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Three Part Question

Does the use of [double sequential defibrillation] improve the chances of [regaining spontaneous circulation] in [adult VF cardiac arrest]?

Clinical Scenario

An ambulance crew attends to a 46-year-old man who has presented in cardiac arrest. His presenting rhythm is VF and advanced life support (ALS) protocol is instigated. The patient remains in VF in spite of early defibrillation with escalated energy and intravenous amiodarone. Pad position is changed to anterior-posterior (AP) pads; and yet the patient remains in VF. He has now received 7 attempts at defibrillation and reversible causes have been optimised. Does escalation to double sequential defibrillation, initially though AP pads followed by anterior pads improve the chances of the patient regaining spontaneous circulation? Can this be extrapolated to in hospital atraumatic adult cardiac arrest?

Search Strategy

A 2-person search of Pubmed, Cochrane and Science Direct was conducted.
((Dual Defibrillation) OR (Double sequential defibrillation)) AND (adult).

Search Outcome

1284 papers were identified using the search criteria, of which 1270 were irrelevant or of insufficient quality. The remaining 14 papers are shown in the table, one cohort study, one observational case-control study, four retrospective case series’, and eight case studies[1].

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Ross, et al. 2016 San Antonio, Texas, USA	302 cases of recurrent or refractory VF were identified from the San Antonio Fire Department (SAFD) database between January 2013 and December 2015. 23 cases had incomplete data. Of the remaining 279 cases, 50 were treated with DSD and 229 received standard 200J defibrillations. DSD was considered following 3 unsuccessful 200J conventional defibrillation attempts. DSD was delivered with 2 sequential 200J shocks in the AP and anterior pad positions.	Therapeutic Retrospective Cohort Study Level 3b Evidence	Primary Outcome – neurologically intact survival to discharge. Secondary outcome - Regain of spontaneous circulation	Primary outcome – no statistically significant difference Secondary outcome – 28% regained spontaneous circulation in the DSD group in comparison to 37.6% in the control group. This was deemed not statistically significant.	Study was not powered for the outcome of regain of spontaneous circulation. Retrospective, unblinded.
Hoch DH et al. 1994 Long Island New York, USA	5,450 routine electrophysiological studies in 2990 patients over 3 consecutive years were isolated. 5 patients developed refractory VF and received double sequential defibrillation. Patients had received between 7 and 20 shocks at 200J and 360J applied through individual lead configurations. DSD was delivered with shocks between 0.5 to 4.5 seconds apart.	Case Series Therapeutic Retrospective Level 4 Evidence	Regain of spontaneous circulation	All 5 patients regained spontaneous circulation with the first attempt at double sequential defibrillation after failing to respond to regular measures.	One patient received their first shock through and ICD. No control group or randomization.
Emerson AC et al. 2017 UK	45 out of hospital VF cardiac arrest patients were treated with DSD prehospitally by LAS advanced paramedics over 18 months. Patients were considered for DSD if they remained in VF following 5 consecutive standard defibrillation attempts and 2 doses of IV amiodarone (300mg and 150mg). 175 patients received more than 6 consecutive standard defibrillation shocks, but not DSD, and were identified for comparison.	Therapeutic Observational Retrospective Case-Control Level 4 Evidence	Regain of spontaneous circulation	Outcomes amongst the standard defibrillation group were similar to the DSD group. In the DSD group 38%(35%) achieved prehospital ROSC and 59%(56%) of these sustained ROSC to hospital. 30%(29%) of these survived to hospital discharge.	Retrospective, unblinded, unrandomized study. The mean number of shocks received was higher than the advised protocol.
Cabañas JG et al. 2015 North Carolina USA	10 cases of adult refractory VF in out of hospital cardiac arrest from January 2008 to December 2010 in an urban emergency services system. Refractory VF was defined as persisting VF following at least 5 unsuccessful single shocks and appropriate antiarrhythmic medication. Following identification, a further single shock was administered with a change of pad position.	Therapeutic Retrospective Case Series Level 4 Evidence	Regain of spontaneous circulation	30% of patients receiving DSD regained spontaneous circulation. None survived to hospital discharge.	Retrospective No control group
Cortez E et al. 2016 Ohio, USA	Of 2428 out of hospital cardiac arrests, 12 patients were identified with refractory VF and treated with DSD between August 2010 to June 2014 in the city of Columbus, Ohio. Refractory VF was defined as persisting VF following at least 5 unsuccessful single shocks.	Therapeutic Retrospective Case Series Level 4 Evidence	Regain of spontaneous circulation	25% of patients regained spontaneous circulation and these survived to hospital discharge. 17% were discharged with a cerebral performance score of 1.	Retrospective No control group
