卡巴胆碱对烧伤犬肠内补液时肠黏膜血流量和吸收效率的影响

目的 研究卡巴胆碱对50%总体表面积(TBSA)Ⅲ度烧伤休克Beagle犬肠内补液时肠黏膜血流量和吸收效率的影响.方法 成年雄性Beagle犬18只,采用凝固汽油燃烧法造成约(51.2±2.6)%TBSAⅢ度烧伤,伤后0.5 h开始按Parkland公式量和速率补液.随机将动物均分为静脉输葡萄糖一电解质液(GES)组(VGES)、肠内输GES组(EGES)和肠内输GES/卡巴胆碱组(EGES/CAR,含0.25 μg/kg卡巴胆碱的GES).在动物清醒状态下观察两个肠内补液组伤后8 h内小肠黏膜血流量(IBF)、水和Na+的吸收速率,以及3组动物血浆Na+浓度、血浆容量(PV)和伤后8 h小肠组织Na+-K+-ATP酶活性的变化.结果 伤后两个肠内补液组水和Na+的吸收速率均较伤前显著降低(P均＜0.05),EGES/CAR组自伤后1.5 h和2.5 h起显著高于EGES组(P均＜0.05),但8 h两组均低于伤前和按Parkland公式补液速率(P＜0.05).EGES组对肠内补液不耐受(腹泻)发生率为83%,显著高于EGES/CAR组的50%.伤后8 h EGES/CAR和EGES组输入肠内的液体仅有47.1%和63.8%被吸收;EGES/CAR组吸收液体总量和吸收率显著多于EGES组.伤后各组IBF均较伤前显著降低;伤后8 h已恢复到伤前水平(P＞0.05);EGES/CAR组IBF伤后2 h起高于EGES组(P＜0.05),但两个肠内补液组伤后8 h仍显著低于伤前和VGES组水平(P均＜0.05).3组伤后8 h小肠黏膜Na+-K+-ATP酶活性比较:VGES组＞EGES/CAR组＞EGES组(P＜0.05).两个肠内补液组伤后8 h内的血浆Na+浓度和PV均显著低于VGES组(P均＜0.05),但伤后4 h起EGES/CAR组显著高于EGES组(P均＜0.05).结论 50%TBSAⅢ度烧伤早期IBF和Na+-K+-ATP酶活性显著降低,肠内补液的吸收效率显著低于按Parkland公式输入速率,不能维持静脉补液的血浆Na+浓度和PV;而卡巴胆碱能增加IBF和Na+-K+-ATP酶活性,提高肠内补液的吸收速率、PV和血浆Na+浓度,改善口服补液的疗效.     

卡巴胆碱对烧伤休克犬口服补液时胃排空和胃黏膜二氧化碳分压的影响

目的 研究卡巴胆碱对烧伤犬休克早期口服补液时胃排空和胃黏膜二氧化碳分压(PgCO2)的影响.方法 将24只成年雄性Beagle犬随机分为4组:35%总体表面积(TBSA)烧伤后口服葡萄糖一电解质液(GES)组及其卡巴胆碱干预组(35%TBSA GES组和35%TBSA GES/CAR组);50%TBSA烧伤后口服GES液组及其卡巴胆碱干预组(50%TBSA GES组和50%TBSA GES/CAR组),每组6只.采用凝固汽油燃烧法分别造成颈背部35%TBSA Ⅲ度烧伤和颈背部+胸腹部50%TBSA Ⅲ度烧伤.各组于烧伤后0.5 h开始按Parkland公式量和速率(4 ml·kg-1·1%TBSA-1,前8 h内补1/e量,后16 h内补另1/2量)口服补液;GES/CAR组于伤后0.5 h口服卡巴胆碱(20 μg/kg溶于GES中).烧伤后2、4、8和24 h测定胃排空率和PgCO2,并观察胃不耐受症状.结果 烧伤后各组犬胃排空率均显著低于伤前(P均＜0.05),伤后2 h 35%TBSA GES组降至51.5%.伤后4 h 50%TBSA GES组降至39.2%,之后逐渐恢复,但伤后24 h仍显著低于伤前(P均＜0.05).35%TBSA GES/CAR组伤后各时间点胃排空率均显著高于同烧伤面积GES组(P均＜0.05),平均提高15.0%,伤后8 h恢复至伤前水平;50%TBSA GES/CAR组于8 h起胃排空率显著高于同烧伤面积GES组,但伤后24 h仍低于伤前水平(P＜0.05).伤后各组犬PgCO2均较伤前显著升高(P均＜0.05),35%TBSA GES/CAR组伤后各时间点显著低于同烧伤面积GES组,50%TBSA GES/CAR组伤后4 h起显著低于同烧伤面积GES组(P均＜0.05).伤后各组犬出现呕吐等胃不耐受症状情况比较:50%TBSA GES组(83.3%,5/6)＞50%TBSA GES/CAR组(50.0%,3/6)＞35% TBSA GES组(16.7%,1/6)＞35%TBSA GES/CAR组(0,0/6).结论 卡巴胆碱能显著改善Beagle犬烧伤休克早期胃对GES的排空,降低PgCO2,提高口服液体复苏的效果.     

