Trial Review

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Trial registered on ANZCTR


Registration number
Help: Registration number
ACTRN12626000138381
Ethics application status
Help: Ethics application status
Approved
Date submitted
Help: Date submitted
19/01/2026
Date registered
Help: Date registered
4/02/2026
Date last updated
Help: Date last updated
2/07/2026
Date data sharing statement initially provided
Help: Data sharing statement date
4/02/2026
Type of registration
Help: Type of registration
Prospectively registered

Titles & IDs
Public title
A comparison of pain levels following injections of hypotonic saline, sterile water or normal saline: A randomised trial
Scientific title
A comparison of pain levels following injections of hypotonic saline, sterile water or normal saline: A randomised trial in healthy adult females aged 18 to 45 years
Additional trial identifiers [1] 316274 0
None
Universal Trial Number (UTN)
Trial acronym
HYPOS trial
Related trial records

Health condition
Health condition(s) studied:
sterile water injections for labour pain management 340308 0
Condition category
Condition code
Reproductive Health and Childbirth 336502 336502 0 0
Childbirth and postnatal care

Intervention/exposure
Study type
Interventional
Description of the intervention or exposure
Intervention group 1: Participants in this group will receive two simultaneous injections of 0.2% sodium chloride solution into the intradermal layer of the skin above the posterior superior iliac spines (PSIS). The injections will done by two registered midwives trained in the procedure. The injections take less than 30 seconds to complete and are given once. The 0.2% sodium chloride solution will be achieved by mixing 0.2mls of 0.9% sodium chloride for injection with 0.8mls of sterile water for injection. The volume injected at each site will be 0.1- 0.3mls depending on the visual assessment of the resulting bleb. Consistency in site selection and procedural continuity will be monitored by the administering investigators.

Intervention group 2: Sterile water. Participants in this group will receive two simultaneous injections of sterile water into the intradermal layer of the skin above the PSIS. The volume injected at each site will be 0.1-0.3 mls.
Intervention code [1] 332917 0
Treatment: Other
Description of the comparator or control
Control group: sodium chloride 0.9% (normal saline). Participants in this group will receive two simultaneous injections of 0.9% sodium chloride solution into the intradermal layer of the skin above the PSIS. The volume injected at each site will be 0.1 -0.3mls.
Control group
Active

Outcomes
Primary outcome [1] 344022 0
Determine the size of the difference between intervention and control groups in the self-reported (visual analogue) injection pain score
Timepoint [1] 344022 0
At time of injections
Secondary outcome [1] 456479 0
Difference in injection pain
Timepoint [1] 456479 0
At 30 seconds post injections
Secondary outcome [2] 456480 0
Difference in injection pain
Timepoint [2] 456480 0
At 1 minute post injection
Secondary outcome [3] 456481 0
Difference in injection pain
Timepoint [3] 456481 0
At 2 minutes post injection
Secondary outcome [4] 456482 0
Difference in injection pain
Timepoint [4] 456482 0
At 5 minutes post injection
Secondary outcome [5] 456483 0
Difference in injection pain
Timepoint [5] 456483 0
At 10 minutes post injection
Secondary outcome [6] 456484 0
Difference in injection pain
Timepoint [6] 456484 0
15 minutes post injection
Secondary outcome [7] 456485 0
Changes in systemic reaction following injections
Timepoint [7] 456485 0
At 1 minute post injections
Secondary outcome [8] 456486 0
Changes in systemic reaction following injections
Timepoint [8] 456486 0
At 10 minutes post injection
Secondary outcome [9] 456487 0
Changes in systemic reaction following injections
Timepoint [9] 456487 0
At 60 minutes post injection

Eligibility
Key inclusion criteria
Student enrolled at the University of Queensland
Substantially healthy (self assessed)
Aged between 18 – 45 years
Female sex (at birth)
Minimum age
18 Years
Maximum age
45 Years
Sex
Females
Healthy volunteers
Yes
Key exclusion criteria
Pregnancy
Chronic or ongoing pain
Use of medication for depression, pain, or sleeping disorder 24?h before the experiment
Smoking, physical activity, and intake of caffeinated beverages (coffee, tea, or energy drink (e.g., Red Bull)) 2 hrs before the experiment.

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)
sealed opaque envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Phase 1
Type of endpoint/s
Pharmacodynamics
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
1/07/2026
Actual
7/05/2026
Date of last participant enrolment
Anticipated
30/06/2027
Actual
22/05/2026
Date of last data collection
Anticipated
30/06/2027
Actual
22/05/2026
Sample size
Target
90
Accrual to date
Final
89
Recruitment in Australia
Recruitment state(s)
QLD

Funding & Sponsors
Funding source category [1] 320871 0
Other
Name [1] 320871 0
NHMRC Investigator grant
Country [1] 320871 0
Australia
Primary sponsor type
University
Name
The University of Queensland
Address
Country
Australia
Secondary sponsor category [1] 323603 0
None
Name [1] 323603 0
Address [1] 323603 0
Country [1] 323603 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 319409 0
The University of Queensland Human Research Ethics Committee A
Ethics committee address [1] 319409 0
Ethics committee country [1] 319409 0
Australia
Date submitted for ethics approval [1] 319409 0
27/01/2026
Approval date [1] 319409 0
14/04/2026
Ethics approval number [1] 319409 0
2025/HE002544

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

Contacts
Principal investigator
Name 147242 0
Dr Nigel Lee
Address 147242 0
School of Nursing, Midwifery and Social Work, Chamberlain Building, University of Queensland, St Lucia, Qld 4072
Country 147242 0
Australia
Phone 147242 0
+61 427231390
Fax 147242 0
Email 147242 0
[email protected]
Contact person for public queries
Name 147243 0
Nigel Lee
Address 147243 0
School of Nursing, Midwifery and Social Work, Chamberlain Building, University of Queensland, St Lucia, Qld 4072
Country 147243 0
Australia
Phone 147243 0
+61 427231390
Fax 147243 0
Email 147243 0
[email protected]
Contact person for scientific queries
Name 147244 0
Nigel Lee
Address 147244 0
School of Nursing, Midwifery and Social Work, Chamberlain Building, University of Queensland, St Lucia, Qld 4072
Country 147244 0
Australia
Phone 147244 0
+61 427231390
Fax 147244 0
Email 147244 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
No
No IPD sharing reason/comment: Individual participant data for some variables may be potentially identifiable. Aggregate data will be made available



What supporting documents are/will be available?

TypeCitationLinkEmailOther DetailsAttachment
Study protocol  [email protected]


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.