Confusion after gastric bypass with Roux-en-Y

At at recent case conference, we discussed a woman who had had a gastric bypass 20 years previously, and now had confusion. To remind you of the details of a gastric bypass: First, a small stomach pouch, approximately one ounce or 30 milliliters in volume, is created by dividing the top of the stomach from the rest of the stomach. Next, the first portion of the small intestine is divided, and the bottom end of the divided small intestine is brought up and connected to the newly created small stomach pouch. The procedure is completed by connecting the top portion of the divided small intestine to the small intestine further down so that the stomach acids and digestive enzymes from the bypassed stomach and first portion of small intestine will eventually mix with the food. I posed this question on twitter, but unfortunately did not give enough specification of the problem. Restated, a patient with progression confusion presents years after the procedure (very successful at weight loss) and no apparent infection. Our leading differential included hyperammonemic encephalopathy, thiamine deficiency, B12 deficiency and d-Lactic acidosis. We excluded d-Lactic acidosis become the symptoms were not episodic and the electrolyte panel did not have a moderately increased anion gap (usually around 18). A B12 level was normal, excluding that possibility. The patient did have both hyperammonemia and thiamine deficiency. She also had several vitamin B deficiencies and low lev...
Source: DB's Medical Rants - Category: Internal Medicine Authors: Tags: Medical Rants Source Type: blogs