How many defibrillator shocks are given during an unsuccessful resuscitation attempt?

How many defibrillator shocks are given during an unsuccessful resuscitation attempt?

One shock for every two minutes of cardiopulmonary resuscitation is the official algorithm, especially if there is a shockable rhythm like ventricular fibrillation. So if the resuscitation continues for 30 minutes as is usual, upto 15 shocks may be delivered. It all depends on other conditions like the type of underlying disease and predicted feasibility of return to a good quality of life.