Differences in Intraischemic Temperature Influence Neurological Outcome After Deep Hypothermic Circulatory Arrest in Newborn Dogs
Differences in Intraischemic Temperature Influence Neurological Outcome After Deep Hypothermic Circulatory Arrest in Newborn Dogs
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新生犬深低温循环骤停后缺血内温度的差异影响神经系统结果
DOI：
10.1161/01.str.25.7.1433
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发表时间：
1994
期刊：
影响因子：
8.3
通讯作者：
R. Vannucci
中科院分区：
文献类型：
--
作者：
D. Mujsce;J. Towfighi;D. Heitjan;R. Vannucci
背景和目的在婴幼儿心脏直视手术中，将体温降至16℃至24℃已成为延长心脏骤停“安全”间隔的既定程序。本实验旨在确定低温循环停止时核心（直肠）温度的差异是否影响新生犬缺血性脑损伤的存在和程度。方法新生犬（出生后3 ~ 5天）采用氟烷麻醉（4%诱导，0.5%维持），插管麻痹，70%氧化亚氮/30%氧气人工通气。之后，用冰袋将狗表面冷却到16°C （n=6）、20°C （n=8）或24°C （n=6）。然后通过静脉注射KC1进行1.75小时的循环停止，随后静脉注射NaHCO3和肾上腺素，人工通气和闭式胸部心脏按摩使狗复苏。存活8小时后恢复的狗（n=16）进行神经行为检查，然后对其大脑进行灌注固定以进行病理分析。结果所有新生犬均在1.75小时心脏骤停后成功复苏，恢复体温至37℃，最终脱离麻醉和呼吸支持。4只狗在4至7小时内出现继发性全身并发症并死亡。所有幸存的狗都保持稳定，全身血压、心率、动脉血氧和酸碱平衡都在正常、正常的范围内。在16只幸存的狗中，除1只外，其余狗在8小时恢复时均表现出脑损伤的组织学证据。对易损灰质结构中坏死神经元数量的形态计量学分析表明，在24°C时大脑皮层损伤最大，在16°C时大脑皮层损伤最小(通过回归分析（r= 0.62； P= 0.01）或重复测量模型（P= 0.008）。三个温度组尾状核的损伤程度相似，而杏仁核在24℃的损伤程度比20℃更大，但在20℃和16℃的损伤程度没有差异。幸存犬的神经行为缺陷与大脑皮层损伤程度密切相关（r= 0.72； P=.001）。结论深低温循环停搏时脑内核心温度的差异影响新生犬大脑皮层损伤的严重程度。具体来说，温度在24℃以下越低，对缺血损伤的保护作用越强。此外，皮层损伤越大，神经行为缺陷就越严重。杏仁核，尤其是尾状核的情况并非如此。因此，核心温度的差异，即使是非常低的水平，似乎对在低温循环停止时新生儿大脑的最佳保护至关重要。(中风。1994;25:1433 1442。)
Background and Purpose Hypothermia to core temperatures ranging from 16°C to 24°C has become an established procedure to extend the “safe” interval of cardiac arrest during open heart surgery in human infants. The present experiment was designed to ascertain whether differences in core (rectal) temperature during hypothermic circulatory arrest influence the presence and extent of ischemic brain damage in newborn dogs. Methods Newborn dogs (postnatal age, 3 to 5 days) were anesthetized with halothane (4% induction; 0.5% maintenance), intubated, paralyzed, and artificially ventilated with 70% nitrous oxide/30% oxygen. Thereafter, the dogs were surface cooled with ice packs to either 16°C (n=6), 20°C (n=8), or 24°C (n=6). The dogs then were subjected to circulatory arrest for 1.75 hours by the intravenous injection of KC1, following which they were resuscitated with intravenous NaHCO3 and epinephrine, artificial ventilation, and closed chest cardiac massage. Those dogs that survived for 8 hours of recovery (n=16) underwent neurobehavioral examination followed by perfusion‐fixation of their brains for pathological analysis. Results All newborn dogs were successfully resuscitated after 1.75 hours of cardiac arrest, rewarmed to 37°C, and ultimately weaned from anesthesia and ventilatory support. Four dogs sustained secondary systemic complications with death at 4 to 7 hours. All surviving dogs remained stable, with systemic blood pressure, heart rate, arterial oxygen, and acid‐base balance within the normal, normothermic range. Of the 16 surviving dogs, all except 1 showed histological evidence of brain damage at 8 hours of recovery. Morphometric analysis of the number of necrotic neurons in the vulnerable gray matter structures showed the greatest damage to cerebral cortex at 24°C and the least damage to this structure at 16°C by either regression analysis (r=.62; P=.01) or a repeated‐measures model (P=.008). The extent of damage to the caudate nucleus was similar in the three temperature groups, while damage to the amygdaloid nucleus was greater at 24°C compared with 20°C but with no difference in the severity of damage between 20°C and 16°C. A close correlation existed between neurobehavioral deficits in the surviving dogs and the severity of damage to the cerebral cortex (r=.72; P=.001). Conclusions The findings indicate that differences in intraischemic core temperature during deep hypothermic circulatory arrest influence the severity of damage to the cerebral cortex of newborn dogs. Specifically, the lower the temperature below 24°C, the more protected the structure from ischemic injury. Furthermore, the greater the cortical damage, the more severe the neurobehavioral deficits. Such was not the case for the amygdaloid nucleus and especially for the caudate nucleus. Accordingly, differences in core temperature, even at very low levels, appear critical for optimal protection of the newborn brain during hypothermic circulatory arrest. (Stroke. 1994;25:1433‐1442.)
犬深低温治疗性停循环：失血性休克“不可挽回”损伤的复苏方式。
DOI：
--
发表时间：
1990
期刊：
The Journal of trauma
影响因子：
--
作者：
Tisherman,SA;Safar,P;Radovsky,A;Peitzman,A;Sterz,F;Kuboyama,K
通讯作者：
Kuboyama,K
与左心发育不全综合征相关的获得性神经病理学病变。
影响因子：
8
作者：
Glauser,TA;Rorke,LB;Weinberg,PM;Clancy,RR
通讯作者：
Clancy,RR
与深低温（15摄氏度）相比，深低温（低于10摄氏度）可以改善狗在两小时停循环以进行复苏手术后的神经系统结果。
DOI：
--
发表时间：
1991
期刊：
The Journal of trauma
影响因子：
--
作者：
Tisherman,SA;Safar,P;Radovsky,A;Peitzman,A;Marrone,G;Kuboyama,K;Weinrauch,V
通讯作者：
Weinrauch,V