Determining the epidural space by loss of resistance technique with lidocaine 2% in comparing to normal saline 0.9% and effectiveness on onset of action and outcome of block

Abstract

Background: The epidural space is the space that lies between the spinal meninges and the sides of the vertebral canal. It can be categorized into cervical, thoracic, lumbar and sacral epidural spaces. Identification of the epidural space is of crucial importance as it is technically demanding. Any techniques identifying the epidural space should be simple and straightforward, effective, safe, and reliable to minimize the number of complications associated with it. One of the most reliable methods in identifying the space depends on Loss of Resistance (LOR). This method of identification uses either air or a liquid such as saline or a local anesthetic to achieve it such as lidocaine.Aim of study: This study was designed to assess the onset of single shot epidural anesthesia and reduce the volume of local anesthetic agent to reach the desired dermatome level with less associated side effects.Methods: Fifty patients enrolled in this study was randomly divided in to two groups, twenty five patients received epidural anesthesia after detection of epidural space by using LOR technique with 3ml of normal saline(0.9%NaCl) and the other 25 patients with 3 ml of (lidocaine 2%). The two groups received 12 ml of 2% Lidocaine with Epinephrine (1:200000) every 10 min. the sensory and motor blockade level was recorded with other monitoring parameters including blood pressure.Results: The data showed that the median time to achieving sensory readiness in lidocaine group is (8min) while in normal saline group is about (18 min) with P value ? 0.01which is statistically significant, also the median time for motor blockade was about (10min) in lidocaine group and (25min) in normal saline group with P value 0.008 which is highly significant difference. There was no significant difference in the distribution of maximum sensory level and regression of block in both groups. There was significant difference in the distribution, in which Bromage score was higher in lidocaine group.Conclusion: The use of lidocaine 2% for detection of epidural space by using loss of resistance technique was found to be faster in achieving the desired sensory and motor block in comparison with normal saline 0.9%. There were no significant differences between the two groups concerning the hemodynamic stability and regression of block.