Silvers K M, Darlow B A, Winterbourn C C
Department of Pathology, Christchurch School of Medicine, New Zealand.
JPEN J Parenter Enteral Nutr. 1998 Sep-Oct;22(5):311-4. doi: 10.1177/0148607198022005311.
Calcium and heparin are known to destabilize the lipid emulsion of total parenteral nutrition (TPN). However, these observations were made over long periods of time, using 5 to 10 times the amount of heparin used in a neonatal intensive care unit. We investigated the effects of lower heparin concentrations with lipid-to-nutrient ratios normally administered to premature infants.
Lipid emulsion stability was assessed over 30 minutes by measuring viscosity at 10 mmol/L calcium after the addition of 0, 0.5, 1, and 5 IU heparin/mL. This was done at a range of lipid-to-nutrient ratios in clinical use. The effect of varying calcium concentration and different multivitamin preparations on emulsion stability also was observed.
Heparin caused an immediate increase in viscosity of pure Intralipid 20% (Intralipid; Kabi Pharmacia AB, Stockholm, Sweden), which eventually separated into two phases. Although changes in viscosity were observed at 1:1 lipid-to-nutrient ratios, no effect was seen at a 1:9 ratio. With the 1:1 ratio, the multivitamin preparations, MVI Pediatric (Rhone-Poulec Rorer, Montreal, Canada) and Vitlipid (Kabi Pharmacia AB), reduced the increase in viscosity.
Heparin and calcium destabilize Intralipid. This is unlikely to cause problems for most infants receiving TPN, provided low heparin concentrations are used. In all cases, especially where the lipid ratio is high, the risk of the lipid phase separating out can be further minimized by (1) the addition of multivitamin preparations containing detergent or an emulsifying agent and (2) by having the shortest possible delivery tube between the point of mixing the lipid and amino acid solutions of TPN and entry into the infant.
已知钙和肝素会破坏全胃肠外营养（TPN）的脂质乳剂稳定性。然而，这些观察结果是在长时间内得出的，使用的肝素量是新生儿重症监护病房常用量的5至10倍。我们研究了在以通常用于早产儿的脂质与营养素比例下，较低肝素浓度的影响。
在添加0、0.5、1和5 IU肝素/毫升后，通过测量10 mmol/L钙时的粘度，在30分钟内评估脂质乳剂稳定性。这是在一系列临床使用的脂质与营养素比例下进行的。还观察了不同钙浓度和不同多种维生素制剂对乳剂稳定性的影响。
肝素使纯20%英脱利匹特（英脱利匹特；瑞典斯德哥尔摩卡比制药公司）的粘度立即增加，最终分离成两个相。尽管在脂质与营养素比例为1:1时观察到粘度变化，但在1:9比例时未观察到影响。在1:1比例下，多种维生素制剂，儿科用多种维生素注射液（加拿大蒙特利尔罗纳-普朗克-罗瑞尔公司）和维他利匹特（卡比制药公司）减少了粘度增加。
肝素和钙会破坏英脱利匹特的稳定性。如果使用低肝素浓度，这对大多数接受TPN的婴儿不太可能造成问题。在所有情况下，特别是脂质比例较高时，通过（1）添加含有去污剂或乳化剂的多种维生素制剂和（2）在混合TPN的脂质和氨基酸溶液点与进入婴儿处之间使用尽可能短的输送管，可进一步将脂质相分离的风险降至最低。
