Although most anesthesiologists agree that a thoracic “test
dose” is important, no evidence-based standard recipe for
this procedure exists.59,60 Prevalent practice has been to
adopt one of the commonly used lumbar regimens.
However, lumbar dosing is guided by experience from spinal
anesthesia, anticipating that a positive test result in a
sitting patient would develop no more than a traditional
“saddle block.” In contrast, thoracic dosing has no equivalent
to spinal anesthesia for guidance