Transplant Unit, Intensive Care Unit, Nova Medical School, Curry Cabral Hospital, Lisbon, Portugal.
Intensive Care Unit, Curry Cabral Hospital, Lisbon, Portugal.
Liver Int. 2024 Oct;44(10):2651-2659. doi: 10.1111/liv.16043. Epub 2024 Jul 17.
BACKGROUND & AIMS: Ammonia is metabolized into urea in the liver. In acute liver failure (ALF), ammonia has been associated with survival. However, urea variation has been poorly studied.
Observational cohort including ALF patients from Curry Cabral Hospital (Lisbon, Portugal) and Clinic Hospital (Barcelona, Spain) between 10/2010 and 01/2023. The United States ALF Study Group cohort was used for external validation. Primary exposures were serum ammonia and urea on ICU admission. Primary endpoint was 30-day transplant-free survival (TFS). Secondary endpoint was explanted liver weight.
Among 191 ALF patients, median (IQR) age was 46 (32; 57) years and 85 (44.5%) were males. Overall, 86 (45.0%) patients were transplanted and 75 (39.3%) died. Among all ALF patients, following adjustment for age, sex, body weight, and aetiology, higher ammonia or lower urea was independently associated with higher INR on ICU admission (p < .009). Among all ALF patients, following adjustment for sex, aetiology, and lactate, higher ammonia was independently associated with lower TFS (adjusted odds ratio (95% confidence interval [CI]) = 0.991 (0.985; 0.997); p = .004). This model predicted TFS with good discrimination (area under receiver operating curve [95% CI] = 0.78 [0.75; 0.82]) and reasonable calibration (R of 0.43 and Brier score of 0.20) after external validation. Among transplanted patients, following adjustment for age, sex, actual body weight, and aetiology, higher ammonia (p = .024) or lower (p < .001) urea was independently associated with lower explanted liver weight.
Among ALF patients, serum ammonia and urea were associated with ALF severity. A score incorporating serum ammonia predicted TFS reasonably well.
氨在肝脏中代谢为尿素。在急性肝衰竭（ALF）中，氨与存活率有关。然而，尿素的变化研究甚少。
本研究纳入了 2010 年 10 月至 2023 年 1 月期间来自葡萄牙库里卡瓦尔医院（里斯本）和西班牙 Clinic 医院（巴塞罗那）的 ALF 患者以及美国 ALF 研究组队列进行观察性队列研究。主要暴露因素为 ICU 入院时的血清氨和尿素。主要终点为 30 天无移植存活率（TFS）。次要终点为肝移植重量。
191 例 ALF 患者中，中位（IQR）年龄为 46（32；57）岁，85 例（44.5%）为男性。总体而言，86 例（45.0%）患者接受了移植，75 例（39.3%）患者死亡。在所有 ALF 患者中，在校正年龄、性别、体重和病因后，较高的氨或较低的尿素与 ICU 入院时较高的 INR 独立相关（p<0.009）。在所有 ALF 患者中，在校正性别、病因和乳酸后，较高的氨与较低的 TFS 独立相关（调整后的优势比（95%置信区间 [CI]）=0.991（0.985；0.997）；p=0.004）。该模型经外部验证后具有良好的区分度（接受者操作特征曲线下面积 [95%CI] =0.78 [0.75；0.82]）和合理的校准度（R 为 0.43，Brier 评分 0.20）。在移植患者中，在校正年龄、性别、实际体重和病因后，较高的氨（p=0.024）或较低的尿素（p<0.001）与较低的肝移植重量独立相关。
在 ALF 患者中，血清氨和尿素与 ALF 严重程度相关。包含血清氨的评分能够较好地预测 TFS。
