CO2 Versus Lund De-airing Technique in Heart Surgery
Primary Purpose
Aortic Valve Disorder
Status
Completed
Phase
Not Applicable
Locations
Study Type
Interventional
Intervention
Lund de-airing technique
carbon-dioxide insufflation
Sponsored by
About this trial
This is an interventional prevention trial for Aortic Valve Disorder focused on measuring Cardiac de-airing, CO2 insufflation, Air emboli, Trans cranial doppler, Intraoperative echocardiography
Eligibility Criteria
Inclusion Criteria:
- Patients planned for aortic valve/root replacement or repair will be selected for the study
Exclusion Criteria:
Patients with known
- chronic obstructive pulmonary disease,
- emphysema,
- previous thoracic or cardiac surgery,
- history of CVA or stroke and
- evidence of intraoperative pleural adhesions will be excluded from the study.
- Patients requiring internal mammary artery coronary bypass will also be excluded.
Sites / Locations
Arms of the Study
Arm 1
Arm 2
Arm Type
Experimental
Active Comparator
Arm Label
Lund de-airing
Carbon-dioxide insufflation
Arm Description
Lund de-airing technique
carbon-dioxide insufflation will be provided to the open mediastinal wound in a standardized manner
Outcomes
Primary Outcome Measures
Number of Air Microemboli Registered Over the Middle Cerebral Arteries by On-line Trans-cranial Echo-Doppler (TCD).
The number of air microemboli (also referred to as gaseous microembolic signals) was concomitantly counted in the right and left medial cerebral artery. The number of signals from the right and the left medial cerebral artery were summed, and presented as the total sum of the gaseous micromebolic signals from the right and left side. Counting of gaseous microembolic signals was done during three time intervals: Before cardiac ejection, after cardiac ejection and during 10 minutes after cardiopulmonary bypass.
Number of Air Microemboli Registered Over the Middle Cerebral Arteries by On-line Trans-cranial Echo-Doppler (TCD).
The number of air microemboli (also referred to as gaseous microembolic signals) was concomitantly counted in the right and left medial cerebral artery. The number of signals from the right and the left medial cerebral artery were summed, and presented as the total sum of the gaseous micromebolic signals from the right and left side. Counting of gaseous microembolic signals was done during three time intervals: Before cardiac ejection, after cardiac ejection and during 10 minutes after cardiopulmonary bypass.
Number of Air Microemboli Registered Over the Middle Cerebral Arteries by On-line Trans-cranial Echo-Doppler (TCD).
The number of air microemboli (also referred to as gaseous microembolic signals) was concomitantly counted in the right and left medial cerebral artery. The number of signals from the right and the left medial cerebral artery were summed, and presented as the total sum of the gaseous micromebolic signals from the right and left side. Counting of gaseous microembolic signals was done during three time intervals: Before cardiac ejection, after cardiac ejection and during 10 minutes after cardiopulmonary bypass.
Number of Participants With <=Grade I Gas Emboli as Assessed by Trans-esophageal Echocardiography TEE).
Grade 0, no residual gas emboli; grade I, gas emboli observed in 1 of the 3 anatomic areas - left atrium, left ventricle or aortic root during 1 cardiac cycle; grade II, gas emboli observed simultaneously in 2 of the 3 anatomic areas during 1 cardiac cycle; grade III, gas emboli observed simultaneously in all 3 anatomic areas during 1 cardiac cycle.
Number of Participants With <=Grade I Gas Emboli as Assessed by Trans-esophageal Echocardiography TEE).
Grade 0, no residual gas emboli; grade I, gas emboli observed in 1 of the 3 anatomic areas - left atrium, left ventricle or aortic root during 1 cardiac cycle; grade II, gas emboli observed simultaneously in 2 of the 3 anatomic areas during 1 cardiac cycle; grade III, gas emboli observed simultaneously in all 3 anatomic areas during 1 cardiac cycle.
Number of Participants With <=Grade I Gas Emboli as Assessed by Trans-esophageal Echocardiography TEE).
Grade 0, no residual gas emboli; grade I, gas emboli observed in 1 of the 3 anatomic areas - left atrium, left ventricle or aortic root during 1 cardiac cycle; grade II, gas emboli observed simultaneously in 2 of the 3 anatomic areas during 1 cardiac cycle; grade III, gas emboli observed simultaneously in all 3 anatomic areas during 1 cardiac cycle.
