From the Guidelines
Atropine is no longer recommended as a routine treatment for asystole. Current advanced cardiac life support (ACLS) guidelines emphasize high-quality CPR, epinephrine administration, and identifying and treating underlying causes rather than using atropine, as stated in the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1. The removal of atropine from asystole protocols occurred because multiple studies failed to demonstrate any benefit in improving survival or neurological outcomes, and available evidence suggests that routine use of atropine during PEA or asystole is unlikely to have a therapeutic benefit (Class IIb, LOE B) 1.
Key Considerations
- High-quality CPR, including chest compressions of adequate rate and depth, allowing complete chest recoil after each compression, minimizing interruptions in chest compressions and avoiding excessive ventilation, is crucial in asystole management 1.
- Epinephrine 1 mg IV/IO should be administered every 3-5 minutes during cardiac arrest.
- The focus should be on identifying and treating underlying causes, such as the "H's and T's", including hypoxia, hypovolemia, hydrogen ion abnormalities (acidosis), hypo/hyperkalemia, hypothermia, toxins, cardiac tamponade, tension pneumothorax, thrombosis (coronary or pulmonary), and trauma.
- Atropine works by blocking parasympathetic (vagal) influences on the heart, which can be beneficial in bradycardia but has limited physiological rationale in asystole where there is complete electrical standstill.
Management Approach
- Securing the airway, providing ventilation, obtaining vascular access, and continuous quantitative waveform capnography for confirmation and monitoring of endotracheal tube placement are essential components of asystole management 1.
- Physiologic monitoring to optimize CPR quality and detect return of spontaneous circulation (ROSC) is also crucial.
From the FDA Drug Label
Atropine Sulfate Injection, USP, is indicated for temporary blockade of severe or life threatening muscarinic effects, e.g., as an antisialagogue, an antivagal agent, an antidote for organophosphorus or muscarinic mushroom poisoning, and to treat bradyasystolic cardiac arrest. Adequate doses of atropine abolish various types of reflex vagal cardiac slowing or asystole
Atropine can be used to treat asystole. The primary mechanism is through its antivagal effects, which can help abolish reflex vagal cardiac slowing or asystole 2. It is indicated for the treatment of bradyasystolic cardiac arrest, which includes asystole 2.
From the Research
Atropine for Asystole
- Atropine may be of value in the treatment of ventricular asystole, as suggested by a study where all eight patients with ventricular asystole responded to atropine administration with a regular rhythm 3.
- The American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) during asystole include the administration of atropine, along with epinephrine and other treatments 4.
- However, the use of atropine in asystole is not universally recommended, and its effectiveness may depend on various factors, such as the underlying cause of the cardiac arrest and the patient's overall condition.
Comparison with Other Treatments
- Epinephrine is the primary vasopressor used during cardiopulmonary resuscitation, but high-dose epinephrine (>1 mg) is not recommended for general use 5.
- Arginine vasopressin may be considered in patients presenting with asystole or who are unresponsive to initial treatment with epinephrine 5.
- Norepinephrine and lidocaine drips have been shown to improve survival rates in patients with asystole, particularly when used in combination 4.
Outcomes and Prognosis
- The prognosis for patients with asystole is generally poor, with low survival rates and unfavorable neurological outcomes 6, 7.
- However, certain factors, such as hypothermia, acute coronary syndrome, and arrhythmia, may be associated with more favorable outcomes 7.
- Extracorporeal cardiopulmonary resuscitation (ECPR) may be considered in selected patients with asystole, particularly those with certain underlying conditions or favorable clinical characteristics 7.