Rationale and published recommendations for the use of thiamine in hospitalized patients

 

Several times recently on wards we have discussed thiamine administration in

hospitalized patients. My literature search on this topic  found two very helpful 

reviews linked below:

Wernicke Encephalopathy—Clinical Pearls

Mayo Clinic Proceedings  Volume 94, Issue 6p1065-1072June 2019

Myths and misconceptions of Wernicke's encephalopathy: what every emergency physician should know

Ann Emerg Med  Volume 50, Issue 6p715-721December 2007

Here are the key points from these articles: 

Although treatment and prevention of WE are overlapping categories, 

thiamine is most effectively used as prevention. 

In other words, if you wait to give thiamine until you “ suspect”  WE you have

 probably waited until it's too late. Approximately 80% of patients recognized as

WE already have dementia.

The recommended route for thiamine is IV not PO. 

Although dose recommendations are not supported by high-level data, published 

recommendations range from 200 mg q12 hours to 500 mg Q8 hours, IV. 

WE can result from any state of malnutrition, not just alcoholism. 

Risk factors other than alcoholism include:

Cancer

Post operative patients especially those who have had gastric bypass

Hyperemesis gravidarum 

Eating Disorders 

Hospitalized patients given dextrose. 

The existence of WE is common although recognition is rare. 

80% of the time WE is first recognized at autopsy.

Wernicke encephalopathy is a clinical diagnosis. 

Lab testing may be reasonable but is seldom helpful. Neuroimaging (although 

routinely done in cases of altered mental status and sometimes showing 

confirmatory findings) has low sensitivity. 

The triad of ocular manifestations, ataxia and altered mental status is seen

in only 10% of patients. 

Thiamine deficiency is associated with clinical syndromes other than WE

 including unexplained hypotension, unexplained lactic acidosis,

 neuropathy, heart failure and unexplained hypothermia.