Encephalopathy, lactic acidosis, hyperammonaemia and 5-fluorouracil toxicity

Severe Encephalopathy, Lactic Acidosis and Hyperammonaemia With FOLFIRI Plus Aflibercept After Two-stage Hepatectomy: A Case Report

BACKGROUND/AIM

Recent advances in chemotherapy have increased the possibility of conversion hepatectomy for patients with initially unresectable liver metastases. Although long-term chemotherapy and subsequent extensive hepatectomy are becoming more common, the toxicities of such chemotherapies are unclear.

PATIENTS AND METHODS

We present a case report of a patient with metastatic colorectal cancer who developed severe encephalopathy with lactic acidosis and hyperammonaemia caused by 5-fluorouracil-based chemotherapy. Administration of vitamin B1 and continuous haemodiafiltration rapidly improved the patient's symptoms.

CONCLUSION

Intensive treatment of metastatic colorectal cancer patients with 5-fluorouracil can induce rare adverse events.

Lactic acidosis: recognition, kinetics, and associated prognosis

Lactic acidosis is a common condition encountered by critical care providers. Elevated lactate and decreased lactate clearance are important for prognostication. Not all lactate in the intensive care unit is due to tissue hypoxia or ischemia and other sources should be evaluated. Lactate, in and of itself, is unlikely to be harmful and is a preferred fuel for many cells. Treatment of lactic acidosis continues to be aimed the underlying source.

Hyperammonemia encephalopathy: an important cause of neurological deterioration following chemotherapy

Idiopathic hyperammonemic encephalopathy is an uncommon but frequently fatal complication of chemotherapy. It is characterised by abrupt alteration in mental status with markedly elevated plasma ammonia levels in the absence of obvious liver disease or any other identifiable cause, and frequently results in intractable coma and death. It usually occurs in patients with haematologic malignancies during the period of neutropenia following cytoreductive therapy or bone marrow transplantation, and in solid organ malignancies treated with 5-fluorouracil. Although the aetiology of this syndrome is yet to be determined, it appears to be multi-factorial in nature. Optimal management remains to be formally established, and the critical step is increased awareness of the syndrome by measurement of plasma ammonium levels in patients with neurological symptoms, leading to early diagnosis and the prompt implementation of therapy.

Encéphalopathie aiguë fatale secondaire à un traitement par 5-fluoro-uracile

INTRODUCTION

Encephalopathies from 5 fluorouracil (5FU) are rare and generally resolve favorably.

CASE

Six days after her first course of chemotherapy combining 5FU and cisplatin, a 45-year-old woman developed acute encephalopathy with altered consciousness and convulsions. MRI showed hyperintense signals of the white matter, mainly ventricular. Despite symptomatic treatment and thiamine perfusion in intensive care, the patient deteriorated and resuscitation failed. Blood tests confirmed 5FU toxicity.

DISCUSSION

5FU encephalopathies are rare and most often resolve favorably after treatment is stopped. Two pathophysiologic mechanisms may explain these encephalopathies: a deficit of dihydropyridine dehydrogenase, leading to an increased level of serum uracil with digestive and mucosal toxicity, or interaction of 5FU catabolites with various intracerebral metabolic pathways.