Trial Review

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Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12626001129370p
Ethics application status
Help: Ethics application status
Submitted, not yet approved
Date submitted
Help: Date submitted
18/08/2026
Date registered
Help: Date registered
10/09/2026
Date last updated
Help: Date last updated
10/09/2026
Date data sharing statement initially provided
Help: Data sharing statement date
10/09/2026
Type of registration
Help: Type of registration
Prospectively registered

Titles & IDs
Public title
Assessing the safety of the Cardiac Return Air Blanket (CRAB) on healthy volunteers
Scientific title
Assessing the safety of the Cardiac Return Air Blanket (CRAB) on healthy volunteers
Additional trial identifiers [1] 318219 0
nil
Universal Trial Number (UTN)
U1111-1345-5378
Trial acronym
CRAB Safety
Related trial records
ACTRN12621000840886. Follow up Study.

Health condition
Health condition(s) studied:
Low Central Venous Pressure 343277 0
Condition category
Condition code
Anaesthesiology 339393 339393 0 0
Other anaesthesiology
Inflammatory and Immune System 339394 339394 0 0
Allergies
Cardiovascular 339395 339395 0 0
Other cardiovascular diseases

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
The Cardiac Return Air Blanket (CRAB) is an inflatable blanket, which is positioned over the abdomen and upper legs of the patient and held in position by 3 Velcro hook straps which pass under the table and adhere to 3 sections of Velcro loops onto the blanket. The air blanket is inflated by a battery powered, computer controlled, electric air pump. The blanket evenly compresses the abdomen and upper legs to physically squeeze the venous blood of the lower body to the upper body, increasing the Central Venous Pressure (CVP).

The participant will present at the allotted time to study room at Sir Charles Gairdner Hospital.

A research nurse will re-confirm participant consent and answer any questions (or escalate to the Chief Principal Investigator (CPI), enter the demographic data, and confirm the inclusion / exclusion criteria have been met. A urinary pregnancy test will be offered to any females unsure if they are pregnant.

The participant will lie flat on a narrow hospital trolley or operating theatre bed.
The non-invasive monitoring placed on the participant will include:
• 3 lead ElectroCardioGram (ECG) – continuous reading of Lead II, giving Heart rate (HR), and rhythm
• Non-Invasive Blood Pressure (BP) –2 minutely recordings
• Pulse Oximetry (SaO2)– continuous reading of oxygen saturations.
If the participant has any exposed skin between chest and knees a sheet will be placed over the participant’s body. The CRAB blanket will be placed on the patient with the top of the blanket (orange strap just below the xiphisternum and secured with the Velcro straps. The lower edge of the blanket will reach the knees or below.
The CRAB Pump will then be attached to the CRAB blanket and turned on.
The participant will be reminded they can have the protocol stopped at any stage.

• Baseline HR, BP and SaO2 will be recorded.
• When both the participant and the equipment are ready, the research nurse will start the timer and pressurised the CRAB to 20cm H20.
• One minute after inflation – HR, BP and SaO2 will be recorded.
• Two minutes after inflation the research nurse will check if the participant consents to the increased pressure. If the participant is consenting the CRAB will be pressurised to 40cm H20 (Full pressure).
• One minute after the increase in pressure– HR, BP and SaO2 will be recorded.
• Two minutes after the increase in pressure the CRAB pressure will be reduced to zero and the CRAB removed
• The research nurse will check if the participant has any residual symptoms. If the participant is symptom free the monitoring will be removed.

Participants will then be asked to complete the following questionnaire.

