Cardiovascular Center, Na Homolce Hospital, Prague 15030, Czech Republic.
J Transl Med. 2013 May 20;11:124. doi: 10.1186/1479-5876-11-124.
Mild therapeutic hypothermia (HT) has been implemented in the management of post cardiac arrest (CA) syndrome after the publication of clinical trials comparing HT with common practice (ie, usually hyperthermia). Current evidence on the comparison between therapeutic HT and controlled normothermia (NT) in CA survivors, however, remains insufficient.
Eight female swine (sus scrofa domestica; body weight 45 kg) were randomly assigned to receive either mild therapeutic HT or controlled NT, with four animals per group. Veno-arterial extracorporeal membrane oxygenation (ECMO) was established and at minimal ECMO flow (0.5 L/min) ventricular fibrillation was induced by rapid ventricular pacing. After 20 min of CA, circulation was restored by increasing the ECMO flow to 4.5 L/min; 90 min of reperfusion followed. Target core temperatures (HT: 33°C; NT: 36.8°C) were maintained using the heat exchanger on the oxygenator. Invasive blood pressure was measured in the aortic arch, and cerebral oxygenation was assessed using near-infrared spectroscopy. After 60 min of reperfusion, up to three defibrillation attempts were performed. After 90 min of reperfusion, blood samples were drawn for the measurement of troponin I (TnI), myoglobin (MGB), creatine-phosphokinase (CPK), alanin-aminotransferase (ALT), neuron-specific enolase (NSE) and cystatin C (CysC) levels. Reactive oxygen metabolite (ROM) levels and biological antioxidant potential (BAP) were also measured.
Significantly higher blood pressure and cerebral oxygenation values were observed in the HT group (P<0.05). Sinus rhythm was restored in all of the HT animals and in one from the NT group. The levels of TnI, MGB, CPK, ALT, and ROM were significantly lower in the HT group (P<0.05); levels of NSE, CysC, and BAP were comparable in both groups.
Our results from animal model of cardiac arrest indicate that HT may be superior to NT for the maintenance of blood pressure, cerebral oxygenation, organ protection and oxidative stress suppression following CA.
在比较心脏骤停后治疗性低温（HT）与常规治疗（即通常的发热）的临床试验发表后，轻度 HT 已被应用于心脏骤停后综合征的治疗管理。然而，目前关于心脏骤停幸存者中治疗性 HT 与控制性正常体温（NT）比较的证据仍然不足。
将 8 只雌性猪（家猪；体重 45kg）随机分为接受轻度治疗性 HT 或控制性 NT 两组，每组 4 只。建立静脉-动脉体外膜肺氧合（ECMO），在最小 ECMO 流量（0.5L/min）下通过快速心室起搏诱发心室颤动。心脏骤停 20min 后，通过将 ECMO 流量增加至 4.5L/min 恢复循环；随后进行 90min 的再灌注。使用氧合器上的热交换器将目标核心温度（HT：33°C；NT：36.8°C）维持在目标温度。在主动脉弓处测量有创血压，使用近红外光谱评估脑氧合。再灌注 60min 后，进行多达三次除颤尝试。再灌注 90min 后，抽取血样测量肌钙蛋白 I（TnI）、肌红蛋白（MGB）、肌酸磷酸激酶（CPK）、丙氨酸氨基转移酶（ALT）、神经元特异性烯醇化酶（NSE）和胱抑素 C（CysC）水平。还测量了活性氧代谢物（ROM）水平和生物抗氧化潜力（BAP）。
HT 组的血压和脑氧合值明显更高（P<0.05）。所有 HT 动物和 NT 组中的一只动物恢复窦性节律。HT 组的 TnI、MGB、CPK、ALT 和 ROM 水平显著降低（P<0.05）；两组的 NSE、CysC 和 BAP 水平相当。
我们的心脏骤停动物模型结果表明，HT 可能优于 NT，有助于维持心脏骤停后血压、脑氧合、器官保护和抑制氧化应激。
