失血性休克猪氧代谢变化的实验观察

目的观察失血性休克(HS)猪自然病程的氧代谢变化规律和特点。方法健康巴马小型猪8头,体重18～22kg,室温下(18～22℃)麻醉行右颈内静脉剖开置肺动脉漂浮导管和右股动脉剖开置双腔深静脉导管,用于监测心排出量(CO)及采血、放血和血气分析。待操作完毕使其清醒放入特制铁笼内稳定2h后,以15min内30ml/kg的量匀速放血,制成容量控制性HS模型,采用连续心排量监护仪监测猪放血前(T0)和放血后4h内不同时点(T1～T10)的CO;通过动脉血、肺动脉血做血气分析监测乳酸(LA)、混合静脉血氧饱和度(SmvO2),并计算氧摄取量(Ca-vO2)、氧供(DO2)、氧耗(VO2)、氧摄取率(O2ER)和动静脉CO2分压差(ΔPCO2);记录HS猪各时点死亡率。结果 T1时点开始,LA、Ca-vO2和ΔPCO2开始上升,在T1～T4时点差异有统计学意义(P<0.05);SmvO2、DO2和VO2在T1～T10时均下降且差异有统计学意义(P<0.05);O2ER在T1～T10时均增加且差异有统计学意义(P<0.05)。HS猪4h内死亡率为0%。结论 HS代偿期内,DO2、VO2和SmvO2迅速下降,LA、Ca-vO2、O2ER和ΔPCO2明显上升,可迅速、准确地反映机体氧代谢失衡状态。HS失代偿期,SmvO2、VO2、DO2和O2ER仍然与病情变化相一致,可全程反映机体氧供需平衡状态。但HS失代偿期LA、Ca-vO2和ΔPCO2的变化规律和临床意义尚有待进一步研究。

Objective To observe variation and characteristics of oxygen metabolism of natural course in hemorrhagic shock （HS） swine. Methods Eight healthy Bama miniature pigs weighing 18-22kg were anesthetized in the environment of 18-22℃, then right internal jugular vein were cut open for inserting pulmonary artery flotation catheter and right femoral artery were cut open for inserting deep venous catheter and monitoring cardiac output （CO）, blood sampling and blood gas analysis. Pigs were placed in a special cage 2h for awake and stable after operation finished. Blood of all pigs were withdrawn by 30 ml/kg in 15min at equal pace to achieved capacity controlled HS model. Then record models＇CO consecutively and blood gas analysis through the artery and pulmonary artery blood for monitoring blood lactate （LA）, mixed venous oxygen saturation （SmvO2）, and calculating the oxygen uptake （Ca-vO2）, oxygen delivery （DO2）,oxygen consumption（VO2）, oxygen extraction ratio（O2ER）and APCO2 at time of pro-bleed （T0） and different time points in 4h （T1-T10） of post-bleed, Record mortality of pigs at each time point. Results Compare with To, LA, Ca- vO2 and APCO2 was significant difference （P 〈0.05） in the time of T1-T4 ,SmvO2, DO2,VO2 and O2ER were also significant differences （P〈0.05） in the time of T1-T10. The mortality of HS pigs was 0% within 4h. Conclusion In period of HS＇ compensatory, DO2, VO2 and SmvOz decreased rapidly, LA, Ca-vO2, O2ER and APCO2 increased significantly, all indexes can reflect the body＇s imbalance of oxygen dynamics quickly and accurately. In HS＇ decompensated period, SmvO2, DO2, VO2 and O2ER were remain consistent with changes of HS＇ condition, and reflected body＇s oxygen supply and demand balance in the whole process. However, the variation and clinical significance of LA, Ca-vO2 and APCO2 in HS＇ decompensated period remains need to be further studied.