Ropivacaine 0.75% Versus Levobupivacaine 0.5% for Conversion of Labour Epidural (RoLe)
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.
Drug: 0.5% levobupivacaine
Drug: 0.75% Ropivacaine
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Ropivacaine 0.75% Versus Levobupivacaine 0.5% for Conversion of Labour Epidural to Surgical Anaesthesia for Emergency Caesarean Section.|
- Supplementation Rate [ Time Frame: During operation (approximately 1 hour ) ] [ Designated as safety issue: No ]The number of times the epidural anaesthetic requires intra-operative supplementation with more study solution or another drug for pain.
- Pre-operative supplementation [ Time Frame: 10-45mins (top-up to start of surgery) ] [ Designated as safety issue: No ]If further 5mls of study solution is required to achieve block height suitable for surgery to start.
- Pain [ Time Frame: During operation (approximately 1 hour) ] [ Designated as safety issue: No ]Incidence of breakthrough pain and its intensity during the operative phase of the Caesarean section
- Conversion Rate [ Time Frame: At any point between epidural top-up and end of operation (approximately 90mins from epidural top-up) ] [ Designated as safety issue: No ]If the epidural anaesthetic needs to be converted to spinal anaesthetic or general anaesthetic as it is not adequate for conduction of a Caesarean section
- Side effects [ Time Frame: At any point between top-up of epidural and end of operation (approximately 90mins from epidural top-up) ] [ Designated as safety issue: No ]Occurrence of any of nausea, vomiting, itching and shivering during the specified time period
- Blood pressure supplementation rate [ Time Frame: At any point from top-up of epidural to end of operation (approximately 90mins from epidural top-up) ] [ Designated as safety issue: No ]Use of the vasopressor phenylephrine and Hartmannn's solution to be given if mean arterial BP drops greater than 30% below baseline or systolic BP of <100mg Hg.
- Patient Satisfaction [ Time Frame: Prior to leaving operating theatre (approximatelty 120 minutes from epidural top-up) ] [ Designated as safety issue: No ]Maternal satisfaction, asked to verbally score from 1-10 their satisfaction with the anaesthetic.
- Motor block [ Time Frame: prior to top-up and prior to leaving theatre (approximatelty 120 minutes from epidural top-up). ] [ Designated as safety issue: No ]Scored using the Bromage scoring system asking patient to raise legs and noting how able they are to do this.
- Fetal Wellbeing [ Time Frame: After delivery (approximately 5-10 minutes from start of surgery) ] [ Designated as safety issue: No ]Neonatal Apgar scores at 1 and 5 minutes after delivery. pH of umbilical blood following delivery
- Onset Time [ Time Frame: From administration of epidural top-up (approximately 10-45 minutes) ]The time elapsed between administration of the top-up and onset of anaesthesia suitable for surgery to proceed. Defined as a loss of sensation to cold to T4 dermatomal level.
|Study Start Date:||August 2012|
|Estimated Study Completion Date:||August 2014|
|Estimated Primary Completion Date:||August 2013 (Final data collection date for primary outcome measure)|
Active Comparator: 0.5% levobupivacaine
Participants given 15mls of 0.5% levobupivacaine as the solution for their epidural top-up
Drug: 0.5% levobupivacaine
15mls of a 5mg/ml solution of the local anaesthetic levobupivacaine given via the epidural catheter.
Other Name: 0.5% Chirocaine
Active Comparator: 0.75% Rpoivacaine
Participants given 15mls of 0.75% ropivacaine as the solution for their epidural top-up.
Drug: 0.75% Ropivacaine
15mls of a 7.5mg/ml solution of the local anaesthetic ropivacaine given via the epidural catheter.
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.
|St Thomas' Hospital|
|London, United Kingdom, SE1 7EH|
|Study Director:||geraldine e o'sullivan, MBBCh||Guy's and St Thomas' NHS Foundation Trust|