Naorungroj Thummaporn, Yanase Fumitaka, Eastwood Glenn M, Baldwin Ian, Bellomo Rinaldo
Department of Intensive Care, Austin Hospital, Melbourne, Victoria, Australia.
Department of Intensive Care, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Blood Purif. 2021;50(4-5):453-461. doi: 10.1159/000512100. Epub 2020 Dec 4.
Hyperammonemia is a life-threatening condition. However, clearance of ammonia via extracorporeal treatment has not been systematically evaluated.
We searched EMBASE and MEDLINE databases. We included all publications reporting ammonia clearance by extracorporeal treatment in adult and pediatric patients with clearance estimated by direct dialysate ammonia measurement or calculated by formula. Two reviewers screened and extracted data independently.
We found 1,770 articles with 312 appropriate for assessment and 28 studies meeting eligibility criteria. Most of the studies were case reports. Hyperammonemia was typically secondary to inborn errors of metabolisms in children and to liver failure in adult patients. Ammonia clearance was most commonly reported during continuous renal replacement therapy (CRRT) and appeared to vary markedly from <5 mL/min/m2 to >250 mL/min/m2. When measured during intermittent hemodialysis (IHD), clearance was highest and correlated with blood flow rate (R2 = 0.853; p < 0.001). When measured during CRRT, ammonia clearance could be substantial and correlated with effluent flow rate (EFR; R2 = 0.584; p < 0.001). Neither correlated with ammonia reduction. Peritoneal dialysis (PD) achieved minimal clearance, and other extracorporeal techniques were rarely studied.
Extracorporeal ammonia clearance varies widely with sometimes implausible values. Treatment modality, blood flow, and EFR, however, appear to affect such clearance with IHD achieving the highest values, PD achieving minimal values, and CRRT achieving substantial values especially at high EFRs. The role of other techniques remains unclear. These findings can help inform practice and future studies.
高氨血症是一种危及生命的病症。然而，通过体外治疗清除氨尚未得到系统评估。
我们检索了EMBASE和MEDLINE数据库。我们纳入了所有报告通过体外治疗清除氨的出版物，这些出版物涉及成年和儿科患者，其清除率通过直接测定透析液氨或公式计算得出。两名评审员独立筛选和提取数据。
我们找到1770篇文章，其中312篇适合评估，28项研究符合纳入标准。大多数研究为病例报告。高氨血症在儿童中通常继发于先天性代谢缺陷，在成年患者中继发于肝功能衰竭。氨清除率最常在持续肾脏替代治疗（CRRT）期间报告，其变化范围明显从<5 mL/min/m2到>250 mL/min/m2。在间歇性血液透析（IHD）期间测量时，清除率最高且与血流量相关（R2 = 0.853；p < 0.001）。在CRRT期间测量时，氨清除率可能很高且与超滤率（EFR）相关（R2 = 0.584；p < 0.001）。两者均与氨减少无关。腹膜透析（PD）的清除率最低，其他体外技术很少被研究。
体外氨清除率差异很大，有时数值难以置信。然而，治疗方式、血流量和EFR似乎会影响这种清除率，IHD的清除率最高，PD的清除率最低，CRRT的清除率很高，尤其是在高EFR时。其他技术的作用仍不清楚。这些发现有助于为实践和未来研究提供参考。
