What practice has persisted since 1999 that maintains risk of thiamin deficiency in PN?

What practice has persisted since 1999 that maintains risk of thiamin deficiency in PN?

• A. Suboptimal dosing of thiamin in PN
• B. Excess thiamin supplementation
• C. Adequate caloric intake
• D. Rapid mobilization of fat stores

Answer: (A)

The key idea here is that thiamine is essential for energy metabolism, especially when a PN plan delivers significant carbohydrate. Thiamine stores in the body are limited and turnover is rapid, so once a glucose load is provided in PN, the body's demand for thiamine rises. If the PN preparation or regimen under-supplements thiamine, deficiencies can develop despite adequate calories. Since 1999, guidelines have emphasized including thiamine in PN, but practice has often continued with suboptimal dosing, leaving a persistent risk of deficiency. Excess thiamine is unlikely to cause harm in most patients because it is water-soluble and excreted if not needed. Adequate caloric intake by itself doesn’t prevent thiamine deficiency if the thiamine amount in the PN is insufficient. Rapid mobilization of fat stores relates more to refeeding risk in general, not the specific mechanism driving thiamine deficiency in PN.

The key idea here is that thiamine is essential for energy metabolism, especially when a PN plan delivers significant carbohydrate. Thiamine stores in the body are limited and turnover is rapid, so once a glucose load is provided in PN, the body's demand for thiamine rises. If the PN preparation or regimen under-supplements thiamine, deficiencies can develop despite adequate calories. Since 1999, guidelines have emphasized including thiamine in PN, but practice has often continued with suboptimal dosing, leaving a persistent risk of deficiency.

Excess thiamine is unlikely to cause harm in most patients because it is water-soluble and excreted if not needed. Adequate caloric intake by itself doesn’t prevent thiamine deficiency if the thiamine amount in the PN is insufficient. Rapid mobilization of fat stores relates more to refeeding risk in general, not the specific mechanism driving thiamine deficiency in PN.