Background: The randomized, prospective ResQTrial showed that the combination of active compression decompression (ACD) CPR plus an impedance threshold device (ITD) (ACD+ITD) resulted in a 53% improved survival to hospital discharge (HD) with favorable neurological function, as compared with standard CPR (S-CPR). Since restoration and recovery of brain function may continue beyond HD, we hypothesized that patients with poor neurological function at HD would have a greater likelihood of long term neurologic improvement if they had been resuscitated using ACD+ITD. In addition, the use of post-resuscitation therapeutic hypothermia (TH) should further optimize outcomes.
Methods: A post-hoc analysis of ResQTrial data compared survival with favorable neurologic function at 90 days, defined as a Cerebral Performance Category (CPC) score . 2, in patients that had poor neurologic function (CPC.3) at HD. Data were stratified by CPR method and use of TH. Differences in the percent of patients that improved from CPC . 3 at HD to CPC .2 at 90 days were analyzed using a Fisherfs Exact test, with a p-value < 0.05 considered as statistical
Results: There was an overall two-fold increase in the percentage of patients that improved from CPC .3 at HD to . 2 at 90 days in the ACD+ITD group (48.0%, 12/25) compared to S-CPR (21.0%, 4/19), but the difference was not statistically significant (p = 0.113). Among patients receiving TH, however, there was a six-fold statistically significant increase associated with ACD+ITD with TH (69.2%, 9/13) vs. S-CPR with TH (11.1%, 1/9), p = 0.012.
Conclusions: In patients with poor neurological function at hospital discharge, ACD+ITD with TH resulted in a six-fold improvement in neurological function by 90 days compared with SCPR with TH. These observations underscore the importance of longer term follow-up, beyond HD, when evaluating new methods of CPR and post-resuscitation care.