What is a code blue (cardiac arrest emergency)?

What is Code Blue?

Code Blue is a standardized hospital emergency alert system that signals a cardiopulmonary arrest or life-threatening medical emergency requiring immediate resuscitation by a specialized response team. 1

Definition and Activation

Code Blue refers to the universal hospital emergency code used to rapidly mobilize a trained resuscitation team when a patient experiences:

• Cardiac arrest (most common - 54.6% of activations) 2
• Respiratory arrest (14% of activations) 2
• Sudden unresponsiveness with no breathing or only gasping 1
• Acute clinical deterioration requiring immediate advanced life support 3, 2

The term serves as a "universal call to action" that simultaneously alerts all necessary responders and prompts them to bring specialized equipment to the scene without delay. 1

Code Blue Team Composition

The response team must include personnel with specific roles and ACLS certification who are on duty and available 24/7: 1

• Code team leader (guides resuscitative efforts)
• Compressor (performs chest compressions)
• Airway manager (typically respiratory therapist positioned at head of bed) 4, 5
• Medication administrator
• Defibrillator operator
• Recorder (documents events) 4
• Physicians, nurses, respiratory therapists, and pharmacists in varying combinations 1

For maternal cardiac arrests, the team must also include neonatal specialists since two critically ill patients require simultaneous resuscitation. 1

Immediate Response Protocol

When Code Blue is activated, the team follows the American Heart Association's systematic ACLS algorithm: 1, 4

Initial Assessment (within 10 seconds):

• Check for unresponsiveness by tapping shoulder and shouting 1
• Simultaneously assess for absent or abnormal breathing (only gasping) and pulse 1
• If no pulse is definitively felt within 10 seconds, assume cardiac arrest 1

High-Quality CPR Initiation:

• Start chest compressions immediately at 100-120/minute with depth of 2-2.4 inches 4, 1
• Maintain chest compression fraction >80% (minimize all pauses) 4
• Allow complete chest recoil after each compression 1
• Perform 30 compressions followed by 2 ventilations until advanced airway placed 1

Airway Management:

• Begin with two-handed bag-mask ventilation using 100% oxygen at ≥15 L/min 4, 5
• Limit intubation attempts to 2 tries per technique to minimize compression interruptions 1, 4
• Once advanced airway secured, provide continuous compressions with 8-10 breaths/minute (no pauses for ventilation) 1, 4, 5
• Confirm tube placement immediately with continuous capnography 4, 5

Defibrillation:

• Use AED or manual defibrillator as soon as available 1
• Charge during compressions, deliver shock after brief pause, resume compressions immediately without pulse check 4, 1

Medications:

• Establish IV/IO access 1
• Administer epinephrine 1 mg every 3-5 minutes throughout resuscitation 1, 4
• For refractory VF/pVT: amiodarone 300 mg first dose, 150 mg second dose, or lidocaine 1-1.5 mg/kg 1

Common Timing and Location Patterns

Research shows Code Blues occur most frequently: 2

• At shift changes (08:00,14:00, and 22:00 hours) - corresponding to nursing handoffs
• In emergency departments (27.8% of cases) 2
• In infectious disease, hematology/oncology, and cardiology wards 6

Notably, 20% of Code Blue activations are escalated from Medical Emergency Team (MET) calls when patients deteriorate despite initial intervention. 2

Survival Outcomes and Prognostic Factors

Overall survival to discharge from in-hospital cardiac arrest ranges from 11-26%, with better outcomes when: 3

• Initial rhythm is VF/VT (52% survival vs 18% for other rhythms) 1
• Younger age (survivors average 59 years vs non-survivors 66 years) 1
• Shorter CPR duration 3, 6
• Faster team arrival time 6
• Patients receive ACLS-trained nurse as first responder (37.5% vs 10.3% survival) 1

Critical Pitfalls to Avoid

Common errors that reduce survival: 4, 5

• Hyperventilation (>10 breaths/min) - decreases venous return and cardiac output
• Prolonged intubation attempts (>30 seconds) interrupting compressions
• Inadequate compression depth or rate
• Excessive pauses in chest compressions
• Failure to recognize gasping as a sign of cardiac arrest (not normal breathing) 1

Misuse and False Activations

Studies reveal significant misuse of Code Blue systems: 7

• Only 68% of activations represent true cardiopulmonary arrests 3
• Common inappropriate reasons include: staff anxiety about patient (most common), chest pain, presyncope, mental status changes, and conversion disorders 7
• 76% of inappropriate activations are initiated by physicians 7

This misuse highlights the need for better education on activation criteria and implementation of early warning systems like MEWS (Modified Early Warning System) to identify deteriorating patients before arrest occurs. 8

Equipment Requirements

Code carts must be stocked with: 1

• ACLS medications (epinephrine, amiodarone, lidocaine)
• Intubation supplies (including 6.0-7.0mm ETT for pregnant patients) 1
• Respiratory supplies and suction 5
• Defibrillator with CPR feedback capability 4
• Specialty-specific supplies (pediatric equipment, cesarean section tray for maternal codes) 1

Training and Competency

Hospitals should implement: 1, 4

• Mandatory ACLS certification for all code team members
• Unannounced mock codes in actual clinical locations to identify system gaps
• Simulation-based training with CPR feedback devices showing real-time compression depth, rate, and recoil
• Monthly practice sessions (associated with >50% survival improvement in pediatric arrests) 1
• Annual retraining of all hospital staff in basic recognition and bystander CPR 1

Training significantly improves outcomes - one study showed arrival time and recovery time decreased significantly after staff training, with increased ICU transfers and decreased mortality. 6