ISRCTN ISRCTN01054711
DOI https://doi.org/10.1186/ISRCTN01054711
Secondary identifying numbers P110504
Submission date
19/08/2014
Registration date
02/09/2014
Last edited
19/02/2020
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Pregnancy and Childbirth
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data

Plain English summary of protocol

Background and study aims
Epidurals can result in serious complications. These include infections of the spine spinal and injury to nerves in the spine. About 1% of patients who have an epidural suffer what is called a post-dural puncture headache, a headache that develops after injection of an epidural. This can be extremely disabling. The risks of injury in very overweight (obese) women are increased due to technical difficulties. Changes to the training structure of the junior anaesthetists giving the injection and also the need for compliance with the European Working Time Directive (resulting in reduced training opportunities) further worsen this situation. Here, we want to find out about the pressure required to reach the epidural space when inserting an epidural needle into pregnant women of varying weights. Correlation will then be made with ultrasound and Magnetic Resonance Imaging (MRI) scans of their lower spine. The plan is to use the results gained to create a computer graphics and physical epidural injection simulator. This simulator will be used by anaesthetists to practice the epidural technique before performing on pregnant women.

Who can participate?
The study aims to recruit pregnant women with body mass indices (BMIs) that fall within four groups: 18-24.9; 25-34.9; 35-44.9 and over 45. The women will be recruited before they go into labour and also in early labour if they have expressed a desire to have an epidural. .

What does the study involve?
BMI will be calculated using height and weight.The women will be grouped accordingly. An ultrasound scan of the lower back will be performed before insertion of the epidural. If the woman then requests an epidural, the pressure applied to the epidural needle will be measured using a specific sensor attached to the needle. As the anaesthetist inserts the epidural, the change in pressures will be recorded wirelessly and the data transmitted to a distant computer. Following the epidural procedure, an MRI scan of the lower spine will be performed within 72hrs of the patient giving birth and these images will be used for computer animation modelling. This will be performed at a convenient time for the mother following delivery of the baby.

What are the possible benefits and risks of participating?
There will be no immediate benefits to those taking part but the data collected will be used to help to train future anaesthetists acquire the skills and knowledge for epidural insertion. The equipment used comes from standard sterile epidural packs and the pressure sensing device uses a three-way tap that also comes from a sterile pack. Due to the addition of this extra piece of equipment there is a theoretical increased risk of infection, although this is extremely small. However, please bear in mind that the risk of infection following an epidural ranges from 1 in 80,000 to 1 in 300,000. Ultrasound and MRI scans are non-invasive, painless procedures and are considered harmless.

Where is the study run from?
The study has been set up by Poole Hospital NHS Foundation Trust, UK. Poole Maternity Unit will be where the practical elements of the research will occur.

When is study starting and how long is it expected to run for?
The recruitment started in September 2012 and lasted for one year.

Who is funding the study?
National Institute of Academic Anaesthesia, UK.

Who is the main contact?
Prof Michael Wee, mike.wee@poole.nhs.uk
Dr Richard Isaacs, richard.isaacs@uhs.nhs.uk

Contact information

Prof Michael Wee
Scientific

Dept of Anaesthesia
Poole Hospital NHS Foundation Trust
Poole
BH15 2JB
United Kingdom

Study information

Study designSingle-centre observational study
Primary study designObservational
Secondary study designCohort study
Study setting(s)Hospital
Study typeTreatment
Participant information sheet The patient information sheet is available upon request
Scientific titleQuantification of the pressures generated during insertion of an epidural needle and subsequent imaging of the epidural space in labouring women of varying body mass indices
Study objectivesThe primary aim is to measure the resultant pressure exerted on an epidural needle as it is advanced through the interspinous ligament and ligamentum flavum of parturients with increasing body mass indices.
Ethics approval(s)NRES Committee South Central - Portsmouth, 13/06/2011, ref: 11/SC/0196
Health condition(s) or problem(s) studiedEpidural anaesthesia
InterventionThis study will only involve women who have requested to have an epidural as part of their birth plan. All of the epidural procedures will be carried out on the labour ward of Poole Maternity Unit by two experienced anaesthetists using standard equipment. To collect the pressure data we will attach a small electronic sensor onto the epidural needle. As the anaesthetist advances the needle through the ligaments, the electronic sensor will pick up the pressure readings and transfer data wirelessly back to a computer or recording device. An ultrasound of the lower spine will also be performed prior to the epidural, followed by a magnetic resonance imaging (MRI) scan of the spine after delivery. This data will also be used to create the epidural simulator based on patient-specific measurements. These measurements and images will lead to the development of a novel epidural simulator to help train novice and experienced anaesthetists with difficult epidurals.
Intervention typeOther
Primary outcome measureThe primary aim is to measure the pressures required to reach the epidural space when inserting an epidural needle into pregnant women of varying body mass indices. Graphical displays of the pressures will then be produced.
Secondary outcome measuresCorrelation will then be made with ultrasound and Magnetic Resonance Imaging (MRI) scans of their lower spine. The aim will be to create a computer graphics and physical epidural injection simulator. This simulator will be used by anaesthetists to practice the epidural technique in a controlled environment.
Overall study start date01/09/2012
Completion date01/09/2013

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
Upper age limit40 Years
SexFemale
Target number of participants20
Total final enrolment20
Key inclusion criteria1. ASA I or II (healthy) women aged 18-40 inclusive
2. Women having first child or any subsequent children (primi and multiparous)
3. Women in early active labour or prior to induction of labour who have requested epidural
analgesia or been advised by the medical team to have an epidural
4. Singleton pregnancies (i.e. not twins etc)
Key exclusion criteria1. Any of the usual contraindications to epidural anaesthesia
2. Known spinal abnormalities
3. Previous back surgery
4. History of connective tissue disorder
5. Difficult epidural insertion requiring more than 3 attempts
6. Women who already have an epidural in-situ and need a re-site for inadequate block
7. Women with inadequate comprehension of the English language and poor communication
skills
Date of first enrolment01/09/2012
Date of final enrolment01/09/2013

Locations

Countries of recruitment

  • England
  • United Kingdom

Study participating centre

Dept of Anaesthesia
Poole
BH15 2JB
United Kingdom

Sponsor information

Poole Hospital NHS Foundation Trust (UK)
Hospital/treatment centre

Longfleet Road
Poole
BH15 2JB
England
United Kingdom

ROR logo "ROR" https://ror.org/03kdm3q80

Funders

Funder type

Research organisation

National Institute of Academic Anaesthesia (UK) (Obstetric Anaesthetists' Association Large Project Grant) July 2012 (ref: WKR0-2012-0035)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan

Study outputs

Output type Details Date created Date added Peer reviewed? Patient-facing?
Results article 01/12/2017 19/02/2020 Yes No

Editorial Notes

19/02/2020: The following changes have been made:
1. Publication reference added.
2. The final enrolment number has been added from the reference.
11/05/2017: No publications found in PubMed, verifying study status with principal investigator