Abstract 104: Intra-arrest Mild Hypothermia Following Delayed CPR Did Not Improve Survival in Asphyxial Cardiac Arrest Model in Rats
Introduction: Ischemia/reperfusion injury induced cellular damage and organ dysfunction after prolonged cardiac arrest. Ischemia introduced a susceptibility to damage that may worsen by reperfusion with normal blood. Intra arrest cooling was shown significant benefit by many reports.
Hypothesis: We sought to find whether cooling first with delayed CPR by cold blood reperfusion improve survival compared to immediate conventional CPR by warm blood reperfusion and then cooling after ROSC in asphyxial cardiac arrest model in rats.
Methods: Thirty-eight male Wistar rats (260 ~ 310 g) were included in the experiment. Cardiac arrest was induced by 8 minutes asphyxia. Rats were divided into 3 groups: (1) normothermia group (N group, n = 12), rectal temperature maintained at 37 ± 0.5°C during cardiac arrest, CPR, and post-ROSC ventilation periods; (2) intra-arrest hypothermia group (I group, n = 12), after 8 minutes of asphyxia, rats were cooled to 33°C in 3 minutes, and then CPR, rectal temperature maintained at 33 ± 0.5°C until 1 hour after ROSC, and rewarmed gradually to 37 ± 0.5°C during the following 1 hour; (3) post-ROSC hypothermia group (P group, n = 14), rectal temperature maintained at 37 ± 0.5°C during cardiac arrest and CPR periods, rats was cooled to 33°C in 3 minutes after ROSC, rectal temperature was maintained at 33 ± 0.5°C for 1 hour, rewarmed gradually to 37 ± 0.5°C during the following 1 hour. After 2 hour of ROSC, rats were extubated and observed for 3 days.
Results: The time of ROSC in the N group (71.2 ± 38.4 s) and the P group (71.6 ± 28.9 s) was significantly shorter than in the I group (177.1 ± 116.0 s, p < 0.05, respectively). There was no significant difference about the rate of ROSC among the N group (66.7%), the P group (85.7%), and the I group (58.3%). The survival was no difference among groups (Fig. 1).
Conclusions: Intra arrest hypothermia following delayed CPR did not improve survival. Whether it improves neurological function recovery or not needs further studies.
Author Disclosures: J. Liu: None. M. Chen: None. Y. Wang: None. F. Han: None.
- © 2014 by American Heart Association, Inc.