All patients meeting the inclusion/exclusion eligibility criteria will be consecutively
enrolled in the study. The decision to perform PSGB or not and the type of technique
(anatomic or echo-guided) is left to the EMS rescue team medical doctor (MD), according
to clinical practice (standard of care).
The Emergency Medical System (EMS) rescue team medical doctor (MD) will be asked to
perform PSGB after all the actions provided in the ACLS algorithm and which are
considered useful in the clinical situation (intubation and ventilation, administration
of iv/io adrenaline, amiodarone or lidocaine, use of mechanical chest compression, etc.).
Considering that the PGSB is useful for the treatment of refractory Ventricular
Arrhythmias, the PGSB will be performed after the administration of the 4th shock, if the
3rd shock was unsuccessful in restoring a stable perfusing rhythm, considering all the
shocks administered both by an AED or by manual defibrillator. The evaluation of the
effectiveness of the 3rd shock will be carried out at the end of the two-minute cycle
after shock delivery, as recommended by the Guidelines. If the MD will arrive on the
scene after the delivery of the 3rd shock, the PSGB should be executed as soon as
possible after performing all the actions which are considered useful in the clinical
situation. The MD, based on his confidence, can choose to use the anatomic technique or
the echo-guided PSGB technique. The technique will be performed in the pre-hospital
setting. Those patients with refractory OHCA transported with ongoing ACLS who receive
the fourth shock once in the Emergency Department will be also considered. On the
contrary, the patients with pre-Hospital ROSC who suffer a new cardiac arrest once in the
Emergency Department won't be considered in the present study. The MD will be asked to
evaluate also the presence of anisocoria immediately before the PSGB and 1-2 minutes
after the PSGB. In case of absence of anisocoria 2 minutes after PSGB, MD can try PSGB
another time. The anaesthetic that will be used for PSGB is Lidocaine 2% (10cc bolus),
which is already available among EMS drugs. Considering the setting and the need of a
rapid effect of the anaesthetic, it is expected that the anaesthetic used will be
lidocaine 2%, which is also already available among EMS drugs.
After the end of the event, the MD will be asked to fill in a Questionnaire regarding the
feasibility of the technique in the pre-hospital setting, the practicability of its
implementation compared to the usual procedures performed in the pre-hospital setting and
any problems/complications encountered. The responses will be scored from 1 to 10 (1=no
feasibility; 10=perfect feasibility). All eventual complications associated with PSGB
will be carefully recorded.
The effectiveness of the PSGB will be evaluated if at least one shock will be delivered
after the execution of PSGB.
The data will be compared to our historical cohort of patients with the same OHCA
characteristics (first shockable rhythm and who received more than 4 shocks) enrolled in
the Out-of-Hospital Cardiac Arrest Registry "Lombardia CARe" in the Province of Pavia
(Italy).
