重症急性胰腺炎血流动力学和氧代谢变化的实验研究

目的 观察重症急性胰腺炎(SAP)猪的血流动力学和氧代谢变化特点,为临床治疗提供理论依据。方法 通过向主胰管逆行注入含质量分数为4％牛磺胆酸钠和质量分数为1％胰蛋白酶的生理盐水溶液(1 ml／kg)诱导猪SAP模型(n=8);通过Swan-Ganz导管和心电监护仪,连续监测心率(HR)、中心静脉压(CVP)、平均动脉压(MAP)、肺动脉楔压(PAWP)、平均肺动脉压(MPAP)和心排血量,计算心脏指数(CI);通过对制模前(0 h)和制模后6、12、24及36 h的动脉及混和静脉血的血气分析,计算出相应的全身氧输送(DO2)、氧耗(VO2)和氧摄取率(O2ext),分析上述各指标的变化。结果 制模12 h MAP和CI与0 h比较显著下降(P均<0.05)。动脉氧分压(PaO2)和DO2都有下降的趋势。与0 h比较,PaO2在制模后6 h以后下降显著,DO2在制模后24 h下降最显著(P均<0.05)。VO2和O2ext的走势一致,都在制模后6 h上升至最高水平(P均<0.05),然后一直下降,制模后24 h较6 h差异具有显著性(P均<0.05)。结论SAP时不仅有血流动力学紊乱,而且有氧代谢障碍。SAP导致多器官功能障碍综合征(MODS)的因素可能与VO2和O2ext下降有关。

Experimental study of hemodynamics and oxygen metabolism in pigs with severe acute pancreatitis

Objective To observe the changes in hemodynamics and oxygen metabolism in pigs with severe acute pancreatitis (SAP) so as to provide a theoretical basis for clinical treatment. Methods A porcine model of SAP was reproduced by infusing normal saline(1 ml/kg) of sodium taurocholate(4%) and trypsin (1%) into the pancreatic duct(n=8). Heart rate(HR) ,central venous pressure(CVP) ,mean arterial pressure (MAP), pulmonary arterial wedge pressure (PAWP), mean pulmonary arterial pressure(MPAP) and cardiac output were continuously measured with the aid of Swan - Ganz catheter and electrocardiography monitor, and cardiac index (CI) was calculated. Oxygen delivery (DO2), oxygen consumption (VO2) and oxygen extraction(O2ext) were calculated according to the analysis of the blood -gases in arterial and mixed venous blood at 0, 6, 12, 24, 36 hours after taurocholic acid injection, and the results were analyzed. Results Compared with baseline(0 hour), MAP and CI decreased significantly 12 hours after the acid insult (all P<0. 05). Both of partial pressure of artery(PaO2) and DO2 showed a tendency to fall. Compared with 0 hour, PaO2 decreased significantly at 6, 12, 24 and 36 hours (all P<0. 05), and DO2 at 24 hours (P<0. 05). The trends of VO2 and O2ext were consistent, both of them peaked at 6 hours (both P<0. 05), then, began to lower, and the difference was statistically significance at 24 hours (both P<0. 05). Conclusion There is not only hemodynamic disturbances but also oxygen metabolism dysfunction in pigs with SAP. The pathogenesis of multiple organ dysfunction syndrome might be attributable to the lowering of VO2 and O2ext.