Dural Puncture Epidural for labour analgesia in Indian parturients may need dose alteration for maximal benefits!

Abstract

Dear Editor, Dural puncture epidural (DPE) is a relatively new technique for labour analgesia (LA) performed by creating an intentional dural hole using a spinal needle, followed by insertion of an epidural catheter in the epidural space through which local anaesthetics with or without adjuvants are injected.[1] The dural hole acts as a passage for medications to slowly pass from epidural space into subarachnoid space, which provides improved block quality with fewer maternal and foetal side effects.[2,3] Previously, a bolus of 20 ml of 0.125% bupivacaine was found effective in DPE for LA. At our institute, a randomised controlled trial of DPE in LA comparing 0.125% of ropivacaine and 0.125% levobupivacaine was undertaken by the present authors. In the original protocol, DPE was performed in L2-L3 or L3-L4 interspace with a 16-G Tuohy epidural needle and 26-G Whitacre spinal needle with an initial bolus of epidural 20 ml of 0.125% ropivacaine with 2 μg/ml fentanyl or 20 ml of 0.125% levobupivacaine with 2 μg/ml fentanyl. The drug was fractionated into four 5 ml boluses injected over 5 minutes as previously described.[1] In seven of first ten patients, complications of hypotension, motor blockade, and foetal heart rate variability developed [Table 1]. This prompted us to look for possible overlooked causes. On minute analysis, the height of the parturient was found more than that of the present group.[1] The protocol was modified to a maximal drug injection of 20 ml with the end point specified as a decrease in numerical rating scale (NRS) labour pain to 50% of baseline. Thus, about 4 ml of the drug was injected every 2 minutes till the end point was reached. With the modified protocol, considerably less volume of DPE drug was required (about 12 ml) in the next 20 parturients with no further reported morbidity [Table 2].Table 1: Data of first ten patients of DPE with 20 ml of 0.125% ropivacaine or 20 ml of 0.125% levobupivacaineTable 2: Data of ten patients of DPE with 20 ml of 0.125% ropivacaine or 20 ml of 0.125% levobupivacaine with the modified protocol: Graded epidural of 0.125% local anaesthetics, with a maximum limit of 20 mlEpidural injection for LA is associated with slow onset, inadequate sacral spread, and epidural catheter failure, whereas a combined spinal epidural technique gives rapid onset of blockade but is associated with maternal pruritus, maternal hypotension, and foetal bradycardia.[1] To retain the advantages of both and decrease the disadvantages, DPE for LA has been studied with the most effective results seen with a bolus of 20 ml of 0.125% bupivacaine.[2-4] In all previous studies, the height or body mass index (BMI) was more than that of the present study group[2-4] [Table 3]. After reported morbidity, the present protocol was modified to slower injections of the drug with a ceiling to the injected volume targeted to till 50% reduction in labour NRS rather than a fixed volume as previously reported. This significantly decreased the morbidity.Table 3: Studies comparing DPE to Epidural for LATo conclude, DPE with 0.125% of a local anaesthetic agent for LA in Indian parturients should be given in a graded manner till labour pain NRS reduces by 50% of baseline rather than a bolus of 20 ml. The proposal of a graded local anaesthetic for DPE for LA has never been reported previously. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.