Factors Responsible for the Effectiveness of the Lund De-airing Technique

NCT ID: NCT01757704

Last Updated: 2014-02-10

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 20 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2012-09-30
• Study Completion Date: 2014-01-31

Brief Summary

The Lund de-airing technique is employed for cardiac de-airing in open left heart surgery. It consists of two main elements namely, opening of both pleura after the patient is on CPB (cardiopulmonary bypass)and disconnection of the ventilator before opening the left heart to ensure bilateral pulmonary collapse and a staged filling of the heart at termination of the CPB. The aim of this study is to analyze in a randomized manner two groups of patients to establish if one or both components are of primary importance for the effectiveness of the de-airing technique.

Detailed Description

Patients planned for open left heart surgery, mainly aortic valve replacement, will be included in the study. Patients with aortic valve replacement and concomitant coronary artery bypass with vein grafts only can also be included.

Exclusion criteria are; significant chronic obstructive pulmonary disease/emphysema, significant (>50%)carotid artery disease, need of concomitant internal mammary harvesting, prior cardiac or pulmonary surgery, pulmonary adhesions preventing pulmonary collapse, previous radiation to the chest and prior severe chest trauma. Intraoperative exclusion criteria are; failure to obtain adequate bilateral Trans-cranial Echo-Doppler signals from the medial cerebral arteries, finding of adherent pleurae and accidental opening of the pleurae.

Twenty patients will be randomized to two groups:

Group I: Intact pleura bilaterally, disconnection of the ventilator during cardiopulmonary bypass (CPB), followed by staged filling of the heart.

Group II: Open pleura bilaterally, disconnection of the ventilator during cardiopulmonary bypass to ensure bilateral pulmonary collapse followed by conventional filling of the heart.

Data will be compared to a third historical control group, consisting of ten patients with open pleurae with the ventilator disconnected followed by staged filling of the heart.

Primary outcomes:

• Duration of the de-airing procedure from the release of the aortic cross clamp to finished de-airing.
• Air microemboli to the brain registered on-line as gaseous microembolic signals on Trans-cranial Echo-Doppler (TCD). The sum of signals from the right and left middle cerebral artery are registered during the following time periods; from the release of the aortic cross clamp to start of cardiac ejection, from cardiac ejection to finished de-airing, and during ten minutes after finished de-airing.
• Magnitude of residual air emboli in the heart after finished de-airing as monitored by Trans-esophageal Echocardiography (TEE) with a Three-chamber view. The severity of residual air is classified in four grades after the appearance of visible air on TEE in left atrium (LA), left ventricle (LV) and aortic root (AO)as follows; Grade 0: no residual air, grade I: gas emboli detected in one of three anatomic areas during one cardiac cycle, grade II: gas emboli detected simultaneously in two of three anatomic areas during one cardiac cycle; grade III: gas emboli detected in all three anatomic areas during one cardiac cycle.

Conditions

Complication of Surgical Procedure

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: SINGLE

Study Groups

Open pleurae & conventional filling of heart

In this group both pleurae will be opened and the ventilator disconnected during cardiopulmonary bypass to ensure bilateral pulmonary collapse. However, after completion of the left heart procedure, the heart will be filled with blood actively from the heart-lung machine and manual de-airing performed in a conventional manner and de-airing monitored by intraoperative trans-esophageal echocardiography (TEE). After de-airing is complete and patient has been weaned off the cardiopulmonary bypass the residual air in the left heart will be quantitatively assessed by TEE and Trans-cranial Echo-Doppler (TCD) over a period of 10 minutes.

Group Type: EXPERIMENTAL

Open pleurae & conventional filling of heart

Intervention Type: PROCEDURE

After completion of the left heart surgery, the heart will be actively filled with blood from the cardiopulmonary bypass circuit and lungs fully ventilated with positive end-expiratory pressure to flush out all air trapped in the lung veins and left heart. When there is no more visible air seen on Trans-esophageal echocardiography, the patient is weaned from cardiopulmonary bypass.

