人工低温对猪肺血管阻力的影响

The effects of induced hypothermia on porcine pulmonary vascular resistance

目的模拟人工低温，并对低温后的血流动力学变化进行分析。方法体表降温法建立人工低温模型，降温到32℃。检测降温前后主动脉压、中心静脉压、左房压、肺动脉压、肺动脉血流量等指标。比较37℃、32℃各项指标。按“肺血管阻力=80×（肺动脉平均压-左房平均压）／心输出量”公式计算肺血管阻力。结果37℃时，肺血管阻力为（42．100±22．290）kPa·s／L，32℃时为（61．463±29．454）kPa·s／L（P〈0．01）。结论低温治疗能够引发肺血管阻力升高，进而引发肺功能障碍。

Objective Hypothermia is widely used in clinical work. We want to study the pulmonary vascular resistance when induced hypothermia on healthy individuals,in order to facilitate the protection of lung function. Methods Thirty Swedish domestic pigs with a mean weight of 50 kg （range 48-52 kg） were included in the study. A median sternotomy was performed, Open pericardium, put a blood probe around pulmonary artery. Put one catheter in left atrium sinistrum, put one catheter in pulmonary artery for blood pressure measurements and blood sampling. Values of T, HR, AP, CVP, LAP, PAP, PBF will be recor- ded. We cooled the pigs by surface cooling with ice packs to 32 ℃ core temperature. Count PVR use formula ＂PVR = 80 x （mean pulmonary arterial pressure-mean left atrial pressure）/cardiac output＂. Data are expressed as means ± SEM, analysis were done by SPSS 12. 0. Results 37 ℃, PVR： （42. 100 ± 22. 290） kPa.s/L, 32 ℃, PVR： （61. 463 ±29. 454） kPa·s/L （P 〈0. 01 ）. Conclusion Hypothermia may cause complications and dysfunction of ventilation.