一种新的监测早期组织缺氧的方法——无囊胃张力计法的临床研究

目的：评价一种新的张力计法监测胃粘膜早期缺血。方法：病人分为Ｉ（ｎ＝２０，ＮＹＨＡＩ级），Ｉ（ｎ＝２０，ＮＹＨＡＩＩ级）和ＩＩ（ｎ＝１０，ＮＹＨＡＩＶ级）组。在Ｉ和Ｉ组各分为Ｉａ（ｎ＝１０）、Ｉｂ（ｎ＝１０）和Ｉａ（ｎ＝１０），Ｉｂ（ｎ＝１０）两组。病人放置胃管。在Ｉｂ组和Ｉｂ组放置特殊的漂浮导管，连续测定心输出量。所有病人于注入４０ｍｌ空气平衡３０分钟后，抽取胃内气体测定二氧化碳分压。在Ｉａ、ＩＩａ组和ＩＩ组，于平衡开始和３０分钟时测胃内气体二氧化碳分压（ＰｉＣＯ２）并计算其平均值。在Ｉｂ和ＩＩｂ组，分别于平衡开始、１５分钟和３０分钟，测动脉和混合静脉血气并计算其平均值。结果：３组间血流动力学状态存在明显差别。在Ｉ、Ｉ和ＩＩ组，ＰｉＣＯ２与动脉血二氧化碳分压比值（Ｐｉ－ＣＯ２／ＰａＣＯ２）随ＮＹＨＡ分级而增加（Ｐ＜０．００１）。在Ｉｂ和ＩＩｂ组，病人氧供与氧耗高度相关，同时病人的氧耗与其ＰｉＣＯ２／ＰａＣＯ２比值存在高度相关性。结论：①此法可以早期监测组织缺血。②ＰｉＣＯ２／ＰａＣＯ２比值可预示病人的氧债。

A New Method for Monitoring Tissue Ischemia:A Clinical Evaluation of Air Tonometry

Objective:This study was to evaluate a new method for early detection of gastric mucosal ischemia. Methods:Fifty patients were divided into group I ( n =20,NYHA II),II( n =20,NYHA III) and III( n =10,NYHA IV).In group I and II,the patients were each further divided into two subgroups Ia( n =10),Ib( n =10) and IIa( n =10),IIb( n =10).A nasogastric tube was inserted into the lumen of the stomach and the gastric air was measured for CO 2(PiCO 2).In Ib and IIb,a specific thermodilution catheter was used for continual cardiac output monitoring.PiCO 2 was measured after gastric infusion 40 ml of air and equilibration of 30 min.In group Ia,IIa and III,PaCO 2 was detected at the beginning and end of 30 min with mean value calculated.In Ib and IIb group,arterial and mixed venous blood gas were got at the beginning,15 min and 30 min thereafter,and their mean values were obtained. Results:The hemodynamic variables had significant differences among the three groups.The ratio of PiCO 2/PaCO 2 in all groups was increased pacing with the NYHA status ( p <0 001).In Ib and IIb there was a significant correlation between DO 2I and VO 2I ( r=0 93,p <0 0001),meanwhile the VO 2I negatively correlated with the ratio of PiCO 2/PaCO 2( r=-0 82,P <0 001). Conclusion:1,The air tonomeer can be used to estimate gastric mucosal ischemia.2,An increase of PiCO 2/PaCO 2 ratio might be used as an index of oxygen debt.