卡巴胆碱对烧伤休克犬肠内补液时肠组织缺血／再灌注损伤的影响

目的 探讨卡巴胆碱(CAR)对烧伤休克期肠内补液时肠缺血/再灌注损伤的保护作用.方法 18只成年雄性Beagle犬被随机分为3组,每组6只.采用凝固汽油燃烧法造成50%总体表面积(TBSA)Ⅲ度烧伤模型.伤后无治疗(不补液组)或于伤后30 min开始从十二指肠造口分别输入葡萄糖-电解质溶液(GES组)或含CAR的GES(20 μg/kg CAR溶于GES,GES/CAR组),伤后8 h内输液量依据Parkland公式计算.检测伤前和伤后1、2、4、6、8 h小肠黏膜血流量(IMBF)及血浆肿瘤坏死因子-α(TNF-α)含量.伤后8 h处死动物,取空肠组织用干湿重法测定小肠组织含水量;并测定一氧化氮合酶 (NOS)、丙二醛(MDA)、髓过氧化物酶(MPO)、黄嘌呤氧化酶(XOD)水平.结果 各组伤后IMBF均显著降低,TNF-α显著升高;伤后4 h起GES组IMBF显著高于不补液组,6 h后显著低于GES/CAR组(P均<0.01);不补液组与GES组TNF-α含量差异无统计学意义,但伤后2 h和4 h均显著高于GES/CAR组(P均<0.01).伤后8 h GES组NOS、MDA、MPO和XOD均显著高于不补液组,而GES/CAR组分别比GES组低26.0%、17.1%、50.0%和19.2%,差异均有统计学意义(P<0.05或P<0.01).GES/CAR组肠组织含水量也显著低于GES组(P<0.01).结论 CAR能有效减轻烧伤犬肠内补液时肠组织缺血/再灌注损伤,机制可能与增加肠黏膜血流,抗炎和抑制XOD活性,减少炎症因子和氧自由基生成有关.     

卡巴胆碱对烧伤休克口服补液时肠屏障功能的影响

目的 研究拟胆碱药卡巴胆碱对犬烧伤休克口服补液时肠屏障功能的影响.方法成年雄性Beagle犬20只,采用凝固汽油燃烧法造成35% TBSA Ⅲ度烧伤,烧伤后随机分为延迟复苏(DR)组、口服葡萄糖-电解质溶液(GES)组、口服卡巴胆碱(CAL)组、口服葡萄糖-电解质溶液 卡巴胆碱(GES CAL)组.GES按Parkland公式(4 mL?kg-1?1% TBSA-1)经胃管输注,卡巴胆碱20 μg/kg溶于10 mL生理盐水中,分别于伤后30 min和4 h经胃管注入.烧伤24 h后各组均给予静脉输注5%葡萄糖生理盐水液进行延迟复苏.测定各组动物伤前及伤后2、4、8、24、48、72 h血浆二胺氧化酶(DAO)活性、D-乳酸(D-LA)含量和D-木糖(D-XY)含量.结果烧伤后DR组血浆DAO、D-LA和D-XY显著高于另外三组(P＜0.01,P＜0.05).各治疗组间比较,GES CAL组血浆DAO伤后2 h和4 h显著低于GES组和CAL组(P＜0.05),GES CAL组D-XY伤后8 h和24 h显著低于GES组和CAL组(P＜0.05).结论卡巴胆碱对犬烧伤休克口服补液时肠屏障功能有保护作用.     

