What is the initiation of flatline (cardiac arrest)?

From the Guidelines

Flatline initiation should be approached with a focus on immediate recognition of cardiac arrest and activation of the emergency response system, followed by early cardiopulmonary resuscitation (CPR) with a sequence of chest compressions before rescue breaths (CAB), as recommended by the 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1.

Key Considerations

• The importance of chest compression quality, including a depth of at least 2 inches (5 cm) and a rate of 100 to 120/min, cannot be overstated in the context of cardiac arrest management 1.
• The risk of harm to patients is low if they are not in cardiac arrest, making it reasonable for lay rescuers to initiate CPR for presumed cardiac arrest 1.
• Early epinephrine administration is reaffirmed, with a recommendation to administer epinephrine as soon as feasible for cardiac arrest with a nonshockable rhythm 1.

Recommendations for Practice

• Establish vascular access and initiate CPR with a focus on high-quality chest compressions, allowing for minimal interruptions and avoiding excessive ventilation.
• Use a commercially available solution for replacement fluid, at a rate equal to the effluent rate, to achieve zero net fluid removal and maintain hemodynamic stability.
• Consider the patient's underlying condition and the potential need for rapid fluid removal or correction of electrolyte abnormalities when determining the approach to flatline initiation.

Evidence-Based Decision Making

• The 2020 American Heart Association guidelines provide the most recent and highest quality evidence for guiding practice in cardiac arrest management, including the recommendation for a CAB sequence and the importance of high-quality chest compressions 1.
• While earlier guidelines, such as the 2010 American Heart Association guidelines, also provide valuable insights into cardiac arrest management, the 2020 guidelines supersede these recommendations and should be prioritized in practice 1.

From the FDA Drug Label

The most important adverse reactions were hypotension, asystole/cardiac arrest/pulseless electrical activity (PEA), cardiogenic shock, congestive heart failure, bradycardia, liver function test abnormalities, VT, and AV block. The FDA drug label does not answer the question.

From the Research

Flatline Initiation

• The initiation of flatline, also known as asystole, is a critical condition that requires immediate cardiopulmonary resuscitation (CPR) and management of cardiac arrest 2.
• The American Heart Association (AHA) guidelines for CPR during asystole include ventricular defibrillation, intubation, and the administration of epinephrine and atropine 3.
• Studies have shown that aggressive resuscitation efforts, including the addition of norepinephrine and lidocaine drips to the AHA-recommended regimen, may substantially increase the number of 24-hour survivors 3.
• Epinephrine is the primary drug administered during CPR to reverse cardiac arrest, but its use is based on limited animal data and recent studies question its overall benefit for patients 4.
• The physiology of blood flow to the heart and brain during CPR is complex, and recent insights have resulted in novel resuscitation methods and technologies that significantly improve outcomes from cardiac arrest 5.
• Ventilation during CPR is critical, but it may exert detrimental hemodynamic effects that must be balanced with its expected benefits, and recent advances in understanding ventilatory physiology during CPR can help assess the quality of resuscitation and the amount of ventilation produced by chest compressions 6.

Key Factors in Flatline Initiation

• Early recognition and high-quality CPR are crucial for survival with a good neurological outcome after cardiac arrest 2.
• The underlying cause of cardiac arrest can be identified and treated during CPR, and drugs such as epinephrine and amiodarone can improve the success of resuscitation and defibrillation 2, 4.
• The use of supraglottic airway devices and tracheal intubation can help maintain airway patency during CPR, but should only be attempted by skilled rescuers 2.
• Care after cardiac arrest includes controlled reoxygenation, therapeutic hypothermia, percutaneous coronary intervention, circulatory support, and control of blood-glucose levels and seizures 2.

Treatment and Management

• CPR should be performed with high-quality chest compressions and ventilations, and the use of automated external defibrillators (AEDs) can help improve outcomes 2, 5.
• The administration of epinephrine and other medications can help improve the success of resuscitation, but their use should be based on current guidelines and evidence-based practice 3, 4.
• The management of cardiac arrest requires a multidisciplinary approach, including emergency medical services (EMS), hospital staff, and specialist care 2, 5.