Cardiac Arrest and Resuscitation - NREMT: AEMT Level

Ventricular fibrillation (VF). VF is the most frequent initial rhythm in out-of-hospital cardiac arrests in adults, amenable to defibrillation to restore organized rhythm.

$2$ to $2.4$ inches ($5$ to $6$ cm). Adequate depth compresses the heart sufficiently against the spine to generate blood flow without causing injury.

Organized ECG rhythm without a palpable pulse. PEA indicates electrical activity on ECG that should produce a pulse but does not due to underlying mechanical or metabolic issues.

Ventricular fibrillation and pulseless ventricular tachycardia. These rhythms respond to defibrillation as they involve chaotic or rapid ventricular activity that can be terminated by electrical shock.

Asystole and pulseless electrical activity. These rhythms lack ventricular electrical activity suitable for defibrillation, requiring focus on identifying and treating underlying causes.

$30:2$. This ratio balances circulation from compressions with oxygenation from ventilations in basic life support scenarios.

$1$ breath every $6$ seconds ($10$ per minute). This rate provides sufficient oxygenation without causing hyperventilation or gastric distension in intubated patients.

Less than $10$ seconds. Minimizing pauses maintains coronary perfusion pressure, which is critical for successful resuscitation.

About every $2$ minutes (every $5$ cycles of $30:2$). Regular switching prevents rescuer fatigue, ensuring consistent compression quality throughout resuscitation.

$1$ mg IV/IO. Epinephrine acts as a vasopressor to increase coronary and cerebral perfusion pressures during low-flow states.

Every $3$ to $5$ minutes. This interval aligns with epinephrine's pharmacokinetics to maintain therapeutic levels without toxicity.

After the second shock (during the next CPR cycle). Timing allows initial defibrillation attempts before adding vasopressor support in the shockable algorithm.

As soon as possible after IV/IO access is obtained. Early administration in nonshockable rhythms supports perfusion while addressing reversible causes.

Amiodarone $300$ mg IV/IO bolus. Amiodarone stabilizes membranes and prolongs action potential to terminate refractory ventricular arrhythmias.

Amiodarone $150$ mg IV/IO bolus. The reduced second dose maintains efficacy while minimizing cumulative toxicity risks.

Lidocaine $1$ to $1.5$ mg/kg IV/IO. Lidocaine suppresses ventricular ectopy as an alternative when amiodarone is unavailable or contraindicated.

$200$ J (then equal or higher for subsequent shocks). This energy level optimizes first-shock success for biphasic waveforms, with escalation for refractoriness.

$360$ J. Monophasic defibrillators require higher energy to achieve equivalent efficacy to biphasic devices.

Every $2$ minutes. This interval allows assessment without prolonged CPR interruption, balancing rhythm identification with perfusion.

Return of a palpable pulse with signs of perfusion. ROSC confirms restoration of effective cardiac output, distinguishing from transient or artifactual findings.

Clear the patient and deliver the shock, then resume CPR immediately. Immediate shock delivery terminates shockable rhythms, followed by CPR to support circulation post-defibrillation.

Resume CPR immediately and reassess rhythm in about $2$ minutes. Continuing CPR maintains circulation in nonshockable rhythms while preparing for next rhythm assessment.

Prioritize CPR and ventilation; naloxone is not the initial priority. In cardiac arrest from opioids, restoring circulation and oxygenation takes precedence over reversal agents.