Experience from lumbar catheters provides a road map
for dosing but does not provide a rationale for the thoracic
test dose design. We suggest that there may be good reasons
for the thoracic epidural test dose to be different from
the lumbar test dose. In the absence of rigorous scientific
evaluation, a divided thoracic test sequence may offer
advantages but should be a starting point for the development
of a standardized method to facilitate recognition of
thoracic epidural catheter misplacement.