Question

An old patient with alcoholism is admitted with small bowel obstruction and is started on PN providing 400 grams of dextrose. If, after 3 days, the patient develops mental status changes it is most likely due to a deficiency of

1: pyridoxine.
2: thiamin.
3: cyanocobalamin.
4: niacin.

Answer 1

The mental status changes in an old patient with alcoholism on PN with 400 grams of dextrose are most likely due to a deficiency of thiamin (vitamin B1), which can lead to severe brain cell dysfunction and could progress to Wernicke's encephalopathy. option (1)

Step-by-step explanation:

The mental status changes observed in an old patient with a history of alcoholism and who is on parenteral nutrition (PN) providing 400 grams of dextrose could most likely be due to a deficiency of thiamin (vitamin B1). This is because thiamin deficiency affects carbohydrate utilization, leading to an accumulation of pyruvate and lactate, particularly impacting brain cells. Symptoms of severe thiamin deficiency could develop into Wernicke's encephalopathy, which is especially seen in alcoholics and presents with mental status changes, amongst other neurological symptoms. The loss of appetite, cardiovascular changes, weakness, muscular atrophy, and gastrointestinal disorders are also associated with the clinical condition known as Beri-Beri, which stems from thiamin deficiency.

Meanwhile, deficiencies of the other listed vitamins—pyridoxine (B6), cyanocobalamin (B12), and niacin—lead to other specific clinical conditions such as peripheral neuropathy, pernicious anemia, and pellagra, respectively. While these deficiencies have serious consequences, the acute onset of mental status changes following an infusion of dextrose in an alcoholic patient leans more towards thiamin deficiency and the potential development of Wernicke's encephalopathy.