The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12614000730606
Ethics application status
Approved
Date submitted
3/07/2014
Date registered
10/07/2014
Date last updated
3/08/2016
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of lower limb fibreglass cast on the efficacy of the Impulse Intermittent Pneumatic Compression (IPC) device on lower limb venous haemodynamics in healthy subjects
Scientific title
Randomised controlled trial of 24 healthy participants aged between 18 and 65 years, randomised to have one foot placed in an intermittent pneumatic compression device with a lower limb fibreglass cast placed over it, and the other foot placed in an intermittent pneumatic compression device alone, to compare venous haemodynamic effects of the fibreglass cast on the performance of the intermittent pneumatic compression device by measuring venous flow in the popliteal vein of both legs.
Secondary ID [1] 284917 0
None
Universal Trial Number (UTN)
U1111-115813170
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Venous thromboembolism 292387 0
Condition category
Condition code
Blood 292703 292703 0 0
Clotting disorders
Cardiovascular 292704 292704 0 0
Diseases of the vasculature and circulation including the lymphatic system

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
An Intermittent Pneumatic Compression System (IPCS), VENA PRESS System with foot garment. (Website photos and description of features: http://priushcs.com/?page_id=159) will be placed on both feet of healthy volunteers. This is a system that is used regularly for DVT prophylaxis in high risk and immobile patients post-surgery.

The subjects' feet will be placed in a foot compression garment (a cuff) that will be attached by tube assembly to a pump unit. When the pump unit is turned on, a distal aircell within the foot cuff will inflate rapidly to approximately 130mmHg +/-10% and will then settle to 52mmHg, and a proximal aircell follows approximately 0.3 seconds after, to settle at approximately 48mmHg. After 6 seconds of compression at 48-53mmHg, the cuffs deflate. The cycle repeats every minute

Volunteers will then be randomised to have either their left or right foot (and the compression garment) placed within a below knee fibreglass cast, as would normally be placed if someone suffered a fractured ankle or an Achilles tendon rupture.


Ultrasound (USS) measurements of bilateral popliteal vein blood flow will be done to compare the performance of the IPC device within a fibreglass cast to the performnace outside of a fibreglass cast. Measurements will be done at the following times (All USS measures will be done on the left leg first, regardless of which is randomised to the cast, and will be undertaken twice for each measure – the mean of both measures will be used for statistical analysis).
- Baseline (Time 0)
- 40 minutes: prior to starting the IPC device
- 60 minutes: after the IPC device has been running for 10 minutes continuously

After obtaining the final measure at 60 minutes, the study will be deemed to have been completed. At the end of the study the cast and IPC devices will be removed.
Intervention code [1] 289737 0
Prevention
Intervention code [2] 289758 0
Treatment: Devices
Comparator / control treatment
The comparator will be the lower limb of the same volunteer that has the only IPC on it, (ie, the IPC that is not under the fibreglass cast)
Control group
Active

Outcomes
Primary outcome [1] 292545 0
In the seated position: the peak systolic velocity (cm/s) in the popliteal vein of the casted limb compared to the non-casted limb at 60 minutes as assessed by ultrasonography (USS).
Timepoint [1] 292545 0
60 minutes after the IPC device has been running for 10 minutes continuously
Secondary outcome [1] 309195 0
Peak systolic velocity, in the popliteal vein of casted versus non-casted limb as assessed by Ultrasound Sonography (USS).

Timepoint [1] 309195 0
- 40 minutes, immediately prior to starting the IPC device, 50 minutes, after the IPC device has been running for 10 minutes continuously
Secondary outcome [2] 309196 0
Mean flow velocity (cm/s), in the popliteal vein of casted versus non-casted limb, as assessed by Ultrasound Sonography (USS).
Timepoint [2] 309196 0
- 40 minutes, immediately prior to starting the IPC device, 50 minutes, after the IPC device has been running for 10 minutes continuously
Secondary outcome [3] 309197 0
Vein diameter (mm) in the popliteal vein of casted versus non-casted limb as assessed by Ultrasound Sonography (USS).


Timepoint [3] 309197 0
- 40 minutes, immediately prior to starting the IPC device, 50 minutes, after the IPC device has been running for 10 minutes continuously

Eligibility
Key inclusion criteria
- Aged between 18 to 65 years
- Able to provide informed consent
Minimum age
18 Years
Maximum age
65 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. History of previous or current deep vein thrombosis
2. Pregnancy (this may alter lower limb venous return from compression at the level of the iliac vein)
3. Any hyper-coagulable disorders including history of cancer other than basal cell carcinoma of the skin, non-invasive basal cell carcinoma of the skin
4. History or clinical features of peripheral vascular disease (including arterial and venous insufficiency), or other lower limb abnormalities, such as peripheral neuropathy, scleroderma, lymphoedema, or joint deformity from inflammatory arthritis
5. Abnormal clinical examination of the lower limbs, which may indicate one of the above mentioned exclusion medical conditions. (i.e. such as the presence of ischemic ulceration)

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Subjects will be assessed to ensure they meet the inclusion / exclusion criteria, and for informed consent.

