无心跳兔呼出气中异戊二烯浓度变化

摘要

目的 观察兔心跳停止后不同时间呼出气中异戊二烯浓度变化.方法 无心跳兔随机分为A-E组(n=8),分别为心跳停止后0 min、30 min、60 min、90 min和120 min.使用气相色谱-质谱仪测量呼出气中异戊二烯浓度;传统肺损伤检测方法包括:肺脏组织湿干重(W/D)比、丙二醛(MDA)浓度、肺损伤评分(LIS)和气道压30 cm H2O时肺容积(Vmax).结果 A-E组呼出气中异戊二烯浓度[中位数(四分位区间)]分别为1.39(3.70-0.68)ppb、0.94(2.02-0.32)ppb、1.00(1.73-0.48)ppb、0.95(0.99-0.86)ppb和0.39(1.45-0.34)ppb,E组显著低于A组(P<0.05).传统肺脏损伤检测指标随时间进行性加重,E组损伤最重.结论 呼出气中异戊二烯浓度在心跳停止120 min内随肺损伤加重呈渐进性下降.%Objective To detect the concentrations of isoprene in expiratory air during different periods of rabbits without heartbeat ( CA ). Methods 40 rabbits were randomly and evenly divided into 5 groups at 0 min, 30 min, 60 min, 90 min, and 120 min after cardiac arrest respectively. The concentrations of isoprene were collected by gas chromatography-mass spectrometer. The traditional detection methods of lung injury included wet-to-dry ( W/D ) ratio, malonaldehyde ( MDA ) concentrations, lung injury scores ( LIS ) and maximal volume of lung when the airway pressure reached 30 cmH2 0 ( Vmax ). Results From the group A to E, the median concentrations of isoprene were 1. 39 ( 3. 70 -0. 68 ) ppb, 0. 94 ( 2. 02 - 0. 32 ) ppb, 1. 00 ( 1. 73 - 0. 48 ) ppb, 0. 95 ( 0. 99 - 0. 86 ) ppb and 0. 39 ( 1. 45 -0. 34 ) ppb respectively, and the isoprene concentration was significantly lower in the group E than in the group A ( P <0. 05 ). The indexes of traditional lung injury aggravated with time and the group E was the most severe group. Conclusion The concentration of exhaled isoprene decreases with the severity of lung injury within 120 min after CA.