A pilot study to compare epidural identification and catheterization using a saline-filled syringe versus a continuous hydrostatic pressure system

We are introducing a new continuous hydrostatic pressure system for identification and catheterization of epidural space in adults. One hundred and eight patients scheduled for elective endoscopic urological procedures were enrolled in this prospective randomized study. They were assigned to perform loss of resistance epidural technique by either the conventional saline-filled syringe (group C) or the new pressure technique (group P). The latter depends on observing passage of free flow of pressurized normal saline (50 mmHg) connected to epidural needle during its advancement, and then the epidural catheter was inserted to "float" easily while saline was flowing. Ten ml of bupivacaine 0.5 % with 50 μg fentanyl were injected. Time to identify epidural space, number of attempts, ease of catheterization, sensory and motor block by Bromage scale after 20 min, quality of anesthesia and any side effects were recorded. Significant reduction was found in group P versus group C concerning time to identify epidural space [20 (6-40) vs. 60.5 (23-75) s with p = 0.001], number of attempts [1 (1-2) vs. 1 (1-4) with p = 0.02] and motor block [1 (0-3) vs. 2 (0-2) with p = 0.02], respectively. No significant difference in epidural catheterization, sensory block, quality of anesthesia and incidence of side effects. We concluded that this new technique is an easy way to identify epidural space using available tools in the operating room.