摘要目的 探讨心肺复苏后近期脑血流动力学变化.方法 用交流电致颤法,对6只比格犬诱导心脏骤停(CA),选取4个时间点:CA前(基础时),心肺复苏后自主循环恢复(ROSC)4(第1天),ROSC 28(第2天)和ROSC 52(第3天),分别行脑磁共振灌注加权成像(PWI)扫描,并记录和比较诱发不同时间点的平均动脉血压(MAP)、平均右颈总动脉流量(MQ)、颅内微循环灌注量(HEAD).结果 4个时间点MAP差异无统计学意义(P＞0.05).MQ第1天最低,与基础时和第3天差异有统计学意义(P＜0.05).HEAD第1天最低,与另3个时间点差异均有统计学意义(均P＜0.05).时间峰值强度/基础值在第1天最低(0.93±0.05),与基础时和第2天差异均有统计学意义(均P＜0.05).平均通过时间/基础值在第1天最高(2.30±0.33),与另3个时间点差异均有统计学意义(均P＜0.05).相对脑血容量/基础值在第1天最高(1.80±0.60),与基础时差异有统计学意义(均P＜0.05).相对脑血流量/基础值在第1天最低(0.69±0.13),与另3个时间点差异均有统计学意义(均P＜0.05).结论 复苏后第1天犬脑有明显的微循环障碍,脑PWI可观察复苏后脑血流动力学.

abstractsObjective To investigate the changes in perfusion-weighted magnetic resonance imaging (MRI) in canine models of cardiac arrest (CA) and cerebral hemodynamics following return of spontaneous circulation (ROSC).Methods Six beagle dogs underwent PWI scanning prior to CA (baseline)and at 4 (day 1),28 (day 2) and 52 (day 3) after ROSC,respectively.This was followed by comparison on mean arterial blood pressure (MAP),right common carotid artery flow(MQ) and intracranial microcirculation (HEAD).Results There was no significant difference for MAP at all time points(P＞0.05).MQ was mostly reduced at day 1 and differed statistically with that at baseline and day 3 (both P＜0.05).A most significantly reduced level of HEAD was recorded at day 1 and differed considerably with that at baseline and days 2 and 3 (all P＜0.05).The lowest ratio of time to peak(TTP) to baseline level recorded at day 1 (0.93±0.05) was markedly reduced (P＜0.05) as compared with that at baseline and day 2.The ratio of mean transition time (MTT) to baseline increased impressively at day 1 (2.30±0.33) as compared with that at other time points (P＜0.05).A considerable increase in the ratio of relative cerebral blood volume (RCBV) to baseline (1.80±0.60) recorded at day 1 appeared statistically different from that at baseline(P＜0.05).Furthermore,the most markedly reduced ratio of relative cerebral blood flow (RCBF) to baseline (0.69±0.13) at day 1 differed statistically with that at other time points (P＜0.05).Conclusion Cerebral microcirculation is significantly disrupted at day 1 during recovery,in which PWI may be employed to determine the cerebral hemodynamic changes.