Secondary Outcome Measures
Total Time Required for De-airing
The total de-airing time as measured in minutes.
De-airing Time Before Cardiac Ejection
Time in minutes starting at t1 (removal of aortic cross clamp) and ending at t2 (beginning of cardiac ejection).
De-airing Time After Cardiac Ejection
The duration in minutes of the period after cardiac ejection to finished de-airing procedure.
Oxygenator Gas Flow at 45 Minutes of CPB
The amount of carbon dioxide gas flow through the oxygenator was measured and compared between groups.
pH at 45 Min of CPB
pH measured by arterial bloodgas at 45 minutes of CPB, comparison between groups
Full Information
1. Study Identification
Unique Protocol Identification Number
NCT00934596
Brief Title
CO2 Versus Lund De-airing Technique in Heart Surgery
Official Title
CO2 Insufflation vs Lund De-airing Technique For Open Left Heart Surgery - Safety and Efficacy
Study Type
Interventional
2. Study Status
Record Verification Date
October 2013
Overall Recruitment Status
Completed
Study Start Date
June 2009 (undefined)
Primary Completion Date
October 2009 (Actual)
Study Completion Date
October 2009 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Lund University
4. Oversight
Data Monitoring Committee
No
5. Study Description
Brief Summary
To evaluate which of the two de-airing methods (CO2 insufflation vs. Lund de-airing technique) can shorten the left heart de-airing time and prevent or minimize cerebral air emboli during open surgery involving exposure of the left heart to the ambient air.
To evaluate the cost effectiveness and possible side effects of CO2 de-airing technique compared to Lund de-airing technique.
Detailed Description
Study design:
Prospective, randomized and controlled study involving 20 patients, 10 in each group. The de-airing time and the efficiency of the techniques will be assessed by trans-esophageal echocardiography (TEE) and trans-cranial echo-doppler monitoring (TCD). The cardiologists analyzing the TEE recordings will be blinded to the de-airing technique used (the recorded videos will be analyzed at the end of the study). The TCD monitoring will be done by on-line automatic recording of the micro embolic signals (MES) from the right and or left middle cerebral arteries and performed by single surgeon. The CO2 insufflation of the operating field will be performed according to manufacturer's guide lines. During entire study course one type of extracorporeal perfusion system will be used.The study will be registered in the international database. A prior approval will be sought from the hospital ethical committee for the study.
Patient selection:
Patients planned for aortic valve/root replacement or repair will be selected for the study
Exclusion criteria:
Patients with known: a) chronic obstructive pulmonary disease, b) emphysema, c) previous thoracic or cardiac surgery, d) history of CVA or stroke and e) evidence of intraoperative pleural adhesions will be excluded from the study. Patients requiring internal mammary artery coronary bypass will also be excluded.
Patient consent:
A written consent previously approved by the hospital ethical committee will be obtained from all patients before they are enrolled in the study (enclosure 3).
De-airing procedure:
Enrolled patients will be assigned randomly to one of the two following groups:
Control group ( newly developed de-airing technique in Lund ) :
In these patients (n=10) the pleura will be opened on both sides and the ventilator will be disconnected before aorta is cross-clamped and cardioplegia administered. At the end of the cardioplegic arrest, the aortic root and the LV will be actively vented and aortic cross clamp released. The time will be noted down (T1). The heart will be defibrillated to sinus or pacemaker induced rhythm. The heart will be kept empty by the LV vent and ejection avoided as monitored by continual intraoperative TEE and systemic arterial pressure tracing. At 35 Celsius body temperature, as measured from the thermistor in the urinary bladder, and with apparently good cardiac contraction the de-airing will begin. Inotropic drugs or systemic arterial vasodilators will be used as and when necessary to achieve good cardiac contraction. The time will be noted down (T2) (T2 - T1 = Pre ejection de-airing time). The LV preload will first now be successively increased by reducing the venous return from the heart-lung machine to raise CVP between 5-10 cm water. LV vent will be continuously regulated depending upon the amount of residual air showing in the left heart. When no air is seen on TEE monitoring in the left heart (LA, LV & Aorta), half the calculated minute ventilation with 100% oxygen and a PEEP of 5 cm H2O will be started. De-airing will be continued and when the TEE shows no or minimal air in left heart, full ventilation with unchanged PEEP will be restored. The patient will be weaned successively from the CPB thereby ensuring that entire cardiac output is diverted through the native fully ventilated lungs. When TEE will show no air in the left heart, the de-airing will be considered complete and the time noted again (T3) (T3 - T2 = Post ejection de-airing time).
