Implementation of double sequential defibrillation (DSD): an Aotearoa New Zealand observational study

Area of Science:

• Emergency medicine
• Cardiology
• Clinical research

Background:

• Double sequential defibrillation (DSD) is a new treatment for refractory ventricular fibrillation (VF) and ventricular tachycardia (VT) in New Zealand.
• Its effectiveness and impact on patient survival are not yet well understood.

Purpose of the Study:

• To compare patient characteristics before and after DSD implementation.
• To evaluate the impact of DSD on survival outcomes in cardiac arrest patients.
• To analyze survival differences between patients receiving DSD and those not receiving DSD (NDSD), including early- and late-DSD subgroups.

Main Methods:

• Retrospective cohort study analyzing data from two 18-month periods (pre- and post-DSD implementation).
• Included cardiac arrest patients receiving more than three prehospital defibrillations.
• Compared outcomes using Chi-Square and Mann-Whitney U tests; logistic regression analyzed survival associations.

Main Results:

• No significant difference in Return of Spontaneous Circulation (ROSC) or 30-day survival was found between pre- and post-DSD periods.
• Forty-three percent of patients received DSD.
• Patients receiving any-DSD or late-DSD showed lower odds of ROSC and 30-day survival compared to NDSD patients.

Conclusions:

• DSD implementation did not demonstrate a survival benefit for cardiac arrest patients.
• Lower survival in DSD patients may be due to confounding factors, such as use in patients with poorer prognoses.
• Further investigation is required to determine optimal DSD timing and usage criteria.