Kitzberger Reinhard, Funk Georg Christian, Holzinger Ulrike, Miehsler Wolfgang, Kramer Ludwig, Kaider Alexandra, Ferenci Peter, Madl Christian
Department of Gastroenterology, Hepatology and Medical Intensive Care Medicine, Medical University Hospital Vienna, Vienna, Austria.
Clin Gastroenterol Hepatol. 2009 Sep;7(9):1000-6. doi: 10.1016/j.cgh.2009.05.019. Epub 2009 May 22.
BACKGROUND & AIMS: Ionized ammonia (NH(3)) and partial pressure of the gaseous ammonia (pNH(3)) are associated with hepatic encephalopathy and intracranial hypertension in patients with acute liver failure; NH(3) is also believed to contribute to extrahepatic organ failure. We investigated whether the severity of organ failure was associated with intracranial hypertension and evaluated the correlation between NH(3) and pNH(3) and grade of hepatic encephalopathy.
In 87 patients with acute liver failure admitted to the intensive care unit, we simultaneously evaluated arterial ammonia, pNH(3), clinical grade of hepatic encephalopathy, the sequential organ failure assessment score (SOFA score), and evidence of intracranial hypertension.
In comparing patients with intracranial hypertension (n = 37) with patients without intracranial hypertension (n = 50), the highest NH(3) and pNH(3) levels and SOFA scores before onset of intracranial hypertension were independent predictors of intracranial hypertension (P < .001). Among patients with NH(3) levels less than 146 mumol/L, those with intracranial hypertension had a higher SOFA score than those without intracranial hypertension (median, 10 vs 5.5; P = .004), despite the patients' similar levels of NH(3). NH(3) (r = 0.68, P < .0001) and pNH(3) (r = 0.78, P < .0001) both correlated with grade of hepatic encephalopathy. However, in multiple regression analysis, only pNH(3) (P < .0001) was shown to be a significant independent parameter for predicting grade of hepatic encephalopathy (P = .27).
SOFA score and ammonia levels are independent predictors of intracranial hypertension. In patients with acute liver failure admitted to the intensive care unit, pNH(3) level is a better predictor of clinical grade of hepatic encephalopathy than arterial NH(3) level.
离子化氨（NH₃）和气态氨分压（pNH₃）与急性肝衰竭患者的肝性脑病及颅内高压相关；NH₃也被认为与肝外器官衰竭有关。我们研究了器官衰竭的严重程度是否与颅内高压相关，并评估了NH₃和pNH₃与肝性脑病分级之间的相关性。
在入住重症监护病房的87例急性肝衰竭患者中，我们同时评估了动脉血氨、pNH₃、肝性脑病临床分级、序贯器官衰竭评估评分（SOFA评分）以及颅内高压的证据。
在比较有颅内高压的患者（n = 37）和无颅内高压的患者（n = 50）时，颅内高压发作前最高的NH₃和pNH₃水平以及SOFA评分是颅内高压的独立预测因素（P <.001）。在NH₃水平低于146 μmol/L的患者中，有颅内高压的患者SOFA评分高于无颅内高压的患者（中位数分别为10和5.5；P =.004），尽管这些患者的NH₃水平相似。NH₃（r = 0.68，P <.0001）和pNH₃（r = 0.78，P <.0001）均与肝性脑病分级相关。然而，在多元回归分析中，只有pNH₃（P <.0001）被证明是预测肝性脑病分级的显著独立参数（P =.27）。
SOFA评分和血氨水平是颅内高压的独立预测因素。在入住重症监护病房的急性肝衰竭患者中，pNH₃水平比动脉血NH₃水平更能预测肝性脑病的临床分级。
