Effect of Dural Puncture Epidural technique on Onset and Duration of Labor Analgesia:A Randomized Control Trial

Background:  Labor pain is regarded as one of the most painful events in the lifetime of women and the intensity of labour pain often exceeds the patient’s expectations. The advantages of combined spinal-epidural (CSE) technique over conventional epidural (CE) is its rapid onset, profound analgesia, high patient satisfaction and verification of epidural space by the definitive return of cerebrospinal fluid, causing a reduction in epidural catheter failures. However, the CSE technique has the potential of causing hemodynamic instability and foetal bradycardia. To reduce these side effects, dural puncture epidural (DPE) technique in which a dural hole is created without intrathecal administration of drugs is assessed. Primary Objective: Comparison of onset and duration of analgesia of DPE with CE.Secondary objectives: To compare the quality of analgesia, neonatal outcome and side effects.Design of the Study: A prospective randomized controlled double-blinded study.Sample size:  We intend to conduct a pilot study with 10 patients in each group anticipating statistically significant results.

Materials and Methods****Inclusion Criteria:   ASA 1 AND 2 patients in active labour requesting analgesia will be included in this study. **Exclusion criteria:**Hypersensitivity to study drugs, bleeding disorders, decreased platelet counts, local or systemic sepsis, hypertensive disorders, pre-existing cardiac diseases, a history of drug abuse and parturient refusal. Parturient with uncomplicated pregnancy in active labour will be recruited after taking informed written consent. After attaching monitors (ECG, non-invasive blood pressure, saturation probe) and securing intravenous access, baseline VAS score and vitals will be noted. All patients will be preloaded with 500ml of ringer lactate. All procedures will be performed by the same consultant anaesthetist. Post-procedural observations will be made by an anaesthetist who will be unaware of the technique followed. Patients will be randomly assigned to two groups, using a computer-generated random sequence of numbers.  Group CEpatients will receive conventional labour epidural using Portex epidural (Smiths Medical, Czech Republic ) and Group DPE patients will receive dural puncture epidural using Portex CSE kit with pencil point spinal 27G Whitacre needle(Smiths Medical, USA). Epidural catheter will be placed in the left lateral position either in L3-4/L4-5 space using the loss of resistance technique and catheter will be threaded cephalad 5cm into the epidural space. After negative aspiration of blood and CSF, a 20 ml dose of the study medication (20ml of 0.1% ropivacaine with 30mcg of fentanyl) will be administered in small aliquots. An additional 10 ml of study drug will be administered in case adequate analgesia (VAS ≤3) is not achieved even after 15 min. If analgesia is inadequate after 15 min of additional dose, epidural will be considered as a failure and catheter will be recited /reinserted/rescue analgesia will be provided and the patient will be withdrawn from the study. VAS score, motor blockade, heart rate and mean blood pressure will be recorded at 5 min interval up to 15 minutes and thereafter every 30 min till delivery. Foetal heart rate will be continuously monitored using a cardiotocograph. Same dose regimen will be followed as subsequent top-up dose on patient demand for pain relief.  A minimum gap of 15 min will be kept between two subsequent top-up doses. VAS score will be assessed on a scale of zero (no pain) to ten (the worst imaginable pain)

.Motor block in the lower extremities will be assessed by using a Breen Modified Bromage scale. Grade 1 �’ complete motor block, Grade 2 – able to move feet only, Grade 3 – just able to move knees, Grade 4 –full flexion of knees, Grade 5 – No detectable weakness of hip flexion while supine, Grade 6 – Able to perform partial knee bend. The onset of analgesia will be defined as duration from injection of first initial epidural bolus dose to the attainment of VAS ≤3 and duration of analgesia will be defined as the time of administration of the first bolus to demand of top up for the first time. Mode of delivery- normal/instrumental delivery/caesarean delivery will be noted. Injection delivery interval will be noted as the time from first initial epidural dose until the delivery. Neonatal outcome will be assessed using Apgar score at 1 and 5 min and fetal ABG. Quality of maternal expulsive efforts will be assessed by an obstetrician and graded as zero to three (Grade 0 = Failure, 1 = Incomplete, 2 = Good, 3 = Excellent). Quality of analgesia will be assessed by asking parturient to grade from zero to three (Grade 0 = Failure, Grade 1 = Incomplete, Grade 2 = Good, Grade 3 = Excellent) after delivery. The occurrence of side effects such as nausea, vomiting, hypotension, hypersensitive reaction, shivering, fever, drowsiness, pruritus, respiratory depression and retention of urine will be noted.

After the collection of data, the results will be analysed statistically.