All cardiac cannulae including the LV vent will be left in situ but clamped, patient weaned completely from the cardiopulmonary bypass and monitored for residual air by TEE & TCD for 10 minutes continually. The LV vent will be re-opened whenever the residual air in the left heart exceeds grade II. The frequency of theses measures will be noted in the protocol. If the patient has by now achieved 36 Celsius core temperature, the heart will be decannulated and CPB removed. Otherwise CPB will be restarted and patient warmed to 36 Celsius before final weaning and decannulation.
Study group ( CO2 insufflation ):
In these patients (n=10) the pleurae will not be opened. During aortic cross-clamp period the ventilator will be adjusted to provide dead space ventilation only i.e. 5cm PEEP, ventilator frequency 5/min and the minute ventilation = 1,5 liter. Fio2 = 50%. The operating field will be insufflated with CO2 at a flow rate of 10 L / minute starting 2 minutes before cardiac cannulation and continued until 10 minutes after termination of the CPB.
At the end of the cardioplegic arrest, the aortic root and the LV will be actively vented and the time noted down (T1). The LV preload will be successively increased by reducing the venous return from the heart-lung machine to raise CVP between 5-10 cm water. LV venting will be continued and when no air bubbles are seen in the left heart (LA, LV & Aorta) under TEE monitoring, the calculated minute ventilation with 100% oxygen and PEEP of 5 cm H2O will be restored. De-airing will be continued and when no or minimal air is seen in the left heart the time will be noted down (T2) (T2 - T1 = Pre ejection de-airing time). Aortic cross-clamp will be released now and heart defibrillated to sinus or pacemaker induced rhythm and de-airing continued. At 35 Celsius body temperature, as measured from the thermistor in the urinary bladder, and with apparently good cardiac contraction the patient will be weaned successively from the CPB ensuring thereby that the entire cardiac output is diverted through the native fully ventilated lungs. Inotropic drugs or systemic arterial vasodilators will be used as and when necessary to achieve good cardiac contraction. When TEE will show no air in the left heart, the de-airing will be considered complete and the time noted again (T3) (T3 - T2 = Post ejection de-airing time). The patient will be weaned completely from the cardiopulmonary bypass and all cardiac cannulae including the LV vent will be left in situ but clamped. The patient will be monitored now for residual air by TEE & TCD for 10 minutes continually. The LV vent will be re-opened whenever the residual air showing on TEE in the left heart exceeds grade II. The frequency of theses measures will be noted in the protocol. The C02 insufflations will continue until the 10- minute post CPB monitoring interval is completed. If patient by now has achieved 36 Celsius core temperature, the heart will be decannulated and CPB removed. Otherwise CPB will be restarted and patient warmed to 36 Celsius before final weaning and decannulation.
Trans-esophageal echocardiographic study (TEE):
After completion of the cardioplegic arrest and for 10 minutes after termination of the CPB, all the patients will be monitored by TEE for air in the left heart. The residual air showing on TEE after the termination of CPB will be quantified in 4 grades depending upon presence of air in LA, LV and aortic root during one cardiac cycle (grade 0 = no or occasional air in LA, grade 1 = air showing in LA only, grade 2 = air showing simultaneously in LA and LV, grade 3 = air showing simultaneously in LA, LV and the aortic root). The 10-minute post CPB TEE recording will be saved on a video-tape.
Trans-cranial echo-doppler study (TCD):
After release of the aortic cross clamp and for 10 minutes after the patient has been weaned off from the CPB, the patient will be continuously monitored for micro embolic signals by on-line automatic TCD placed on middle cerebral arteries.
