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Drip infusion method as a useful indicator for identification of the epidural space.

BACKGROUND
Cervical epidural anesthesia (CEA) is used for pain control and surgical procedures of the head and neck or upper arm areas. However, the failure rate of CEA is reported to be high, is the failure rate being quite higher than other sites, because of the anatomical differences of the cervical spine. We hypothesized that the loss of resistance (LOR) method combined with the drip infusion method for confirmation of the cervical epidural space can reduce the failure rate. This study investigated the usefulness of the drip infusion method.


METHODS
One hundred chronic renal failure patients undergoing arteriovenous bridge graft for hemodialysis at the upper arm under cervical epidural anesthesia were recruited for this study. In the cervical epidural puncture, we identified the cervical epidural space using a combination of the LOR method with the drip infusion method. After confirmation of the epidural space with LOR method, we decided it was the true epidural space when fluid dripping to the space was present. Otherwise, if fluid dripping was not present, we designated it was pseudo LOR, and we found the true epidural space using the drip infusion method only.


RESULTS
In all cases, the combined LOR with drip infusion method, identify the epidural space.


CONCLUSIONS
Combined LOR with drip infusion method is an efficacious method for the confirmation of the cervical epidural space.