EFFECTS OF HYPOTHERMIC EXTRACORPOREAL LUNG AND HEART ASSIST (ECLHA) ON CARDIOPULMONARY AND CEREBRAL RESUSCITATION

背景与目的：尽管常温体外循环心肺辅助（ECLHA）可以改善心脏结局，但患者不能从低血压介导的脑保护中获益。方法：15只犬随机分为低温组（7只，33 ℃）和常温组（8只，37.5 ℃）。所有犬均诱导常温室颤（VF）15 min，随后ECLHA 24 h和重症监护72 h。低温组复苏后20 h维持中心肺动脉温度33 ℃，28 h复温。结果评价包括：1.死亡率，2.儿茶酚胺剂量，3.拔管时间，4.坏死心肌质量（g），5.结果：常温组4只犬死于心源性休克，1只犬死于氧合不良。2只存活犬仍处于昏迷状态（NDS 60.5 ± 4.9%），坏死心肌质量为14.5 ± 3.5 g。低温组1只死于肺功能不全，其余6只存活。存活的狗显示脑损伤（29.8 ± 2.5%），但有证据表明有一定的脑保护作用。低温组坏死心肌质量为4.2 ± 1.3g，是常温组的3.4倍。低温组存活率明显高于常温组（P <0.01）。结论：心脏骤停后立即诱导的长期亚低温和ECLHA可改善存活率以及脑和心脏的预后。

Background and purpose : Although normothermic extracorporeal lung and heart assist (ECLHA) improves cardiac outcomes, patients can not benefit from hypothermia-mediated brain protection. The present study evaluated the effects of long-term ECLHA with mild to moderate hypothermia (33℃) in a canine model of prolonged cardiac arrest.Methods : Fifteen dogs were assigned to either the hypothermic (7 dogs, 33℃) or normothermic group (8 dogs, 37.5℃). All dogs were induced to normothermic ventricular fibrillation (VF) for 15 min, followed by 24 h of ECLHA and 72 h of intensive care. The hypothermia group maintained core (pulmonary artery) temperature at 33℃ for 20 h starting from resuscitation, then were rewarmed by 28 h. Outcome evaluations included : 1. mortality, 2. catecholamine dose, 3. time to extubation, 4. necrotic myocardial mass (g), 5. Neurological Deficits Score (NDS).Results : In the normothermic group 4 dogs died of cardiogenic shock and 1 dog succumbed to poor oxygenation. The 2 surviving dogs remained comatose (NDS 60.5 ± 4.9%) with necrotic myocardial mass of 14.5 ± 3.5 g. In the hypothermic group, one dog died from pulmonary dysfunction, the other 6 dogs survived. The surviving dogs showed brain damage (29.8 ± 2.5%), but there was evidence of some brain-protective effect. The mass of necrotic myocardium was 4.2 ± 1.3 g in the hypothermic group or 3.4 times smaller than in the normothermic group. The survival rate was significantly higher in the hypothermic than in the normothermic group (P<0.01). The catecholamine requirement was also lower in the hypothermic than in the normothermic dogs (P<0.05).Conclusions : Long-term mild to moderate hypothermia with ECLHA induced immediately after cardiac arrest improved survival as well as cerebral and cardiac outcomes.