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.

The effect of carbachol on pulmonary vascular permeability and lung water content during oral fluid resusci-tation of burn shock induced by a 50%total body surface area full-thickness flame injury in dogs

Objective To investigate the effects of carbachol(CAR)on pulmonary vascular perme-ability and pulmonary water content during oral fluid resuscitation of burn shock.Methods Twelve male Beagle dogs with intubation of carotid artery and jugular vein for 24 hours were subjected to a 50%total body surface area(TBSA)full-thickness burn,then they were equally divided into oral resuscitation(OR)and OR plus CAR groups(OR+CAR).Dogs were given either a glucose-electrolyte solution(GES)in OR group or GES containing CAR(20 μg/kg)in OR+CAR group by gavage within 24 hours after burn.Dogs in each group were given intravenous fluid resuscitation after 24 post burn hour(PBH).The delivery rate and volume of GES was in accordance with that of Parkland formula.Respiratory rate(RR),arterial partial pressure of oxygen(PaO2),extravascular lung water index(ELWI)and pulmonary vascular permeability index(PVPI)were determined before burn(0 hour),and at 2,4,8,24,48 and 72 PBH.At 72 PBH or before death,dogs were sacrificed to collect lung tissue for evaluation of myeloperoxidase(MPO), malondialdehvde(MDA),and assessment of the tissue water content by dry to wet weight.Results Compared with those before burn,RR,ELWI and PVPI were greatly increased,and PaO2 obviously decreased in two groups after burn(all P<0.01).At 72 PBH,PaO2 returned to preburn level,while RR, ELWI and PVPI were still higher than preburn levels.RR,ELWI and PVPI at 4,8 and 24 PBH,and PaO2 at 8,24,48 PBH in OR+CAR group were respectively lower or higher than those in OR group(P<0.05 or P<0.01),but those measurements showed no statistical differences between two groups at 72 PBH(all P> 0.05).MPO,MDA and lung water contents in OR+CAR group were significantly lower than those in OR group at 72 PBH(2.64±0.38)U/mg VS.(4.12±0.46)U/mg,P<0.01;(3.60±0.54)/μmol/mg vs. (5.14±0.62)μmol/mg,P<0.01;(77.40±0.56)%vs.(78.30±0.54)%,P<0.01].Conclusion The results indicate that CAR inhibits inflammatory response and oxidative damage in lung tissue,and alleviates pulmonary vascular permeability and lung edema during oral fluid resuscitation of burn shock.