Chang Wei-Kuo, Chao You-Chen, Yeh Ming-Kung
Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No 325, Cheng-Kung Rd, Sec.2, Neihu 114, Taipei, Taiwan, ROC.
Asia Pac J Clin Nutr. 2008;17(1):116-22.
Parenteral nutrition (PN) solution contains various concentrations of dextrose, amino acids, lipids, vitamins, electrolytes, and trace elements. Incorrect preparation of PN solution could lead to patient death. In this study we used the refractive index as a quality assurance tool to monitor the preparation of PN solution. Refractive indices of single nutrient components and PN solutions consisting of various concentrations of dextrose, amino acids, electrolytes, and lipids were measured. A mathematical equation and its linear plot were generated then used to predict the refractive index of the PN solution. The best-fit refractive index for PN solution (i.e., the predicted refractive index)=0.9798x(% dextrose)+1.2889x(% amino acids)+1.1017x(% lipids)+0.9440x(% sum of the electrolytes)+0.5367 (r2=0.99). This equation was validated by comparing the measured refractive indices of 500 clinical PN solutions to their predicted refractive indices. We found that 2 of the 500 prepared samples (0.4%) had less than the predicted refractive index (<95%). Refractive index can be used as a reliable quality assurance tool for monitoring PN preparation. Such information can be obtained at the bedside and used to confirm the accuracy of the PN solution composition.
肠外营养（PN）溶液含有不同浓度的葡萄糖、氨基酸、脂质、维生素、电解质和微量元素。不正确配制PN溶液可能导致患者死亡。在本研究中，我们使用折射率作为质量保证工具来监测PN溶液的配制。测量了单一营养成分以及由不同浓度葡萄糖、氨基酸、电解质和脂质组成的PN溶液的折射率。生成了一个数学方程及其线性图，然后用于预测PN溶液的折射率。PN溶液的最佳拟合折射率（即预测折射率）=0.9798×（葡萄糖百分比）+1.2889×（氨基酸百分比）+1.1017×（脂质百分比）+0.9440×（电解质总和百分比）+0.5367（r2=0.99）。通过比较500份临床PN溶液的测量折射率与其预测折射率，对该方程进行了验证。我们发现，500份配制样品中有2份（0.4%）的折射率低于预测折射率（<95%）。折射率可作为监测PN配制的可靠质量保证工具。此类信息可在床边获取，并用于确认PN溶液成分的准确性。
