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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
The efficacy of low-frequency ultrasonic debridement (LFUD) and Polyhexamethylene Biguanide (PHMB) combination therapy for adults with chronic wounds; a randomised controlled trial
Scientific title
The efficacy of low-frequency ultrasonic debridement (LFUD) and Polyhexamethylene Biguanide (PHMB) combination therapy for adults with chronic wounds; a randomised controlled trial
Secondary ID [1] 292728 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Chronic wounds 304491 0
Condition category
Condition code
Infection 303829 303829 0 0
Studies of infection and infectious agents
Skin 303830 303830 0 0
Other skin conditions

Study type
Description of intervention(s) / exposure
Each participant will receive ultrasonic debridement on their wound weekly for six weeks in a specified specialist wound clinic in the University Health Clinics. The ultrasonic procedure involves the use of a low-frequency ultrasound machine using the Sonoca 185 by Soring. This machine operates at 25kHz and is applied for 20 seconds per 1 cm2 of tissue to attain adequate bacterial kill, at 60-80% intensity, or at 40% and double the time. The use of LMX4 topical anaesthetic cream can be used prior to debridement if required to minimise discomfort.
A wound swab will be taken prior to debridement, post debridement, and, post antiseptic soak (if in the intervention group). A small piece of tissue scraping can be taken during debridement treatment if able, at week 1, 3, 6 & 12 as well as the wound swab culture.
Those in the intervention group will receive the application of antiseptic PHMB post ultrasonic debridement and in a sustained primary dressing. The antiseptic solution Prontosan contains the active ingredient PHMB and is applied as per the manufacturer guidelines for 15 mins in a soaked sterile gauze square. The dressing product that contains PHMB will be left on the wound until next dressing change. Frequency of dressing change will be determined by exudate amount. Those that require dressing changes between weekly clinic visits will require strict adherence to the regime of the Prontosan soak and continual application of the PHMB dressing product, if in the intervention group.
The debridement therapy will be performed by the Chief investigator/Clinician/Registered Nurse or the Podiatrist in the Wound Clinic who has been trained with the ultrasonic device and debridement techniques. The Registered Nurse has up to 3 years experience with this debridement method and 17 years as a Registered Nurse working with chronic wounds.
The participants will be followed weekly for a further six weeks post the six weeks of ultrasonic therapy, with either the antiseptic solution and medicated dressing product with PHMB, or if in the control group, a non-medicated dressing, for a total of 12 weeks.

To assess intervention fidelity, the participant and carer (if applicable) must first understand the importance of adhering to the particular regime and agree to attend weekly clinic visits for 12 weeks. Carers or nurses who will attend to the dressings during the week will be advised and provided with a clear written plan of the dressing trial regime and the importance of adherence. The main clinician in the clinic will ask the participant each week if the correct product was applied and check during the participant's visit. The contact details for the clinician is supplied to the participant, carer and nurses if any queries arise about the trial between clinic visits. Any violation in the protocol will involve cessation of the trial for that participant, When the participant cannot attend a weekly visit due to illness or other event, nine out of 12 visits will be considered acceptable, and will not result in cessation of the trial for that participant. All data will be included, using the intention to treat policy,
Intervention code [1] 298970 0
Treatment: Drugs
Intervention code [2] 298971 0
Treatment: Devices
Comparator / control treatment
The control group will receive the same treatment with the weekly LFUD for six weeks, but will not receive any PHMB antiseptic solution as a soak or cleanser, and will have a non-medicated dressing, similar to the PHMB dressing, but with no antimicrobial action on their wound. i.e., the only difference is the use of the PHMB in the intervention group with the cleanser, soak, and impregnated PHMB foam dressing.
Control group

Primary outcome [1] 303190 0
Bacterial counts measured via colony forming units (CFUs) from swab cultures.

Timepoint [1] 303190 0
CFUs will be assessed at baseline, week 3, 6 & 12.