Merlin MA et al. 2016 New Jersey, USA	7 patients were identified in a 4-month period from January 2015 to April 2014 in New Jersey who were treated with DSD for refractory VF. Refractory VF was diagnosed following 3 standard shocks. The mean number of single shocks was 5.4 prior to DSD (range 3-9).	Therapeutic Retrospective Case Series Level 4 Evidence	Regain of spontaneous circulation	VF was converted in 57.1%. 43% of patients survived to hospital discharge. 28.6% had no or minimum neurological disability.	Retrospective Small patient sample No control group
Leacock BW. 2013 Missouri, USA	A 51-year-old man presenting with an out of hospital VF cardiac arrest following an ST elevation myocardial infarction. ALS protocol was initiated. He received 5 single biphasic shocks of 200J through AL pads. DSD was used with 200J per device through 2 sets of adjacent AL pads.	Therapeutic Retrospective Case Report Level 5 Evidence	Regain of spontaneous circulation	The patient regained spontaneous circulation following DSD. Following cardiac stenting and post-arrest management he was discharged from hospital with no neurological impairment.	Case report Small sample No control group
Lybeck AM et al. 2015 Missouri, USA	A 40-year-old man presenting with an out of hospital VF cardiac arrest. ALS protocol was initiated. He received 6 AL single biphasic shocks of 200J and a 7th of 360J. DSD was administered on the 8th shock with 2 simultaneous 200J shocks using 2 sets of AL pads placed adjacent to each other. It is not mentioned whether he received chemical antiarrhythmic agents were used.	Therapeutic Retrospective Case Report Level 5 Evidence	Regain of spontaneous circulation	The patient regained spontaneous circulation following DSD. He was discharged from hospital following multiple complications without neurological deficit and a cerebral performance category score of 1.	Case report Small sample No control group
Tawil CE et al. 2017 Beirut, USA	A 54-year-old man presenting with an out of hospital VF cardiac arrest. ALS protocol was initiated. He received 7 single biphasic shocks of 200J in the AL position. The patient received a total of 3 DSD shocks, with 200J per device. Pad position was not documented.	Therapeutic Retrospective Case Report Level 5 Evidence	Regain of spontaneous circulation	The patient regained spontaneous circulation following DSD. He was discharged from hospital without neurological deficit.	Case report Small sample No control group
Pound J et al. 2016 Ontario, Canada	A 52-year-old man presenting with an out of hospital VF cardiac arrest. ALS protocol was initiated. Following an unknown number of single biphasic shocks, he received 2 DSD shocks. Pad position and energy of the shocks delivered was not documented.	Therapeutic Retrospective Case Report Level 5 Evidence	Regain of spontaneous circulation	The patient regained spontaneous circulation following DSD. He was discharged from hospital without neurological deficit and a cerebral performance category score of 1.	Case report Small sample No control group
Gerstein NS et al. 2015 New Mexico, USA	A 66-year-old man presenting with an ST elevation myocardial infarction had an in-hospital VF cardiac arrest. ALS protocol was initiated. Following 15 single biphasic shocks at 200J in the standard AL pad position, he received 2 DSD shocks with 200J per device through adjacent AL pads.	Therapeutic Retrospective Case Report Level 5 Evidence	Regain of spontaneous circulation	The patient regained spontaneous circulation following the second DSD. However, due to the duration of his resuscitation, he had a significant anoxic brain injury and care was withdrawn.	Case report Small sample No control group
Sena RC et al. 2016 USA	A 56-year-old woman was admitted to the emergency department with chest pain. She developed an in-hospital VF cardiac arrest. ALS protocol was initiated. Following 4 single biphasic shocks at 200J in the standard AL pad position, she received a DSD shock with 300J per device through adjacent AL pads.	Therapeutic Retrospective Case Report Level 5 Evidence	Regain of spontaneous circulation	The patient regained spontaneous circulation following the DSD shock. The patient was discharged 1 week later with no neurological deficit.	Case report Small sample No control group
Bell CR et al. 2017 Denver, USA	A 53- year-old man presenting with chest pain had an out of hospital VF cardiac arrest en route to the hospital. ALS protocol was initiated. Following 4 single biphasic shocks at 200J in the standard AL pad position, he received a DSD shock with 200J per device through AL and AP pads. Following initial regain of spontaneous circulation a further VF cardiac arrest occurred. He received 1 further DSD shock with AL and AP pads.	Therapeutic Retrospective Case Report Level 5 Evidence	Regain of spontaneous circulation	The patient regained spontaneous circulation and sustained this following the second DSD shock. He was eventually discharged from hospital with no neurological deficit, cerebral performance score of 1.	Case report Small sample No control group
Boehm KM et al. 2016 Michigan, USA	A 67-year-old man presenting with cardiac chest pain sustained an in-hospital VF cardiac arrest. ALS protocol was initiated. Following 4 single biphasic shocks at 200J and a 5th at 300J in the AL pad position, 2 DSD shocks with 300J per device were performed with both AL and AP pads. The patient also received esmolol after the first DSD shock.	Therapeutic Retrospective Case Report Level 5 Evidence	Regain of spontaneous circulation	The patient regained spontaneous circulation and was discharged from hospital without any neurological deficit.	Case report Small sample No control group

