As of January this year, Aotearoa New Zealand became just the second country (after Canada) to adopt a groundbreaking new procedure for patients experiencing cardiac arrest.

DSED is a novel method that provides rapid sequential shocks to the heart using two defibrillators. The pads are attached in two different locations: one on the front and side of the chest, the other on the front and back.

A single operator activates the defibrillators in sequence, with one hand moving from the first to the second. According to a recent randomised trial in Canada, this approach could more than double the chances of survival for patients with ventricular fibrillation or pulseless ventricular tachycardia who are not responding to standard shocks.

The guidelines now specify that if ventricular fibrillation or pulseless ventricular tachycardia persist after two shocks with standard defibrillation, the DSED method should be administered. Two defibrillators need to be available, and staff must be trained in the new approach.

Though the existing evidence for DSED is compelling, until recently it was based on theory and a small number of potentially biased observational studies. The Canadian trial was the first to directly compare DSED to standard treatment.

From a total of 261 patients, 30.4% treated with this strategy survived, compared to 13.3% when standard resuscitation protocols were followed.