Blood gases will be monitored in all patients as following:
Blood gas analysis from arterial & venous blood of the patient every 15 minutes in the operating room in both groups until 15 minutes post CPB) - following attached tables (Anesthesia, Perfusion and TCD & Invous monitoring)
Measurement of end-tidal PCO2 and volume of expired CO2 every 15 minutes after the patient is intubated and till the time patient leaves the operating room in both groups. (No measurements possible in the control group during cardioplegic arrest)
Blood gas analysis from arterial & venous blood lines of the oxygenator and from the LV vent line every 15 minutes while the patient is on CPB in both groups.
Continuous on-line monitoring of CO2 content and PCO2 in the blood at the inflow and outflow ports of the oxygenator in both groups using CDI & new machine. Variations in gas flow and the FiO2 needed to adjust PaCO2 to within a fixed desirable range will be recorded and extra blood gas sample will be taken whenever any such adjustment is made.
Alfa stat will be employed for blood gas analysis. A core temperature at 30 C will be used for all patients unless positively indicted.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Aortic Valve Disorder
Keywords
Cardiac de-airing, CO2 insufflation, Air emboli, Trans cranial doppler, Intraoperative echocardiography
7. Study Design
Primary Purpose
Prevention
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
20 (Actual)
8. Arms, Groups, and Interventions
Arm Title
Lund de-airing
Arm Type
Experimental
Arm Description
Lund de-airing technique
Arm Title
Carbon-dioxide insufflation
Arm Type
Active Comparator
Arm Description
carbon-dioxide insufflation will be provided to the open mediastinal wound in a standardized manner
Intervention Type
Procedure
Intervention Name(s)
Lund de-airing technique
Other Intervention Name(s)
cardiac de-airing, cardiac venting
Intervention Description
In these patients the pleura will be opened on both sides and the ventilator will be disconnected before aorta is cross-clamped and cardioplegia administered. At the conclusion of the surgical procedure, the LV preload will first now be successively increased. When no air is seen on TEE monitoring in the left heart (LA, LV & Aorta), half the calculated minute ventilation with 100% oxygen and a PEEP of 5 cm H2O will be started. Deairing will be continued and when the TEE shows no or minimal air in left heart, full ventilation with unchanged PEEP will be restored. The patient will be weaned successively from the CPB. When TEE will show no air in the left heart, the de-airing will be considered complete.
Intervention Type
Drug
Intervention Name(s)
carbon-dioxide insufflation
Other Intervention Name(s)
Cardiac de-airing, Cardiac venting
Intervention Description
In these patients (n=10) the pleurae will not be opened. During aortic cross-clamp period the ventilator will be adjusted to provide dead space ventilation only i.e. 5cm PEEP, ventilator frequency 5/min and the minute ventilation = 1,5 liter. Fio2 = 50%. The operating field will be insufflated with Co2 at a flow rate of 10 L / minute starting 2 minutes before cardiac cannulation and continued until 10 minutes after termination of the CPB.At the end of the cardioplegic arrest, the de-airing procedure is similar to that in the Lund de-airing group.
Primary Outcome Measure Information:
Title
Number of Air Microemboli Registered Over the Middle Cerebral Arteries by On-line Trans-cranial Echo-Doppler (TCD).
Description
The number of air microemboli (also referred to as gaseous microembolic signals) was concomitantly counted in the right and left medial cerebral artery. The number of signals from the right and the left medial cerebral artery were summed, and presented as the total sum of the gaseous micromebolic signals from the right and left side. Counting of gaseous microembolic signals was done during three time intervals: Before cardiac ejection, after cardiac ejection and during 10 minutes after cardiopulmonary bypass.
Time Frame
Before cardiac ejection
Title
Number of Air Microemboli Registered Over the Middle Cerebral Arteries by On-line Trans-cranial Echo-Doppler (TCD).
Description
The number of air microemboli (also referred to as gaseous microembolic signals) was concomitantly counted in the right and left medial cerebral artery. The number of signals from the right and the left medial cerebral artery were summed, and presented as the total sum of the gaseous micromebolic signals from the right and left side. Counting of gaseous microembolic signals was done during three time intervals: Before cardiac ejection, after cardiac ejection and during 10 minutes after cardiopulmonary bypass.
Time Frame
After cardiac ejection
Title
Number of Air Microemboli Registered Over the Middle Cerebral Arteries by On-line Trans-cranial Echo-Doppler (TCD).
