烧伤休克犬肠黏膜血流量动态监测方法的研究

Experimental study on continuous monitoring of intestine mucosal blood flow in burn shock dog

目的:建立一种可动态监测实验动物肠黏膜血流量的方法。方法:8只成年雄性Beagle犬,无菌手术行十二指肠造口置管和动、静脉置管术,24h后给予丙泊酚短时静脉麻醉,凝固汽油燃烧制成35%TBSAⅢ度烧伤模型,烧伤后30 min按Parkland公式进行静脉液体复苏,在烧伤前和烧伤后2、4、8、24、48、72 h共7个时间点将激光多普勒血流仪(LDF)的光纤探头通过造口置入十二指肠腔,测量十二指肠黏膜血流量(DMBF),同时采用张力测定法测量胃黏膜二氧化碳分压(PgCO_2),采用热稀释法测量心排血量(CO),统计学方法分析DMBF测量值与PgCO_2和CO的相关性。结果:所有十二指肠造口术均一次成功,动物死亡率为零。烧伤后2 h DMBF下降了24%,随后逐渐恢复,至72 h仍较伤前降低16%;PgCO_2伤后迅速升高,伤后2 h较伤前升高138%,然后缓慢降低,72 h仍较伤前升高67%;而CO变化不明显。烧伤后动物DMBF与PgCO_2呈负相关并有统计学意义(r =-0.8075,P<0.05),DMBF与CO无统计学相关性(r=0.1171,P>0.05)。结论:本实验所建立的肠黏膜血流量监测法简便易行,测量结果符合动物烧伤后病程生理变化,可信度较高,适用于犬、猪等大型动肠黏膜血流量的连续监测。

Objective：To establish a method for continuous measurement of intestine mucosal blood flow（IMBF） in dog.Methods：In eight male Beagle dogs[-（11±0.5）kg]duodenostomy and venous catheterization were performed aseptically.Then they were subjected to a 35% TBSA full-thickness flame injury with a 10 minute anes thesia（intravenous injection of propofol）24 hours later.Each dog received intravenous resuscitation with lactated Ringer＇s solution according to Parkland formula 30 minutes after burns.At 0,2,4,8,24.48 and 72 hours after burns,duodenum mucosal blood flow（DMBF）was measured with a laser Doppler flowmetry（LDF）by inserting the flexible probe into duodenum through the duodenostomy stoma prepared before the injury.The partial pressure of carbon dioxide in gastric mucosa（PgCO_2）was measured by tonometry and cardiac output（CO）by thermodilu- tion method at the same time.The correlation between DMBF and PgCO_2,as well as that between DMBF and CO,was determined.Results：35% TBSA burn injury resulted in a marked reduction of DMBF at 4 hours after burn.Until 72 hours postburn,DMBF was still lower than pre-injury level（P〈0.05）.On the contrary,the Pg- CO2 was significantly increased after burn and then reduced slowly.The PgCO2 was significantly negatively corre- lated with DMBF（r=-0.807 5,P〈0.05）,however,the correlation between CO and DMBF was not significant statiscally（r=0.1171,P〉0.05）.Conclusions：Our experimental method is easy to perform and it can provide ac curate as well as trustworthy results.Therefore the technique can be used for measuring IMBF of big animals such as dog or swine.