Primary outcome [2] 303191 0
A change in visual signs of wound biofilm/chronic infection via a newly designed Visual Biofilm Tool.
Timepoint [2] 303191 0
Clinical signs of biofilm will be assessed at baseline, week 6 and at week 12.
Primary outcome [3] 303281 0
Wound biofilm associated with the bacterial burden measured via molecular techniques: polymicrobial numbers from DNA sequencing from swab cultures and tissue samples.
Timepoint [3] 303281 0
At baseline, 6 weeks and 12 weeks.
Secondary outcome [1] 338188 0
Percentage of wounds healed at end of the study via the PUSH Tool (Pressure Ulcer Scale for Healing).
Timepoint [1] 338188 0
This will be measured at the end of the 12 week study period, and will include the use of a blind assessor who will use the PUSH Tool via photos of: the wound, exudate from old dressings and the Visitrak tracing grid,
Secondary outcome [2] 338189 0
Rate of wound healing measured via the PUSH Tool and Visitrak tracing device.
Timepoint [2] 338189 0
This will be measured at the timepoints week 1, 4, 8 & 12 and will include the use of a blind assessor who will use the PUSH Tool via photos of: the wound, exudate from old dressings and the Visitrak tracing grid,
Secondary outcome [3] 338190 0
Pain levels will be assessed and measured via the Numerical Rating Scale (NRS).
Timepoint [3] 338190 0
These pain levels will be measured at each weekly visit, prior to treatment, during and post treatment, written by the participant.
Secondary outcome [4] 338191 0
Quality of Life (QOL) will be measured via the Wound QoL questionnaire on Health related Quality of Life in Chronic Wounds.
Timepoint [4] 338191 0
QOL will be measured at baseline and at the end of the 12 week study, or upon wound healing. If the wound heals prior to the 12 week mark, the trial will end for that participant, and the QOL tool will be measured.
Secondary outcome [5] 338566 0
Adverse reactions will be monitored via clinical observations of: increased pain by 2-3 levels using the Numerical Rating Scale (NRS); increased wound size by 20% or > in the small group, or 10% 0r > in the large group, using the Visitrak tracing device at weekly intervals; any reaction to the PHMB product such as skin rash at site of application or stinging/discomfort on application; periwound area breakdown such as skin maceration.

Timepoint [5] 338566 0
Adverse reactions to be measured at weekly intervals, at each clinic visit.

Key inclusion criteria
Adults 18 years plus
Chronic wound for more than 6 weeks
Wound suitable for debridement therapy
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Cognitive deficit
Malignant wound or systemic condition
spreading infection in the wound
autoimmune disease
Type 1 diabetes
sensitivity to PHMB
cartilage exposed in the wound
wound size < 2 cm 2 , or > 100 cm 2

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
sealed opaque envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Stratified block randomisation. Strata are large and small wounds. Blocks of six will be used for randomisation to the two groups.
Small wound group are any wounds that measure below 10cm 2. The large wound group are wounds that measure above 10cm 2. Those that measure exactly 10cm2 will be included into the small group.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
Intervention assignment
Other design features
A blinded outcome assessor will assess the rate of wound healing and percentage of wounds healed via photographs of the wounds and the tracing grid, at week 1, 4, 8 & 12.
Phase 3
Type of endpoint(s)
Statistical methods / analysis
Sample size calculation was based on estimated 20% difference in healing rate in the treatment/intervention group compared to the control group. The results of a small case study prior to this trial were combined with anecdotal evidence with the combination therapy and the results of a published trial (2012) were all examined. It was determined that in order to achieve 90% power with an alpha of 5% 23 participants will be required for each group. Allowing for drop outs a total of 50 participants is anticipated to be enrolled into the study, This number was also based on current clinic patient numbers and days of operation in the clinic.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 17094 0
4556 - Sippy Downs

Funding & Sponsors
Funding source category [1] 297366 0
Name [1] 297366 0
University of the Sunshine Coast
Address [1] 297366 0
University of the Sunshine Coast
Locked Bag 4
Maroochydore DC 4558
Country [1] 297366 0
Primary sponsor type
Marianne Wallis
School of Nursing, Midwifery and Paramedicine
University of the Sunshine Coast
Locked Bag 4
Maroochydore DC 4558
Secondary sponsor category [1] 296343 0
Name [1] 296343 0
Address [1] 296343 0
Country [1] 296343 0

