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Trial registered on ANZCTR


Registration number
ACTRN12623000948695p
Ethics application status
Not yet submitted
Date submitted
11/08/2023
Date registered
1/09/2023
Date last updated
1/09/2023
Date data sharing statement initially provided
1/09/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
A pilot study for optimising nutrition delivery using a smart feeding tube in healthy volunteers
Scientific title
Optimising nutrition delivery in acute and chronic diseases using a smart tube: A pilot healthy volunteer study
Secondary ID [1] 310333 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Patients requiring enteral feeding 331062 0
Condition category
Condition code
Oral and Gastrointestinal 327853 327853 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Intervention
This is a single-arm intervention study that uses an innovative dual pressure sensing nasogastric feeding tube system to measure biofeedback from the gut to optimise the safe delivery of enteral feed.
A custom-engineered feeding tube system measures back-propagated pressure and solid-state pressure by employing two pressure sensors attached to a single tube. Back-propagated pressure will be an external measurement of the gut pressure. A pressure transducer is placed between the feeding pump giving set and the feeding tube to measure the intraluminal pressure via back-propagation through the feed filling the feeding tube’s lumen. Solid-state pressure will be an internal measurement of the gut pressure. A microtip pressure sensor will be passed through the lumen of the feeding tube to directly measure intraluminal pressure at the distal end of the feeding tube where the feed exits. Gastric electrophysiology will be mapped by placing an FDA-approved 64-electrode array over the abdomen. Bowel sounds will be recorded by placing two digital stethoscopes on each side of the median plane. Cardiac and respiratory rate measurements will be taken with a three lead ECG.

Protocol
The study will be conducted at the Clinical Research Centre located at the University of Auckland.
1. Participants will visit the clinic in after an overnight fast (>8hours), nil-by-mouth.
2. Anthropometrics will be measured.
3. Prior to inserting the feeding tube, the solid-state (Millar®) pressure sensor will be incorporated into the nasogastric tube. It will be 2cm less than full insertion, so that the sensor unit is fully within the tube and not exposed in the hole at the end of the tube, to avoid the risk of it being snagged during insertion.
4. The nasogastric feeding tube will then be inserted via the nose into the stomach (without anaesthesia) as per the Auckland City Hospital clinical guidelines for enteral tube management. Participants will sit in an upright position with the head kept straight. The length of the tube will be measured and marked from the tip of the nose to ear lobe and then down to the xiphoid process. The end of the tube will be lubricated with a gel, and the tube inserted from the nose until the marked length is reached. The participant will be offered a glass of water to assist passage of tube through the oro-pharynx. The tube will be strapped and secured at the top of the nose using a plaster.
5. Correct positioning of the feeding tube will be confirmed by testing the pH of the gastric aspirate.
6. The Millar sensing unit will be advanced the final 2cm, to allow the sensor to be exposed within the terminal hole of the tube without extending into the stomach lumen.
7. Following the feeding tube insertion, three standard ECG dots will be applied to the participants chest and abdomen. The ECG dots will be connected to a signal processing unit (ProtoCentral Electronics) and a data acquisition unit to interpret the cardiac and respiration rate measurements.
8. Next, a body surface gastric mapping (BSGM) electrode adhesive array (Alimetry®) will be placed over the skin on the stomach region (as per Alimetry’s protocol) by asking the participants to lie in a supine position.
9. Following the BSGM electrode array placement, two digital stethoscopes (Thinklabs Medical LLC®) will be placed on the participants’ abdomen area for recording bowel sounds. Stethoscopes will be placed one on each side of the median plane, positioned in the mid-clavicular line, and at least one centimetre below the lower edge of the BSGM electrode array. The stethoscopes will be connected to a digital recorder for dual bowel sounds recording from the left and right abdominal quadrants.

