## **Core Concept**
Celiac plexus block is a procedure used to manage chronic abdominal pain, particularly for patients with pancreatic cancer or other intra-abdominal malignancies. The celiac plexus, also known as the solar plexus, is a complex network of nerve fibers located in the upper abdomen, involved in transmitting pain signals from the abdominal organs. The block involves injecting a local anesthetic or neurolytic agent into or around the celiac plexus to interrupt pain signals.

## **Why the Correct Answer is Right**
The correct answer, **orthostatic hypotension**, is a common complication due to the blockade of the sympathetic nerves that innervate the abdominal organs. The celiac plexus contains sympathetic fibers that, when blocked, can lead to vasodilation of the splanchnic vessels, reducing peripheral resistance and potentially causing a drop in blood pressure, especially when standing up. This is because the body's ability to compensate for changes in posture through vasoconstriction is impaired.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While diarrhea could potentially occur due to the effects on the autonomic nervous system, it is not the most common complication of celiac plexus block.
- **Option B:** Infection is a risk with any invasive procedure but is not specific or the most common complication related directly to the technique of celiac plexus block.
- **Option C:** While bleeding is a potential risk, it is not the most frequently encountered complication specifically associated with the physiological effects of the block.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that patients undergoing celiac plexus block should be informed about the risk of orthostatic hypotension and managed appropriately post-procedure, including fluid resuscitation and possibly the use of compression stockings to mitigate this effect.

## **Correct Answer:** . Orthostatic hypotension