2.5 Cardiac Arrest Management
Key Takeaways
- The AHA Chain of Survival for out-of-hospital cardiac arrest includes: early recognition and activation of EMS, early CPR, early defibrillation, advanced resuscitation, and post-cardiac arrest care
- Cardiac arrest is recognized by unresponsiveness, absent or abnormal breathing (agonal gasps), and no detectable pulse within 10 seconds
- The BLS algorithm follows the C-A-B sequence: Compressions first, then Airway, then Breathing, to minimize delays in starting chest compressions
- Return of spontaneous circulation (ROSC) signs include a palpable pulse, rising end-tidal CO2, spontaneous breathing, purposeful movement, and improving skin color
- Special circumstances in cardiac arrest include drowning (prioritize ventilations with A-B-C approach), hypothermia (continue resuscitation until rewarmed), and trauma arrest (address reversible causes)
- In team-based resuscitation, EMTs fill roles including compressor, airway manager, AED operator, timekeeper/recorder, and team leader to coordinate high-quality care
- EMTs may consider stopping resuscitation when ROSC is achieved, care is transferred to higher-level providers, the rescuer is physically exhausted, or a valid DNR/POLST is presented
Cardiac arrest is the cessation of effective heart function, resulting in the absence of circulation. Rapid recognition and intervention are critical, as brain damage begins within 4-6 minutes without blood flow.
Chain of Survival (AHA 2025 Guidelines)
The American Heart Association's Chain of Survival for out-of-hospital cardiac arrest (OHCA) consists of five links:
- Early recognition and activation of EMS - Bystanders recognize cardiac arrest and call 911
- Early CPR - Immediate high-quality chest compressions (with or without ventilations)
- Early defibrillation - AED use within the first few minutes
- Advanced resuscitation - Paramedic-level interventions (IV/IO access, medications, advanced airways)
- Post-cardiac arrest care - Targeted temperature management, cardiac catheterization, ICU care
Every link in the chain must be strong. Survival decreases approximately 7-10% for every minute without CPR and defibrillation.
Recognizing Cardiac Arrest
Cardiac arrest is confirmed by the presence of all three criteria:
| Finding | Assessment |
|---|---|
| Unresponsive | Tap and shout; no response to stimulation |
| No normal breathing | No breathing or only agonal gasps (occasional, irregular gasping breaths that are NOT adequate breathing) |
| No pulse | Check carotid pulse (adult/child) or brachial pulse (infant) for no more than 10 seconds |
Important: Agonal gasps are NOT normal breathing. They occur in up to 40% of cardiac arrest patients and should not delay CPR. If in doubt, begin CPR.
BLS Algorithm: C-A-B Approach
The current BLS sequence prioritizes C-A-B (Compressions-Airway-Breathing):
- Confirm unresponsiveness and call for help (activate EMS, get AED)
- Check for a pulse (no more than 10 seconds)
- C - Compressions: Begin chest compressions immediately (30 compressions)
- A - Airway: Open the airway (head-tilt/chin-lift or jaw thrust if trauma suspected)
- B - Breathing: Deliver 2 rescue breaths (1 second each, visible chest rise)
- Continue 30:2 cycles until AED arrives or advanced help takes over
- Apply AED as soon as available; follow prompts
- Resume CPR immediately after shock delivery (do not check pulse first)
Why C-A-B instead of A-B-C? Starting with compressions ensures that blood flow to the brain and heart begins immediately. Delays in opening the airway and providing breaths can waste critical seconds.
Team-Based Resuscitation
Effective cardiac arrest management requires coordinated team effort. Common roles include:
| Role | Responsibilities |
|---|---|
| Team Leader | Directs the resuscitation, assigns roles, monitors quality, makes decisions |
| Compressor | Performs high-quality chest compressions, rotates every 2 minutes |
| Airway Manager | Opens airway, provides ventilations with BVM, suctions as needed |
| AED/Monitor Operator | Applies AED pads, operates device, announces rhythm analysis |
| Timekeeper/Recorder | Tracks time, documents interventions, announces 2-minute intervals |
Effective team communication:
- Use closed-loop communication (confirm orders by repeating them back)
- Announce actions clearly: "I'm starting compressions," "Charging AED"
- The team leader should assign tasks by name: "John, take over compressions"
- Any team member can speak up if they see a quality issue
When to Stop Resuscitation (EMT Level)
EMTs may consider stopping resuscitation when:
- ROSC is achieved - Patient regains a pulse and spontaneous breathing
- Care is transferred to a higher-level provider (paramedic, physician)
- A valid DNR or POLST is presented (Do Not Resuscitate / Physician Orders for Life-Sustaining Treatment)
- The scene becomes unsafe for rescuers
- Rescuers are physically exhausted and no relief is available
- Medical direction orders cessation of resuscitation
- Follow local protocol for determination of death in the field
Return of Spontaneous Circulation (ROSC)
Signs that indicate ROSC has been achieved:
- Palpable pulse returns
- Rising end-tidal CO2 (ETCO2) - A sudden increase (typically >40 mmHg) during CPR
- Spontaneous breathing resumes
- Purposeful movement (patient moves, coughs, or gags)
- Improving skin color - From cyanotic/pale to pink
- Blood pressure becomes measurable
Post-Cardiac Arrest Care (EMT Level)
If ROSC is achieved, the EMT should:
- Maintain the airway - Continue to manage and support ventilation
- Administer oxygen - Titrate to maintain adequate oxygenation
- Monitor vital signs - Frequent reassessment (every 5 minutes)
- Keep the patient warm - Avoid hypothermia (but do not actively rewarm unless protocol directs)
- Position appropriately - Supine; recovery position if breathing adequately and no trauma
- Prepare for re-arrest - Leave AED pads in place; cardiac arrest can recur
- Transport rapidly to a facility capable of post-cardiac arrest care (cardiac catheterization, ICU)
- Provide emotional support to the patient if conscious
Special Circumstances
| Situation | Key Considerations |
|---|---|
| Drowning | Prioritize ventilations (A-B-C approach is recommended for drowning); remove from water first; suspect cervical spine injury if diving accident; hypothermia may be protective |
| Hypothermia | Continue resuscitation efforts; "They're not dead until they're warm and dead"; reduce to 1 pulse check for up to 60 seconds; transport for active rewarming; defibrillation may be ineffective until core temp >86degF (30degC) |
| Trauma arrest | Address reversible causes (tension pneumothorax, massive hemorrhage); survival rates are low for traumatic cardiac arrest; follow local protocol |
| Pregnancy | Perform CPR with manual left uterine displacement (push uterus to left) to relieve aortocaval compression; do not delay CPR or defibrillation |
| Opioid overdose | Administer naloxone (Narcan) per protocol; continue CPR if no pulse; respiratory arrest may precede cardiac arrest |
| Electrocution | Ensure scene safety first (power source disconnected); cardiac arrest may result from V-fib; standard BLS protocols apply |
What is the correct sequence for the BLS algorithm?
Which of the following is a sign of return of spontaneous circulation (ROSC)?
When managing a cardiac arrest in a drowning victim, what is the recommended approach?
A cardiac arrest patient in severe hypothermia is not responding to defibrillation. What should the EMT do?
In a team-based resuscitation, what communication technique should the team leader use when assigning tasks?
Which of the following is an appropriate reason for an EMT to stop resuscitation efforts?
Arrange the links of the AHA Chain of Survival for out-of-hospital cardiac arrest in the correct order:
Arrange the items in the correct order