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

NCT ID: NCT01205594

Last Updated: 2011-08-10

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE2
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2009-05-31

Brief Summary

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).

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

Conditions

Coronary Artery Disease

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: HEALTH_SERVICES_RESEARCH
• Blinding Strategy: NONE

Study Groups

ITPR device

the ITPR will be inserted in the anesthesia circuit and activated to provide -10 mmHg ETP.

Group Type: EXPERIMENTAL

ITPR

Intervention Type: DEVICE

the ITPR will be inserted in the anesthesia circuit and activated to provide -10 mmHg ETP.

Interventions

ITPR

the ITPR will be inserted in the anesthesia circuit and activated to provide -10 mmHg ETP.

Intervention Type: DEVICE

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Virginia

OTHER

Sponsor Role: lead

Responsible Party

University of Virginia Anesthesiology

Principal Investigators

Edward C Nemergut, MD

Role: PRINCIPAL_INVESTIGATOR

University of Virginia Anesthesiology

Locations

University of Virginia Health System

Charlottesville, Virginia, United States

Countries

United States

References

Lurie KG, Zielinski TM, McKnite SH, Idris AH, Yannopoulos D, Raedler CM, Sigurdsson G, Benditt DG, Voelckel WG. Treatment of hypotension in pigs with an inspiratory impedance threshold device: a feasibility study. Crit Care Med. 2004 Jul;32(7):1555-62. doi: 10.1097/01.ccm.0000131207.29081.a2.

Reference Type: BACKGROUND

PMID: 15241102 (View on PubMed)

Lurie KG, Zielinski T, McKnite S, Aufderheide T, Voelckel W. Use of an inspiratory impedance valve improves neurologically intact survival in a porcine model of ventricular fibrillation. Circulation. 2002 Jan 1;105(1):124-9. doi: 10.1161/hc0102.101391.

Reference Type: BACKGROUND

PMID: 11772887 (View on PubMed)

Lurie KG, Voelckel WG, Zielinski T, McKnite S, Lindstrom P, Peterson C, Wenzel V, Lindner KH, Samniah N, Benditt D. Improving standard cardiopulmonary resuscitation with an inspiratory impedance threshold valve in a porcine model of cardiac arrest. Anesth Analg. 2001 Sep;93(3):649-55. doi: 10.1097/00000539-200109000-00024.

Reference Type: BACKGROUND

PMID: 11524335 (View on PubMed)

Lurie KG, Mulligan KA, McKnite S, Detloff B, Lindstrom P, Lindner KH. Optimizing standard cardiopulmonary resuscitation with an inspiratory impedance threshold valve. Chest. 1998 Apr;113(4):1084-90. doi: 10.1378/chest.113.4.1084.

Reference Type: BACKGROUND

PMID: 9554651 (View on PubMed)

Yannopoulos D, McKnite S, Metzger A, Lurie KG. Intrathoracic pressure regulation improves 24-hour survival in a porcine model of hypovolemic shock. Anesth Analg. 2007 Jan;104(1):157-62. doi: 10.1213/01.ane.0000249047.80184.5a.

Reference Type: BACKGROUND

PMID: 17179262 (View on PubMed)

Yannopoulos D, McKnite SH, Metzger A, Lurie KG. Intrathoracic pressure regulation for intracranial pressure management in normovolemic and hypovolemic pigs. Crit Care Med. 2006 Dec;34(12 Suppl):S495-500. doi: 10.1097/01.CCM.0000246082.10422.7E.

Reference Type: BACKGROUND

PMID: 17114984 (View on PubMed)

Yannopoulos D, Metzger A, McKnite S, Nadkarni V, Aufderheide TP, Idris A, Dries D, Benditt DG, Lurie KG. Intrathoracic pressure regulation improves vital organ perfusion pressures in normovolemic and hypovolemic pigs. Resuscitation. 2006 Sep;70(3):445-53. doi: 10.1016/j.resuscitation.2006.02.005. Epub 2006 Aug 9.

Reference Type: BACKGROUND

PMID: 16901611 (View on PubMed)

Yannopoulos D, Nadkarni VM, McKnite SH, Rao A, Kruger K, Metzger A, Benditt DG, Lurie KG. Intrathoracic pressure regulator during continuous-chest-compression advanced cardiac resuscitation improves vital organ perfusion pressures in a porcine model of cardiac arrest. Circulation. 2005 Aug 9;112(6):803-11. doi: 10.1161/CIRCULATIONAHA.105.541508. Epub 2005 Aug 1.

Reference Type: BACKGROUND

PMID: 16061732 (View on PubMed)

Other Identifiers

14296

Identifier Type: -

Identifier Source: org_study_id