I will chime in: first off, I would not advocate the utilization of an epidural in this scenario. Rather, I would ask the surgeon to remove the source of the inflammation, i.e., the GB itself. Second, inflammation of viscera, the GB in this case, is what leads to the referred pain. This order of events is relevant and important, as this specific site of inflammation is what actually leads to what is called 'viscero-somatic convergence,' which is what is responsible for the "referred thoracic/shoulder" pain that you are alluding to. Based on this reasoning, one should assume that placing a thoracic epidural that covers the "visceral inflammed fibers" of the GB should alleviate any referred thoracic/shoulder pain. We know this to be factual, since when the surgeon actually removes the GB, these people never re-experience their referred pain. By placing your thoracic epidural, you would be "pharmacologically" removing the GB, or atleast the signals from this inflammed site that lead to the referred pain. In my practice, I have gotten consults to place short term epidurals (no more than four days) before an inflammed viscera can be surgically excised (mainly due to surgeon scheduling and patient optimization reasons....). Once placed, these people never had any referred pain after epidural placement. Keep in mind that if there is visceral hyperalgesia due to a chronic inflammatory state, then the referred pain may not be alleviated, as at this stage the culprit behind the referred pain is increased central sensitization. This is an important piece of information that must be obtained from the H&P and documented in the consult note: if the inflammaiton is chronic (IBS patients, for example), then any and all referred pain may be due to central sensitization and, even after surgery and removal of the "inflammed visceral fibers," these patients can still very much have referred pain.... Linked, for your review pleasure, is a review of the sensory pathways.
Regards