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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Epidural Blood Patch - The Effect of Volume
Scientific title
Epidural Blood Patch - The Effect of Volume on efficacy- a Multi-National, Multi-Centre, Randomised Controlled Trial.
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Post dural puncture headache (PDPH) after inadvertent dural puncture with an epidural needle. 407 0
Condition category
Condition code
Other 478 478 0 0

Study type
Description of intervention(s) / exposure
This multinational, multi-centre, randomised controlled trial is to address the question: "What is the volume of blood for injection at epidural blood patch that most effectively relieves post-dural puncture headache?" The volume of blood empirically recommended for epidural blood patch (EBP) has increased from 2-3 ml at its first description in the 1960s, to 10 ml during 1970-90, to 15-20 ml in the 1990s. Currently, some obstetric anaesthetists advocate the maximum amount tolerated by the patient before back discomfort limits further injection.
The study will randomise pregnant or early postpartum women who have headache secondary to inadvertent dural puncture with an epidural needle to one of three groups, to receive 15 ml, 20 ml or the maximum tolerated volume of blood (maximum 30 ml). The primary endpoint is the partial success rate of EBP, that is, >50% reduction in headache severity after 4 hours or complete relief of headache at 4 hours but return of postural headache subsequently. The secondary endpoint is the complete success rate (that is the complete relief of headache at 4 hours and thereafter, with no recurrence of headache).
Blood patching is the "gold standard" therapy for headache due to low intracranial pressure or following inadvertent or deliberate dural puncture. The significance of this project is that there is no scientific evidence on which to base the choice of volume of injected blood for EBP. Larger volumes of blood are currently favoured, but may be associated with a higher incidence of patient pain during injection (higher epidural and subarachnoid space pressure) and subsequent back soreness. The results would be relevant internationally.
Intervention code [1] 305 0
Treatment: Other
Comparator / control treatment
Control group
Dose comparison

Primary outcome [1] 548 0
Complete or partial relief of headache
Timepoint [1] 548 0
Assessed at 2, 4, 24, 48 & 72 hours and 5 days post epidural blood patch
Secondary outcome [1] 1163 0
The presence of symptoms resulting from the epidural blood patch (e.g. back pain).
Timepoint [1] 1163 0
Assessed at 4, 24, 48 & 72 hours and 5 days post epidural blood patch.
Secondary outcome [2] 1164 0
Functional assessment
Timepoint [2] 1164 0
At 24, 48, 72 hours and 5 days post epidural blood patch (whether headache is interfering with activities).
Secondary outcome [3] 1165 0
Requirement for analgesic medications up to 5 days post epidural blood patch for relief of headache.
Timepoint [3] 1165 0
Secondary outcome [4] 1166 0
Time of discharge from hospital after epidural blood patch.
Timepoint [4] 1166 0

Key inclusion criteria
Obstetric patients.PDPH after a confirmed or likely unintentional dural puncture with an epidural needle. PDPH is defined as "A headache with clear postural characteristics" (onset or significant exacerbation when erect and relieved or significantly diminished by lying flat). The diagnosis is supported by distribution in the frontal or occipital region, with associated neck ache.Medically suitable and consented for epidural blood patch (EBP) for treatment of PDPH.
Minimum age
18 Years
Maximum age
Not stated
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Previous EBP related to the same unintentional dural puncture (including prophylactic EBP).Scheduled EBP to be performed within 24 hours or more than 5 days after the unintentional dural puncture.History of significant low or radicular back pain (requiring treatment) during pregnancy.Women in whom a further dural puncture occurs at the time of epidural needle insertion for the EBP. Diagnosis of headache other than PDPH subsequently confirmed.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Opaque sealed envelopes for allocation
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computer generated randomisation sequence using Scramble Random Numbering System software package.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
To account for the possible impact of early versus late timing of EBP, randomisation will be stratified for EBP performed within 48 hours of dural puncture versus beyond 48 hours. Participants will be assigned to one of 3 groups, to receive sterile autologous blood: 15 ml, 20 ml or maximum tolerated volume (max 30 ml).
Type of endpoint(s)
Statistical methods / analysis

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)

Funding & Sponsors
Funding source category [1] 541 0
Commercial sector/Industry
Name [1] 541 0
Abbott Australasia
Address [1] 541 0
Country [1] 541 0
Funding source category [2] 542 0
Name [2] 542 0
Australian Society of Anaesthetists (ASA) Research Grant
Address [2] 542 0
Country [2] 542 0
Primary sponsor type
Professor Michael Paech, Professor of Obstetric Anaesthesia, School of Medicine and Pharmacology, University of Western Australia
Secondary sponsor category [1] 438 0
Name [1] 438 0
Dorota Doherty, Senior Biostatistician
Address [1] 438 0
Women and Infant's Research Foundation
King Edward Memorial Hospital
Perth WA 6008
Country [1] 438 0

