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?
A-B-C: Airway, Breathing, Compressions
C-A-B: Compressions, Airway, Breathing
B-C-A: Breathing, Compressions, Airway
A-C-B: Airway, Compressions, Breathing
Which of the following is a sign of return of spontaneous circulation (ROSC)?
Agonal gasps with no pulse
A sudden rise in end-tidal CO2 during CPR
Asystole on the cardiac monitor
Fixed and dilated pupils
When managing a cardiac arrest in a drowning victim, what is the recommended approach?
Standard C-A-B approach with compressions first
A-B-C approach prioritizing ventilations because drowning is primarily a respiratory event
Defibrillation only, without CPR
Do not attempt resuscitation for drowning victims
A cardiac arrest patient in severe hypothermia is not responding to defibrillation. What should the EMT do?
Stop all resuscitation efforts and declare death
Continue CPR and transport for active rewarming; the patient is not dead until warm and dead
Administer nitroglycerin to increase heart rate
Apply heating pads directly to the patient's chest and defibrillate again
In a team-based resuscitation, what communication technique should the team leader use when assigning tasks?
Shout general orders to the group without specifying who should do what
Use closed-loop communication and assign tasks by name
Only communicate with the most experienced team member
Write orders on a whiteboard for team members to read
Which of the following is an appropriate reason for an EMT to stop resuscitation efforts?
The patient has been in cardiac arrest for 5 minutes
A family member requests that you stop
A valid Do Not Resuscitate (DNR) order is presented
The patient is elderly
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
Early CPR
Early recognition and activation of EMS
Post-cardiac arrest care
Early defibrillation
Advanced resuscitation
Sections you finish are checked off in the contents.