Acute hyperammonemic encephalopathy masquerading as postoperative delirium in a patient who underwent lung surgery: a case report

Abstract Background Acute hyperammonemic encephalopathy (AHE) is a life-threatening condition. Hyperammonemia-induced mental disorders that appear after surgery and general anesthesia can be easily confused with postoperative delirium, especially in patients without signs of liver dysfunction. Curre...

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Main Authors: Chao-Qin Chen, Zhen-Ping Hu, Xu-Jie Ma, Xiao-Dong Tang, Xia Zheng, Yong-Xing Yao
Format: Article
Language:English
Published: BMC 2025-07-01
Series:BMC Anesthesiology
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Online Access:https://doi.org/10.1186/s12871-025-03202-y
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author Chao-Qin Chen
Zhen-Ping Hu
Xu-Jie Ma
Xiao-Dong Tang
Xia Zheng
Yong-Xing Yao
author_facet Chao-Qin Chen
Zhen-Ping Hu
Xu-Jie Ma
Xiao-Dong Tang
Xia Zheng
Yong-Xing Yao
author_sort Chao-Qin Chen
collection DOAJ
description Abstract Background Acute hyperammonemic encephalopathy (AHE) is a life-threatening condition. Hyperammonemia-induced mental disorders that appear after surgery and general anesthesia can be easily confused with postoperative delirium, especially in patients without signs of liver dysfunction. Currently, no reports of AHE precipitated by operative stress or general anesthesia exists. Here, we describe a patient without obvious liver dysfunction who developed AHE after general anesthesia and was diagnosed with postoperative delirium. Gene sequencing revealed that the patient had ornithine transcarbamylase deficiency (OTCD), which led to AHE and hepatic coma. Case presentation A 41-year-old man with a history of mild hypertension and depression was scheduled to undergo lung wedge resection under general anesthesia. Laboratory examination revealed low blood urea nitrogen levels. The anesthesia and surgery were uneventful. Four hours after returning to the surgical ward, the patient experienced agitation and developed mental disorders. His Confusion Assessment Method score was positive, and the Nursing Delirium Screening Scale score was 6; therefore, he was medically treated for postoperative delirium. However, his symptoms did not improve over the following days. On the 3rd postoperative day, the patient became unconscious and experienced limb twitching. Blood analysis revealed severe hyperammonemia (498 µmol/L) and respiratory alkalosis. Consequently, the patient underwent tracheal intubation and continuous venovenous hemodiafiltration, along with comprehensive supportive treatments, including intracranial pressure reduction and antiviral and gamma globulin therapy. However, the patient’s serum ammonia level remained high. A computed tomography scan of the head revealed diffuse cerebral swelling. On the ninth postoperative day, the patient remained in a deep coma, with loss of brainstem reflex and brain electrical activity, at which point the treatment was terminated by family members. Postmortem genetic sequences revealed that the patient had OTCD. Conclusions AHE following general anesthesia with no evidence of liver failure can be easily misdiagnosed because of its non-characteristic clinical features. We recommend that in patients who experience refractory mental disorders after surgery, clinicians should remain vigilant for signs of hyperammonemia.
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spelling doaj-art-e181cf7609be47e9b239e652ff4eb9f32025-08-20T03:04:10ZengBMCBMC Anesthesiology1471-22532025-07-012511710.1186/s12871-025-03202-yAcute hyperammonemic encephalopathy masquerading as postoperative delirium in a patient who underwent lung surgery: a case reportChao-Qin Chen0Zhen-Ping Hu1Xu-Jie Ma2Xiao-Dong Tang3Xia Zheng4Yong-Xing Yao5Department of Anesthesia, First Affiliated Hospital, Zhejiang University School of MedicineDepartment of Anesthesia, First Affiliated Hospital, Zhejiang University School of MedicineDepartment of Anesthesia, First Affiliated Hospital, Zhejiang University School of MedicineDepartment of Anesthesia, First Affiliated Hospital, Zhejiang University School of MedicineDepartment of Intensive Care Unit, First Affiliated Hospital, Zhejiang University School of MedicineDepartment of Anesthesia, First Affiliated Hospital, Zhejiang University School of MedicineAbstract Background Acute hyperammonemic encephalopathy (AHE) is a life-threatening condition. Hyperammonemia-induced mental disorders that appear after surgery and general anesthesia can be easily confused with postoperative delirium, especially in patients without signs of liver dysfunction. Currently, no reports of AHE precipitated by operative stress or general anesthesia exists. Here, we describe a patient without obvious liver dysfunction who developed AHE after general anesthesia and was diagnosed with postoperative delirium. Gene sequencing revealed that the patient had ornithine transcarbamylase deficiency (OTCD), which led to AHE and hepatic coma. Case presentation A 41-year-old man with a history of mild hypertension and depression was scheduled to undergo lung wedge resection under general anesthesia. Laboratory examination revealed low blood urea nitrogen levels. The anesthesia and surgery were uneventful. Four hours after returning to the surgical ward, the patient experienced agitation and developed mental disorders. His Confusion Assessment Method score was positive, and the Nursing Delirium Screening Scale score was 6; therefore, he was medically treated for postoperative delirium. However, his symptoms did not improve over the following days. On the 3rd postoperative day, the patient became unconscious and experienced limb twitching. Blood analysis revealed severe hyperammonemia (498 µmol/L) and respiratory alkalosis. Consequently, the patient underwent tracheal intubation and continuous venovenous hemodiafiltration, along with comprehensive supportive treatments, including intracranial pressure reduction and antiviral and gamma globulin therapy. However, the patient’s serum ammonia level remained high. A computed tomography scan of the head revealed diffuse cerebral swelling. On the ninth postoperative day, the patient remained in a deep coma, with loss of brainstem reflex and brain electrical activity, at which point the treatment was terminated by family members. Postmortem genetic sequences revealed that the patient had OTCD. Conclusions AHE following general anesthesia with no evidence of liver failure can be easily misdiagnosed because of its non-characteristic clinical features. We recommend that in patients who experience refractory mental disorders after surgery, clinicians should remain vigilant for signs of hyperammonemia.https://doi.org/10.1186/s12871-025-03202-yOrnithine transcarbamylase deficiencyHyperammonemiaEncephalopathyDeliriumCase report
spellingShingle Chao-Qin Chen
Zhen-Ping Hu
Xu-Jie Ma
Xiao-Dong Tang
Xia Zheng
Yong-Xing Yao
Acute hyperammonemic encephalopathy masquerading as postoperative delirium in a patient who underwent lung surgery: a case report
BMC Anesthesiology
Ornithine transcarbamylase deficiency
Hyperammonemia
Encephalopathy
Delirium
Case report
title Acute hyperammonemic encephalopathy masquerading as postoperative delirium in a patient who underwent lung surgery: a case report
title_full Acute hyperammonemic encephalopathy masquerading as postoperative delirium in a patient who underwent lung surgery: a case report
title_fullStr Acute hyperammonemic encephalopathy masquerading as postoperative delirium in a patient who underwent lung surgery: a case report
title_full_unstemmed Acute hyperammonemic encephalopathy masquerading as postoperative delirium in a patient who underwent lung surgery: a case report
title_short Acute hyperammonemic encephalopathy masquerading as postoperative delirium in a patient who underwent lung surgery: a case report
title_sort acute hyperammonemic encephalopathy masquerading as postoperative delirium in a patient who underwent lung surgery a case report
topic Ornithine transcarbamylase deficiency
Hyperammonemia
Encephalopathy
Delirium
Case report
url https://doi.org/10.1186/s12871-025-03202-y
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