Rady M Y, Kirkman E, Cranley J, Little R A
Surgical Intensive Care Unit, Cleveland Clinic Foundation, OH 44195, USA.
Crit Care Med. 1996 Apr;24(4):623-30. doi: 10.1097/00003246-199604000-00013.
To examine if either nociceptive somatic nerve stimulation or skeletal muscle injury modified systemic hemodynamics and oxygen transport and utilization after resuscitation from hemorrhage in anesthetized pigs.
Prospective, randomized, controlled laboratory study.
Animal laboratory.
Twenty isoflurane-anesthetized and mechanically ventilated large white pigs.
Three groups of animals were instrumented with femoral arterial and thermodilution pulmonary artery catheters. One group of animals had bilateral brachial nerve electric stimulation before hemorrhage (brachial nerve stimulation + hemorrhage, n = 7). The second group of animals had bilateral hindlimbs skeletal muscle injury induced by firing a captive-bolt handgun with standard charges before hemorrhage (skeletal muscle injury + hemorrhage, n = 6). The third group had neither insult before hemorrhage (control, n = 7). Controlled bleeding was initiated to reduce the cardiac index and systemic oxygen delivery (Do2) by 50% in all animals. Animals were then left for 30 mins before resuscitation. All animals were resuscitated with 4.5% human serum albumin at 45 mL/kg and observed for 2 hrs.
Plasma volume, systemic hemodynamics, and oxygen transport variables were measured and calculated after resuscitation. Similar increases of plasma volume and supranormal cardiac index were observed in all groups immediately after resuscitation. The branchial nerve stimulation and hemorrhage group maintained higher heart rate, cardiac index, Do2, and oxygen consumption (Vo2) than the hemorrhage group. In contrast, the skeletal muscle injury and hemorrhage group had lower systemic mean arterial pressure and vascular resistance, and a tendency for decrease in Vo2, than the hemorrhage group, although heart rate, cardiac index, and Do2 were similar in both groups. Hemorrhage increased the arterial plasma lactate concentration, which was later normalized in all groups 60 mins after resuscitation.
Neither nociceptive brachial nerve stimulation nor skeletal muscle injury attenuated the increase in plasma volume, cardiac index, or the repayment of systemic oxygen debt after resuscitation from hemorrhage. Brachial nerve stimulation was associated with augmented cardiac index, systemic Do2, and increased Vo2 requirements related to increased sympathetic nervous system activation. Skeletal muscle injury produced early systemic arterial hypotension and vasodilation, and a decrease in Vo2 that was suggestive of pathologic supply dependency on systemic Do2.
研究伤害性躯体神经刺激或骨骼肌损伤是否会改变麻醉猪出血复苏后的全身血流动力学以及氧的运输和利用。
前瞻性、随机、对照实验室研究。
动物实验室。
20只接受异氟烷麻醉并机械通气的大白猪。
三组动物均植入股动脉导管和热稀释肺动脉导管。一组动物在出血前进行双侧臂丛神经电刺激（臂丛神经刺激+出血，n = 7）。第二组动物在出血前用标准装药的栓式手枪射击诱导双侧后肢骨骼肌损伤（骨骼肌损伤+出血，n = 6）。第三组在出血前未进行任何损伤（对照组，n = 7）。所有动物均开始控制性出血，使心脏指数和全身氧输送（Do2）降低50%。然后让动物维持30分钟再进行复苏。所有动物均用45 mL/kg的4.5%人血清白蛋白进行复苏，并观察2小时。
复苏后测量并计算血浆容量、全身血流动力学和氧运输变量。复苏后立即在所有组中观察到血浆容量的类似增加和超常的心脏指数。臂丛神经刺激和出血组的心率、心脏指数、Do2和氧耗量（Vo2）维持高于出血组。相比之下，骨骼肌损伤和出血组的全身平均动脉压和血管阻力较低，Vo2有下降趋势，低于出血组，尽管两组的心率、心脏指数和Do2相似。出血增加了动脉血浆乳酸浓度，在复苏后60分钟时所有组该浓度均恢复正常。
伤害性臂丛神经刺激和骨骼肌损伤均未减弱出血复苏后血浆容量、心脏指数的增加或全身氧债的偿还。臂丛神经刺激与心脏指数增加、全身Do2增加以及与交感神经系统激活增加相关的Vo2需求增加有关。骨骼肌损伤导致早期全身动脉低血压和血管舒张，并导致Vo2下降，提示存在对全身Do2的病理性供应依赖。