They will be randomised on a 1:1 basis to have one leg placed in a below-knee fibreglass cast after both feet have been placed in a VENA PRESS foot compression garment that is attached to the intermittent pneumatic compression device.

Randomisation schedule will be computer-generated and provided by a biostatistician. The randomisation slips will be placed in an opaque envelope for each volunteer by a non-blinded coordinator. The investigators undertaking the study will remain blinded to the randomisation schedule.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation schedule will be computer-generated and provided by a biostatistician.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Other
Other design features
participants receive the same treatment - one IPC device on each foot and one limb randomised to have a fibreglass below-knee cast placed over the IPC device.
The non-casted IPC device in each participant effectively becomes the control
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Based on a paired SD for peak systolic velocity of 6.8 cm/s with an IPC (outside of a fiberglass cast) used in a previous haemodynamic study, a sample size of 24 has 90% power with an alpha of 5% to detect a paired difference of 4.8 cm/s in peak systolic velocity. (The mean peak systolic velocity in the seated position after 20 minutes from previous studies was 5.3 cm/s, increasing to 20.1 cm/s with an IPC device, representing a 3.8-fold increase from baseline).

Paired t-tests will compare the outcome variables (the mean of two readings) for the casted limb versus the non-casted limb, at each time point separately, and also for the change from baseline. A mixed linear model will be used to estimate the overall difference between the two interventions, the effect of time, and whether there was an interaction between the interventions and the effect of time.

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 outside Australia
Country [1] 6192 0
New Zealand
State/province [1] 6192 0
Wellington

Funding & Sponsors
Funding source category [1] 289542 0
Government body
Name [1] 289542 0
Health Research Council of New Zealand
Address [1] 289542 0
PO Box 5541,
Wellesley Street,
Auckland 1141
Country [1] 289542 0
New Zealand
Primary sponsor type
Charities/Societies/Foundations
Name
Medical Research Institiute of New Zealand
Address
Private Bag 7902
Wellington 6242
Country
New Zealand
Secondary sponsor category [1] 288228 0
University
Name [1] 288228 0
Victoria University of Wellington
Address [1] 288228 0
School of Biological Sciences
Victoria University of Wellington
PO Box 600
Wellington 6140
New Zealand
Country [1] 288228 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 291283 0
Health and Disability Ethics Committee
Ethics committee address [1] 291283 0
C/- MEDSAFE, Level 6, Deloitte House
10 Brandon Street
PO Box 5013
Wellington 6145
Ethics committee country [1] 291283 0
New Zealand
Date submitted for ethics approval [1] 291283 0
Approval date [1] 291283 0
03/07/2014
Ethics approval number [1] 291283 0
14/STH/82

Summary
Brief summary
There is a device called an Intermittent Pneumatic Compression (IPC) device, that may be used to improve blood flow in the legs of patients when they have had operations or been admitted to hospital. IPCs have been shown to reduce the risk of developing blood clots in the legs (Deep Vein Thrombosis – DVT) and the lungs (Pulmonary Embolism – PE) due to long periods of immobility. They work by placing an inflatable cuff on the patients’ calf or foot, which is then inflated several times a minute while the patient is immobilized. The inflated cuff squeezes the veins in the sole of the foot and the calf, reducing pooling of blood in the leg, and thus reducing the risk of blood clots forming in the veins.

We want to see whether the fibreglass cast impairs the performance of the IPC underneath it.

To figure this out, we want to measure the return of blood from the legs in study participants who have an IPC device on both feet, and who then have one leg placed in a fibreglass cast.
Trial website
Trial related presentations / publications
Public notes
A manuscript covering this study has been submitted to JRSM Open

Contacts
Principal investigator
Name 49674 0
Dr Irene Braithwaite
Address 49674 0
Medical Research Institute of New Zealand
Private Bag 7902
Wellington 6242
Country 49674 0
New Zealand
Phone 49674 0
+6448050245
Fax 49674 0
Email 49674 0
irene.braithwaite@mrinz.ac.nz
Contact person for public queries
Name 49675 0
Dr Irene Braithwaite
Address 49675 0
Medical Research Institute of New Zealand
Private Bag 7902
Wellington 6242
Country 49675 0
New Zealand
Phone 49675 0
+6448050245
Fax 49675 0
Email 49675 0
irene.braithwaite@mrinz.ac.nz
Contact person for scientific queries
Name 49676 0
Dr Irene Braithwaite
Address 49676 0
Medical Research Institute of New Zealand
Private Bag 7902
Wellington 6242
Country 49676 0
New Zealand
Phone 49676 0
+6448050245
Fax 49676 0
Email 49676 0
irene.braithwaite@mrinz.ac.nz

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