Division of Intensive Care, Department of Surgery and Anatomy, Faculty of Medicine of Ribeirão Preto-University of São Paulo, SP 14049-900 Ribeirão Preto, Brazil.
J Crit Care. 2010 Sep;25(3):445-50. doi: 10.1016/j.jcrc.2009.05.009. Epub 2009 Aug 13.
Adequate energy provision and nitrogen losses prevention of critically ill patients are essentials for treatment and recovery. The aims of this study were to evaluate energy expenditure (EE) and nitrogen balance (NB) of critically ill patients, to classify adequacy of energy intake (EI), and to verify adequacy of EI capacity to reverse the negative NB.
Seventeen patients from an intensive care unit were evaluated within a 24-hour period. Indirect calorimetry was performed to calculate patient's EE and Kjeldhal for urinary nitrogen analysis. The total EI and protein intake were calculated from the standard parenteral and enteral nutrition infused. Underfeeding was characterized as EI 90% or less and overfeeding as 110% or greater of EE. The adequacy of the EI (EI EE(-1) × 100) and the NB were estimated and associated with each other by Spearman coefficient.
The mean EE was 1515 ± 268 kcal d(-1), and most of the patients (11/14) presented a negative NB (-8.2 ± 4.7 g.d(-1)). A high rate (53%) of inadequate energy intake was found, and a positive correlation between EI EE(-1) and NB was observed (r = 0.670; P = .007).
The results show a high rate of inadequate EI and negative NB, and equilibrium between EI and EE may improve NB. Indirect calorimetry can be used to adjust the energy requirements in the critically ill patients.
为了治疗和康复，危重症患者需要充足的能量供应和预防氮丢失。本研究旨在评估危重症患者的能量消耗（EE）和氮平衡（NB），对能量摄入（EI）的充足性进行分类，并验证 EI 能否充分纠正负 NB。
对 ICU 中的 17 名患者进行了 24 小时评估。采用间接热量法计算患者的 EE，并通过凯氏定氮法分析尿氮。通过输注的标准肠外和肠内营养计算总 EI 和蛋白质摄入量。摄入不足定义为 EI＜90%EE，摄入过度定义为 EI＞110%EE。估计 EI（EI EE(-1)×100）和 NB 的充足性，并通过 Spearman 系数进行相关分析。
平均 EE 为 1515±268 kcal·d(-1)，大多数患者（11/14）存在负 NB（-8.2±4.7 g·d(-1)）。发现能量摄入不足的发生率很高（53%），EI EE(-1)与 NB 之间存在正相关（r=0.670；P=0.007）。
结果表明 EI 不足和负 NB 的发生率较高，EI 与 EE 之间的平衡可能会改善 NB。间接热量法可用于调整危重症患者的能量需求。