Comment(s)

All evidence provided is 3b and below. There is no high-grade evidence to support the use of DSD in the treatment of refractory VF in cardiac arrest. All authors have suggested there may be a role for DSD however, the timing of delivery, level of energy and best pad position have not been stated. There is a requirement for further investigation into the effectiveness of DSD in both the pre-hospital and in-hospital setting. There is also no evidence that the use of DSD has caused harm to the receiving patient.

Clinical Bottom Line

There may be a role for DSD in the treatment of refractory VF in cardiac arrest however there is no significant evidence base for its use.

References

1. Ross EM et al. Dual defibrillation in out-of-hospital cardiac arrest: A retrospective cohort analysis. Resuscitation. 2016; 106:14-17
2. Hoch DH et al. Double sequential external shocks for refractory ventricular fibrillation Journal of the American College of Cardiology 1994; 23(5):1141-1145
3. Emmerson AC et al. Double sequential defibrillation therapy for out-of-hospital cardiac arrests: The London Experience Resuscitation 2017; 117:97-101
4. Cabañas JG et al. Double sequential external defibrillation in out-of-hospital refractory ventricular fibrillation: A report of 10 cases. Prehospital Emergency Care 2015; 19:126-130
5. Cortez E et al. Use of double sequential external defibrillation for refractory ventricular fibrillation during out-of-hospital cardiac arrest Resuscitation 2016; 108:82-86
6. Merlin MA et al. A Case Series of Double Sequence Defibrillation Prehospital Emergency Care 2016; 20(4):550-553
7. Leacock BW. Double simultaneous defibrillators for refractory ventricular fibrillation Journal of Emergency Medicine 2014; 46(4):472-474
8. Lybeck AM et al. Double sequential defibrillation for refractory ventricular fibrillation: A case report. Prehospital Emergency Care 2015; 19(4):554-557
9. Tawil CE et al. Double sequential defibrillation for refractory ventricular fibrillation. American Journal of Emergency Medicine 2017; 35(12):1985.e3-1985.e4
10. Pound J et al. CPR Induced Consciousness During Out-of-Hospital Cardiac Arrest: A Case Report on an Emerging Phenomenon Prehospital Emergency Care 2017; 21(2):252-256
11. Gerstein NS et al. Simultaneous use of two defibrillators for the conversion of refractory ventricular fibrillation Journal of Cardiothoracic and Vascular Anaesthesia 2015; 29(2):421-424
12. Sena RC et al. Refractory ventricular fibrillation successfully cardioverted with dual sequential defibrillation Journal of Emergency Medicine 2016; 51(3):e37-e40
13. Bell CR et al. Make it two: A case report of dual sequential external defibrillation Canadian Journal of Emergency Medicine 2017:1-6
14. Boehm KM et al. First report of survival in refractory ventricular fibrillation after dual-axis defibrillation and esmolol administration Western Journal of Emergency Medicine 2016; 17(6):762-765