Shock determination based on prior shocks

An external defibrillator system for managing care of a person receiving emergency cardiac assistance, the external defibrillator system comprising:

• one or more capacitors for delivering a defibrillating shock to the person;
• one or more electronic ports for receiving signals from sensors for obtaining indications of an electrocardiogram (ECG) for the person;
• a patient treatment module comprising one or more computer processors;
• and
• one or more computer readable media comprising instructions that, when executed by the one or more computer processors, cause the patient treatment module to carry out operations comprising:
• determining a metric indicative of a likelihood of success from delivering a future defibrillating shock to the person with the one or more capacitors during a session of the emergency cardiac assistance, by using information about an indication of success associated with a prior defibrillating shock delivered during the session of the emergency cardiac assistance and a value that is a function of current ECG signals from the person;
• and
• causing the one or more capacitors to be charged based on the metric indicative of the likelihood of success from delivering the future defibrillating shock.