Ethics approval
Ethics application status
Ethics committee name [1] 298468 0
UnitingCare Queensland Human Research Ethics Committee
Ethics committee address [1] 298468 0
Level 5, 192 Ann St
Brisbane QLD 4001
Ethics committee country [1] 298468 0
Date submitted for ethics approval [1] 298468 0
Approval date [1] 298468 0
Ethics approval number [1] 298468 0

Brief summary
The aim of this research is to determine the effectiveness of one dressing product over another on bacterial levels/counts and wound healing outcomes in a controlled clinical trial that includes the use of ultrasonic debridement therapy for adults with chronic wounds.

Chronic wounds place an enormous burden on the individual and the health care system. it is well known that individuals with non-healing wounds suffer from a reduced quality of life, experience pain, anxiety, report a financial strain, and attend frequent medical appointments. They often require antibiotics and have an increased risk of infection and further complications. There are a wide variety of dressing products available these days, all of which aim to assist the healing process. One way to assess the effectiveness of one product over another is within a clinical trial. This type of investigation can provide information to help the researcher determine how wound products perform at a cellular level.

This clinical trial will involve participants being randomly assigned to receive one of two different regimes to find out which one works best. Each participant will receive ultrasonic therapy weekly for six weeks, after that a particular dressing product will continue for a further six weeks, totaling 12 weeks or upon healing. It is hypothesised that the application of ultrasound therapy will assist with reducing the bacterial burden that is common in chronic wounds and furthermore the application of dressing products with antiseptics in combination with the ultrasound are thought to further assist with preventing bacterial burden reformation and promote wound healing. This study aims to assess this hypothesis.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 77178 0
Prof Marianne Wallis
Address 77178 0
School of Nursing, Midwifery and Paramedicine
Locked Bag 4
University of the Sunshine Coast
Sippy Downs, 4556
Country 77178 0
Phone 77178 0
+ 61 427 633 708
Fax 77178 0
Email 77178 0
Contact person for public queries
Name 77179 0
Mrs Alison Vallejo
Address 77179 0
Wound Solutions Clinic
9 Ochre Way
Sippy Downs,
QLD 4558
Country 77179 0
Phone 77179 0
+61 413 054 870
Fax 77179 0
+ 61 7 54 501 882
Email 77179 0
Contact person for scientific queries
Name 77180 0
Prof Marianne Wallis
Address 77180 0
School of Nursing, Midwifery and Paramedicine
Locked Bag 4
University of the Sunshine Coast
Sippy Downs, 4556
Country 77180 0
Phone 77180 0
+ 61 427 633 708
Fax 77180 0
Email 77180 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Individual data will not be publicly available due to specifications of the human research ethics committee approvals. On reasonable request an amendment will be sponsored by the authors.
What supporting documents are/will be available?
Study protocol
Informed consent form
Ethical approval
'Other' documents specified
The new updated Screening Tool has been added, following the amendment to the exclusion criteria.
How or where can supporting documents be obtained?
Type [1] 3493 0
Study protocol
Citation [1] 3493 0
Link [1] 3493 0
Email [1] 3493 0
Other [1] 3493 0
The study protocol is currently being submitted to a journal for publication and will not be available to share until this has been completed. Once published a link will be made available.
Attachment [1] 3493 0
Type [2] 3494 0
Informed consent form
Citation [2] 3494 0
Link [2] 3494 0
Email [2] 3494 0
Other [2] 3494 0
The Participant Information Pack has been uploaded with the informed consent form attached.
Type [3] 3495 0
Ethical approval
Citation [3] 3495 0
Link [3] 3495 0
Email [3] 3495 0
Other [3] 3495 0
A variation approval letter has been uploaded from the Uniting Care HREC.

The approval for the change in the eligibility criteria in relation to the Type 2 diabetes was received via email.
Attachment [3] 3495 0
Type [4] 3496 0
Citation [4] 3496 0
Link [4] 3496 0
Email [4] 3496 0
Other [4] 3496 0
The new updated Screening Tool has been added.
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