卡巴胆碱对犬50%总体表面积烧伤口服补液时肺血管通透性和肺组织含水量的影响

目的 研究卡巴胆碱(CAR)对犬50%总体表面积(TBsA)烧伤休克期口服补液时肺血管通透性和肺组织含水量的影响.方法 成年雄性Beagle犬12只,先行颈动、静脉置管,24 h后造成50%TBSAⅢ度烧伤.伤后24 h随机分为口服补液组和口服补液+CAR组,每组6只,从胃内分别输注葡萄糖一电解质溶液(GES)和含CAR的GES液(20 gg/kg CAR溶于GES),伤后24 h起实施静脉延迟补液,补液量和速率均根据Parkland公式确定.于伤前(0)及伤后2、4、8、24、48和72 h测定各组犬呼吸频率(RR)、动脉血氧分压(PaO2)、血管外肺水指数(ELWI)和肺血管通透性指数(PVPI);于伤后72 h处死动物,取肺组织测定髓过氧化物酶(MPO)活性、丙二醛(MDA)含量以及肺组织含水量.结果 烧伤后两组动物RR、ELWI和PVPI较伤前均显著增加,PaO2显著降低(P均<0.01);伤后72 h PaO2恢复至伤前水平.口服补液+CAR组伤后4、8和24 h RR、ELWI和PVPI显著低于口服补液组,伤后8、24、48 h PaO2显著高于口服补液组(P<0.05或P<0.01),但伤后72 h两组间上述指标差异均无统计学意义(P均>0.05).伤后72 h口服补液+CAR组肺组织MPO活性、MDA含量及肺组织含水量均显著低于口服补液组[(2.64±0.38)U/mg比(4.12±0.46)U/rag,P<0.01;(3.60±0.54)μtmol/mg比(5.14±0.62)μmol/mg,P<0.01;(77.40±0.56)%比(78.30±0.54)%,P<0.01].结论 50%TBSA烧伤口服补液时给予CAR能抑制肺组织炎症反应和过氧化损伤,减轻烧伤休克引起的肺血管通透性增加和肺水肿.     

卡巴胆碱对大鼠烫伤休克期肠内补液时肠道的影响

目的 研究拟胆碱药卡巴胆碱对大鼠烫伤休克期肠内补液时肠道局部炎症反应和肠组织损伤的影响,为烧伤休克胃肠道补液研究提供依据.方法 38只雄性Wistar大鼠,采用沸水法(100℃,10 s)造成背部35%TBSAⅢ度烫伤.随机分为不复苏组(单烫组,n=8)、葡萄糖-电解质溶液(glucose electrolyte solution)复苏组(GES组,n=10)、卡巴胆碱治疗组(CAR组,n=10)和GES+卡巴胆碱复苏组(GES/CAR组,n=10).两液体复苏组大鼠在烫伤后30 min将GES经十二指肠造口匀速泵入,按Parkland公式设定补液速率,即烫伤后第一个24 h补液总量4 ml·1%TBSA-1·kg-1,前8 h匀速补一半.CAR组和GES/CAR组大鼠在伤后30 min将CAR以60μg·kg-1溶于0.5 ml生理盐水中一次注入十二指肠.所有大鼠在烫伤后4 h处死,取空肠组织测定一氧化氮合酶(N0s)、一氧化氮(NO)、肿瘤坏死因子-α(TNF-α)含量和髓过氧化物酶(MPO)活性,同时测定血浆二胺氧化酶(DAO)活性,采用组间方差分析统计比较各组上述指标的差别.结果 GES组的肠组织NOS、NO、TNF-α、MPO和血浆DAO水平与单烫组差异无统计学意义;GES/CAR组各指标较GES组均明显降低[NOS(1.276±0.39I vs.(1.818±0.436),P＜0.01;NO(0.925±0.402)vs.(1.561±0.379),P＜0.01;TNF-α(0.87±0.13)vs.(1.94±0.47),P＜0.01;MPO(0.465±0.092)vs.(0.832±0.214),P＜0.01;DAO(0.732±0.192)vs.(1.381±0.564),P＜0.01],CAR组各指标也较单烫组和GES组明显降低(P＜0.05或P＜0.01).结论 卡巴胆碱能减轻烫伤休克大鼠肠内液体复苏时的肠道局部炎症反应和组织损伤,其作用机制可能与其兴奋胆碱能神经N受体,抑制促炎因子释放的作用有关.     

