不同补液量对重度烧冲复合伤犬脏器功能的影响

Effects of resuscitating fluid volume changes on internal organ functions after burn-blast combined injury

目的探讨烧冲复合伤休克期不同补液量对机体脏器功能的影响,从而明确烧冲复合伤休克期补液适当的补液量。方法将32只健康雄性比格犬建立Ⅲ度烧伤35%总体表面积并中度冲击伤的烧冲复合伤模型后,随机分为对照组、增量10%组、增量20%组、增量30%组,每组8只。对照组按Parkland公式进行补液治疗,增量10%组、增量20%组、增量30%组则分别在Parkland公式补液量基础上增加10%、20%、30%补液量,其补液速度亦相应分别提升10%、20%、30%,各时间段匀速补液。在伤前及伤后4、8、24、48 h时,分别通过Pi CCO心肺容量监护仪测量心输出量、血管外肺水指数;通过生化检验测量血清谷丙转氨酶、血肌酐、血尿素氮等;通过快速血气分析检测动脉血氧分压。通过尿路置管记录伤后24 h尿量,并计算尿输出量。结果伤后4 h,对照组、增量10%组、增量20%组和增量30%组尿输出量依次为(0.39±0.11)、(0.55±0.13)、(0.77±0.17)、(0.98±0.19)m L·kg-1·h-1,增量20%组和增量30%组均高于对照组(t=5.308、7.601)和增量10%组(t=2.908、5.283),差异均有统计学意义(均P<0.05);伤后24 h,四组尿量依次为(0.59±0.05)、(0.70±0.07)、(0.88±0.05)、(1.21±0.09)m L·kg-1·h-1,两两比较差异均有统计学意义(均P<0.05)。对照组、增量10%组、增量20%组和增量30%组伤后心输出量较伤前降低,4 h时分别为(1.25±0.17)、(1.36±0.17)、(1.57±0.19)、(1.72±0.19)L/min,增量20%组和增量30%组高于对照组,差异均有统计学意义(t=3.550、5.214,均P<0.05);伤后24 h,四组心输出量依次为(2.63±0.24)、(2.64±0.21)、(2.76±0.18)、(2.40±0.19)L/min,增量20%组高于增量30%组,差异具有统计学意义(t=3.890,P<0.05)。伤后对照组和增量30%组谷丙转氨酶高于增量20%组,伤后24 h(t=2.745、3.864)、48 h(t=5.080、6.869)和72 h(t=4.195、5.143),差异均有统计学意义(P<0.05)。伤后4 h和8 h时,增量20%组、增量30%组血尿素氮低于对照组,伤后4 h(t=4.372、7.429),伤后8 h(t=3.719、6.171),差异均有统计学意义(均P<0.05),增量20%组、增量30%组低于增量10%组,伤后4 h(t=3.519、6.508)、伤后8 h(t=3.922、6.835),差异均有统计学意义(均P<0.05)。伤后各组间血肌酐比较差异均无统计学意义(均P>0.05)。四组伤后较伤前,血管外肺水指数均上升,动脉氧分压下降,组间比较差异均无统计学意义(均P>0.05)。结论犬Ⅲ度烧伤35%总体表面积并中度冲击伤休克适宜的补液量应按Parkland公式补液量增量20%计算,即第一个24 h内4.8 m L·kg-1·h-1,第二个24 h内2 m L·kg-1·h-1,与Parkland公式补液量及增量10%相比,可在伤后早期显著改善尿输出量和心输出量,且不会引起肺水肿的加重;增量30%与增量20%相比,尿输出量提升过高,早期容量负荷过重。

Objective To figure out an optimal resuscitating fluid volume after burn-blast combined injury by determining effects of gradient volume changes on internal organ functions. Methods Thirty-two healthy male beagle dogs were subjected to a burn-blast combined injury （35% total body surface area full thickness burn combined with middle severity blast injury） and randomLy assigned into 4 groups, namely, the controlled group, volume increasing group 10% , 20% and 30% , with 8 dogs in each group. The controlled group was resuscitated with the Parkland formula, while additional 10%, 20%, 30% fluid were given to the increasing group 10% , 20% , 30% , respectively, and their infusing rates were also increased by 10% , 20% , 30% , respectively. Cardiac output, extravascular lung water index were determined with PiCC0（Pulse indicated Continuous Cardiac Output）device pre and 4, 8, 24, 48 h post injury. Serum alanine aminotransferase, creatinine, blood urea nitrogen were determined through biochemical arrays pre and 4, 8, 24, 48, 72 h post injury. Arterial oxygen pressure were determined with blood gas analysis pre and 4, 8, 24, 48 h post injury. Urinary volume was recorded throughout 24 h post injury to calculate the urinary output 4, 8, 24 h post injury. Results Urinary output in the controlled group and volume increasing group 10%, 20%, 30% at4 h post injury were （0.39±0. 11）, （0.55±0. 13）, （0.77±0. 17）, （0.98±0.19）mL·kg-1·h-1, respectively. Volume increasing group 20% and 30% were both remarkably higher than either the controlled group （t = 5. 308,7. 601, P 〈 0.05 ）or volume increasing group 10% （t = 2. 908,5. 283, P 〈 0.05 ）. They were （0.59±0.05 ）, （0.70±0.07 ）, （0.88±0.05 ）, （1.21±0.09） mL·kg^-1·h^-1 at 24 h post injury. Significant differences exist between every two groups （P 〈 0.05）. Cardiac output decreased considerably to （ 1.25±0.17 ）, （ 1.36±0.17 ）, （ 1.57±0. 19）, （1.72±0.19） L/min at 4 h post injury, respectively. Volume increasing group 20% and 30% were both remarkably higher than the controlled group （ t = 3. 550,5. 214, P 〈0. 05）. While cardiac output were （2.63±0.24）, （2.64±0.21）, （2.76±0.18）, （2.40 ±0.19） L/min at 24 h post injury. Volume increasing group 20% were significantly higher than Volume increasing group 30% （ t = 3. 890, P 〈 0.05 ）. Serum alanine aminotransferase were remarkably higher in the controlled group and volume increasing group 30% than in volume increasing group 20% at 24 h post injury（t =2. 745,3. 864 ,P 〈0.05） ; the differences remained at 48 h （ t = 5. 080,6. 869, P 〈 0.05 ） and 72 h （ t = 4. 195,5. 143, P 〈 0.05 ） post injury. No significant difference was seen between every two group on extravaseular lung water index, creatinine and arterial oxygen pressure （ P 〉 0.05 ）. Conclusion Burn- blast combined injury concerned in this experiment requests additional 20% fluid when being resuscitated with the Parkland formula, i. e. 4.8 mL·kg^-1·h^-1 lactated ringer＇s solution administrated over the 1st 24 h and 2 mL·kg^-1·h^-1 over the 2nd 24 h. This volume promotes cardiac output and urinary output better during the early stage post injury, while won＇t aggravate lung edema. Further more fluid seems to contribute to fluid overload characterized by overly high urinary output and unsatisfying low cardiac output during the late stage.