High-Quality CPR and Defibrillation Principles

Key Points

• High-quality CPR is a primary contributor to survival after cardiac arrest.
• CPR actions are rhythm and pulse dependent; not all interventions are indicated in all arrests.
• Defibrillation is emergently indicated for ventricular fibrillation and pulseless ventricular tachycardia.
• Synchronized cardioversion is used for selected unstable tachydysrhythmias with a pulse.
• Asystole is not a shockable rhythm and requires non-shock resuscitation priorities.
• Team role clarity and concise communication during transitions are essential to minimize pauses and treatment delay.

Pathophysiology

Cardiac arrest eliminates effective perfusion, rapidly threatening cerebral and multisystem viability. CPR provides temporary circulatory support through chest compressions and ventilatory support strategies until return of spontaneous circulation or definitive advanced care.

Defibrillation interrupts nonperfusing ventricular electrical chaos to enable organized cardiac activity. Rhythm recognition is therefore central to selecting shock versus non-shock pathways.

Classification

• Respiratory arrest with pulse: Rescue breathing indicated; chest compressions are not routine first action.
• Pulseless arrest: CPR indicated to maintain perfusion.
• Unstable tachydysrhythmia with pulse: Synchronized cardioversion pathway (for example PSVT, narrow-complex SVT, rapid atrial fibrillation/flutter, torsades with pulse, or ventricular tachycardia with pulse).
• Shockable arrest rhythms: Ventricular fibrillation and pulseless ventricular tachycardia.
• Non-shockable arrest rhythms: Asystole and pulseless electrical activity (PEA).

Nursing Assessment

NCLEX Focus

Questions emphasize immediate differentiation of pulse/no-pulse states and shockable versus non-shockable rhythms.

• Assess responsiveness, pulse status, and breathing adequacy without delay.
• Assess monitor rhythm rapidly when equipment is available.
• Assess CPR quality indicators during active resuscitation.
• Assess need for AED/manual defibrillator and team role assignment.
• Anticipate synchronized-shock timing behavior: once sync mode is active, delivery may be briefly delayed until the next R-wave peak.

Nursing Interventions

• Initiate high-quality CPR immediately for pulseless arrest.
• Apply AED or defibrillator promptly when shockable rhythm criteria are met.
• Use AED mode for bystander-focused rhythm analysis/shock guidance, and use manual defibrillator mode in acute-care units when rhythm visualization, synchronized cardioversion, or external pacing is required.
• Assign explicit roles early (team lead, compressor, airway, medication, recorder) and rotate compressors about every 1-2 minutes (about 5 CPR cycles) to sustain compression quality.
• Maintain compression quality targets during CPR (about 100-120/min, depth around 2 in with full chest recoil) and minimize pauses.
• For unstable rhythms with a pulse, prepare synchronized cardioversion and verify sync markers on R waves before shock delivery.
• Before planned cardioversion with anesthesia support, keep the patient NPO per protocol and confirm preprocedure preparation steps.
• For stable new-onset atrial fibrillation/flutter with clearly known onset within about 48 hours, anticipate provider evaluation for rhythm-control options that may include synchronized cardioversion.
• In hemodynamically stable new atrial fibrillation/flutter with onset >48 hours or unknown onset, support thrombus-risk evaluation (such as pre-cardioversion TEE) before elective cardioversion.
• Prepare for provider-selected electrical dose parameters (often low-energy cardioversion ranges, commonly around 100-200 J with biphasic systems).
• After cardioversion, continue rhythm/hemodynamic monitoring and assess recovery from monitored anesthesia during early postprocedure observation (commonly around 2 hours per unit protocol).
• During monitor rhythm analysis, ensure no one touches or moves the patient to avoid analysis artifact and unsafe shock decisions.
• Continue coordinated CPR-defibrillation cycles per current algorithm guidance.
• Resume or continue high-quality compressions immediately after shock and maintain compressions for about 2 minutes before routine rhythm recheck unless protocol indicates otherwise.
• For asystole/PEA pathways, continue non-shock resuscitation priorities with high-quality CPR, epinephrine support, airway/ventilation escalation, and systematic reversible-cause search.
• Use available code-cart resources to support airway, medications, and rhythm management.
• Anticipate unit code-cart essentials such as backboard, airway devices/BVM, emergency medications, and manual defibrillator-monitor setup.
• In pulseless VT/VF pathways, support BVM ventilation with high-concentration oxygen and anticipate ACLS medication sequencing (for example epinephrine with antiarrhythmic support such as amiodarone or lidocaine) per protocol.
• After each rhythm/pulse check, resume CPR immediately when no carotid pulse is present.
• Support provider-selected defibrillation energy dosing (commonly within about 150-300 J depending on device type and rhythm protocol).
• In witnessed arrest, prioritize immediate intervention because delay beyond the first few minutes markedly worsens survival outcomes.
• Perform structured post-event handoff documenting rhythm, shocks, and response.
• Use shock safety controls for all electrical therapy: clear all contact, keep staff off client/bed, and move nearby oxygen equipment away during shock delivery.
• During ACLS progression, support reversible-cause evaluation using the Hs-and-Ts framework when perfusion is not restored.

Rhythm-Action Mismatch

Delivering unsynchronized shocks in pulse-present rhythms or shocking non-shockable rhythms (asystole/PEA) can worsen outcomes.

Pharmacology

During advanced resuscitation, emergency medications are integrated with CPR and rhythm-guided defibrillation; nursing roles include preparation, administration support, and event-timeline documentation. Common classes include antiarrhythmics and catecholamine vasopressors/inotropes per protocol and rhythm context.

Clinical Judgment Application

Clinical Scenario

A patient with sudden collapse has no palpable pulse; monitor rhythm appears nonperfusing.

• Recognize Cues: Pulselessness confirms need for immediate perfusion support.
• Analyze Cues: Rhythm category determines whether defibrillation is indicated.
• Prioritize Hypotheses: Rapid CPR plus correct rhythm-specific pathway is the top survival determinant.
• Generate Solutions: Begin compressions, prepare defibrillator, coordinate team roles.
• Take Action: Deliver algorithm-concordant CPR and shock decisions.
• Evaluate Outcomes: Rhythm and perfusion reassessment guide ongoing cycles and escalation.

Related Concepts

• ecg-waveform-basics-and-12-lead-application - Rhythm interpretation principles support emergency rhythm recognition.
• advanced-airways-and-intubation - Airway control may be required during prolonged or unstable resuscitation.
• manual-resuscitators-and-manual-ventilation - Bag-valve-mask support is core to arrest airway management.
• oxygen-therapy-device-selection-and-monitoring - Oxygen strategy integrates with emergency ventilation support.
• respiratory-failure - Respiratory deterioration may precede arrest and requires early intervention.

Self-Check

1. Why is asystole managed without defibrillation?
2. Which rhythms are classically shockable in pulseless arrest?
3. How does CPR quality influence post-arrest survival potential?