CPR, AED, Rapid Transport, and Handoff

High-Quality CPR: The Numbers That Save Brains

When a patient is unresponsive, not breathing (or only gasping/agonal), and pulseless, the EMR begins high-quality CPR immediately. The metrics are tested verbatim, so memorize them:

Beyond rate and depth, the five characteristics of high-quality CPR are: rate 100–120/min, adequate depth, full chest recoil between compressions, minimal interruptions (aim for a high compression fraction), and avoiding excessive ventilation. Allowing the chest to fully recoil lets the heart refill; leaning on the chest between compressions cuts blood flow. Compressions should not be paused for more than about 10 seconds even to give breaths or apply the AED.

Using the AED

The automated external defibrillator (AED) is the EMR's most important cardiac-arrest tool because early defibrillation of ventricular fibrillation is the single strongest survival factor. The sequence:

1. Turn it on as soon as it arrives and follow the voice prompts.
2. Bare and dry the chest; apply pads (upper-right chest and lower-left side). Use pediatric pads/dose attenuator for children under ~8 years or 25 kg if available; if not, use adult pads.
3. Clear for analysis — "I'm clear, you're clear, everyone clear" — touching no one.
4. If a shock is advised, clear again and deliver the shock.
5. Resume chest compressions IMMEDIATELY after the shock — do not check a pulse first. The AED re-analyzes about every 2 minutes.

Common exam traps: stopping CPR to check a pulse right after a shock (wrong — resume compressions), delaying compressions to set up the AED (keep compressing until pads are ready to place), and applying pads over a medication patch or implanted device (remove the patch, offset the pad). Minimize the hands-off time around every analysis and shock.

Teamwork, Transport, and Handoff

CPR is exhausting and quality fades within a couple of minutes, so rotate compressors about every 2 minutes (during the AED rhythm analysis), keeping the switch under ~5 seconds. EMRs typically deliver continuous high-quality CPR and AED care on scene until a transporting unit (EMT/Paramedic) arrives, then assist; many systems emphasize "stay and play" effective resuscitation rather than rushing a non-perfusing patient into a moving vehicle, because compressions degrade during transport.

When higher-level care arrives, give a concise, complete verbal handoff — the SBAR or MIST/MIVT framework works well:

• Situation: age, what was found, time of collapse and when CPR started.
• Background: witnessed arrest? bystander CPR? known history?
• Assessment: number of shocks delivered, current rhythm/AED messages, response.
• Recommendation/Request: what you need and what has been done (airway, ventilations, oxygen).

Worked scenario

An adult collapses; he is unresponsive, not breathing, pulseless. A lone EMR starts 30:2 CPR at 100–120/min, ≥2 inches deep, full recoil, and when the AED arrives applies it, clears, and shocks, then immediately resumes compressions for 2 minutes before the AED re-analyzes. When EMTs arrive, the EMR hands off: "56-year-old, witnessed collapse 6 minutes ago, bystander CPR immediate, two shocks delivered, last about 90 seconds ago, ventilating 30:2 with BVM and high-flow oxygen." Clear numbers and a clean handoff complete the chain of survival.

The Chain of Survival and When to Begin

EMR cardiac-arrest care is organized around the Chain of Survival: early recognition and activation of EMS, early high-quality CPR, early defibrillation, advanced care, and post-arrest care. The EMR drives the first three links, which are the ones most tied to survival. The decision to start CPR is simple and must be fast: an adult who is unresponsive and not breathing normally (no breathing or only agonal gasps) gets compressions started while a pulse check of no more than 10 seconds is performed; if no definite pulse is felt, begin CPR.

When in doubt, the bias is to start compressions — the harm of withholding CPR from an arrested patient far outweighs the harm of brief compressions on a patient who turns out to have a pulse.

EMRs generally do not stop resuscitation in the field; CPR continues until the patient revives (return of spontaneous circulation), care is transferred to a higher-level provider, a valid do-not-resuscitate order is presented, or the rescuer is physically unable to continue or the scene becomes unsafe. Pronouncement and termination of resuscitation are not EMR decisions.

Special AED and CPR Situations

A few special circumstances are high-yield exam material:

The overarching theme is to minimize interruptions and never delay defibrillation. Compressions continue while the AED is readied and pads are applied; the only true pauses are the brief moments to clear during analysis and shock. After every 2-minute cycle the AED re-analyzes, the EMR rotates the compressor, and the team rechecks that ventilations are producing chest rise. High-quality, minimally interrupted CPR plus prompt defibrillation is, by a wide margin, the most effective thing an EMR can do for a patient in cardiac arrest — and on the exam, the correct answer almost always protects compression quality and early shock.