35% TBSA Ⅲ度烫伤大鼠肠内补液时葡萄糖电解质液的吸收效率研究

Efficiency of intestinal absorption to glucose electrolyte solution during enteral rehydration in 35% TBSA scalded rats

目的观察35% TBSA Ⅲ度烫伤早期肠内补液时电解质和水的吸收效率变化,了解葡萄糖对小肠吸收电解质溶液的影响。方法雄性Wistar大鼠30只,20%乌拉坦(100mg/kg)肌注麻醉后,行十二指肠和回肠插管,与输液泵相连。将林格液或葡萄糖-林格液作为灌流液置于37℃恒温水浴箱中,通过输液泵控制流速进行肠内补液并形成肠内灌流环路(灌流液-十二指肠插管-十二指肠-回肠-回肠插管-灌流液)。实验动物随机分为假烫补林格液组(假烫LR组)、烫伤补林格液组(烫伤LR组)和烫伤补葡萄糖-林格液组(烫伤LR/G组,林格氏液中加入20g/L的葡萄糖粉),每组10只。烫伤组采用沸水法(100℃,15s)造成35%TBSA Ⅲ度烫伤。各组于烫伤后0.5h按1/2Parkland公式量和速率(2ml.1%TBSA-1.kg-1)进行肠内补液,测定肠道对水分和Na+的吸收速率。伤后4h处死动物测定血Na+浓度和血细胞比容。结果与假烫LR组比较,两烫伤组小肠对水和Na+的吸收以及血Na+浓度均显著降低(P<0.01),血细胞比容显著增高(P<0.01),伤后3h烫伤LR组水和Na+的吸收效率仅为伤前的29.7%和34.5%。烫伤LR/G组对水和Na+的吸收优于烫伤LR组,从伤后2h起差别显著(P<0.05);伤后4h烫伤LR/G组血细胞比容显著低于烫伤LR组(P<0.05),但两组血Na+浓度无显著差异(P>0.05)。结论大鼠35% TBSA Ⅲ度烫伤早期小肠对水和电解质液的吸收效率显著降低,肠内补液时葡萄糖-电解质液的吸收效率和扩容效果优于单纯电解质溶液。

Objective To investigate the changes in efficiency of intestinal absorption to glucose electrolyte solution during enteral rehydration in scalded rats, and evaluate the effects of glucose on the gut absorbability to electrolyte and water. Methods Thirty male Wistar rats were randomly divided into three groups （10 each） ： shame scald with enteral Ringers solution （shame LR）, scald with enteral LR （scald LR） and scald with enteral LR containing 20g/L glucose group （scald LR/G）. Scald injury on back of about 35% TBSA was produced with boiling water （100℃, 15s）. For all the animals, 0. 5cm silica gel eannula were inserted into duodenal and ileum respectively under anesthesia. Fluid （LR or LR containing glucose） was given with a perfusion pump into the duodenum, and it was collected from ileum to form a fluid circulation. The amount and delivery speed of resuscitation fluid were estimated according to 1/2 of Parkland formula （2ml · 1% TBSA^1 · kg^1 within 4 hours post scald） from 0. 5h post injury. During the first 4 hours post scald, intestinal absorption rate of water and Na was continuously assessed using phenol red as an absorption indicator. Animals were sacrificed at 4h after scald, and the plasma concentrations of Na and hematocrit were determined. Results The scald injury resulted in a significant decrease in efficiency of gut absorption to water and Na , and hematocrit was elevated in two scald groups compared with those in sham LR group （P〈0. 01）. The efficiency of intestinal absorption to water and Na in scald LR/G group was significantly enhanced compared with that in scald LR group from 2h after injury （P〈0. 05）. There was also much significant lowering of hematocrit in scald LR/G rats than that in scald LR group at 4h post scald. Conclusion 35% TBSA of scald injury may lower the gut absorptive ability of rats to water and Na significantly. Enteral rehydration with glucose-electrolyte solution is superior to electrolyte solution in improving the intestinal absorption and expanding the plasma volume.