RANDOMIZED
  • Interventional Model: SINGLE_GROUP
  • Masking: NONE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
EXPERIMENTAL: ITPR device
the ITPR will be inserted in the anesthesia circuit and activated to provide -10 mmHg ETP.
the ITPR will be inserted in the anesthesia circuit and activated to provide -10 mmHg ETP.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
hemodynamic variables
Time Frame: baseline & 2 minutes post device activation
hemodynamic variables (pulmonary and systemic blood pressure, central and pulmonary venous pressure, cardiac output, calculated SVR) will be collected at baseline & 2 minutes post device activation
baseline & 2 minutes post device activation

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
left ventricular performance
Time Frame: baseline &2 minutes after activation of the device
left ventricular performance (including estimates of LVEDV, LVESV, EF, FAC, etc.) will be assessed using TEE.
baseline &2 minutes after activation of the device

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Edward C Nemergut, MD, University of Virginia Anesthesiology

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

May 1, 2009

Primary Completion (ACTUAL)

May 1, 2010

Study Registration Dates

First Submitted

September 17, 2010

First Submitted That Met QC Criteria

September 17, 2010

First Posted (ESTIMATE)

September 20, 2010

Study Record Updates

Last Update Posted (ESTIMATE)

August 10, 2011

Last Update Submitted That Met QC Criteria

August 9, 2011

Last Verified

August 1, 2011

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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