Prognostic value of serum ammonia in critical patients with non-hepatic disease: A prospective, observational, multicenter study

Yue Li; Zhipeng Yao; Yunlong Li; Zhenyu Yang; Ming Li; Zhendong Chen; Shujie Liu; Jianguo Gong; Libin Huang; Ping Xu; Yan Li; Haihong Li; Xuan Liu; Li Zhang; Guixia Zhang; Hongliang Wang

doi:10.2478/jtim-2022-0021

Prognostic value of serum ammonia in critical patients with non-hepatic disease: A prospective, observational, multicenter study

J Transl Int Med. 2022 Jul 2;11(4):401-409. doi: 10.2478/jtim-2022-0021. eCollection 2023 Dec.

Authors

Yue Li¹, Zhipeng Yao¹, Yunlong Li¹, Zhenyu Yang¹, Ming Li¹, Zhendong Chen², Shujie Liu³, Jianguo Gong⁴, Libin Huang⁵, Ping Xu⁶, Yan Li⁷, Haihong Li⁸, Xuan Liu⁹, Li Zhang¹⁰, Guixia Zhang¹¹, Hongliang Wang¹

Affiliations

¹ Department of Intensive Care Medicine, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, Heilongjiang Province, China.
² Department of Intensive Care Medicine, The First Affiliated Hospital of Jiamusi University, Jiamusi 154004, Heilongjiang Province, China.
³ Department of Intensive Care Medicine, Mudanjiang City Second People's Hospital, Mudanjiang 157199, Heilongjiang Province, China.
⁴ Department of Intensive Care Medicine, The Fifth Affiliated Hospital of Harbin Medical University, Daqing 163711, Heilongjiang Province, China.
⁵ Department of Intensive Care Medicine, Harbin Fifth Hospital, Harbin 150001, Heilongjiang Province, China.
⁶ Department of Intensive Care Medicine, General Hospital of Heilongjiang Province Land Reclamation Bureau, Harbin 150001, Heilongjiang Province, China.
⁷ Department of Intensive Care Medicine, The First Hospital of Harbin, Harbin 150001, Heilongjiang Province, China.
⁸ Department of Intensive Care Medicine, Hongqi Hospital Affiliated to Mudanjiang Medical University, Mudanjiang 157000, Heilongjiang Province, China.
⁹ Department of Intensive Care Medicine, Jiamusi Central Hospital, Jiamusi 154003, Heilongjiang Province, China.
¹⁰ Department of Intensive Care Medicine, Daqing Oilfield General Hospital, Daqing 163001, Heilongjiang Province, China.
¹¹ Department of Intensive Care Medicine, The Longnan Hospital of Daqing, Daqing 163458, Heilongjiang Province, China.

Abstract

Background and objectives: Non-hepatic hyperammonemia can damage the central nervous system (CNS), and possible prognostic factors are lacking. This study aimed to investigate the prognostic and risk factors for patients admitted to the intensive care unit (ICU).

Materials and methods: This prospective, observational, multicenter study was conducted between November and December 2019 at 11 ICUs in the Chinese Heilongjiang province. Changes in blood ammonia level during and after ICU admission were continuously monitored and expressed as the high level (H-), mean level (M-), and initial level (I-) of ammonia. The risk factors of poor prognosis were investigated by conducting univariate and multivariate logistic regression analyses. Receiver operating characteristic (ROC) curve analysis was conducted to compare the predictive ability of Acute Physiologic Assessment and Chronic Health Evaluation II (APACHE-II) score, lactic acid, total bilirubin (TBil), and M-ammonia.

Results: A total of 1060 patients were included in this study, of which 707 (67%) had a favorable prognosis and 353 (33%) had a poor prognosis. As shown by univariate models, a poor prognosis was associated with elevated serum levels of lactic acid, TBil, and ammonia (P < 0.05) and pathologic scores from three assessments: APACHE-II, Glasgow Coma Scale (GCS), and Sequential Organ Failure Assessment (SOFA). Multivariate analysis revealed that circulating mean ammonia levels in ICU patients were independently associated with a poor prognosis (odds ratio [OR] = 1.73, 95% confidence interval [CI]: 1.07-2.80, P = 0.02). However, the APACHE-II score (area under the curve [AUC]: 0.714, sensitivity: 0.86, specificity: 0.68, P < 0.001) remained the most predictive factor for patient prognosis by ROC analysis.

Conclusion: Elevated serum levels of ammonia in the blood were independently prognostic for ICU patients without liver disease.

Keywords: Acute Physiologic Assessment and Chronic Health Evaluation; hyperammonemia; intensive care unit; lactic acid; non-hepatic; prognostic factor; serum ammonia.

© 2023 Yue Li, Zhipeng Yao, Yunlong Li, Zhenyu Yang, Ming Li, Zhendong Chen, Shujie Liu, Jianguo Gong, Libin Huang, Ping Xu, Yan Li, Haihong Li, Xuan Liu, Li Zhang, Guixia Zhang, Hongliang Wang, published by De Gruyter on behalf of Scholar Media Publishing.