Question

A 50-year-old man with chronic pancreatitis has persistent, severe epigastric pain unresponsive to opioids and enzyme replacement therapy. He undergoes a celiac plexus block for pain relief. Shortly after the procedure, he develops dizziness and lightheadedness on standing. Which of the following best explains this finding?

• A. Pregabalin
• B. Celiac ganglion block
• C. Endoscopy
• D. Enzyme therapy (PERT)

Hint:

The most common immediate adverse effect of a Celiac Plexus Block is Orthostatic Hypotension (due to splanchnic vasodilation) and temporary Diarrhea (due to the sudden relative overactivity of the parasympathetic system). Always pre-hydrate these patients!

Answer 1

The Correct Option is B

Concept:
A middle-aged man suffering from severe, intractable pain secondary to chronic pancreatitis undergoes a specialized interventional pain management procedure, specifically a celiac plexus block.
Immediately following the procedure, he rapidly develops severe orthostatic hypotension (manifesting as profound dizziness and lightheadedness upon standing). The clinical task is to identify the direct physiological etiology of this acute adverse effect.
Explanation:
• Chronic pancreatitis is notorious for causing unrelenting, severe, and debilitating epigastric pain, which is often highly refractory to standard oral medical management, including massive doses of opioids and pancreatic enzyme replacement therapy.

• When medical therapy fails, a highly effective interventional strategy is to perform a percutaneous or endoscopic ultrasound-guided Celiac Plexus Block (or neurolysis).

• The celiac plexus is a massive, dense network of autonomic nerves located retroperitoneally, specifically wrapping around the origin of the celiac trunk. It serves as the primary relay center transmitting severe visceral pain signals from the upper abdominal organs, primarily the pancreas, up to the brain.

• Crucially, the celiac plexus is heavily composed of major sympathetic nerve fibers that also control the vasomotor tone of the vast splanchnic (mesenteric) venous bed.

• During a celiac block (Option B), a local anesthetic (like bupivacaine) or a neurolytic agent (like absolute alcohol) is forcefully injected into this plexus.

• This injection successfully blocks the sensory pain fibers, but it simultaneously and unavoidably blocks the sympathetic efferent fibers as well.

• The sudden loss of sympathetic tone causes massive, immediate vasodilation of the entire splanchnic vascular bed.

• This massive vasodilation causes a huge volume of blood to suddenly pool in the abdomen, drastically reducing venous return to the heart. When the patient attempts to stand, they experience a precipitous drop in blood pressure (severe orthostatic hypotension), which perfectly explains the dizziness and lightheadedness.

• Pregabalin (Option A), Endoscopy (Option C), and Pancreatic Enzyme Replacement Therapy (PERT) (Option D) do not cause acute, profound vasodilation and orthostasis immediately following an interventional procedure.
Final Answer:
The celiac ganglion block unavoidably disrupts sympathetic vasomotor tone, causing massive splanchnic vasodilation and subsequent orthostatic hypotension.