Measurements
Measurements will be done at eight timepoints over approximately 75-90 minutes. The measurements will include intraluminal pressure (via the prototype NG tube), gastric mapping (by BSGM), heart rate and respiratory rate (by three lead electrocardiogram (ECG)), and bowel sounds (via a digital stethoscope).
For timepoints 1-3, participants will lie in the supine position to measure the effects of feeding.
• Timepoint 1: Once the participant lies on the bed, all the recording devices will be turned on. After a devices ‘warm-up’ period of 15 minutes, fasting baseline measurements will be taken for 10 minutes.
• Timepoint 2: The feeding tube will then be adjusted (advanced 5cm and withdrawn 2cm) and measurements repeated for 5 minutes.
• Timepoint 3: An enteral feed (Nutricia®) will be given at a rate of 400 mL/hour for 15 minutes (total energy content 150 kcal). After 15 minutes, the feeding pump will be turned off. Measurements will be recorded for 10 minutes.
The recordings for timepoints 4-8 will measure the effects of body movement. The feeding pump will be off for the following measurements.
• Timepoint 4: Participants will be asked to turn to their side (right side down) from supine position and 5 minutes of measurements recorded.
• Timepoint 5: Participants will be sat up (60 - 90 degrees from horizontal) and 5 minutes of measurements recorded.
• Timepoint 6: Participants will be asked to cough for 15 seconds, and measurements continued through this period.
• Timepoint 7: Participants will be asked to perform Valsalva’s manoeuvre for 30 seconds and measurements continued through this period.
• Timepoint 8: Participants will resume supine position (as in Time point 1) and a further 10 minutes of measurements will be taken.
After completion of this protocol the feeding tube, BSGM electrode array, and stethoscope attachments will be carefully removed.
Intervention code [1] 326734 0
Early detection / Screening
Comparator / control treatment
No control group.
This is a single arm intervention study.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 335700 0
Real-time changes in gut intraluminal pressure after an enteral feed by measuring back-propagated pressure using a pressure transducer placed between the feeding pump giving set and the feeding tube.
Timepoint [1] 335700 0
Measurements will be taken continuously over 75-90 minutes post insertion of smart tube.
Primary outcome [2] 335707 0
Real-time changes in gut intraluminal pressure after an enteral feed by measuring solid-state pressure by passing a microtip pressure sensor through the lumen of the feeding tube.
Timepoint [2] 335707 0
Continuously over 75-90 minutes post insertion of smart tube.
Secondary outcome [1] 425241 0
Effect of change in feeding tube position on pressure measurements
Timepoint [1] 425241 0
Measured for 5 minutes within 75-90 minutes of the study duration
Secondary outcome [2] 425242 0
Effect of body movement on pressure measurements
Timepoint [2] 425242 0
Measured for 5 minutes within 75-90 minutes of the study duration
Secondary outcome [3] 425243 0
Gastric electrophysiology using a body surface gastric mapping electrode array placed on abdomen
Timepoint [3] 425243 0
Continuously over 75-90 minutes post insertion of smart tube
Secondary outcome [4] 425244 0
Heart rate measurements using a three-lead ECG applied to participants chest and abdomen.
Timepoint [4] 425244 0
Continuously over 75-90 minutes post insertion of smart tube
Secondary outcome [5] 425876 0
Respiratory rate measurements using a three-lead ECG applied to participants chest and abdomen
Timepoint [5] 425876 0
Continuously over 75-90 minutes post insertion of smart tube
Secondary outcome [6] 425877 0
Bowel sounds using two digital stethoscopes placed on each side of the median plane
Timepoint [6] 425877 0
Continuously over 75-90 minutes post insertion of smart tube

Eligibility
Key inclusion criteria
1. Adults
2. Health volunteers
3. Provide informed consent
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. Individuals with functional gastric disorders (diabetic/ idiopathic and post-surgical gastroparesis, chronic motility disorders)
2. Pregnant or postpartum


Study design
Purpose of the study
Prevention
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
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
10 healthy volunteers will be recruited.
This is a pilot study to validate the performance of an innovative medical technology. Hence, a sample size power calculation was not done.

