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Trial registered on ANZCTR


Registration number
ACTRN12625000087459p
Ethics application status
Submitted, not yet approved
Date submitted
10/01/2025
Date registered
28/01/2025
Date last updated
28/01/2025
Date data sharing statement initially provided
28/01/2025
Type of registration
Prospectively registered

Titles & IDs
Public title
Does intra-operative humidification with warmed CO2 reduce the time to return of bowel function? A multi-centre randomized control trial in patients undergoing elective and emergency open colorectal resection
Scientific title
Does intra-operative humidification with warmed CO2 reduce the time to return of bowel function? A multi-centre randomized control trial in patients undergoing elective and emergency open colorectal resection
Secondary ID [1] 313665 0
Nil known
Universal Trial Number (UTN)
U1111-1317-5230
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Open Colorectal Surgery 336237 0
Bowel function 336238 0
Condition category
Condition code
Surgery 332772 332772 0 0
Other surgery

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
HumiGard system.

The investigational device to be used will be the Fisher and Paykel HumiGard Surgical Humidification System. The HumiGard system is a heat delivery system that allows insufflation of warm humidified CO2 into the open wound cavity for the entire duration of the procedure, ranging from 2 to 4 hours. Dry medical CO2 is delivered at a flow rate of 10 litres per minute and a pressure of 4.5 bar from a medical pressurized gas cylinder via a 6.35 mm PVC tube to an open surgery humidification system. It consists of a bacterial filter, and a humidification chamber filled with 180 ml sterile water, positioned on a humidifier controller that includes an integrated temperature and flow sensor The outlet of the humidification chamber is connected to a thermally insulated 2.5 m long heated insufflation tube that maintains temperature and humidity of the gas to its outlet. The humidified and warm CO2 enters a gas diffuser (VITAdiffuser, Cardia Innovation AB, Stockholm, Sweden) consisting of a 25 cm long PVC tube (inner diameter of 2.5mm) with polyurethane foam at its end. The cylindrical polyurethane foam tip diverts the gas jet into multiple directions via the many small paths inside the foam. The gas is thus uniformly distributed and the large diffuser surface area greatly reduces the velocity of the outflow.

The Fisher and Paykel Healthcare Ltd HumiGard system will be set up as per user instructions in the theatre by the investigators. The device will be operated by the circulating nurse and the sterile portion placed in the wound by the consulting surgeon. The intervention will be closely assessed and monitored for adherence during the procedure will clear documentation on medical records. The anaesthetist will be made aware of the CO2 and may need to change ventilation to compensate for CO2 absorption.

The study-related risk is considered to be extremely low, since the application of CO2 insufflation in open surgery is approved on the Australian Therapeutic Goods Register, and Medsafe WAND notified, and is used in clinical settings routinely outside the study.
Intervention code [1] 330263 0
Treatment: Devices
Comparator / control treatment
The comparator/control treatment group will not receive the HumiGard system intervention during their open colorectal surgery procedure (i.e. no additional treatment)
Control group
Active

Outcomes
Primary outcome [1] 340301 0
Return of bowel function, assessed using clinical criteria such as the passage of flatus or stool using Bristol Stool Chart and tolerance of oral intake.
Timepoint [1] 340301 0
Assessment of bowel function at 24, 48, and 72 (primary timepoint) hours post-operatively
Secondary outcome [1] 443645 0
Length of hospital stay, time (in days) from surgery to discharge from hospital; to be assessed using data-linkage to medical records (composite).
Timepoint [1] 443645 0
Time (in days) from original laparotomy operation to discharge as documented by the medical team, noted at the time of discharge.
Secondary outcome [2] 443646 0
Return to theatre for any post-operative complications, not limited to issues related to bowel function (such as post-operative ileus, anastomotic leak)
Timepoint [2] 443646 0
Time (in days) from original laparotomy operation to the date of return to theatre for further intervention; to be assessed using data-linkage to medical records, noted at the time of event.
Secondary outcome [3] 443647 0
Incidence of post-operative nausea and vomiting (PONV), which can impact the time to return of bowel function.
Timepoint [3] 443647 0
Daily assessment until discharge from the hospital.
Secondary outcome [4] 443648 0
Use of oral Gastrografin follow-through (GGFT) to evaluate bowel motility and anastomotic integrity.
Timepoint [4] 443648 0
Imaging performed if clinically indicated based on patient's recovery progress, typically within 5 to 7 days post-operatively, or as ordered by the treating physician.

Eligibility
Key inclusion criteria
1. Patients undergoing elective or emergency open colorectal resection
2. Able to give informed consent
Minimum age
18 Years
Maximum age
80 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. Pregnancy
2. Terminal organ impairment
3. Patients that have to return to theatre for pathology unrelated to return of bowel function such as revisions or re-look laparotomy washouts.
4. Evidence, preoperatively, of any of the following: sepsis, severe sepsis, or septic shock
5. Contraindication for CO2
6. BMI > 40 as patients with morbid obesity will have higher mortality
7. Current slow transit constipation
8. History of laparotomy within the last 60 days
9. Systemic steroid use or other immunosuppressant medication
10. ASA score greater than or equal to 4

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Separate randomisation will be put in place for the elective and emergency cases to account for selection bias. Given this is a single blinded trial, blinding will occur at the level of the patient. It is not practically feasible to blind surgeons from the intervention. No subjective outcomes are assessed by the surgeon so not being blinded will not introduce any bias. Participants will be blinded to their allocation. It is impossible to blind surgeons to the intervention/device, however post-operative assessment will occur by other investigators who are therefore blinded to the intervention.

