Cervical Epidural Waveform Analysis Using Pressure Monitoring Kit

Reliability of Epidural Waveform Analysis for Cervical Epidural Blocks

The purpose of this study is to analyze the reliability of epidural wave form during cerivical epidural injection.

The epidural space can be confirmed by loss of resistance (LOR) technique. However, LOR has very low specificity, although its sensitivity is high. Especially, cysts between ligaments, clefts in ligamentum flavum, paraspinal muscle and nonspecific spaces between muscles make false LOR.

Epidural wave form analysis (EWA) is very simple and reliable method which can substitue the LOR technique. If the epidural needle is located correctly in the epidural space, the investigators can observe a pulsatile wave and this pulsatile wave corresponds to arterial wave. Generally, sensitivity of EWA through needle is known to be superior to the sensitivity of EWA through catheter and most studies were focused on catheter EWA.

Cervical epidural space shows high false LOR rate and Lee et al demonstrated that false LOR at cervical epidural space was 68.7%. Therefore, nonspecificity of LOR technique require substitution method which can confirm epidural space.

Inclusion Criteria:

• Cerivical Herniated nucleusus
• Cerivical spinal stenosis
• acute herpes zoster

Exclusion Criteria:

• Coagulopathy
• Infectious cervical disease
• Pregnancy