Sodium bicarbonate buffering and needle gauge in percutaneous needle aponeurotomy: A blinded controlled trial evaluating injection pain reduction
| ISRCTN | ISRCTN87104670 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN87104670 |
| Sponsor | Peninsula Health |
| Funder | Investigator initiated and funded |
- Submission date
- 04/11/2025
- Registration date
- 07/12/2025
- Last edited
- 21/11/2025
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Musculoskeletal Diseases
Plain English summary of protocol
Background and study aims
Injecting local anaesthetic into the palm during percutaneous needle aponeurotomy (PNA) for Dupuytren’s disease can be uncomfortable. This study aims to find out whether mixing (buffering) lignocaine with sodium bicarbonate can reduce the pain felt during the injection, and whether the size of the needle used (25G or 27G) affects how painful the injection feels.
Who can participate?
Adults aged 18 years or older with Dupuytren’s disease affecting one hand and who are scheduled to undergo PNA can take part in the study.
What does the study involve?
Participants will receive a local anaesthetic injection in the palm before their PNA procedure. They will be randomly allocated to receive either standard 1% lignocaine or lignocaine that has been mixed with sodium bicarbonate. The injection will be given using either a 25G or a 27G needle. Participants will be asked to rate the level of pain they feel during the needle insertion and during the injection using a simple 0–10 pain scale. The procedure will continue as normal, and no extra visits are required. The study is single-blind, meaning the participant does not know which type of anaesthetic they receive.
What are the possible benefits and risks of participating?
There is no guaranteed direct benefit to taking part, but the information gained may help improve patient comfort during future hand procedures. All anaesthetic solutions used in this study are routinely used in clinical practice, and the risks are minimal. Possible side effects include mild discomfort from the injection, temporary numbness, or rare allergic reactions. Participation does not involve any additional cost or significant added risk beyond standard care.
Where is the study run from?
The study is being carried out at Peninsula Health, Frankston Hospital, in Victoria, Australia.
When is the study starting and how long is it expected to run for?
The study is expected to begin in early 2025 and will run for approximately 6 months, until recruitment and data collection are complete.
Who is funding the study?
Investigator initiated and funded
Who is the main contact?
Dr Ishith Seth
Department of Plastic and Reconstructive Surgery, Peninsula Health
Email: ishithseth1@gmail.com
Contact information
Public, Scientific, Principal investigator
2 Hastings Rd
Melbourne
3199
Australia
 ORCID ID |
0000-0001-5444-8925 |
|---|---|
| Phone | +61 397847777 |
| iseth@phcn.vic.gov.au |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Single-centre interventional single-blind randomized controlled parallel-group trial |
| Secondary study design | Randomised controlled trial |
| Scientific title | A single-centre, single-blind controlled trial evaluating the effect of sodium bicarbonate-buffered versus plain lignocaine and needle gauge on injection pain during percutaneous needle aponeurotomy for Dupuytren’s disease |
| Study acronym | BAPNA |
| Study objectives | The primary objective of this study is to determine whether buffering 1% lignocaine with 8.4% sodium bicarbonate reduces patient-reported injection pain during percutaneous needle aponeurotomy (PNA) for Dupuytren’s disease when compared with plain 1% lignocaine. Secondary objectives are to: 1. Evaluate whether needle gauge (25G versus 27G) influences needle insertion pain during local anaesthetic administration for PNA. 2. Assess whether demographic factors (age and sex) are associated with variation in pain scores during injection. 3. Record the incidence of any immediate adverse events related to the administration of buffered or plain lignocaine. Hypotheses: Primary hypothesis: Buffered 1% lignocaine results in significantly lower patient-reported injection pain scores compared with plain 1% lignocaine during PNA. Secondary hypothesis: Needle gauge (25G versus 27G) does not produce a clinically significant difference in needle insertion pain during PNA. |
| Ethics approval(s) |
Approved 14/10/2025, Peninsula Health HREC (Research Governance Office, 2 Hastings Road, Frankston, Melbourne, 3199, Australia; +61 397847777; iseth@phcn.vic.gov.au), ref: HREC/116536/PH-2025-491800 |
| Health condition(s) or problem(s) studied | Dupuytren’s disease requiring percutaneous needle aponeurotomy in adult patients. |
| Intervention | Participants will be randomly allocated to receive either 1% plain lignocaine or 1% lignocaine buffered with 8.4% sodium bicarbonate (10:1 ratio) for local anaesthetic infiltration during percutaneous needle aponeurotomy. Injections will be administered using either a 25-gauge or 27-gauge needle, with allocation concealed and the injecting surgeon blinded to group assignment. The anaesthetic will be delivered into the subcutaneous plane of the palm at standardised injection sites, with 4 mL infiltrated over approximately 60 seconds for the initial injection. Randomisation was performed using a computer-generated random sequence prepared by a co-investigator not involved in injections or outcome assessment. Allocation was concealed using sealed, opaque, sequentially numbered envelopes, opened only at the time of patient preparation. The injecting surgeon remained blinded to the allocation. |
| Intervention type | Procedure/Surgery |
| Primary outcome measure(s) |
Patient-reported pain during local anaesthetic infiltration measured using a 0–10 Visual Analogue Scale (VAS) at the time of injection |
| Key secondary outcome measure(s) |
1. Pain at needle puncture measured using a 0–10 Visual Analogue Scale (VAS) at the moment of needle insertion |
| Completion date | 30/06/2026 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 100 Years |
| Sex | All |
| Target sample size at registration | 200 |
| Key inclusion criteria | 1. Adults aged 18 years or older 2. Clinical diagnosis of Dupuytren’s disease requiring percutaneous needle aponeurotomy 3. Disease affecting a single hand 4. Able to provide informed consent 5. Able to understand study procedures and complete pain scoring assessments |
| Key exclusion criteria | 1. Known allergy or hypersensitivity to lignocaine or sodium bicarbonate 2. Previous sensory deficit or paraesthesia in the affected hand 3. Local infection at or near the planned injection site 4. Cognitive impairment that may affect the ability to provide informed consent or reliably report pain scores 5. Inability to understand study procedures or complete Visual Analogue Scale (VAS) assessments |
| Date of first enrolment | 21/10/2025 |
| Date of final enrolment | 30/06/2026 |
Locations
Countries of recruitment
- Australia
Study participating centre
Melbourne
3199
Australia
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | The datasets generated and/or analysed during the current study will be available upon reasonable request from the corresponding author, Dr Ishith Seth (ishithseth1@gmail.com). De-identified individual participant data (including pain scores, demographic variables, and adverse event data) will be available beginning 6 months after publication of the study results and for up to 5 years thereafter. Data will be shared with researchers for ethically approved scientific purposes, following submission of a brief proposal outlining the intended use. Only anonymised data will be provided, and no information that could identify individual participants will be shared. |
Editorial Notes
21/11/2025: Trial's existence confirmed by Peninsula Health HREC.
