Double sequential external defibrillation (DSED) is now recommended for use in cases where standard single-shock defibrillation is ineffective, particularly in refractory ventricular fibrillation (VF). It involves the use of two defibrillators to deliver two sequential shocks as close together as possible. DSED is a valuable tool in the emergency medical arsenal, offering a new layer of strategy for treatment-resistant cardiac arrhythmias, especially considering that this group has a mortality of 85-97%.

Understanding DSED

DSED should be employed when a patient’s heart is in VF and has not responded to three attempts at defibrillation with a single shock. VF, a condition where the heart quivers instead of pumping due to disorganized electrical activity, is often fatal if not rapidly corrected.

The Procedure

The DSED procedure involves placing one set of pads in the anterolateral position and the other set in an anteroposterior position. This allows for an electrical current to be delivered from two different vectors. Ideally, the shocks should be administered as close together as possible — typically within milliseconds of each other. This approach may enhance the defibrillation threshold and increase the likelihood of converting VF to a normal rhythm.

When to Consider DSED

Double sequential defibrillation may be considered when:

• A patient’s VF persists after three standard defibrillation attempts.
• Available pharmacological interventions have failed.
• Additional defibrillation devices are available to the clinician.

Clinical Considerations and Safety

Before implementing DSED, it is crucial to consider all clinical guidelines and safety protocols:

• Two of the responding units should bring in their defibrillators (we’ll include tips and best practices when it is a combination of different brand monitors, or even an AED and a manual defibrillator).
• Ensure that all team members are aware of the procedure and their respective roles.
• Check that both defibrillators are properly functioning, and one provider is ready to charge and defibrillate both devices (best practice).

The Evidence

We’ve included 15 peer reviewed studies on Double Sequential External Defibrillation in the DropBox folder below.

Conclusion

Double sequential external defibrillation represents an important advance in our ability to manage difficult cases of VF. For emergency responders and healthcare providers like EMTs, paramedics, ED nurses, and physicians, understanding and applying DSED can be critical to improving patient outcomes in life-threatening situations.

As this field evolves, continuous learning and adaptation to new evidence-based practices will be essential in ensuring the highest standards of care. Always consult with your medical director and adhere to your local protocols when considering DSED.