Utility of an Epidural Pressure Checker in the Administration of Trans-Laminar Epidural Blocks |
Nam Lee1, Sam Sun Park2, Gyu Yeul Ji2, Byeong Woo Kim2, Chang Kyu Lee2, Eui Chul Kim2, Dong Ah Shin2 |
1Department of Neurosurgery, Dong-Eui Medical Center, Busan, Korea 2Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea |
Correspondence:
Dong Ah Shin, Tel: 82-2-2228-2150, Fax: 82-2-393-9979, Email: shindongah@me.com |
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Abstract |
Objective Loss of resistance technique has been performed to identify the epidural space. However, this technique has some disadvantages including frequent lack of midline ligamentum flavum, erroneous subjective sensing, and higher failure rate. The aims of this study were to identify the optimal negative pressure representing the epidural space and to evaluate the efficacy of an epidural pressure checker to detect the epidural space.
Methods Ninety-six patients who received a trans-laminar epidural block in the spine at our institute were enrolled. Half of them received a cervical epidural block (cervical group) and the other half received a lumbar epidural block (lumbar group). Patients were randomly assigned to one of the set pressure groups (-8, -7, -6, -5, -4, -3 mbar). When the needle penetrated the ligamentum flavum, the epidural pressure checker detected negative pressure at the epidural space and alarmed with sound and light if the pressure detected was below the set pressure.
Results In the cervical group, detection rates were 62.5%, 75%, 75% at set pressure values of -8, -7, -6 mbar, respectively, and 87.5% at -5 mbar. In the lumbar group, rates were 50%, 62.5%, 62.5% at set pressure values of -8, -7, -6 mbar, respectively, and 87.5% at -5 mbar. False positives were frequent below a set pressure of -4 mbar.
Conclusion The optimal pressure value to detect the epidural space was -5 mbar. The epidural pressure checker may be a reliable, easy and useful tool to aid in the administration of a trans-laminar epidural block. |
Key Words:
Epidural space; Pressure; Measurement; Epidural block; Epidural anesthesia. |
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