V-Fib Arrest Management

1) Keys running a successful code

• Remember the two most important factors in determining successful outcomes: 1) Time to defibrillation for shockable rhythm (i.e. VT/VF), and 2) High quality CPR.
• Key is to get defibrillator pads on ASAP to determine rhythm - if VT/VF, immediately defibrillate (unsynchronized, high energy shock).  If PEA/Asystole, no role for shocks.
• Meds are secondary, and not proven to improve long-term outcome; in fact, RCT in 2009 JAMA of ~1000 pts with out of hospital arrest comparing ACLS with drugs to ACLS without drugs showed some improvement in short-term success (i.e. survival to ICU admission), but no improvement in primary outcome of survival to hospital discharge. 

·      If no good IV access (as in this patient), meds can be given intraosseously, or down ET tube - meds that can be given down ET tube are NAVEL (Naloxone, Atropine, Vasopressin, Epinephrine, and Lidocaine).  The dose for meds this route is 2-2.5 times the normal dose.

 2) Evaluation of a sudden cardiac arrest survivor: Note - technically, sudden cardiac arrest (SCA) refers to people who survived, while sudden cardiac death (SCD) refers to people who died
Look for acute, reversible causes:

• Acute ischemia MI - check EKG, serial troponins
• Check electrolytes, look for severe hypo or hyperkalemia, calcium, magnesium (although note that electrolytes are affected by the code - i.e. acidosis causing hyperkalemia)
• Look for antiarrhythmic drugs or other QT prolonging drugs.

In terms of etiology of SCD, the majority are cardiac:
 i. Coronary artery disease - ~70% of cases - both acute MI and arrhythmias associated with stable CAD with prior infarction
ii.  CHF - 1/3rd of CHF patients die from SCD!
iii. Other structural heart disease - myocarditis, HOCM, etc
iv.  Noncardiac (~15% of causes) - bleeding, trauma, pulmonary embolism, drug overdose, near drowning

3) Review basics of cooling protocol for SCD survivors
Induced hypothermia has been shown in 2 NEJM RCTS in 2002 to improve neurological outcome and survival in survivors of out-of-hospital V-fib arrests who remain unconscious following return of spontaneous circulation.  Basically, idea is to protect brain from hypoxic injury.  It is actually done by using cooling blankets and ice packs to cool the body temperature to 32-34 degrees celsius x 24 hrs, then passive rewarming.
Our patient did not need the cooling protocol, because after resuscitation he was noted to be responsive.

4) Brief overview of role of ICDs in secondary prevention of VT/VF arrest
Note that secondary prevention refers to preventing recurrent SCD in patients who actually have experienced it, vs primary prevention = preventing it in high risk patients.

AVID trial (NEJM 1997) was largest trial looking at ICDs vs antiarrhythmics in survivors of SCD, which showed significant mortality benefit with ICDs.

(Chanu Rhee MD, 7/16/10)