Clinical trial NCT01160965: Ropivacaine 0.75% Versus Levobupivacaine 0.5% for Conversion of Labour Epidural
Official title: Ropivacaine 0.75% Versus Levobupivacaine 0.5% for Conversion of Labour Epidural to Surgical Anaesthesia for Emergency Caesarean Section.
Study type: INTERVENTIONAL
Overall status: WITHDRAWN
Phase: PHASE4
Conditions: Caesarean Section
Keywords: epidural top-up
emergency Caesarean section
Lead sponsor: Guy's and St Thomas' NHS Foundation Trust
Sponsor class: OTHER
First posted: 2010-07-13
Enrollment: 0
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: The aim of this trial is to compare the local anaesthetic ropivacaine to local anaesthetic levobupivacaine in converting the standard patient controlled labour epidural to provide anaesthesia for an emergency Caesarean section. This is a technique commonly known as an epidural top-up. The investigators set out to disprove the hypothesis that there is no difference between the 2 local anaesthetics in the time of onset and number of times epidural top-up needs supplementing during surgery.

Detailed description: In a randomised controlled trial involving 45 patients the speed of onset of the effects of 20mls of 0.75% ropivacaine was found to be similar to that of 20mls of 0.5% bupivacaine1. However it was also found to be more efficacious at preventing 'breakthrough' pain and therefore had a lower intra-operative supplementation rate. Unfortunately the study was probably not powered adequately to confirm this finding. Bupivacaine has now largely been replaced in the this field by the less cardio-toxic stereoisomer levobupivacaine. A trial comparing 0.75% ropivacaine to 0.5% levobupivacaine and a lignocaine/adrenaline/fentanyl mixture was conducted in Singapore in 20082. It did not show a clinical difference between any of the agents. Whether the population studied is comparable to that in the UK is doubtful and it was not adequately powered to detect a difference in intra-operative supplementation rate. Local experience has shown ropivacaine 0.75% to provide a block with a rapid onset that has little requirement for supplementation intra-operatively. The need to supplement a local anaesthetic block during surgery means that the mother is experiencing a degree of pain that is unacceptable and we view this as a major consideration in choice of local anaesthetic for an epidural top-up. Whilst speed of onset is important, in that it influences the decision to delivery time of the baby, the evaluation of intraoperative supplementation will be a major focus of this trial.

Eligibility criteria: Inclusion Criteria:

Any subject requiring a grade 2 or 3 EmCS on the Hospital Birth Centre, St Thomas' who has:

1. Labour analgesia provided by the standard patient controlled epidural (solution containing 0.1% levobupivacaine and 2mcg/ml fentanyl). That is providing analgesia via the patient controlled epidural analgesia infusion pump without the need for multiple extra boluses of epidural local anaesthetic and or opiates from the anaesthetist on the labour ward..
2. Singleton pregnancy.
3. Established labour, determined by the midwife responsible for the patient (usually by vaginal examination of the cervix).
4. Gestation \>36 weeks
5. No complex past medical history according to the judgement of the investigator
6. \> 18 years of age
7. EmCS starts between the hours 0800 and 1800.
8. The ability to understand the patient information sheet and willing to provide informed consent.
9. Had a minimal total dose of 50mcg of fentanyl since insertion of epidural

Exclusion Criteria:

1. Pre-eclampsia / Eclampsia
2. Antepartum haemorrhage
3. Any congenital, structural or ischaemic heart disease.
4. Category 1 EmCS.
5. Participation in another therapeutic study in the last 12 weeks. -

Primary outcomes:
measure: Supplementation Rate
timeFrame: During operation (approximately 1 hour )
Secondary outcomes:
measure: Pre-operative supplementation
timeFrame: 10-45mins (top-up to start of surgery)
measure: Pain
timeFrame: During operation (approximately 1 hour)
measure: Conversion Rate
timeFrame: At any point between epidural top-up and end of operation (approximately 90mins from epidural top-up)
measure: Side effects
timeFrame: At any point between top-up of epidural and end of operation (approximately 90mins from epidural top-up)
measure: Blood pressure supplementation rate
timeFrame: At any point from top-up of epidural to end of operation (approximately 90mins from epidural top-up)
measure: Patient Satisfaction
timeFrame: Prior to leaving operating theatre (approximatelty 120 minutes from epidural top-up)
measure: Motor block
timeFrame: prior to top-up and prior to leaving theatre (approximatelty 120 minutes from epidural top-up).
measure: Fetal Wellbeing
timeFrame: After delivery (approximately 5-10 minutes from start of surgery)
measure: Onset Time
timeFrame: From administration of epidural top-up (approximately 10-45 minutes)
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: St Thomas' Hospital
Study officials:
affiliation: Guy's and St Thomas' NHS Foundation Trust
name: geraldine e o'sullivan, MBBCh
role: STUDY_DIRECTOR
References:
citation: Sanders RD, Mallory S, Lucas DN, Chan T, Yeo S, Yentis SM. Extending low-dose epidural analgesia for emergency Caesarean section using ropivacaine 0.75%. Anaesthesia. 2004 Oct;59(10):988-92. doi: 10.1111/j.1365-2044.2004.03753.x.
citation: Sng BL, Pay LL, Sia AT. Comparison of 2% lignocaine with adrenaline and fentanyl, 0.75% ropivacaine and 0.5% levobupivacaine for extension of epidural analgesia for urgent caesarean section after low dose epidural infusion during labour. Anaesth Intensive Care. 2008 Sep;36(5):659-64. doi: 10.1177/0310057X0803600505.