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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Comparing a Conservative Fluid Management Strategy to Usual Care in Participants after Cardiac Surgery
Scientific title
A Multi-centre, Open Label, Randomised Controlled Trial to Compare a Conservative Fluid Management Strategy to Usual Care in Participants after Cardiac Surgery
Secondary ID [1] 290115 0
Universal Trial Number (UTN)
Trial acronym
The FAB study
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cardiovascular disease 300212 0
Condition category
Condition code
Cardiovascular 300092 300092 0 0
Other cardiovascular diseases

Study type
Description of intervention(s) / exposure
A protocol guided strategy for administering bolus fluid utilising stroke volume variation to limit fluid administration to those likely to be fluid responsive.
Once the patient returns to the ICU following cardiac surgery, bedside staff - nursing and medical - will utilise a protocol to guide fluid administration. If the clinician suspects the patient to have a known or suspected inadequate cardiac output (i.e. the cardiac index is < 2.5L/min/m2; poor perfusion;poor urine output) and the stroke volume variation (SVV) is >13 then they will be instructed to administer a fluid bolus of 250mls of crystalloid or colloid as determined by the treating clinician. If the SVV is <13 then the treating clinician should consider using vasopressors to maintain or improve cardiac output. Type of vasopressor and dose will be determined by the treating clinician. The protocol will continue until the patient is desedated and extubated or they reach 24 hours post-operative if still mechanically ventilated. Deviations from the protocol will be collected by the research nurses at each site.
Intervention code [1] 295879 0
Treatment: Other
Comparator / control treatment
Participants receive fluid administration as determined by the bedside clinician.
Standard fluid administration postoperatively in the ICU - fluid boluses administered by the treating clinician based on blood pressure, central venous pressure etc. These boluses are usually 250 - 500mls per bolus and depend on the treating clinician.
Control group

Primary outcome [1] 299586 0
Intensive care unit length of stay from hospital database..
Timepoint [1] 299586 0
To day 28 post randomisation
Secondary outcome [1] 327621 0
Incidence of wound infections from review of medical records
Timepoint [1] 327621 0
Day 28 post randomisation
Secondary outcome [2] 327623 0
Timepoint [2] 327623 0
180 days post randomisation
Secondary outcome [3] 327624 0
Quality of life using EQ5D
Timepoint [3] 327624 0
Days 90 and 180 post randomisation
Secondary outcome [4] 327626 0
Disability free survival using WHODAS 2.0
Timepoint [4] 327626 0
Days 90 and 180 post randomisation
Secondary outcome [5] 327627 0
Requirement for renal replacement therapy from review of medical records
Timepoint [5] 327627 0
Day 90 post randomisation
Secondary outcome [6] 327628 0
Length of mechanical ventilation from review of medical records
Timepoint [6] 327628 0
During hospital stay
Secondary outcome [7] 327629 0
Development of acute kidney injury using KDIGO criteria
Timepoint [7] 327629 0
During hospital stay
Secondary outcome [8] 327706 0
Incidence of wound breakdown from review of medical records
Timepoint [8] 327706 0
Day 28 post randomisation
Secondary outcome [9] 327707 0
Requirement for diuretic therapy from review of medical records
Timepoint [9] 327707 0
During hospital stay
Secondary outcome [10] 327708 0
Requirement for vasopressor therapy from review of medical records
Timepoint [10] 327708 0
While in ICU

Key inclusion criteria
1. Adult participants 16 years or older
2. Having elective cardiac surgery with cardiopulmonary bypass
3. Preoperative EUROSCORE II of 0.9 or greater
Minimum age
16 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1. Emergency procedure
2. Contraindication to FloTrac monitoring such as Atrial fibrillation; IABP in situ or anticipated; Open chest;
3. Critical post-operative condition or Participant not expected to survive for more than 24 hours or Open chest
4. ECMO or Ventricular assist device in situ or anticipated
5. Indication for specific fluid management post-operatively such as Adult congenital heart surgery or End stage renal failure requiring dialysis
6. Enrolment not considered to be in the participant's best interest

