延迟复苏增加失血性休克犬肺组织含水量和血管通透性

Increased canine lung water content and pulmonary vascular permeability due to delayed fluid resuscitation during hemorrhagic shock

目的:研究延迟补液对失血性休克犬肺组织含水量和血管通透性的影响。方法:Beagle犬14只,先期无菌手术行颈动、静脉置管,24h后从颈动脉放血造成失血性休克,总失血量为全身血容量的42%。随机分为延迟补液组(n=8)和立即补液组(n=6)。失血后第1个24h延迟补液组无治疗,立即补液组静脉输入3倍失血量的乳酸林格氏液。失血后24h起两组犬均实施静脉补液。于失血前(0h)和失血后第2、4、8、24、48h和72h测定动物非麻醉状态下的呼吸频率(RR)、动脉氧分压(PaO2)、血管外肺水指数(ELWI)和肺血管通透性指数(PVPI),于失血后72h或动物濒死前测定肺组织含水率。结果:失血后72h延迟补液组死亡率为5/8(62.5%),而立即补液组为0。失血后8h,延迟补液组MAP[(55.8±4.1)mmHg]和PaO2[(86.3±2.9)mmHg]分别比失血前降低46.2%和22.4%;ELWI[(168.8±12.1)mL]和PVPI(5.9±0.6)增加31.4%和78.8%。立即补液组MAP和PaO2显著高于延迟补液组;ELWI和PVPI显著低于延迟补液组(均P<0.05)。延迟补液组肺组织含水率[(88.37±2.73)%]显著高于立即补液组[(81.52±2.13)%,P<0.05]。结论:延迟补液显著增加失血休克动物肺血管通透性和肺组织含水量,加重肺脏功能障碍。

Objective To investigate the effect of delayed fluid resuscitation on pulmonary vascular permeability and lung water content in dogs with hemorrhagic shock. Methods Fourteen Beagle dogs underwent cannulation of carotid artery and jugular vein and 24 hours later were subjected to a loss of 42% of total blood volume to establish a model of hemorrhagic shock. Within 24 hours of blood loss,the dogs were randomly assigned to receive no fluid resuscitation （DR group,n = 8） or prompt lactated Ringer＇s solution three times of the blood loss volume （IR group,n = 6）. All the dogs received intravenous fluid therapy from the second 24 fours. Mean arterial pressure （MAP）,PaO2,extravascular lung water index （ELWI）,and pulmonary vascular permeability index （PVPI） were determined at baseline level and at 2,4,8,24,48,and 72 hours after blood loss. At 72 hours of blood loss or at the moment before death,lung water content was detected. Results Over 72 h,5 of the 8 dogs in DR group were dead,while no dogs died in VR group. 8 hours after blood loss,as compared with the baseline,MAP and PaO2 decreased by 46.2% and 22.4% in DR group,respectively; and ELWI and PVPI increased by 31.4% and 78.8%. ELWI and PVPI were significantly lower while MAP and PaO2 were markedly higher in IR group than in DR group （P 0.05 for all comparisons）. Lung water content was evidently higher in DR group than in IR group [（88.37 ± 2.73）% vs. （81.52 ± 2.13）%,P 0.05]. Conclusions Delayed fluid resuscitation markedly increases pulmonary vascular permeability and lung water content in dogs with hemorrhagic shock,which aggravates lung dysfunction.