Clinician miscalibration of survival estimate in hypothermic cardiac arrest : HOPE-estimated survival probabilities in extreme cases

Aim: Patients with hypothermic cardiac arrest may survive with an excellent outcome after extracorporeal life support rewarming (ECLSR). The HOPE (Hypothermia Outcome Prediction after ECLS) score is recommended to guide the in-hospital decision on whether or not to initiate ECLSR in patients in cardiac arrest following accidental hypothermia. We aimed to assess the HOPE-estimated survival probabilities for a set of survivors of hypothermic cardiac arrest who had extreme values for the variables included in the HOPE score. Methods:Survivors were identified and selected through a systematic literature review including case reports. We calculated the HOPE score for each patient who presented extraordinary clinical parameters. Results: We identified 12 such survivors. The HOPE-estimated survival probability was ≥10% for all (n = 11) patients for whom we were able to calculate the HOPE score. Conclusion: Our study confirms the robustness of the HOPE score for outliers and thus further confirms its external validity. These cases also confirm that hypothermic cardiac arrest is a fundamentally different entity than normothermic cardiac arrest. Using HOPE for extreme cases may support the proper calibration of a clinician’s prognosis and therapeutic decision based on the survival chances of patients with accidental hypothermic cardiac arrest.