OAA Large Project Grant
A comparison of intrathecal hyperbaric prilocaine vs bupivacaine for regional anaesthesia indicated for cervical cerclage in pregnancy. A randomised, controlled, trial (PRILOCC Trial)
Dr David Thomas Monks
Background
Very early birth or loss of pregnancies may be due to the inability of the neck of the womb (cervix) to retain the foetus. Cervical cerclage is used to prevent early loss or delivery of a pregnancy by tying a stitch around the neck of the womb.
This procedure is performed with either an injection to make the lower half of the body weak and numb (spinal anaesthetic) or a general anaesthetic (going to sleep for an operation). In order to prevent the need to stay in hospital overnight the anaesthetic should wear off so that they can walk and take themselves to the toilet to pass urine. If unable to feel the sensation to pass urine, the bladder can over distend and cause permanent damage and long term difficulties in passing urine.
The most common technique used is spinal anaesthetic (an injection in the back) but some doctors still prefer to provide general anaesthesia (being put to sleep) on the basis of patient preference and ease with which the patient can be discharged from hospital on the same day. There are however, some concerns about the safety of exposing the developing foetus to general anaesthesia drugs. Conversely, spinal anaesthesia can sometimes produce prolonged (>4 hours) weakness of the legs and a delay in the return of bladder control. This lack of bladder control can lead to the bladder over distending and the need for a catheter to empty the bladder.
Two common choices of drug for spinal anaesthesia are bupivacaine and prilocaine. Prilocaine has been shown to produce a quicker return of muscle power in the legs and bladder control. None of these studies were in pregnant women having cervical cerclage.
Aims
We want to assess whether patients who are undergoing cerclage recover more quickly when using the prilocaine rather than bupivacaine for spinal anaesthesia.
Methodology
This is a randomised controlled trial comparing prilocaine or bupivacaine with regard to the recovery from spinal anaesthesia. We will measure the onset and offset of the numbness and weakness induced by spinal anaesthesia (every 15 minutes) and compare the time taken for complete muscle power and bladder control to return. We will also measure the amount of urine in the bladder (every 60 minutes) so that we can empty the bladder using a tube (catheter) should it become dangerously full. We expect the recovery from prilocaine spinal anaesthesia to be quicker than that for bupivacaine and for there to be fewer incidences of needing to empty the bladder. We will also compare the incidence of well-known side effects from both treatments as well as the satisfaction with the treatment.
Implications
This may result in these patients spending less time in hospital and reduce their chances of needing a tube to empty their bladder, while improving their levels of satisfaction. This may lead more units to use prilocaine for their spinal anaesthesia for cervical cerclage and may discourage the use of general anaesthesia, which is considered by many to be dangerous for the developing foetus.
