Abilés Jimena, de la Cruz Antonio Pérez, Castaño José, Rodríguez-Elvira Manuel, Aguayo Eduardo, Moreno-Torres Rosario, Llopis Juan, Aranda Pilar, Argüelles Sandro, Ayala Antonio, de la Quintana Alberto Machado, Planells Elena Maria
Nutrition and Dietary Unit, Virgen de las Nieves Hospital, Fuerzas Armadas Avenue, 18014 Granada, Spain.
Crit Care. 2006;10(5):R146. doi: 10.1186/cc5068.
Critically ill patients suffer from oxidative stress caused by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Although ROS/RNS are constantly produced under normal circumstances, critical illness can drastically increase their production. These patients have reduced plasma and intracellular levels of antioxidants and free electron scavengers or cofactors, and decreased activity of the enzymatic system involved in ROS detoxification. The pro-oxidant/antioxidant balance is of functional relevance during critical illness because it is involved in the pathogenesis of multiple organ failure. In this study the objective was to evaluate the relation between oxidative stress in critically ill patients and antioxidant vitamin intake and severity of illness.
Spectrophotometry was used to measure in plasma the total antioxidant capacity and levels of lipid peroxide, carbonyl group, total protein, bilirubin and uric acid at two time points: at intensive care unit (ICU) admission and on day seven. Daily diet records were kept and compliance with recommended dietary allowance (RDA) of antioxidant vitamins (A, C and E) was assessed.
Between admission and day seven in the ICU, significant increases in lipid peroxide and carbonyl group were associated with decreased antioxidant capacity and greater deterioration in Sequential Organ Failure Assessment score. There was significantly greater worsening in oxidative stress parameters in patients who received antioxidant vitamins at below 66% of RDA than in those who received antioxidant vitamins at above 66% of RDA. An antioxidant vitamin intake from 66% to 100% of RDA reduced the risk for worsening oxidative stress by 94% (ods ratio 0.06, 95% confidence interval 0.010 to 0.39), regardless of change in severity of illness (Sequential Organ Failure Assessment score).
The critical condition of patients admitted to the ICU is associated with worsening oxidative stress. Intake of antioxidant vitamins below 66% of RDA and alteration in endogenous levels of substances with antioxidant capacity are related to redox imbalance in critical ill patients. Therefore, intake of antioxidant vitamins should be carefully monitored so that it is as close as possible to RDA.
危重症患者遭受由活性氧（ROS）和活性氮（RNS）引起的氧化应激。尽管在正常情况下ROS/RNS会持续产生，但危重症会大幅增加其生成量。这些患者血浆和细胞内抗氧化剂、自由电子清除剂或辅助因子水平降低，参与ROS解毒的酶系统活性下降。在危重症期间，促氧化剂/抗氧化剂平衡具有功能相关性，因为它与多器官功能衰竭的发病机制有关。本研究的目的是评估危重症患者氧化应激与抗氧化维生素摄入及疾病严重程度之间的关系。
采用分光光度法在两个时间点测量血浆中的总抗氧化能力以及脂质过氧化物、羰基、总蛋白、胆红素和尿酸水平：重症监护病房（ICU）入院时和第7天。记录每日饮食情况，并评估抗氧化维生素（A、C和E）的摄入量是否符合推荐膳食摄入量（RDA）。
在ICU入院至第7天期间，脂质过氧化物和羰基显著增加，同时抗氧化能力下降，序贯器官衰竭评估评分恶化更严重。抗氧化维生素摄入量低于RDA的66%的患者，其氧化应激参数的恶化程度显著高于摄入量高于RDA的66%的患者。无论疾病严重程度（序贯器官衰竭评估评分）如何变化，抗氧化维生素摄入量为RDA的66%至100%可使氧化应激恶化风险降低94%（比值比0.06，95%置信区间0.010至0.39）。
入住ICU患者的危急状况与氧化应激恶化有关。抗氧化维生素摄入量低于RDA的66%以及具有抗氧化能力的内源性物质水平改变与危重症患者的氧化还原失衡有关。因此，应仔细监测抗氧化维生素的摄入量，使其尽可能接近RDA。
