窒息法和室颤法诱导建立大鼠心脏停搏模型的比较

Comparison between two rat models of cardiac arrest: asphyxiation and ventricular fibrillation

目的·比较室颤和窒息2种方法诱导的心脏停搏动物模型在成模大鼠心功能和神经功能的差异。方法·20只成年健康雄性SD大鼠随机分为3组:按室颤法(n=8)和窒息法(n=8)建立心脏停搏-复苏动物模型,另4只SD大鼠作为空白对照假手术组。所有成模大鼠均观察24 h,其中呼吸机等生命支持1 h。比较2个模型组大鼠复苏后心电变化,复苏后1、3、5、6 h的射血分数(ejection fraction,EF)及心输出量(cardiac output,CO),复苏后6、12、18、24 h的神经功能缺失评分(neurological deficit score,NDS)及24 h生存率等方面的差异。结果·2个模型组大鼠复苏后,CO和EF较同时期假手术组均明显下降(P=0.000)。复苏后1 h,室颤组CO由(98.84±4.86)m L/min下降至(59.17±22.99)m L/min,窒息组CO由(99.86±10.34)m L/min下降至(46.02±22.32)m L/min,但2组间差异无统计学意义(P=0.792)。随着时间延长,室颤组CO逐渐恢复;在复苏后3、5、6 h,室颤组CO均高于窒息组,且差异具有统计学意义(P=0.041,P=0.007,P=0.020)。复苏后1 h,室颤组EF由(82.17±6.21)%下降至(70.23±13.24)%,窒息组由(83.24±3.01)%下降至(65.46±13.11)%,但2组间差异无统计学意义(P=0.877)。随着时间延长,EF也呈逐渐恢复趋势,室颤组更为明显;在复苏后3、5 h,室颤组EF均高于窒息组,且差异具有统计学意义(P=0.031,P=0.024)。室颤组24 h生存率75.0%,窒息组62.5%,差异无统计学意义(P=0.393)。复苏后2组大鼠神经功能受损明显,NDS明显低于基础值,随着时间延长有改善趋势,室颤组神经系统预后似优于窒息组,但差异无统计学意义。结论·室颤和窒息同为诱导心脏停搏的常用方法,但是2种模型在复苏后心功能方面略有差异。研究中应结合自己的需要选择合适的模型。

Objective · To compare the differences in cardiac function and neurological function between asphyxia and ventricular fibrillation（VF） induced cardiac arrest rat model. Methods · Twenty healthy adult male SD rats were randomly divided into VF group（n=8）, asphyxial group（n=8） and sham group（n=4）. Cardiac arrest models were established in VF group and asphyxial group by VF and asphyxia respectively. All animals were observed for 24 h and advanced life support was offered for the first 1 h after resuscitation. During the 24 h, ejection fraction（EF） and cardiac output（CO） were measured with the help of cardiac ultrasonography at 1, 3, 5 and 6 h post resuscitation. Electrocardiographic changes, 24 h survival analysis and neurological deficit score（NDS） were also recorded and analyzed at 6, 12, 18 and 24 h post resuscitation. Results · Both EF and CO decreased dramatically after resuscitation compared with sham group at the same time point（P=0.000）. At 1 h post resuscitation, the CO decreased from（98.84±4.86） m L/min to（59.17±22.99） m L/min in VF group and from（99.86±10.34） m L/min to（46.02±22.32） m L/min in asphyxial group, but there was no difference between the two groups（P=0.792）. At 3, 5 and 6 h post resuscitation, the CO in VF group was higher than that in asphyxial group（P=0.041, P=0.007, P=0.020）. At 1 h post resuscitation, the EF decreased from（82.67±6.21）% to（70.23±13.24）% in VF group and from（83.24±3.01）% to（65.46±13.11）% in asphyxial group, but no difference was observed between the two groups（P=0.877）. Then a recovery tendency was observed in both groups, but more obvious in VF group at 3 and 5 h post resuscitation（P=0.031, P=0.024）. No difference was found between the two groups in survival rate during 24 h and the NDS after resuscitation, although the neurological function was greatly impaired. Conclusion · VF and asphyxia are most commonly used methods to induce cardiac arrest, but these models may differ in cardiac function post resuscitation. Researchers need to choose appropriate models according to their study objectives.