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Trial registered on ANZCTR


Registration number
ACTRN12614001081606
Ethics application status
Approved
Date submitted
16/09/2014
Date registered
9/10/2014
Date last updated
5/02/2016
Type of registration
Retrospectively registered

Titles & IDs
Public title
A study to compare 2 methods of inserting a pulmonary artery catheter in high risk cardiac surgical patients.
Scientific title
A randomized controlled trial using video fluoroscopy or conventional pressure waveform analysis for the insertion of pulmonary artery catheters in high-risk patients undergoing cardiac surgery
Secondary ID [1] 285351 0
Nil
Universal Trial Number (UTN)
U1111-1161-8205
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
High risk cardiac surgical patients 293075 0
Severe tricuspic regurgitation 293076 0
Severe left ventricular systolic dysfunction 293077 0
Mitral valve disease with severe pulmonary hypertension 293078 0
Condition category
Condition code
Surgery 293350 293350 0 0
Other surgery
Anaesthesiology 293351 293351 0 0
Other anaesthesiology
Cardiovascular 293352 293352 0 0
Other cardiovascular diseases

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
All high risk cardiac surgical patients who require a pulmonary artery catheter (PAC) will have a PAC inserted by using video flouroscopy (directly screening of the catheter by vision into the pulmonary artery), or by conventional pressure wave form analysis (i.e floating the catheter into the pulmonary artery by using the pressure wave form trace as the catheter traverses through the superior vena cava into the right atrium into the right ventricle and then in to the pulmonary artery.

The duraration of the intervention will be for the insertion of the PAC only. This will take approximately 30 seconds to 15 minutes, depending of the difficulty.
Intervention code [1] 290269 0
Treatment: Devices
Comparator / control treatment
The control intervention will inserting the PAC by conventional pressure wave form analysis (i.e floating the catheter into the pulmonary artery by using the pressure wave form trace as the catheter traverses through the superior vena cava in to the right atrium in to the right ventricle and then in to the pulmonary artery.

This is standard practice for the insertion of PAC.

Control group
Active

Outcomes
Primary outcome [1] 293184 0
Time in seconds to float the pulmonary artery catheter
Timepoint [1] 293184 0
The primary timpoint is when position of the pulmonary artery catheter is in the pulmonary artery
Secondary outcome [1] 310542 0
Final positioning and exact catheter location in the pulmonary artery (recorded with transoesophageal echocardiography)
Timepoint [1] 310542 0
When the pulmonary artery catheter is in the pulmonary artery
Secondary outcome [2] 310543 0
Number of attempts at floatation. An attempt is defined as withdrawing the catheter back into the superior vena cava or right atrium
Timepoint [2] 310543 0
When the pulmonary artery catheter is in the pulmonary artery
Secondary outcome [3] 310544 0
Electrocardiographic rhythm disturbances
Timepoint [3] 310544 0
Recorded continuously with an ECG during the insertion of the pulmonary artery catheter into the pulmonary artery
Secondary outcome [4] 310545 0
Malposition or coiling of the catheter in the atrium or ventricle. This outcome will be assessed intraoperatively with transoesophageal echocardiography, and postoperatively with a chest radiograph performed on arrival in the Intensive Care Unit. Both these modalities will be able to assess malposition and/or coiling of the pulmonary artery catheter.
Timepoint [4] 310545 0
During the insertion of the pulmonary artery catheter into the pulmonary artery and with a chest radiograph performed immediately on arrival in the Intensive Care Unit.

Eligibility
Key inclusion criteria
1. Poor left ventricular function defined as ejection fraction < 35%
2. Low cardiac output syndromes: cardiac index < 1.5 l/min
3. Cardiac surgery for mitral valve disease with severe pulmonary hypertension (Mean PAP > 40mmHg)
4. Severe tricuspid insufficiency
5. Floating the catheter from a left internal jugular or left subclavian vein
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Failure to obtain informed consent
Pregnancy
Age less than 18 years

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Patients will be informed about the study and consented at the cardiac surgery or cardiac anaesthesia pre-anaesthesia admission clinic. On the day of surgery, an independent anaesthetist or research nurse who is not a study investigator will open a sealed opaque randomisation envelope.

Participants will be randomly assigned to one of two groups using a random number allocation system with permuted blocks. One group will have the pulmonary artery catheter inserted using video flouroscopy; the other group will have the pulmonary artery catheter inserted using
conventional pressure wave form analyses.

If patients are radomised to the conventional pressure wave form analyses group, and the catheter cannot be floated into the pulmonary artery within a 10 minute period, they will be crossed over to the videoflouroscopy group.



Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation by using a randomization table created by a computer software (i.e., computerised sequence generation) will be performed. For each patient, an opaque envelope containing the group assignment will be prepared, sealed and sequentially numbered. On the morning of surgery the anaesthetist will open the envelope and randomised the patients into one of the two groups described above.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Phase 4
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Power analysis will be based data surveillance for patients undergoing cardiac surgery who received a pulmonary artery catheter in our institution, the mean time to float the catheter is 320 seconds (SD = 130 seconds). Assumption of constant variance seems appropriate. Assuming a standard deviation in both groups of 130 seconds, in order to detect a clinically important difference of 50% between the intervention group (Flouroscopy group) and Usual Care group, a sample size of 14 patients in each group was required for a power of 90% (significance level of 0.05). This difference would be considered clinically significant i.e. a reduction in time to insert the catheter by 50%. In order to demonstrate an important clinical difference in our secondary end points, in particular, the incidence of arrhythmias, a total of 25 patients will be enrolled in each group to allow for loss of data.