Other planned statistical analyses include
1. Comparison of pressure measurements obtained from two methods: back-propagated pressure and direct solid-state pressure measurements.
2. Determine the effect of feeding on pressure, electrophysiology, and bowel sounds.
3. Determine the effect of catheter position, body position, coughing and raised abdominal pressure on the intraluminal pressure measurements, electrophysiology, and bowel sounds.
4. Analysing the pressure trace to optimise the pressure signal analysis, particularly to filter out the effects of feeding, body movement, cardiac and respiratory rate/movement.

Recruitment
Recruitment status
Not yet recruiting
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] 25698 0
New Zealand
State/province [1] 25698 0
Auckland

Funding & Sponsors
Funding source category [1] 314538 0
Other
Name [1] 314538 0
Health Research Council of New Zealand
Country [1] 314538 0
New Zealand
Funding source category [2] 314543 0
Other
Name [2] 314543 0
Ministry of Business, Innovation and Employment
Country [2] 314543 0
New Zealand
Primary sponsor type
University
Name
The University of Auckland
Address
9 Symonds Street Level 1 Student Commons, Auckland 1010
Country
New Zealand
Secondary sponsor category [1] 316499 0
None
Name [1] 316499 0
Address [1] 316499 0
Country [1] 316499 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 313580 0
Health and Disability Ethics Committees
Ethics committee address [1] 313580 0
Ministry of Health, Health and Disability Ethics Committees, PO Box 5013 Wellington 6140
Ethics committee country [1] 313580 0
New Zealand
Date submitted for ethics approval [1] 313580 0
15/09/2023
Approval date [1] 313580 0
Ethics approval number [1] 313580 0

Summary
Brief summary
Current enteral feeding tube systems deliver nutritional fluids through simple catheters connected to infusion pumps which deliver the fluid at a prescribed flow rate. Gastrointestinal dysfunction after an enteral feed results in the feeding regimen to be stopped till the feeding intolerance symptoms subside. This could result in patients getting suboptimal nutrition. We have developed a custom-engineered enteral feeding tube that uses biofeedback to measure elevated gut pressure as an early indicator of feeding associated intolerance.

This study will provide real-time data on changes in gut pressure in healthy volunteers given an enteral feed. Two types of pressure measurements will be taken - back-propagated measure and solid-state pressure, which will assess the validity our hypothesis on gut pressure being a good indicator of early onset of feeding associated gastrointestinal dysfunction. Additionally, the mechanistic understandings of the gastric movements and during an enteral feed in healthy individuals will help us further enhance the design of the prototype for use in acute and critically ill patients.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 128626 0
Prof John Windsor
Address 128626 0
Surgical and Translational Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, 22-30 Park Road, Grafton, Auckland 1023
Country 128626 0
New Zealand
Phone 128626 0
+64 09 923 9791
Fax 128626 0
Email 128626 0
Contact person for public queries
Name 128627 0
Dr Sakina Bharmal
Address 128627 0
Surgical and Translational Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, 22-30 Park Road, Grafton, Auckland 1023
Country 128627 0
New Zealand
Phone 128627 0
+64 09 923 7384
Fax 128627 0
Email 128627 0
Contact person for scientific queries
Name 128628 0
Dr Sakina Bharmal
Address 128628 0
Surgical and Translational Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, 22-30 Park Road, Grafton, Auckland 1023
Country 128628 0
New Zealand
Phone 128628 0
+64 09 923 7384
Fax 128628 0
Email 128628 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Participant identifying information will be de-identified and made anonymous, and pooled together before analyses. Hence IPD will not be available.


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
19982Study protocol    386392-(Uploaded-23-08-2023-12-45-32)-Study-related document.pdf
19983Informed consent form    386392-(Uploaded-23-08-2023-12-49-09)-Study-related document.pdf



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.