背景:接受体外生命支持(ECLS)的患者,用于呼吸或心脏支持,营养不良的风险很高;重症监护营养指南尚未纳入有关这些环境的确凿证据。这篇叙述性综述的目的是收集现有文献中的可用证据,并将一般原则转化为ECLS人群。
方法:关于ECLS期间营养的观察性和干预性研究的文献综述,并从这个角度对营养指南进行评估。
结果:营养对于改善ECLS的结果至关重要,以及危重病人。ECLS期间的热量需求可以根据临床状态的严重程度而变化,镇静,瘫痪和温度稳定性。通过间接量热法精确评估能量消耗是困难的,因为ECLS是一个致力于去除二氧化碳的系统;然而,由从膜肺中获取的二氧化碳值组成的修正方程是可用的。指南建议采用低热量(70%-80%的需求)策略开始早期肠内营养(EN)。也在急性状态,如败血症或心源性休克。此外,EN,尽管之前有担忧,在俯卧位是可行的,机械通气期间越来越采用的策略。这些患者的分解代谢状态最大,导致蛋白质和肌肉减少。因此,足够的蛋白质递送应通过给予高达2g/kg/天的高蛋白摄入量来保证。
结论:有必要进行针对ECLS患者的营养研究。早期低热量EN与高蛋白摄入,在间接量热法上量身定制,可能是最合适的选择。
BACKGROUND: Patients on extracorporeal life support (ECLS), either for respiratory or cardiac support, are at high risk of malnutrition;
guidelines on nutrition in critical care have not incorporated solid evidence regarding these settings. The aim of this narrative review is to gather the available evidence in the existing literature and transpose general principles to the ECLS population.
METHODS: A literature review of observational and interventional studies on nutrition during ECLS, and evaluation of nutrition
guidelines in this perspective.
RESULTS: Nutrition is paramount for improving outcomes in ECLS, as well as in critically ill patients. The caloric needs during ECLS can vary according to the severity of the clinical state, sedation, paralysis, and temperature stability. Precise evaluation of energy expenditure by indirect calorimetry is difficult because ECLS is a system dedicated to removing carbon dioxide; however, modified equations composed of carbon dioxide values taken from the membrane lung are available.
Guidelines suggest starting early enteral nutrition (EN) with a hypocaloric (70%-80% of the needs) strategy, also in acute states such as septic or cardiogenic shock. Moreover, EN, despite previous concerns, is feasible in prone position, an increasingly adopted strategy during mechanical ventilation. The catabolic state is maximal in these patients, causing a protein and muscular reduction. Therefore, adequate protein delivery should be guaranteed by administering a high protein intake of up to 2 g/kg/day.
CONCLUSIONS: Studies on nutrition tailored to ECLS patients are warranted. Early hypocaloric EN with high protein intake, tailored on indirect calorimetry, may be the most appropriate option.