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Opaque, sealed, sequentially numbered envelopes will be used to conceal allocation until the point of randomisation.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A permuted block randomisation method of variable block size, stratified by hospital, will be used to allocate participants in a 1:1 ratio.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Sample size calculations were based on findings from our pilot study in which there was a median difference in ICU hours between treatment and intervention arms that was greater than 20 hours. Based on an observed standard deviation of 56, with 590 participants this study will have a 90% power (2 sided p-value=0.05) to detect a 15 hour difference and an 80% power (2 sided p-value=0.05) to detect a 13 hour difference in ICU hours. Differences of this magnitude are both conservative in comparison to what we have previously observed and clinically relevant as they will enable participants to be discharged from the ICU on or before the morning of the second post-operative day, enabling a new participant to be admitted on that day and thus resolving a principal barrier to increasing cardiac surgical participant throughput. By recruiting a total of 700 participants, we further allow for inflation due to one interim analysis, a 3% drop-out rate and 15% for potential non-normality in ICU LOS.
All data will be analysed according to the intention to treat principle. Data will be tested for normality prior to analysis. Between-group comparisons for continuous data will be performed by means of Student’s t or Mann-Whitney U tests - as appropriate - or for categorical data with the chi-square test. A p value of <0.05 will be considered to indicate statistical significance. Data will be entered into an electronic database at the study site and extracted into SAS version 9.4 for analysis. Subgroup analysis will be undertaken by type of surgery and centre.
One blinded interim analysis will be conducted when fifty percent of participants have been enrolled and subsequently discharged from the ICU. This data will be made available to the DSMB for the purposes of safety assessment.
A formal statistical analysis plan will be published prior to the final analysis.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 8223 0
New Zealand
State/province [1] 8223 0

Funding & Sponsors
Funding source category [1] 294501 0
Name [1] 294501 0
Heart Foundation of New Zealand
Address [1] 294501 0
PO Box 17-160 Greenlane, Auckland 1546
Country [1] 294501 0
New Zealand
Funding source category [2] 301136 0
Name [2] 301136 0
A+ Charitable Trust
Address [2] 301136 0
Level 14, Support Building, Auckland City Hospital
Park Road
New Zealand
Country [2] 301136 0
New Zealand
Primary sponsor type
Rachael Parke
CVICU Research
Private Bag 110147
Auckland City Hospital
Auckland 1148
New Zealand
Secondary sponsor category [1] 293365 0
Name [1] 293365 0
Address [1] 293365 0
Country [1] 293365 0

Ethics approval
Ethics application status
Ethics committee name [1] 295935 0
Northern B Health and Disability Ethics Committee
Ethics committee address [1] 295935 0
Ministry of Health
Ethics Department
Freyberg Building
Reception – Ground Floor
20 Aitken Street
Wellington 6011
Ethics committee country [1] 295935 0
New Zealand
Date submitted for ethics approval [1] 295935 0
Approval date [1] 295935 0
Ethics approval number [1] 295935 0

Brief summary
Cardiovascular disease is the leading cause of death in New Zealand and a significant burden on the health system economically and socially. High cancellation rates for cardiac surgery are a significant issue in New Zealand due to lack of access to Intensive Care Unit (ICU) beds. This is an NZ health delivery issue and major concern for participants, clinicians and policy makers.
Cardiac surgical participants are frequently treated with fluid in the ICU to prevent development of organ dysfunction. However fluid administration may also have deleterious effects including an increased risk of morbidity and mortality. We have demonstrated previously that a strategy designed to avoid unnecessary fluid administration significantly reduces fluid loading and ICU length of stay. This randomised controlled trial aims to determine if a protocolised strategy avoiding unnecessary fluid administration reduces ICU length of stay, overcoming a major bottleneck to effective delivery of cardiac surgery in NZ, and improves participant-centred outcomes.
Trial website
Trial related presentations / publications
Design and statistical analysis plan for a trial comparing a conservative fluid management strategy with usual care in patients after cardiac surgery: the FAB study.
Parke R, Gilder E, Gillham M, Walker L, Bailey M, McGuinness S; Fluids After Bypass Study Investigators.
Critical care and resuscitation. 2018 Sep;20(3):190-197
Public notes

Principal investigator
Name 68902 0
Dr Rachael Parke
Address 68902 0
CVICU Research
Cardiothoracic and Vascular Intensive Care Unit
PO Box 110147
Auckland City Hospital
Auckland 1148
Country 68902 0
New Zealand
Phone 68902 0
Fax 68902 0
Email 68902 0
Contact person for public queries
Name 68903 0
Dr Rachael Parke
Address 68903 0
CVICU Research
Cardiothoracic and Vascular Intensive Care Unit
PO Box 110147
Auckland City Hospital
Auckland 1148
Country 68903 0
New Zealand
Phone 68903 0
Fax 68903 0
Email 68903 0
Contact person for scientific queries
Name 68904 0
Dr Rachael Parke
Address 68904 0
CVICU Research
Cardiothoracic and Vascular Intensive Care Unit
PO Box 110147
Auckland City Hospital
Auckland 1148
Country 68904 0
New Zealand
Phone 68904 0
Fax 68904 0
Email 68904 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Currently not allowed fro in ethics application.
What supporting documents are/will be available?
No other documents available
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