口服补液对犬50%TBSA烧伤休克期循环氧动力学指标的影响

目的 研究口服补液对50%TBSA烧伤休克期循环氧动力学指标的影响,为提高烧伤休克口服补液的复苏效果提供依据.方法 成年雄性Beagle犬18只,先期无菌手术行颈动、静脉置管,24 h后用凝固汽油燃烧法造成50%体表面积Ⅲ度烧伤.随机分为不补液组(n=6)、口服补液组(n=6)和静脉补液组(n=6).伤后第一个24 h不补液组无治疗,口服补液组和静脉补液组根据Parkland公式分别从胃内或静脉输注葡萄糖-电解质溶液;伤后24 h起三组均实施延迟静脉补液.测定动物非麻醉状态下的平均动脉压(MAP)、红细胞压积(HCT)和血乳酸(LAC)含量,抽取动脉和混合静脉血测定动、静脉氧分压和血氧含量.计算氧供量(DO2)、氧耗量(VO2)和氧摄取(Oext),并统计3 d死亡率.结果 不补液组伤后8 h MAP比伤前降低77.1%,HCT和血乳酸分别升高48.5%和533.7%;DO2,VO2和Oext水平伤后进行性降低,24 h内动物全部死亡.两补液组上述指标逐渐恢复,伤后72 hMAP和HCT恢复至伤前(P＞0.05),但血乳酸水平仍显著高于伤前(P＜0.01).伤后24 h内同期比较,口服补液组MAP,DO2,VO2和Oext水平显著高于不补液组(P＜0.01),但低于静脉补液组;血乳酸低于不补液组,但高于静脉补液组(P＜0.01).伤后24 h起Do2与静脉补液组差异无统计学意义(P＞0.05),但VO2和Oext仍显著低于静脉补液组(P＜0.01).72 h死亡率:不补液组100%、口服补液组50%(3/6),而静脉补液组为零.结论 50%TBSA烧伤休克期采用口服补液能显著改善动物循环氧动力学指标,减轻高乳酸血症,降低动物的病死率.     

血浆代用品血定安应用于烧伤休克复苏的临床研究

目的 :验证血浆代用品 (血定安 )在烧伤休克液体复苏中的临床疗效。方法 :2 0例烧伤总体表面积( TBSA)大于 40 %且因延迟复苏导致休克的烧伤患者 ,随机分为血定安复苏组 (血定安组 ,n=11)和血浆复苏组 (血浆组 ,n=9)进行复苏 ,观察休克期心排血量 ( CO)、氧供给 ( DO2 )、血细胞比容、血液黏度、血浆黏度、乳酸( L A)含量及碱缺失 ( BD)等血流动力学、血液流变学及氧代谢指标的变化。结果 :快速补液 2 h后 ,CO和 DO2显著升高 ( P<0 .0 5或 P<0 .0 1) ,血细胞比容、血液黏度、血浆黏度、L A和动脉血 BD显著下降 ( P<0 .0 5或P<0 .0 1)。两组间比较 ,伤后 2 4h内血定安组补液后血浆黏度显著低于血浆组 ( P均 <0 .0 5 ) ,其余指标无显著性差异 ( P均 >0 .0 5 )。结论 :在烧伤后休克复苏中 ,血浆代用品血定安与血浆的疗效相近 ,可以在烧伤休克早期救治中广泛应用。     