Randomisation for the allocated group will occur after consent is obtained and after the patient’s eligibility is confirmed based on the inclusion and exclusion criteria. Patients deemed eligible for the study will have the primary surgeon draw an envelope that simply has ‘Humigard study’ written on it and inside will be a piece of paper that has either ‘control’ or ‘Humigard’. These will be prepared by the primary investigator before commencement of the study.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomised table created by computer software (such as computerised sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
2/03/2025
Actual
Date of last participant enrolment
Anticipated
2/03/2027
Actual
Date of last data collection
Anticipated
2/04/2027
Actual
Sample size
Target
298
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 27457 0
Dandenong Hospital- Monash Health - Dandenong
Recruitment hospital [2] 27458 0
Monash Medical Centre - Clayton campus - Clayton
Recruitment postcode(s) [1] 43569 0
3175 - Dandenong
Recruitment postcode(s) [2] 43570 0
3168 - Clayton
Recruitment outside Australia
Country [1] 26809 0
New Zealand
State/province [1] 26809 0

Funding & Sponsors
Funding source category [1] 318130 0
Commercial sector/Industry
Name [1] 318130 0
Fisher and Paykel Ltd
Country [1] 318130 0
Australia
Primary sponsor type
Individual
Name
Mr Asiri Arachchi, Department of Colorectal Surgery, Monash Health
Address
Country
Australia
Secondary sponsor category [1] 320515 0
Individual
Name [1] 320515 0
Dr Kumail Jaffry, Department of Colorectal Surgery, Monash Health
Address [1] 320515 0
Country [1] 320515 0
Australia
Secondary sponsor category [2] 320517 0
Hospital
Name [2] 320517 0
Dandenong Hospital, Monash Health
Address [2] 320517 0
Country [2] 320517 0
Australia
Secondary sponsor category [3] 320518 0
Hospital
Name [3] 320518 0
Monash Medical Centre, Monash Health
Address [3] 320518 0
Country [3] 320518 0
Australia
Other collaborator category [1] 283349 0
Individual
Name [1] 283349 0
Mr William Teoh, Department of Colorectal Surgery, Monash Health
Address [1] 283349 0
Country [1] 283349 0
Australia
Other collaborator category [2] 283350 0
Hospital
Name [2] 283350 0
Austin Health
Address [2] 283350 0
Country [2] 283350 0
Australia
Other collaborator category [3] 283351 0
Hospital
Name [3] 283351 0
Tauranga Hospital
Address [3] 283351 0
Country [3] 283351 0
New Zealand
Other collaborator category [4] 283377 0
Individual
Name [4] 283377 0
Asiri Arachchi, co-Principal Investigator, Department of Colorectal Surgery, Monash Health
Address [4] 283377 0
Country [4] 283377 0
Australia

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 316778 0
Monash Health Human Research Ethics Committee A
Ethics committee address [1] 316778 0
https://monashhealth.org/research/resources/resource-library/
Ethics committee country [1] 316778 0
Australia
Date submitted for ethics approval [1] 316778 0
10/01/2025
Approval date [1] 316778 0
Ethics approval number [1] 316778 0

Summary
Brief summary
Research Aims
To assess the efficacy of warm humidified carbon dioxide (CO2) insufflation in reducing the time to return of bowel function in patients undergoing open colorectal surgery.

Participants
Adult participants undergoing open colorectal surgery at Dandenong Hospital who meet the inclusion and exclusion criteria.

Methods
Eligible participants will be randomised to receive standard of care or standard of care plus warm humidified carbon dioxide insufflation of the open wound during their scheduled open colorectal procedure. Insufflation will be provided with the HumiGard Surgical Humidification system, up to 10L of carbon dioxide gas will be slowly insufflated into the surgical cavity for the duration of the operation. Participants will be blinded to their allocation.

Expected outcomes
Completing this project will allow us to determine whether warmed and humidified carbon dioxide gas can assist with accelerating the recovery of bowel function postoperatively, potentially leading to shorter hospital stays and improved patient outcomes.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 138986 0
Dr Kumail Jaffry
Address 138986 0
Colorectal Surgery Unit, Dandenong Hospital, 135 David Street, Dandenong VIC 3175
Country 138986 0
Australia
Phone 138986 0
+61455800074
Fax 138986 0
Email 138986 0
[email protected]
Contact person for public queries
Name 138987 0
Dr Asiri Arachchi and Kumail Jaffry
Address 138987 0
Colorectal Surgery Unit, Dandenong Hospital, 135 David Street, Dandenong VIC 3175
Country 138987 0
Australia
Phone 138987 0
+61403902215
Fax 138987 0
Email 138987 0
[email protected]
Contact person for scientific queries
Name 138988 0
Dr Asiri Arachchi and Kumail Jaffry
Address 138988 0
Colorectal Surgery Unit, Dandenong Hospital, 135 David Street, Dandenong VIC 3175
Country 138988 0
Australia
Phone 138988 0
+61 3 9554 1000
Fax 138988 0
Email 138988 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Data will be stored by research investigators, data tabulated into a password protected and encrypted database, and paper form of the diary will then be shredded. This project stores patients, surgical, anaesthetic, and post-operative data in a de-identified format. We will not have de-identified individual participant data available.


What supporting documents are/will be available?

No Supporting Document Provided



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.