Analysis will be on an intention-to-treat basis. Simple descriptive statistics were used to analyze the results. The unpaired Student’s t-test and the Mann-Whitney U-test will be used to analyse univariate parametric and non-parametric data respectively. The Chi-squared test will be used to compare categorical data. Regression modelling will be used to investigate for independent factors associated with floating the catheter. A p value < 0.05 will be considered significant.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 3001 0
Austin Health - Austin Hospital - Heidelberg
Recruitment postcode(s) [1] 8714 0
3084 - Heidelberg

Funding & Sponsors
Funding source category [1] 289969 0
Hospital
Name [1] 289969 0
Department of Anaesthesia, Austin Hospital
Address [1] 289969 0
Studley Road, Heidelberg, Victoria, 3084
Country [1] 289969 0
Australia
Primary sponsor type
Hospital
Name
Austin Hopsital
Address
Department of Anaesthesia
Studley Road, Heidelberg, Victoria, 3084
Country
Australia
Secondary sponsor category [1] 288657 0
None
Name [1] 288657 0
Address [1] 288657 0
Country [1] 288657 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 291679 0
Austin Health Research Ethics Unit
Ethics committee address [1] 291679 0
Austin Health Research Ethics Unit
Henry Buck Building
Austin Hospital
Studley Road
Heidelberg, 3084, Victoria
Ethics committee country [1] 291679 0
Australia
Date submitted for ethics approval [1] 291679 0
Approval date [1] 291679 0
06/11/2009
Ethics approval number [1] 291679 0
H2009/03740

Summary
Brief summary
The pulmonary artery catheter (PAC), also known as Swan-Ganz catheter, is a catheter that is inserted into the heart through a large vein in the neck or groin. It is used routinely in all patients undergoing cardiac surgery at Austin Hospital and allows direct, simultaneous
measurement of pressures in the right atrium and right ventricle of the heart and pulmonary artery. In addition, it allows the calculation of important cardiac and respiratory physiological information. The PAC is also used to evaluate the effects of drugs on the cardiovascular system, assess and optimise fluid requirements, and manage complications of cardiac surgery such as myocardial infarction and heart failure.

Complications from PAC insertion, although infrequent can be harmful. Mal-positioning can lead to arrhythmias, trauma to the pulmonary artery causing bleeding or thrombosis (clotting), infection and pneumothorax (puntured lung).

The “standard” anaesthetic technique used to insert the PAC involves slow advancement of the catheter through the heart chambers. The catheter cannot be visualised as it is inserted, however as the catheter traverses the chambers
of the heart (right atrium, right ventricle, and pulmonary artery), a characteristic change in cardiac pressure waveforms is seen in each chamber. This change in waveform allows the clinician to advance the catheter through the heart chambers until is its final positioning in the pulmonary artery. Because the catheter is inserted “blindly”, malposition of the catheter commonly occurs. Prolonged and repeated attempts at placing the PAC increase the risks of complications, particularly arrythmias (irregular heart beats), coiling and incorrect position.

A technique commonly used by radiologists to guide catheter placement is the use of an X-ray image intensifier, or video flouroscopy. This allows the catheter to be visualised as it is being inserted through the heart chambers into its final position in the pulmonary artery. This
technique is also commonly employed by anaesthetists to insert the PAC if it insertion by the standard "blind" method fails. The use of this technique to insert the PAC has never been studied any any scientific way, therefore we propose to study this X-ray technique on patients who are at increased risk from having a complication from PAC insertion. High-risk patients will include those with poor heart function, high pre-existing pulmonary artery pressures, or severe valvular heart disease.

The use of the X-ray image intensifier involves X-ray exposure to the patient, but studies have shown that the risk is very minimal.

We hypothesize that the use of the X-ray image intensifier to guide positioning of the PAC in high-risk patients undergoing cardiac surgery results in a shorter insertion time, with fewer attempts at insertion, and precise final positioning of the catheter in the pulmonary artery when
compared to standard "blind" insertion.

Primary end point: time taken in seconds to insert the PAC and final positioning of the PAC.

Secondary end points: number of attempts at insertion and complications from insertion

Final correct PAC positioning will be checked in theatre by trans-oesophageal echocardiography.
Trial website
Nil
Trial related presentations / publications
Published: Weinberg et al. Journal of cardiothoracic and Vascular anesthesia, Vol 29. No 6 (Dec), 2015: pp 1511-1516
Public notes
At the time this study was designed, and approved by Austin Hospital Ethics Committee (Nov 2009), prospective Clinical Trial Registration was not a requisite. The study has therefore been retrospective registered. The study protocol, including the primary aims, secondary aims, design and execution, and statistical methodology have not been modified in any way. The full ethics approved protocol is available if requested.

Contacts
Principal investigator
Name 51486 0
Dr Laurence Weinberg
Address 51486 0
Department of Anaesthesia Austin Hospital Studley Road Heidelberg, 3084, Victoria
Country 51486 0
Australia
Phone 51486 0
+61 3 94965000
Fax 51486 0
+61 3 94596421
Email 51486 0
Laurence.Weinberg@austin.org.au
Contact person for public queries
Name 51487 0
Dr Laurence Weinberg
Address 51487 0
Department of Anaesthesia Studley Road Heidelberg, 3084 Victoria, Australia
Country 51487 0
Australia
Phone 51487 0
+61 3 94965000
Fax 51487 0
+61 3 94596421
Email 51487 0
Laurence.Weinberg@austin.org.au
Contact person for scientific queries
Name 51488 0
Dr Laurence Weinberg
Address 51488 0
Department of Anaesthesia Studley Road Heidelberg, 3084 Victoria, Australia
Country 51488 0
Australia
Phone 51488 0
+61 3 94965000
Fax 51488 0
+61 3 94596421
Email 51488 0
Laurence.Weinberg@austin.org.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary