Kinderspital Zurich, Division of Metabolism, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland.
Eur J Pediatr. 2011 Jan;170(1):21-34. doi: 10.1007/s00431-010-1369-2. Epub 2010 Dec 17.
Hyperammonemia is a life-threatening condition which can affect patients at any age. Elevations of ammonia in plasma indicate its increased production and/or decreased detoxification. The hepatic urea cycle is the main pathway to detoxify ammonia; it can be defective due to an inherited enzyme deficiency or secondary to accumulated toxic metabolites or substrate depletion. Clinical signs and symptoms in hyperammonemia are unspecific but they are mostly neurological. Thus, in any unexplained change in consciousness or in any unexplained encephalopathy, hyperammonemia must be excluded as fast as possible. Any delay in recognition and start of treatment of hyperammonemia may have deleterious consequences for the patient. Treatment largely depends on the underlying cause but is, at least in pediatric patients, mainly aimed at establishing anabolism to avoid endogenous protein breakdown and amino acid imbalances. In addition, pharmacological treatment options exist to improve urea cycle function or to remove nitrogen, but their use depend on the underlying disorder. To improve the prognosis of acute hyperammonemia, an increased awareness of this condition is probably more needed than anything else. Likewise, the immediate start of appropriate therapy is of utmost importance. This review focuses on a better understanding of factors leading to ammonia elevations and on practical aspects related to diagnosis and treatment in order to improve clinical management of hyperammonemia.
高氨血症是一种危及生命的疾病，可发生于任何年龄的患者。血浆中氨升高表明其产生增加和/或解毒减少。肝脏尿素循环是解毒氨的主要途径；由于遗传酶缺陷或累积毒性代谢物或底物耗竭，其可能发生缺陷。高氨血症的临床体征和症状无特异性，但大多为神经症状。因此，在任何原因不明的意识改变或任何原因不明的脑病中，必须尽快排除高氨血症。对高氨血症的识别和治疗的任何延迟都可能对患者产生有害影响。治疗主要取决于潜在病因，但至少在儿科患者中，主要目的是建立合成代谢以避免内源性蛋白质分解和氨基酸失衡。此外，存在改善尿素循环功能或去除氮的药物治疗选择，但它们的使用取决于潜在疾病。为了改善急性高氨血症的预后，可能比任何其他因素都更需要提高对这种疾病的认识。同样，立即开始适当的治疗至关重要。这篇综述重点介绍了导致氨升高的因素以及与诊断和治疗相关的实际方面，以改善高氨血症的临床管理。
