A Case of Esophageal Carcinoma who Developed Disturbance of Consciousness due to Hyperammonemia during Neoadjuvant Chemotherapy

Abstract

Hyperammonemia is a rare, serious adverse drug reaction to 5-FU. There have been a few reports of its occurrence in patients with colorectal carcinoma, but very few in patients with esophageal carcinoma. We herein report a case of a patient who developed disturbance of consciousness due to hyperammonemia during the administration of neoadjuvant chemotherapy with 5-FU and cisplatin (FP therapy) for esophageal carcinoma is presented.

A 67-year-old man had experienced a feeling of obstruction while swallowing and vomiting for three months, and he was diagnosed with squamous cell carcinoma of the esophagus at his previous hospital. This was diagnosed as LtAe, 70×30 mm², type 3, SCC, cT3, cN3, cM0, cStage III, and it was decided to administer preoperative chemotherapy with FP therapy (5-FU days 1-5, CDDP day 1). Early on day 3 after starting treatment, the patient became drowsy. His level of consciousness subsequently decreased to JCSIII-200. Blood tests showed an elevated blood ammonia level (132 μg/dl), and the disturbance of consciousness was considered to be caused by 5-FU-induced hyperammonemia. 5-FU was discontinued, and branched-chain amino acid infusion were administered. The patient's level of consciousness then improved rapidly. For the second course, the 5-FU dose was decreased by 50%, and oral lactulose and branched-chain amino acid infusion were administered to enable chemotherapy to continue. Thoracoscopic subtotal esophagectomy and gastric tube reconstruction were performed, but tracheal invasion by metastatic lymph nodes (numbers 106tbL and 106recL) was observed, followed by an R2 resection. Enteral nutrition was started on postoperative day 1, and the patient started eating on postoperative day 7 and was discharged on postoperative day 19. In this case, the hyperammonemia may have been triggered by anemia, hypoalbuminemia, and skeletal muscle loss.