Description
The number of air microemboli (also referred to as gaseous microembolic signals) was concomitantly counted in the right and left medial cerebral artery. The number of signals from the right and the left medial cerebral artery were summed, and presented as the total sum of the gaseous micromebolic signals from the right and left side. Counting of gaseous microembolic signals was done during three time intervals: Before cardiac ejection, after cardiac ejection and during 10 minutes after cardiopulmonary bypass.
Time Frame
During 10 minutes after cardiopulmonary bypass
Title
Number of Participants With <=Grade I Gas Emboli as Assessed by Trans-esophageal Echocardiography TEE).
Description
Grade 0, no residual gas emboli; grade I, gas emboli observed in 1 of the 3 anatomic areas - left atrium, left ventricle or aortic root during 1 cardiac cycle; grade II, gas emboli observed simultaneously in 2 of the 3 anatomic areas during 1 cardiac cycle; grade III, gas emboli observed simultaneously in all 3 anatomic areas during 1 cardiac cycle.
Time Frame
0-3 minutes after end of cardiopulmonary bypass
Title
Number of Participants With <=Grade I Gas Emboli as Assessed by Trans-esophageal Echocardiography TEE).
Description
Grade 0, no residual gas emboli; grade I, gas emboli observed in 1 of the 3 anatomic areas - left atrium, left ventricle or aortic root during 1 cardiac cycle; grade II, gas emboli observed simultaneously in 2 of the 3 anatomic areas during 1 cardiac cycle; grade III, gas emboli observed simultaneously in all 3 anatomic areas during 1 cardiac cycle.
Time Frame
3-6 minutes after end of cardiopulmonary bypass
Title
Number of Participants With <=Grade I Gas Emboli as Assessed by Trans-esophageal Echocardiography TEE).
Description
Grade 0, no residual gas emboli; grade I, gas emboli observed in 1 of the 3 anatomic areas - left atrium, left ventricle or aortic root during 1 cardiac cycle; grade II, gas emboli observed simultaneously in 2 of the 3 anatomic areas during 1 cardiac cycle; grade III, gas emboli observed simultaneously in all 3 anatomic areas during 1 cardiac cycle.
Time Frame
6-10 minutes after end of cardiopulmonary bypass
Secondary Outcome Measure Information:
Title
Total Time Required for De-airing
Description
The total de-airing time as measured in minutes.
Time Frame
After removal of aortic cross-clamp to complete de-airing, an average of 11 minutes
Title
De-airing Time Before Cardiac Ejection
Description
Time in minutes starting at t1 (removal of aortic cross clamp) and ending at t2 (beginning of cardiac ejection).
Time Frame
Measured during intraoperative course
Title
De-airing Time After Cardiac Ejection
Description
The duration in minutes of the period after cardiac ejection to finished de-airing procedure.
Time Frame
During de-airing procedure
Title
Oxygenator Gas Flow at 45 Minutes of CPB
Description
The amount of carbon dioxide gas flow through the oxygenator was measured and compared between groups.
Time Frame
Intraoperative
Title
pH at 45 Min of CPB
Description
pH measured by arterial bloodgas at 45 minutes of CPB, comparison between groups
Time Frame
Intraoperative
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
90 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
Patients planned for aortic valve/root replacement or repair will be selected for the study
Exclusion Criteria:
Patients with known
chronic obstructive pulmonary disease,
emphysema,
previous thoracic or cardiac surgery,
history of CVA or stroke and
evidence of intraoperative pleural adhesions will be excluded from the study.
Patients requiring internal mammary artery coronary bypass will also be excluded.
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Bansi L Koul, MD, PhD
Organizational Affiliation
Cardiothoracic Surgery, Heart & Lung Division, University Hospital Lund, Sweden
Official's Role
Principal Investigator
12. IPD Sharing Statement
Citations:
PubMed Identifier
23246060
Citation
Landenhed M, Al-Rashidi F, Blomquist S, Hoglund P, Pierre L, Koul B. Systemic effects of carbon dioxide insufflation technique for de-airing in left-sided cardiac surgery. J Thorac Cardiovasc Surg. 2014 Jan;147(1):295-300. doi: 10.1016/j.jtcvs.2012.11.010. Epub 2012 Dec 13.
Results Reference
derived
PubMed Identifier
20817209
Citation
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.
Results Reference
derived
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CO2 Versus Lund De-airing Technique in Heart Surgery
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