Comparative Study of the Loading Dose Administrated Via Epidural Needle or Epidural Catheter for Labor Analgesia

Epidural anesthesia (EP) is widely used for labor analgesia. Time to onset of adequate pain relief of EP technique for labor analgesia may be 15 to 20 minutes.More rapid injection is often passible through the needle compared to catheter and could enhance the spread of medication within the epidural space.There is lack of research assessing the onset of labor analgesia with a large priming dose of local anesthetic through the epidural needle compared with the epidural catheter.

The epidural analgesia was performed in the left lateral decubitus position at the L3-L4 or L2-L3 interspace using a 18 G Tuohy needle. The epidural space was accessed by the loss of resistance to air or saline (2ml or less) technique. In the epidural needle group, after identification of epidural space, a dose of 3 ml of 0.1%ropivacaine with 0.3ug/ml sufentanil was given via the epidural needle ,3 minutes later labor analgesia was initiated with 15ml of 0.1 ropivacaine with 0.3ug/ml sufentanil over 30 seconds via the epidural needle, and then the catheter was inserted 3-5cm into the epidural space. In the epidural catheter group, the catheter was inserted 3-5cm into the epidural space after identification of epidural space, a dose of 3 ml of 0.1% ropivacaine with 0.3ug/ml sufentanil was given via the epidural catheter, 3minutes later labor analgesia was initiated with 15ml of 0.1%ropivacaine with 0.3ug/ml sufentanil as the same of group N.