35%总体表面积烧伤犬小肠对葡萄糖-电解质液吸收效率的研究

目的 研究35%总体表面积(TBSA)Ⅲ度烧伤休克对Beagle犬小肠葡萄糖一电解质液(GES)吸收效率的影响,比较肠内补液与静脉补液的复苏效果.方法 成年雄性Beagle犬12只,采用凝固汽油燃烧法造成35%TBSAⅢ度烧伤,伤后0.5 h开始按Parkland公式计算的量和速率补液.随机分为肠内输注GES组(EGES)和静脉输注乳酸林格液组(IVLR).在清醒状态下观察EGES组伤后8 h内肠道对水分和Na+的吸收速率,以及两组动物血浆Na+浓度、血浆容量(PV)、平均动脉压(MAP)、心排血量(CO)和尿量的变化;伤后8 h收集肠内残余的液体计算吸收总量.结果 伤后肠道对水分和Na+的吸收速率明显降低,3.5 h降至伤前的21%和37%,其后缓慢回升,至伤后8 h仍低于伤前;8 h内液体平均吸收速率(99±47)ml·h-1·m-1]与输入速率(81±11)ml·h-1·m-1]比较差异无统计学意义(P＞0.05),吸收液体总量为输入量的(94.8±3.7)%.伤后8 h内两组血浆Na+浓度、MAP、CO的变化趋势一致,差异均无统计学意义(P均＞0.05).伤后4 h EGES组尿量和PV均明显少于IVLR组(P均＜0.05),但8 h两组比较差异无统计学意义(P均＞0.05).结论 35% TBSA烧伤休克进行肠内补液时,液体吸收效率和吸收总量可满足Parkland公式要求,能达到与静脉补液同样的扩容和改善血流动力学效果.

Study on intestinal absorption rate of glucose-electrolyte solution during enteral resuscitation of 35% total body surface area burn injury in dog

OBJECTIVE: To investigate the intestinal absorption rate of glucose-electrolyte solution (GES) during enteral resuscitation of burn injury in Beagle dogs, and compare the effect of enteral intake with that of intravenous infusion resuscitation. METHODS: Twelve male Beagle dogs were subjected to a 35% total body surface area (TBSA) full-thickness flame III degree injury. Thirty minutes after burn, each dog was given either enteral resuscitation with a GES (EGES group) or intravenous resuscitation with lactated Ringer's solution (IVLR group), and the amount and speed of replenishment of fluid were in accordance with Parkland formula. In the first 8 hours post burn, intestinal absorption rates of water and Na+ were continuously assessed using phenol red as a nonabsorbable marker for water absorption rate. The plasma volume (PV) was measured by the dye (indocyanine green) dilution technique, and the plasma concentration of Na+, mean arterial pressure (MAP) cardiac output (CO), and urine volume were also determined in the first 8 hours. All above measurement were performed in animals without anesthesia. At the end of 8-hour-period of experiment, the remnant fluids in the intestine were collected to calculate the total volume of fluid absorbed in 8 hours. RESULTS: The intestinal absorption rates of water and Na+ reduced markedly down to lowest level (21% and 37% of pre-injury level) at 3.5 hours post burn, and then increased slowly. But the mean absorption rate of water was similar to infusing rate according to Parkland formula (99+/-47) mlxh(-1)xm(-1) vs. (81+/-11) mlxh(-1)xm(-1), P>0.05]. The total fluid absorbed by intestine was (94.8+/-3.7)% of the total fluid infused within 8 hours post burn. There were no significant differences in plasma concentration of Na+, MAP and CO between two groups at 8 hours post burn. The urine volume and PV at 4 hours in EGES group were lower than those in IVLR group (both P<0.05), but those indexes at 8 hours showed no significant difference between two groups (both P>0.05). CONCLUSION: Intestinal absorption rate of fluid given according to Parkland formula after burn injury is sufficient to resuscitate shock in animals suffering from a 35%TBSA full-thickness burn. Enteral resuscitation with GES may attain a similar therapeutic effect in expanding PV and maintain hemodynamic parameters.