Hyperammonemia and Pyroglutamic Acidemia in a Sepsis Patient with Gamma-Glutamyl-Cyclus Failure- A Case and Literature Review

Abstract

We report the rare case of an adult sepsis patient with very low urea blood values, a high anion gap metabolic acidosis, and high ammonia levels. After exclusion of a primary disturbance of the urea cycle, we found a severe pyroglutamic (also called 5-oxoproline) acidemia, 841 µmol l-1 (norm: 5-150), indicating a disrupture of the gamma-glutamyl cycle, a cycle which is responsible for amino acid transportation, redox metabolism, and detoxification of medications, e.g., analgesics and antibiotics. The patient initially was treated with long-term, high-dosage rifampicine, linezolid, and piperacillin/tazobactam. Such cycle defects are rarely reported and are mostly found as an inborn disease in early childhood. In adults, diseases of the liver or renal failure, sepsis or diabetes, and certain medications may trigger a secondary cycle disturbance by depletion of vitally important glutathione stores or enzyme inhibition. We recommend that physicians remain aware of extremely low blood urea values that may indicate the beginning of gamma-glutamyl-cycle failure. Countermeasures such as discontinuation of causative medication and nutrition adaption must follow.