Identification of epidural space by drip method.

In 100 pregnant women, identification of the epidural space was performed by a modified drip method. A saline infusion was prepared, leaving the distal 40 cm of infusion tubing full of air, and then attached to the hub of a Tuohy needle. Accurate identification of the epidural space was accomplished in less than one minute in 95% of cases. There were no unintentional dural punctures. This technique has advantages over the hanging drop and the manual loss of resistance techniques.