延迟快速复苏对烧伤休克犬若干炎症介质变化的影响

目的：探讨烧伤后延迟复苏情况下,快速补液对若干炎症介质浓度变化的影响。方法：利用犬40％TBSAⅢ度烫伤模型,24只狗被随机分为烧伤对照组（C组）、延迟均匀被补液组（E组）和延迟快速补液组（R组）进行补液,观察伤前及伤后2、6、8、12、36和48h血中肿瘤坏死因子（TNF）、内皮素（ET）、一氧化氮（NO）、血管紧张素（AⅡ）和丙二醛（MDA）等指标的组快速补流2h后（伤后8h)各指标显著低于E组。结论：在烧伤后延迟复苏情况下,快速补液可以迅速降低体内炎症介质含量,可能对减轻失控性炎症反应有积极作用。     

严重烧伤后血浆IL-12浓度变化的临床护理意义探讨

目的研究严重烧伤后血浆IL－12浓度的变化及其临床护理意义。方法ELISA法检测18例严重烧伤患者伤后2周内的血浆IL－12浓度。结果在40％≤TBSA≤60％组IL－12血浆浓度最低值显著高于TBSA＞60％组；首次切痂后血浆IL－12血浆浓度要高于手术前。结论烧伤程度越重，对IL－12产生的抑制作用越强，预防感染护理越重要。     

How well does the Parkland formula estimate actual fluid resuscitation volumes?

We had anecdotally observed that fluid resuscitation volumes often exceed those estimated by the Parkland Formula in adults with isolated cutaneous burns. The purpose of this study was to compare estimated and actual fluid resuscitation volumes using the Parkland Formula. We performed a retrospective study of fluid resuscitation in patients with burns > or = 15% TBSA. Patients with inhalation injury, high voltage electrical injury, delayed resuscitation, or associated trauma were excluded. We studied 31 patients (mean age 51 +/- 20 years, mean TBSA burn 27 +/- 10%). The 24 hour resuscitation volume of 13 354 +/- 7386 ml (6.7 +/- 2.8 ml/kg/%TBSA) was significantly greater than predicted (P = 0.001) and exceeded estimated volume in 84% of the patients. The mean urine output in the first 24 hrs was 1.2 +/- 0.6 ml/kg/hr. After the first 8 hours of resuscitation, the infusion rate decreased by 34% in 16 patients (DCR group), while in 15 patients the rate increased by 47% (INCR group). Both the DCR and INCR groups received significantly more fluid than predicted, (5.6 +/- 2.1 ml/kg/%TBSA and 7.7 +/- 3.1 ml/kg/%TBSA respectively). The INCR patients had significantly larger full thickness burns (14 +/- 11% vs 3 +/- 6%, P < 0.001). Our findings reveal that despite its effectiveness, the Parkland Formula underestimated the volume requirements in most adults with isolated cutaneous burns, and especially in those with large full thickness burns.     

Evaluation of hyperdynamic resuscitation in 60% TBSA burn-injured sheep

It has been suggested that hyperdynamic (HD) resuscitation improves outcomes. We hypothesized that initial HD resuscitation of burn injury using fluid and inotropes would improve metabolic function as indicated by base excess. We used an anesthetized ovine model of 60% TBSA full-thickness flame burn with delayed resuscitation started at 90 min after burn and continued for 8 h. Three groups (n = 6 each) were included: 1) HD defined as cardiac index (CI) of 1.5x baseline achieved by using Ringer's lactate alone (HD-Fluid); 2) Ringer's lactate and dobutamine (HD-Drug); and 3) Parkland Formula (Parkland) as a control group. Statistical analysis performed using analysis of variance and Tukey's HSD test. Significance accepted at P < 0.05. Higher CI was achieved in both HD-Fluid and HD-Drug groups, e.g., at 8 h the CI was 4.6 +/- 0.4 and 4.7 +/- 0.6 L/min/m respectively, as compared with Parkland 3.6 +/- 0.5 L/min/m. The net fluid balance (fluid infused - urine output) was similar in both Parkland and HD-Drug groups, which were 2.5x more in HD-Fluid (P = 0.001). The mean postburn urinary outputs were similar in both Parkland and HD-Drug groups, e.g., Parkland (0.9 +/- 0.08 mL/kg/h), HD-Drug (1.0 +/- 0.2 mL/kg/h) and increased in HD-Fluid (3.7 +/- 1.0 mL/kg/h; P = 0.0005). Base excess remained positive in both HD-Drug (+2.5 +/- 1 mmol/L) and Parkland (+1.5 +/- 1.7 mmol/L), and declined to -4.0 +/- 3.6 mmol/L in HD-Fluid group (P = 0.036). We conclude that there may be no benefit to using hyperdynamic regimens for the initial resuscitation of burn injury.     

