Original ArticleIntroduction L abour and delivery results in severe pain for many women. The McGill Pain Questionnaire ranks labour pain in the upper part of the pain scale between cancer pain and amputation of a digit [1]. The goal of maternal labour analgesia is relief of pain without compromising maternal safety, progress of labour and foetal well-being. Epidural analgesia is the most effective and least depressant method of intrapartum pain relief in current practice [2]. Low concentration of bupivacaine combined with fentanyl, results in analgesia with minimal side effects [3]. The aim of the study, was to develop a safe dosing regime to provide satisfactory pain relief with minimal side effects.
Material and MethodsIt was a prospective open label study. We studied 45 primiparous and five second gravida women with singleton foetus in vertex position admitted for parturition in the age group of 18-30 years. Parturients with obstetric complications like pre-eclampsia, preterm labour, previous caesarian, abnormal lie and placenta previa were excluded from the study. Once the parturient is in active phase of labour i.e. cervix is 3-4 cms dilated, anaesthesiologist was called for lumbar epidural block.After explaining the procedure, 500 ml of ringer lactate was infused as preload. Pre-epidural pulse, blood pressure (BP), SpO 2 and pain score (using Visual Analogue Scale-VAS) were checked. Foetal heart rate (FHR) was continuously monitored using cardiotocograph. All the parturient were kept fasting, but clear fluids were allowed till delivery. Epidural space was identified in L2-3 / L3-4 interspinous space using loss of resistance to saline and multiorifice epidural catheter inserted. Initial bolus of 10 ml of drug solution (0.1% bupivacaine and 0.0002% fentanyl) was injected in two aliquots, five ml in left lateral and five ml in right lateral position at an interval of five minutes. Maternal pulse, BP, SpO 2 and FHR were monitored every five minutes for the first 30 minutes. After 30 minutes pain score using VAS and motor blockade using modified Bromage Score (Table 1) was checked. If pain relief was satisfactory (VAS <5) and there were no motor block or evidence of significant hypotension an epidural infusion (with syringe infusion pump) of the same drug solution was started at the rate of 5ml /hour. Patient was assessed at 30 minutes interval for pain relief (objective assessment using VAS on 1-10 scale and subjective assessment by mother as excellent/good/fair/poor), maternal haemodynamics, foetal heart rate, motor block, duration of second stage of labour, incidence of caesarian section, instrumental delivery, side effects, complications (sedation, nausea, vomiting, itching, urinary retention) and total dose of bupivacaine and fentanyl used.