Questionnaire
For the CRAB at the lower pressure
1) Rate the discomfort of the CRAB: 0-to-10: 0 No discomfort – 10 Extreme discomfort
2) Did you have pain in any location Y / N
a. If yes: where was the pain
b. If yes: rate the pain: 0-to-10: 0 No pain, 10 Extreme pain
3) Rate the difficulty of breathing: 0-to-10: 0 No difficulty – 10 Extreme difficulty

For the CRAB at the higher pressure
1) Rate the discomfort of the CRAB: 0-to-10: 0 No discomfort – 10 Extreme discomfort
2) Did you have pain in any location Y / N
a. If yes: where was the pain
b. If yes: rate the pain: 0-to-10: 0 No pain, 10 Extreme pain
3) Rate the difficulty of breathing: 0-to-10: 0 No difficulty – 10 Extreme difficulty

After the CRAB deflated were there any residual effects
1) Discomfort
a. Y/N
b. If yes - Rate the residual discomfort of the CRAB: 0 No discomfort – 10 Extreme discomfort
2) Did you have any residual pain in any location
a. Y / N
b. If yes: where was the pain
c. If yes rate the pain: 0-to-10: 0 No pain - 10 Extreme pain
3) Did you have any residual difficulty of breathing
a. Y/N
b. Rate the difficulty of breathing: 0-to-10: 0 No difficulty – 10 Extreme difficulty
4) Any changes in your skin due to the CRAB
a. Y/N
b. If yes – Details
Additional comments about the effects of the CRAB: Free text.

Follow-up
If the participant is symptom free / no residual effects after deflation of the CRAB, then no further participant follow-up will be required.
Any participant who has residual symptoms will be monitored for a further 20minutes. If the participant continues to have residual symptoms, this will be classed as an Adverse Event, and an adequate plan will be made for their symptoms by the PI. This may include follow-up phone calls, medical referral or in unlikely serious circumstances transfer to the emergency department or medical emergency response team call. All participants who have required ongoing monitoring or referral of symptoms will be followed up 30 days post device testing to determine whether symptoms have been resolved or have resulted in ongoing treatment and/or management. The method of this follow-up will be determined by the PI and the participant at the time of the event.
All participants will be supplied with contact detail trial team. They will be encouraged to contact trial team to raise any concern regarding the trial or to report any comments that they feel may be relevant.
Intervention code [1] 335115 0
Treatment: Devices
Description of the comparator or control
No Control Group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 346592 0
• Signs of physiological distress - which will be assessed as a composite outcome
Timepoint [1] 346592 0
During the 4 minutes that the CRAB is Inflated
Primary outcome [2] 346593 0
• Participant-reported discomfort necessitating device deflation
Timepoint [2] 346593 0
During the 4 minutes of CRAB Inflation
Secondary outcome [1] 466575 0
• Participant-reported discomfort scores
Timepoint [1] 466575 0
Completed immediately after the intervention
Secondary outcome [2] 466576 0
• Participant-reported pain
Timepoint [2] 466576 0
Completed immediately after intervention
Secondary outcome [3] 466577 0
• Proportion of participants able to tolerate escalation from 20 cmH2O to 40 cmH2O
Timepoint [3] 466577 0
Completion of the study (4 minutes)
Secondary outcome [4] 466578 0
• Time to onset of any adverse event. Including pain, discomfort, difficulty breathing, headache or intolerance
Timepoint [4] 466578 0
During intervention and immediately after the intervention
Secondary outcome [5] 466579 0
• Qualitative assessment of other symptoms - this is an exploratory outcome (to extend knowledge past the first study)
Timepoint [5] 466579 0
Immediately after intervention
Secondary outcome [6] 467270 0
Participant-reported Difficulty Breathing Scores
Timepoint [6] 467270 0
Immediately after intervention.

Eligibility
Key inclusion criteria
• Stable health, not under investigation for any recent new symptoms.
• Willing and able to provide informed consent to participate
• Available to attend device testing clinic sessions
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Healthy volunteers
Yes
Key exclusion criteria
• Surgery in any body location in the last 3/12.
• Unable to climb 2 flights of stairs
• Pregnant
• BMI > 40
• History of DVT / pulmonary embolism
• Moderate / severe valvular disease, heart failure
• Pulmonary Hypertension.
• Previously diagnosed or suspected cognitive impairment

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Phase 1
Type of endpoint/s
Safety
Statistical methods / analysis
Minor adverse event (mAE) rate calculation and analysis
The minor adverse event (mAE) rate will be calculated as the proportion of participants experiencing at least one minor adverse event attributable to the CRAB device during the study period, divided by the total number of participants exposed to the device. Each participant will be counted once only, regardless of the number of minor adverse events experienced. Raw adverse event data will be recorded prospectively and analysed using an exact one sample binomial framework. The observed mAE proportion will be compared against a pre specified clinically unacceptable threshold of 20% using a one sided hypothesis test at a significance level of 0.05. Point estimates and exact confidence intervals will be reported to characterise uncertainty around the observed rate.