The Parkland formula under fire: is the criticism justified?

Controversy has continued regarding the practicality and accuracy of the Parkland burn formula since its introduction over 35 years ago. The best guide for adequacy of resuscitation is urine output (UOP) per hour. A retrospective study of patients resuscitated with the Parkland formula was conducted to determine the accuracy (calculated vs. actual volume) based on UOP. A review of burn resuscitation from a single institution over 15 years was conducted. The Parkland formula was defined as fluid resuscitation of 3.7 to 4.3 ml/kg/% total body surface area (TBSA) burn in the first 24 hours. Adequate resuscitation was defined as UOP of 0.5 to 1.0 ml/kg/hr. Over-resuscitation was defined as UOP > 1.0 ml/kg/hr. Patients were stratified according to UOP. Burns more than 19% TBSA were included. Electrical burns, trauma, and children (<15 years) were excluded. Four hundred and eighty-three patients were reviewed. Forty-three percent (n = 210) received adequate resuscitation. Forty-eight percent (n = 233) received over-resuscitation. The mean fluid in the adequately and over-resuscitated groups was 5.8 and 6.1 ml/kg/%, respectively (P = .188). Mean TBSA and full thickness burns in the adequately and over-resuscitated groups were 38 and 43%, and 19 and 24%, respectively (P < .05). Inhalation injury was present in 12 and 18% (P = .1). Only 14% of adequately resuscitated and 12% of over-resuscitated patients met Parkland formula criteria. The mean Ivy index in the adequately and over-resuscitated groups was 216 and 259 ml/kg (P < .05). There was no significant difference in complication rates (80 vs. 82%) or mortality (14 vs. 17%). The actual burn resuscitation infrequently met the standard set forth by the Parkland formula. Patients commonly received fluid volumes higher than predicted by the Parkland formula. Emphasis should be placed not on calculated formula volumes, as these should represent the initial resuscitation volume only, but instead on parameters used to guide resuscitation. The Parkland formula only represents a resuscitation "starting" point. The UOP is the important parameter.     

How long do we need to give antioxidant therapy during resuscitation when its administration is delayed for two hours?

Twenty-four guinea pigs with third-degree burns over 70% of the body surface area were divided equally into four groups. All animals received Ringer's lactate (R/L) beginning 30 minutes after burn injury. Group 1 received R/L without vitamin C beginning 2 hours after burn injury. Groups 2, 3, and 4 received R/L with vitamin C until 4, 8, and 24 hours after burn injury, respectively. Beginning 3 1/2 hours after burn injury the hourly fluid volume was reduced to 25% of the Parkland formula calculation. The hourly sodium and fluid intake in each group was the same. Groups 1 and 2 demonstrated higher hematocrit and lower cardiac output values as compared with those values for group 3, indicating hypovolemia and hemoconcentration in these groups. Group 3 showed hematocrit and cardiac output values equivalent to those values for group 4. We conclude that high-dose vitamin C must be given until 8 hours after burn injury to maintain adequate hemodynamic stability in the presence of a reduced resuscitation fluid volume.     

The methamphetamine burn patient

Early aggressive fluid resuscitation has significantly decreased the morbidity and mortality associated with volume losses from large burns. Although most patients are adequately resuscitated using the Parkland formula, we noted increased fluid requirements for shock resuscitation in patients involved in methamphetamine laboratory explosions. Because predominant users are young healthy individuals in their 20s and 30s, we had not anticipated burn shock resuscitation failures in this patient group. We reviewed our experience with burn patients with documented methamphetamine use to determine whether this patient group presents new dilemmas to the burn surgeon. A 2-year retrospective study of 30 patients (15 methamphetamine users, 15 controls) revealed that the methamphetamine burn patient requires two to three times the standard Parkland formula resuscitation. In this study, methamphetamine burns larger than 40% TBSA had a 100% mortality.