Summary

A 51-year-old female presented with acute confusion associated with a non-specific headache and lethargy. The patient’s history included bipolar disorder on valproate and recent travel to northern Vietnam. The patient was subsequently found to have hyperammonaemia as well as a urinary tract infection and bacteraemia with Klebsiellapneumoniae. The patient was presumed to have a multifactorial non-cirrhotic hyperammonaemic encephalopathy due to a combination of a urinary tract infection and bacteraemia with K. pneumoniae, a urease-producing bacteria, and also valproate use, a medication known to interfere with ammonia elimination. The patient’s treatment included supportive care, ceasing valproate, empiric then rationalised antibiotics, N-acetylcysteine and L-carnitine. We present a case of non-cirrhotic hyperammonaemic encephalopathy and explain why it is multifactorial in origin.