Intact pleurae & staged filling of heart

In this group both pleurae will be left intact and the ventilator disconnected during cardiopulmonary bypass. After completion of the left heart procedure, the heart will be filled with blood actively from the heart-lung machine in a staged manner after adequate cardiac contraction has been established. De-airing will be obtained by active cardiac contraction and staged mechanical ventilation and de-airing monitored by intraoperative trans-esophageal echocardiography (TEE). After de-airing is deemed complete and patient has been weaned off the cardiopulmonary bypass (CPB) the residual air in the left heart will be quantitatively assessed by TEE and Trans-cranial Echo-Doppler (TCD) over a period of 10 minutes.

Group Type: EXPERIMENTAL

Intact pleurae & staged filling of heart

Intervention Type: PROCEDURE

After the end of the left heart surgery, the heart is gradually filled with blood from the cardiopulmonary bypass circuit. Cardiac contractions fill the lungs with blood til no more air is seen in left heart on Trans-esophageal Echocardiography. Thereafter the lungs are ventilated with 50% of the estimated lung minute volume and 5 cm positive end-expiratory pressure and cardiac filling and de-airing continued. If no air is seen in the left heart full ventilation is started and the patient is weaned from cardiopulmonary bypass.

Interventions

Open pleurae & conventional filling of heart

After completion of the left heart surgery, the heart will be actively filled with blood from the cardiopulmonary bypass circuit and lungs fully ventilated with positive end-expiratory pressure to flush out all air trapped in the lung veins and left heart. When there is no more visible air seen on Trans-esophageal echocardiography, the patient is weaned from cardiopulmonary bypass.

Intervention Type: PROCEDURE

Intact pleurae & staged filling of heart

After the end of the left heart surgery, the heart is gradually filled with blood from the cardiopulmonary bypass circuit. Cardiac contractions fill the lungs with blood til no more air is seen in left heart on Trans-esophageal Echocardiography. Thereafter the lungs are ventilated with 50% of the estimated lung minute volume and 5 cm positive end-expiratory pressure and cardiac filling and de-airing continued. If no air is seen in the left heart full ventilation is started and the patient is weaned from cardiopulmonary bypass.

Intervention Type: PROCEDURE

Other Intervention Names

Cardiac de-airing; Cardiac venting; Cardiac de-airing; Cardiac venting

Eligibility Criteria

Inclusion Criteria

• Patients planned for aortic valve replacement with or without coronary vein bypass grafts

Exclusion Criteria

• Significant chronic obstructive pulmonary disease and emphysema
• Previous history of thoracic or cardiac surgery
• Patients requiring internal mammary artery harvesting
• Unilateral or bilateral pulmonary adhesions to chest wall
• Previous radiation to the chest

• Inability to obtain adequate bilateral Trans-cranial Echo-doppler signals
• Adherent pleurae
• Accidental opening of the pleurae

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 90 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Lund University

OTHER

Sponsor Role: lead

Responsible Party

Bansi Lal Koul

Med dr. Ph. D.

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Bansi Koul, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Cardiothoracic Surgery, Skåne University Hospital Lund, Sweden

Locations

Lund University

Lund, Skåne County, Sweden

Countries

Sweden

References

Al-Rashidi F, Blomquist S, Hoglund P, Meurling C, Roijer A, Koul B. A new de-airing technique that reduces systemic microemboli during open surgery: a prospective controlled study. J Thorac Cardiovasc Surg. 2009 Jul;138(1):157-62. doi: 10.1016/j.jtcvs.2009.02.037.

Reference Type: BACKGROUND

PMID: 19577073 (View on PubMed)

Al-Rashidi F, Landenhed M, Blomquist S, Hoglund P, Karlsson PA, Pierre L, Koul B. Comparison of the effectiveness and safety of a new de-airing technique with a standardized carbon dioxide insufflation technique in open left heart surgery: a randomized clinical trial. J Thorac Cardiovasc Surg. 2011 May;141(5):1128-33. doi: 10.1016/j.jtcvs.2010.07.013. Epub 2010 Sep 3.

Reference Type: BACKGROUND

PMID: 20817209 (View on PubMed)

Other Identifiers

BKML-003

Identifier Type: -

Identifier Source: org_study_id