Chang W-K, McClave S-A, Chao Y-C
Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Republic of China, Taipei, Taiwan.
Clin Nutr. 2004 Feb;23(1):105-12. doi: 10.1016/s0261-5614(03)00101-8.
BACKGROUND & AIMS: Traditional use of gastric residual volumes (GRVs) is insensitive and cannot distinguish retained enteral formula from the large volume of endogenous secretions. We designed this prospective study to determine whether refractometry and Brix value (BV) measurements could be used to monitor gastric emptying and tolerance in patients receiving continuous enteral feeding.
Thirty-six patients on continuous nasogastric tube feeding were divided into two groups; patients with lower GRVs (<75 ml) in Group 1, patients with higher GRVs (>75 ml) in Group 2. Upon entry, all gastric contents were aspirated, the volume was recorded (Asp GRV), BV measurements were made by refractometry, and then the contents were reinstilled but diluted with 30 ml additional water. Finally, a small amount was reaspirated and repeat BV measurements were made. Three hours later, the entire procedure was repeated a second time. The BV ratio, calculated (Cal) GRV, and volume of formula remaining were calculated by derived equations.
Mean BV ratios were significantly higher for those patients in Group 2 compared to those in Group 1. All but one of the 22 patients (95%) in Group 1 had a volume of formula remaining in the stomach estimated on both measurements to be less than the hourly infusion rate (all these patients had BV ratios <70%). In contrast, six of the 14 patients in Group 2 (43%) on both measurements were estimated to have volumes of formula remaining that were greater than the hourly infusion rate (all these patients had BV ratios >70%). Three of the Group 2 patients (21%) whose initial measurement showed evidence for retention of formula, improved on repeat follow-up measurement assuring adequate gastric emptying. The remaining five patients from Group 2 (35%) had a volume of formula remaining that was less than the hourly infusion rate on both measurements. The pattern of Asp GRVs and serial pre- and post-dilution BVs failed to differentiate these patients in Group 2 with potential emptying problems from those with sufficient gastric emptying.
Refractometry and measurement of the BV may improve the clinical utilization of GRVs, by its ability to identify the component of formula within gastric contents and track changes in that component related to gastric emptying.
传统上对胃残余量（GRV）的使用不够灵敏，无法区分肠道营养制剂残留与大量内源性分泌物。我们开展了这项前瞻性研究，以确定折光测定法和白利度值（BV）测量是否可用于监测接受持续肠内喂养患者的胃排空及耐受性。
36例接受持续鼻胃管喂养的患者被分为两组；第1组患者的GRV较低（<75毫升），第2组患者的GRV较高（>75毫升）。入组时，抽吸所有胃内容物，记录体积（抽吸GRV），通过折光测定法进行BV测量，然后将内容物重新注入，但用30毫升额外的水进行稀释。最后，再次抽吸少量内容物并重复进行BV测量。3小时后，整个操作重复第二次。通过推导公式计算BV比值、计算得出的（Cal）GRV以及剩余的营养制剂体积。
第2组患者的平均BV比值显著高于第1组患者。第1组22例患者中，除1例（95%）外，两次测量估计胃内剩余的营养制剂体积均小于每小时输注速率（所有这些患者的BV比值<70%）。相比之下，第2组14例患者中有6例（43%）两次测量估计胃内剩余的营养制剂体积均大于每小时输注速率（所有这些患者的BV比值>70%）。第2组中有3例（21%）患者初始测量显示有营养制剂残留，重复随访测量时情况改善，表明胃排空充分。第2组其余5例患者（35%）两次测量胃内剩余的营养制剂体积均小于每小时输注速率。抽吸GRV以及系列稀释前和稀释后的BV模式未能区分第2组中存在潜在排空问题的患者与胃排空充分的患者。
折光测定法和BV测量可能会改善GRV的临床应用，因为它能够识别胃内容物中营养制剂的成分，并追踪该成分与胃排空相关的变化。
