Syverud S A, Dronen S C, Chudnofsky C R, van Ligten P F
Department of Emergency Medicine, University of Cincinnati Medical Center, OH 45267-0769.
Resuscitation. 1989 Jun;17(3):287-95. doi: 10.1016/0300-9572(89)90044-0.
We studied the effect of bleed rate on survival time and hemodynamics in a continuous hemorrhage model of fatal hemorrhagic shock in lightly anesthetized swine. Fasted immature swine (12-16 kg) were sedated with intramuscular (i.m.) ketamine, endotracheally intubated, anesthetized with halothane (0.75%), nitrous oxide, and oxygen, and then prepared for experimentation by placement of a pulmonary artery thermodilution catheter, femoral arterial and venous catheters, and by splenectomy. After instrumentation, halothane was discontinued and sedation was maintained with nitrous oxide and intravenous lorazepam. Thirty minutes later, the animals were bled continuously at 1.0 ml/kg per min (n = 8, Group I) or 1.25 ml/kg per min (n = 8, Group II) by a roller pump connected to the femoral arterial catheter. Hemodynamic parameters were recorded every 15 min until death occurred. Mean survival time was 50.2 +/- 3.0 min in Group I and 39.8 +/- 3.2 min in Group II (P less than 0.001). There was a stepwise decrease in blood pressure and cardiac index consistent with progressive hemorrhagic shock. This model results in reproducible survival times with small standard deviations. Although the animals are lightly anesthetized and the experiments are performed acutely, the hemodynamic responses and survival times observed are similar to those reported in previous studies of chronically instrumented, unanesthetized swine. This model may be more practical than unanesthetized, chronically instrumented swine models for evaluating the effects of various interventions on survival time and hemodynamics in acute hemorrhagic shock.
我们在轻度麻醉的猪致死性失血性休克连续出血模型中，研究了出血速率对存活时间和血流动力学的影响。禁食的未成熟猪（12 - 16千克）肌肉注射氯胺酮进行镇静，气管插管，用氟烷（0.75%）、氧化亚氮和氧气麻醉，然后通过放置肺动脉热稀释导管、股动脉和静脉导管以及脾切除术来准备实验。仪器安置后，停用氟烷，用氧化亚氮和静脉注射劳拉西泮维持镇静。30分钟后，通过连接到股动脉导管的滚轴泵，以每分钟1.0毫升/千克（n = 8，第一组）或1.25毫升/千克每分钟（n = 8，第二组）的速度对动物进行连续放血。每15分钟记录一次血流动力学参数，直至动物死亡。第一组的平均存活时间为50.2±3.0分钟，第二组为39.8±3.2分钟（P＜0.001）。血压和心脏指数呈逐步下降，与进行性失血性休克一致。该模型可产生具有小标准差的可重复存活时间。尽管动物处于轻度麻醉状态且实验是急性进行的，但观察到的血流动力学反应和存活时间与先前对长期植入仪器、未麻醉猪的研究报告相似。对于评估各种干预措施对急性失血性休克存活时间和血流动力学影响而言，该模型可能比未麻醉、长期植入仪器的猪模型更实用。