Power analysis
Sample size was calculated using an exact one sample binomial power analysis, implemented in the MKpower R package (power.prop1.test). The analysis used a one sided a = 0.05 and 80% power to detect whether the true mild adverse event (mAE) rate is below a pre specified clinically unacceptable threshold. The expected true mAE rate was set to 7.5%, based on the observation of 1 mAE among 16 participants in the pilot study, while the threshold for an unacceptably high rate was set at 20%, reflecting the highest rate judged clinically tolerable for this intervention given the anticipated benefit. Under these assumptions, the required sample size was estimated to be N = 34.
While 7.5% represents the most plausible clinical scenario based on observed data, sensitivity analyses were performed varying the assumed true AE rate from 2.5% to 10.0%. As expected, required sample size increased when the true AE rate approached the unacceptable limit of 20% and decreased when the anticipated AE rate was further below it. Across all considered scenarios, required sample sizes ranged from N = 18 to N = 48. Therefore, we plan to recruit 48 participants into this safety study.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
1/10/2026
Actual
Date of last participant enrolment
Anticipated
1/10/2027
Actual
Date of last data collection
Anticipated
1/11/2027
Actual
Sample size
Target
48
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
WA
Recruitment hospital [1] 30043 0
Sir Charles Gairdner Hospital - Nedlands
Recruitment postcode(s) [1] 46436 0
6009 - Nedlands

Funding & Sponsors
Funding source category [1] 322781 0
Commercial sector/Industry
Name [1] 322781 0
Coco Industries Pty Ltd
Country [1] 322781 0
Australia
Funding source category [2] 322782 0
Government body
Name [2] 322782 0
Sir Charles Gairdner Hospital
Country [2] 322782 0
Australia
Primary sponsor type
Commercial sector/Industry
Name
Coco Industries Pty Ltd
Address
Country
Australia
Secondary sponsor category [1] 325708 0
None
Name [1] 325708 0
Address [1] 325708 0
Country [1] 325708 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 321222 0
WA Health Central HREC
Ethics committee address [1] 321222 0
Ethics committee country [1] 321222 0
Australia
Date submitted for ethics approval [1] 321222 0
17/07/2026
Approval date [1] 321222 0
Ethics approval number [1] 321222 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 153058 0
Dr James Preuss
Address 153058 0
Anaesthetist, Sir Charles Gairdner Hospital, Hospital Avenue, Nedlands 6009, WA
Country 153058 0
Australia
Phone 153058 0
+61 438905979
Fax 153058 0
Email 153058 0
[email protected]
Contact person for public queries
Name 153059 0
Dr Chris Mitchell
Address 153059 0
Anaesthetic Department, SCGH, Hospital Avenue, Nedlands, 6009. WA
Country 153059 0
Australia
Phone 153059 0
+61 427425854
Fax 153059 0
Email 153059 0
[email protected]
Contact person for scientific queries
Name 153060 0
Dr Chris Mitchell
Address 153060 0
Anaesthetic Department, SCGH, Hospital Avenue, Nedlands, 6009. WA
Country 153060 0
Australia
Phone 153060 0
+61 427425854
Fax 153060 0
Email 153060 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No
No IPD sharing reason/comment: WA Central HREC would not allow this.



What supporting documents are/will be available?

TypeCitationLinkEmailOther DetailsAttachment
Informed consent form    CRAB Safety PISC V1 060726.docx
Study protocol    CRAB Safety Protocol V2 09092026.docx


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.