Failed Epidural Anesthesia During Labor: Evaluation of Risk Factors and Outcome

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