Failed Epidural Anesthesia During Labor: Evaluation of Risk Factors and Impact on Labor ,Maternal and Fetal Outcomes

Women requesting epidural analgesia will receive a bolus of intravenous infusion of lactated Ringer's solution before initiation of the procedure. An 18-gauge Tuohy needle and closed-tip clear catheter with three lateral orifices (Portex, Smith Medical, Hythe, UK) were used in the sitting or lateral position, with a loss-of-resistance to air technique. Epidural catheters will be inserted 5-6 cm inside the epidural space. A test dose of 2 ml of lidocaine 2% iss initiated followed by a loading dose of 10 ml of bupivacaine 0.25%. Analgesia is established and maintained throughout labor and delivery using 0.125% bupivacaine with fentanyl 2 μg/ml with patient-controlled epidural analgesia by means of a continuous epidural infusion (8 ml/h basal rate) and patient-controlled boluses (3 ml each) with 20-minlock-out intervals, continued at the same bolus dose until delivery.

Pain was evaluated using a 0-10 cm visual analogue scale (VAS) before, 15 and 30 min after the loading dose followed by hourly assessment until delivery. VAS score assessment was based specifically on abdominal or back pain resulting from contractions. Failed epidural is defined as VAS score ≥5, 30 min after a loading dose, given after the last attempt. Women who had a repeated attempt due to VAS ≥5 at 30 min or dural puncture or required repositioning of the catheter, resulting in subsequent pain relief expressed as VAS score <5 were not considered to have a Failed epidural. VAS score is assessed by obstetrician and not the anesthesiologist who performed the block. Furthermore, intrapartum vaginal examinations to assess cervical dilatation and fetal head station were also performed by experienced obstetrician.

As part of the study, the women's satisfaction was assessed the morning following delivery using a 1-5 satisfaction scale, where score 1 corresponded to very unsatisfied and score 5 corresponded to very satisfied. Before satisfaction assessment, all women who agreed to participate signed an informed consent and then relevant data was collected from the participants' medical charts.