Asterixis "AKA the flapping tremor", the word sounds like a character in a Japanese anime or in a sci-fi movie. The term derived from the Greek word "a" which means "not" and "stērixis" meaning "fixed position". Asterixis is the most common and reliable sign to assess hepatic encephalopathy (HE). HE is the occurrence of confusion, altered level of consciousness, and coma that occurs as a result of either chronic or acute liver failure, HE develops when the patient has high serum ammonia (a by product of protein which supposed to be metabolized by the liver).
How to assess asterixis?
Ask the patient to outstretched his hands and arms, with palms down, wrists bent up and fingers are spread. A positive asterixis is seen when there is an irregular flapping movements of the fingers and the wrists.
Here is a video of a real patient with Asterixis:
Video credit to: Dr.Rahul Shevale (www.youtube.com)
It is also seen in some patients with kidney failure and azotemia, and in carbon dioxide toxicity.
It can also be a feature of Wilson's disease.
It is also seen in respiratory failure.
It can be prominent after receiving IV phenytoin, also if on narcotics.
Saunders comprehensive review for the NCLEX-RN examination Linda Anne Silvestri