Out-of-hospital CPR: better outcome for our patients

Out-of-hospital cardiac arrest is a leading cause of death in developed countries and early resuscitation attempts are crucial to improve survival rates and neurological outcome. Gräsner and colleagues performed an intriguing analysis on the combined approach of mild therapeutic hypothermia (MTH) and immediate percutaneous coronary intervention (PCI) for post-resuscitation care of 584 patients with out-of-hospital cardiac arrest from the German Resuscitation Registry. PCI was independently associated with good neurological outcome at hospital discharge after successful resuscitation, and MTH was associated as an independent factor with increased chance of 24-hour survival. Moreover, a binary logistic regression analysis did not show statistical significance for MTH, in addition to PCI, as an independent predictor for good neurological outcome. The present study supports the evidence that post-resuscitation care based on standardized protocols is beneficial after successful resuscitation. Further prospective and randomized studies are warranted to elucidate criteria for a better selection of candidates for those strategies and to evaluate the potential, in terms of neurological outcome at hospital discharge, of a prehospital cooling strategy in patients who cannot be referred to immediate PCI.


Abstract
Out-of-hospital cardiac arrest is a leading cause of death in developed countries and early resuscitation attempts are crucial to improve survival rates and neurological outcome. Gräsner and colleagues performed an intriguing analysis on the combined approach of mild therapeutic hypothermia (MTH) and immediate percutaneous coronary intervention (PCI) for post-resuscitation care of 584 patients with out-ofhospital cardiac arrest from the German Resuscitation Registry. PCI was independently associated with good neurological outcome at hospital discharge after successful resuscitation, and MTH was associated as an independent factor with increased chance of 24-hour survival. Moreover, a binary logistic regression analysis did not show statistical signifi cance for MTH, in addition to PCI, as an independent predictor for good neurological outcome. The present study supports the evidence that post-resuscitation care based on standardized protocols is benefi cial after successful resuscitation. Further prospective and randomized studies are warranted to elucidate criteria for a better selection of candidates for those strategies and to evaluate the potential, in terms of neurological outcome at hospital discharge, of a prehospital cooling strategy in patients who cannot be referred to immediate PCI. controlled trials are challenging, primarily because of ethical concerns. Gräsner and colleagues evaluated 584 patients from the German Resuscitation Registry with complete pre-resuscitation and post-resuscitation datasets [1]. Th e authors described the eff ects of a combined approach for the early treat ment of OHCA patients with or without a shockable rhythm. Th ey found that both PCI and MTH were asso ciated with good neurological outcome and increased survival at 24 hours after return of spontaneous circu lation, in line with previous reports [4][5][6]. Th e authors evaluated the eff ects of both MTH and PCI used alone and in combi nation: they found a benefi cial eff ect even for PCI alone, while in a large previous report immediate PCI after OHCA was associated with MTH in 85% of patients [4]. Interestingly, data from binary logistic regression analysis showed that MTH was not an independent predictor of good neuro logic recovery, when used in addition to PCI [1].
Some details are lacking in the present study, however, such as timing and the devices used to achieve cooling, as well as PCI details. Moreover, data on the potential advantage of the combination of PCI and MTH versus PCI alone or MTH alone are lacking.
In the PRINCE study, induction of hypothermia with intranasal cooling devices in a prehospital setting may be useful in reducing time intervals required to cool the patients [13]. An outcome diff erence in com pari son with in-hospital cooling was not found; a post-hoc analysis of patients in which cardiopulmonary resus ci tation (CPR) was started within 10 minutes demon strated a signifi cant eff ect of prehospital cooling on survival rate and neurological recovery. Th e potential of this approach in patients not immediately undergoing PCI due to lack of catheterization facilities is worth studying.
Some other interesting factors deserve further atten tion, particularly the association of fi brinolysis with a worse outcome. Th is association is in contrast to a previous report by Böttiger and colleagues, who found no diff erence of outcome in comparison with placebo using thrombolysis during resuscitation [7], without adjunctive antithrombotic therapies. Fibrinolysis is usually con sidered relatively contraindicated after prolonged CPR, because of the increased risk of bleeding. It could be useful to establish whether factors such as the timing of fi brinolysis administration, the duration of CPR and adjunctive antithrombotic therapies could have infl u enced the unfavorable eff ects observed in the present study.
Post-resuscitation care based on more standardized protocols including PCI and MTH may be benefi cial after successful resuscitation. Further studies are warranted to elucidate criteria for a better selection of candidates, and to demonstrate whether a prehospital rapid cooling strategy during early CPR may be independently associated with an improvement of neurological outcome in patients who cannot be referred for immediate coronary angiography.