Blood ammonia is a predictive biomarker of neurologic outcome in cardiac arrest patients treated with therapeutic hypothermia

• Published in: The American journal of emergency medicine Vol. 30; no. 8; pp. 1395 - 1401
• Main Authors: Cho, Young Mo, MD, Lim, Yong Su, MD, PhD, Yang, Hyuk Jun, MD, PhD, Park, Won Bin, MD, Cho, Jin Seong, MD, Kim, Jin Joo, MD, Hyun, Sung Youl, MD, PhD, Lee, Mi Jin, MD, Kang, Young Joon, MD, Lee, Gun, MD, PhD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.10.2012; Elsevier; Elsevier Limited
• Subjects: Adult; Ammonia; Ammonia - blood; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Biomarkers; Biomarkers - blood; Brain damage; Cardiopulmonary resuscitation; Cooling; CPR; Emergency; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Emergency medical care; Female; Glucose; Heart attacks; Humans; Hypothermia; Hypothermia, Induced; Hypoxia, Brain - blood; Intensive care; Intensive care medicine; Liver cirrhosis; Logistic Models; Male; Medical sciences; Middle Aged; Mortality; Multivariate Analysis; Out-of-Hospital Cardiac Arrest - blood; Out-of-Hospital Cardiac Arrest - therapy; Retrospective Studies; Therapy; Time Factors; Trauma; Ammonia; Cardiocirculatory arrest; Intensive care; Prognosis; Treatment; Cardiovascular disease; Resuscitation; Hypothermia
• ISSN: 0735-6757; 1532-8171
• DOI: 10.1016/j.ajem.2011.10.009

Abstract Purpose The aim of this study was to investigate the value of commonly examined laboratory measurements, including ammonia and lactate, in predicting neurologic outcome of out-of-hospital cardiac arrest (OHCA) patients treated with therapeutic hypothermia (TH). Methods This was a retrospective cohort study of patients with a return of spontaneous circulation after OHCA who were treated with TH between February 2007 and July 2010. We measured typical blood measurements on arrival at the emergency department. The subjects were classified into 2 groups: the good neurologic outcome group (Cerebral Performance Category [CPC] 1-2 at 1 month) and the poor neurologic outcome group (Cerebral Performance Category 3-5). We compared blood biomarker levels and basal characteristics between the 2 groups. Logistic regression analyses were performed to determine independent biomarkers that predict poor neurologic outcome. Results A total of 117 patients were included. Between the 2 groups, significantly different levels of blood measurements included hemoglobin level, pH, Pa o2 , Pa co2 , base excess, albumin, glucose, potassium, chloride, bilirubin, phosphorous, and ammonia. In multivariate analyses, blood ammonia level (>96 mg/dL; odds ratio [OR], 7.240; 95% confidence interval [CI], 1.718-30.512), noncardiac causes (OR, 46.215; 95% CI, 9.670-220.873), and time interval from collapse to return of spontaneous circulation (>33 min; OR, 5.943; 95% CI, 1.543-22.886) were significantly related to poor neurologic outcome. Conclusion Among the blood measurements on emergency department arrival, blood ammonia (>96 mg/dL) was the only independent predictive biomarker of poor neurologic outcome. Thus, higher blood ammonia level was associated with poor neurologic outcome in OHCA patients treated with TH.