Faculty of Medicine, University of Southampton, United Kingdom.
Clin Nutr. 2012 Dec;31(6):974-80. doi: 10.1016/j.clnu.2012.05.001. Epub 2012 Jun 6.
BACKGROUND & AIMS: Recommendations limit infusion of parenteral nutrition (PN) from bags with lipid to 24 h (48 h if lipid free) because lipid putatively encourages contaminant growth. This study aimed to examine these recommendations and identify factors affecting Staphylococcus epidermidis growth in PN.
S. epidermidis growth was assessed in quadruplicate in 12 PN regimens, with and without lipid and varying glucose concentrations.
Baseline colony forming units (cfu)/mL (32.6) less than doubled at 48 h in all infusates. In PN infusates (pH 6.2 + 0.02 (SEM)) growth was independently increased by the presence of 5% w/v lipid (14.2 cfu/mL; P = 0.028), and glucose concentration (25.6 cfu/mL per 10% increase in w/v glucose; P = 0.003). In a separate analysis growth was stimulated by energy density (27.7 cfu/1000 kcal non-nitrogen energy in 2 L; P = 0.002), without a significant effect of % non-protein energy from lipid (-2.6 cfu/ml per 10%).
Using a framework developed to examine growth of potential contaminants in PN, no evidence was found to support the specific recommendation to restrict the maximum infusion duration of lipid containing PN to a greater extent than lipid free PN. S. epidermidis growth was not only affected by the presence of lipid, but also glucose concentration and energy density.
建议将含脂的肠外营养（PN）输注限制在 24 小时（如果无脂则为 48 小时），因为脂质据称会促进污染物的生长。本研究旨在检验这些建议，并确定影响表皮葡萄球菌在 PN 中生长的因素。
在有无脂质和不同葡萄糖浓度的 12 种 PN 方案中，重复评估 4 倍表皮葡萄球菌的生长情况。
所有输注物在 48 小时时的基线菌落形成单位（cfu）/mL（32.6）均未翻倍。在 PN 输注物（pH 6.2±0.02（SEM））中，存在 5%w/v 脂质（14.2cfu/mL；P=0.028）和葡萄糖浓度（w/v 葡萄糖每增加 10%，cfu/mL 增加 25.6；P=0.003）会独立增加生长。在另一项分析中，生长受到能量密度的刺激（2L 中每 1000 千卡非氮能量 27.7cfu/1000 千卡；P=0.002），但脂质中非蛋白能量的百分比（每增加 10%，cfu/ml 减少 2.6）没有显著影响。
使用一种框架来检验 PN 中潜在污染物生长的情况，没有证据支持将含脂 PN 的最大输注时间限制比无脂 PN 更长的具体建议。表皮葡萄球菌的生长不仅受脂质的存在影响，还受葡萄糖浓度和能量密度的影响。