Ethics approval
Ethics application status
Ethics committee name [1] 1539 0
King Edward Memorial Hospital
Ethics committee address [1] 1539 0
374 Bagot Road, Subiaco, Perth, WA, 6008
Ethics committee country [1] 1539 0
Date submitted for ethics approval [1] 1539 0
Approval date [1] 1539 0
Ethics approval number [1] 1539 0
Ethics committee name [2] 1540 0
Ethics committee address [2] 1540 0
Ethics committee country [2] 1540 0
Date submitted for ethics approval [2] 1540 0
Approval date [2] 1540 0
Ethics approval number [2] 1540 0
Ethics committee name [3] 1541 0
Ethics committee address [3] 1541 0
Ethics committee country [3] 1541 0
Date submitted for ethics approval [3] 1541 0
Approval date [3] 1541 0
Ethics approval number [3] 1541 0
Ethics committee name [4] 1542 0
Ethics committee address [4] 1542 0
Ethics committee country [4] 1542 0
Date submitted for ethics approval [4] 1542 0
Approval date [4] 1542 0
Ethics approval number [4] 1542 0
Ethics committee name [5] 1543 0
United States
Ethics committee address [5] 1543 0
Ethics committee country [5] 1543 0
United States of America
Date submitted for ethics approval [5] 1543 0
Approval date [5] 1543 0
Ethics approval number [5] 1543 0
Ethics committee name [6] 1544 0
New Zealand
Ethics committee address [6] 1544 0
Ethics committee country [6] 1544 0
New Zealand
Date submitted for ethics approval [6] 1544 0
Approval date [6] 1544 0
Ethics approval number [6] 1544 0
Ethics committee name [7] 1545 0
New Zealand
Ethics committee address [7] 1545 0
Ethics committee country [7] 1545 0
New Zealand
Date submitted for ethics approval [7] 1545 0
Approval date [7] 1545 0
Ethics approval number [7] 1545 0
Ethics committee name [8] 1546 0
Ethics committee address [8] 1546 0
Ethics committee country [8] 1546 0
Date submitted for ethics approval [8] 1546 0
Approval date [8] 1546 0
Ethics approval number [8] 1546 0
Ethics committee name [9] 1547 0
Saudi Arabia
Ethics committee address [9] 1547 0
Ethics committee country [9] 1547 0
Saudi Arabia
Date submitted for ethics approval [9] 1547 0
Approval date [9] 1547 0
Ethics approval number [9] 1547 0

Brief summary
In this study we wish to work out what volume of blood, injected into the epidural area in an "epidural blood patch" best cures or helps treat headache caused by leak of spinal fluid. This leak occurs because a hole has been made in a membrane containing the spinal fluid, near the epidural space. An epidural blood patch is the only known way of stopping or effectively reducing headache of this type and is used worldwide to treat severe headaches of this type. It can fix the headache completely, but is often only partially effective. Many years ago the volume of blood used in an epidural blood patch was very small. Later the recommended volume was increased to about 15 ml, as this appeared to work better. Subsequently, larger volumes of blood, such as 20 ml, were recommended, while some anaesthetists now claim best results when even more is injected.
There have not been any well controlled studies comparing different volumes of blood for epidural blood patch. Although larger volumes of blood are currently favoured, these may be associated with a higher incidence of mild or moderate low back pain during the injection and subsequent back soreness. A number of maternity units in Australasia and overseas will be involved in this study and the results will be of interest internationally.

What does the study involve?

The epidural blood patch will be performed in the usual way. Patients will be randomised to one of three groups, each group receiving a slightly different volume of blood (15 ml, 20 ml or the maximum volume up to 30 ml that can be injected without causing significant discomfort in the back). It is usually easy to inject 15 or 20 ml without causing significant back discomfort and the volumes chosen are all ones commonly used by maternity units around the world. In addition, to make sure the most accurate results are obtained, neither the patient or the staff asking questions about well-being after the epidural blood patch will know which group the patient was in.

Patients will be asked questions about the severity and characteristics of the headache both before and at regular intervals after the epidural blood patch (at 2, 4, 24, 48, 72 hours and 5 days, by telephone if the patient has left hospital). Patients will also be asked about back discomfort experienced during and after the procedure, and whether they noticed any effects other than relief of the headache.
As is usual practice, patients will be rested flat in bed for 2 hours after the epidural blood patch and then be allowed to get up, according to the usual practice in the hospital. If the patient does not get complete relief of the headache or suffers a return of headache later, they will be able to use a variety of drugs to try and get some relief. Also, if necessary, another blood patch could be performed, once more than 48 hours has passed from the first epidural blood patch.
We will not know whether any particular volume is more effective than another.
With an epidural blood patch, a common effect is mild back discomfort during injection and for a variable time after the blood patch, lasting up to a few days. If the patient experiences significant back pain during the injection, the injection will be stopped according to usual practice, irrespective of whether they have received the amount for their group. Usually back pain during injection is mild and easy to handle. Most women describe back stiffness rather than pain after the epidural blood patch. It has been suggested that injection of the largest volume of blood may be more effective but also cause more back discomfort, but this has not been confirmed by proper study.
There are some very rare serious complications of epidural blood patch, such as infection, severe back pain and blood clots around the brain, but there is no suggestion that taking part in the study is likely to affect the risk of these in any way.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 35148 0
Address 35148 0
Country 35148 0
Phone 35148 0
Fax 35148 0
Email 35148 0
Contact person for public queries
Name 9494 0
Professor Michael Paech or Research Nurses, Desiree Cavill & Tracy Bingham
Address 9494 0
King Edward Memorial Hospital
374 Bagot Road
Subiaco Perth WA 6008
Country 9494 0
Phone 9494 0
+61 8 93402222 Pager 3223 (Mike Paech) or 3433 (Research Nurses)
Fax 9494 0
08 9340 2260
Email 9494 0
Contact person for scientific queries
Name 422 0
Professor Michael Paech
Address 422 0
King Edward Memorial Hospital
374 Bagot Road
Subiaco Perth WA 6008
Country 422 0
Phone 422 0
+61 8 93402222 Pager 3223
Fax 422 0
+61 8 93402260
Email 422 0

No information has been provided regarding IPD availability
Summary results
No Results