Lavoie J C, Bélanger S, Spalinger M, Chessex P
Research Center of Hospital Sainte-Justine, University of Montreal, Montreal, Quebec, Canada.
Pediatrics. 1997 Mar;99(3):E6. doi: 10.1542/peds.99.3.e6.
Peroxides have been reported to contaminate lipid emulsions and amino acid solutions used in total parenteral nutrition (TPN). This is particularly disturbing in newborn infants who are prone to several diseases related to immature defense mechanisms against oxidative challenges. It is not clear whether the antioxidants in multivitamins help protect parenteral nutrients against the hazards of oxidation.
To evaluate the role of a multivitamin preparation (MVI) on the actual peroxide load received by patients on TPN.
The generation of peroxides in parenteral nutrition was tested first using test solutions. We compared the relative contribution of commercially available amino acid solutions, a lipid emulsion, and MVI on the level of peroxides in clinically relevant TPN solutions. Second, we measured the level of peroxides actually infused at the bedside. In both circumstances, the effects of time and light exposure were isolated. The level of peroxides was determined by a colorimetric technique and expressed as microM equivalents tert-butyl hydroperoxide (microM = TBH).
Even when protected from light, the addition of MVI produced a 10-fold increase in peroxides (mean +/- SEM, n = 3, 19 +/- 4 to 189 +/- 8 microM = TBH at 4 h) in the fat-free TPN solution and a fourfold increase (64 +/- 6 to 244 +/- 8 microM = TBH at 4 h) in the lipid-containing TPN solution. A dose-response relationship was found between the concentration of MVI and peroxide levels. The effect of light was the strongest in the presence of multivitamins. The amino acid solutions had a relative inhibitory effect on the generation of peroxides by MVI, which varied (from 54 +/- 1% to 72 +/- 1%) all according to the amino acid blend. In parenterally fed premature infants, protecting the intravenous set from light decreased the load of infused peroxides (146 +/- 15 vs 215 +/- 24 microM = TBH).
The lipid emulsion had a significant but minor additive effect compared with the multivitamin preparation, which was the major contributor to the generation of peroxides. Protection from photooxidation is not sufficient to prevent peroxidation of TPN solutions. Contrary to what one would expect, increasing the concentration of MVI will lead to a greater generation of peroxides, suggesting that the essential antioxidants in MVI do not have antiperoxide properties.
据报道，过氧化物会污染全胃肠外营养（TPN）中使用的脂质乳剂和氨基酸溶液。这在新生儿中尤其令人不安，因为他们容易患几种与针对氧化应激的不成熟防御机制相关的疾病。目前尚不清楚多种维生素中的抗氧化剂是否有助于保护胃肠外营养成分免受氧化危害。
评估一种多种维生素制剂（MVI）对接受TPN治疗的患者实际过氧化物负荷的作用。
首先使用测试溶液检测胃肠外营养中过氧化物的生成情况。我们比较了市售氨基酸溶液、脂质乳剂和MVI对临床相关TPN溶液中过氧化物水平的相对贡献。其次，我们测量了在床边实际输注的过氧化物水平。在这两种情况下，均分离出时间和光照的影响。过氧化物水平通过比色技术测定，并以微摩尔当量叔丁基过氧化氢表示（微摩尔 = TBH）。
即使避光，在无脂TPN溶液中添加MVI会使过氧化物增加10倍（平均值±标准误，n = 3，4小时时从19±4微摩尔 = TBH增至189±8微摩尔 = TBH），在含脂质的TPN溶液中增加4倍（4小时时从64±6微摩尔 = TBH增至244±8微摩尔 = TBH）。发现MVI浓度与过氧化物水平之间存在剂量反应关系。在多种维生素存在的情况下，光照的影响最强。氨基酸溶液对MVI产生过氧化物具有相对抑制作用，根据氨基酸混合比例不同，抑制作用有所变化（从54±1%至72±1%）。在经胃肠外营养喂养的早产儿中，对静脉输液装置进行避光处理可降低输注的过氧化物负荷（146±15微摩尔 = TBH对215±24微摩尔 = TBH）。
与多种维生素制剂相比，脂质乳剂具有显著但较小的累加效应，多种维生素制剂是过氧化物生成的主要贡献者。防止光氧化不足以防止TPN溶液的过氧化。与预期相反，增加MVI的浓度会导致更多过氧化物生成，这表明MVI中的必需抗氧化剂不具有抗过氧化物特性。
