伴有休克的重症患者给予肠内营养期间牛磺酸水平降低

　　背景：重症监护病房（ICU）营养研究表明适当肠内营养（EN）支持有利于临床获益。然而，因休克而接受EN的患者血清氨基酸浓度变化尚不清楚。我们猜测当氨基酸缺乏时，EN能增加血清氨基酸浓度，而长时间缺乏会导致不良结局。

　　方法：对接受EN的33例感染性或心源性休克患者5天血清氨基酸浓度进行检测。同时对氨基酸浓度变化、临床结局相关性变量、回归分析进行研究。

　　结果：入住ICU时，血清中多种氨基酸均缺乏，接着（EN时）血清氨基酸浓度大都有所增加。相反，牛磺酸浓度却下降了50%，第1天就从47.6μmol/L下降到20.0μmol/L，在第5天仍然很低。入院时牛磺酸与机械通气时间相关（R=-0.42，P=0.015），24h内牛磺酸的降低与急性生理和慢性健康评估Ⅱ预测的死亡率（R=0.43，P=0.017）和序贯性器官衰竭评分（R=0.36，P=0.05）相关。回归分析进一步证实了以上相关性。

　　结论：入住ICU时，血清中多种氨基酸均缺乏，但随着EN进行而增加。但是牛磺酸水平下降与长时间机械通气及ICU支持相关。空腹牛磺酸水平下降与器官衰竭严重程度相关。以上发现支持了牛磺酸在局部缺血、再灌注损伤以及炎症期间的作用。牛磺酸是将来纳入重症患者营养支持的一大成分，但仍需更多研究支持这一结论。

JPEN J Parenter Enteral Nutr. 2016;40(2):264-72.

Taurine Concentrations Decrease in Critically Ill Patients With Shock Given Enteral Nutrition.

Vermeulen MA, van Stijn MF, Visser M, Lemmens SM, Houdijk AP, van Leeuwen PA, Oudemans-van Straaten HM.

VU University Medical Center, Amsterdam, The Netherlands; Academic Medical Center, Amsterdam, The Netherlands; Academic Medical Center University of Amsterdam, Amsterdam, The Netherlands; Medical Center Alkmaar, Alkmaar, The Netherlands; Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.

BACKGROUND: Nutrition studies in the intensive care unit (ICU) have shown that adequate enteral nutrition (EN) support has clinical benefits. However, the course of amino acid concentrations in plasma has never been investigated in patients admitted with shock receiving EN. We hypothesized that plasma concentrations, when deficit, increase during EN and that persistent deficiency is associated with poor outcome.

METHODS: In 33 septic or cardiogenic shock patients receiving EN, plasma amino acid concentrations were measured during 5 days. Changes in amino acid concentrations, correlations with clinical outcome variables, and regression analyses were studied.

RESULTS: On ICU admission, several plasma concentrations were deficient. Plasma concentrations of almost all amino acids increased. In contrast, taurine decreased by >50%, from 47.6 µmol/L on admission to 20.0 µmol/L at day 1, and remained low at day 5. Taurine (admission) correlated with time on mechanical ventilation (R = -0.42, P = .015). Taurine decrease within 24 hours correlated with Acute Physiology and Chronic Health Evaluation II predicted mortality (R = 0.43, P = .017) and Sequential Organ Failure Assessment score (R = 0.36, P = .05). Regression analyses confirmed correlations.

CONCLUSIONS: Several amino acids were deficient in plasma on ICU admission but increased during EN. Taurine concentrations declined and were associated with longer periods of mechanical ventilation and ICU support. Fast taurine decline correlated with severity of organ failure. These findings support the role of taurine during ischemia, reperfusion, and inflammation. Taurine may be an essential candidate to enrich nutrition support for critically ill patients, although more research is required.

KEYWORDS: ICU; amino acids; arginine; cardiogenic shock; glutamine; protein; sepsis

PMID: 25587009

DOI: 10.1177/0148607114567199