Cardiovascular 7: Asystole Treatment Portal
See Vol I—Acute Care Portals, Asystole Algorithm.
Patients with asystole have an extremely poor prognosis. The only hope for survival is to find and treat a reversible cause of the patient’s asystole. Often asystole is just the end result of a terminal condition.
Differential Diagnoses of Potential Treatable Causes of Asystole Include:
Severe hypoxia requires adequate airway management.
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Severe hyperkalemia. Treat with sodium bicarbonate, regular insulin, dextrose, calcium chloride, Kayexalate, and furosemide. If these measures fail or if the patient experiences complications, use dialysis.
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Severe hypokalemia. Treat with potassium IV.
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Pre-existing acidosis. Treat by maximizing oxygen and ventilation, correcting the underlying problem, and, if the pH is low, administering sodium bicarbonate. If the patient is intubated, use hyperventilation.
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Drug overdoses. Treat specific to the overdose.
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Hypothermia. Treat by re-warming the patient. Prolonged resuscitation may be necessary.
See other possibilities in Hs and Ts.
General Treatment for Asystole is Similar to PEA.
An early consideration in the resuscitation attempt of a patient in asystole is whether the resuscitation should be started at all or continued. The resuscitation team needs to seek objective evidence of a DNR status. Look for a bracelet or anklet with resuscitation information. Determine if there is a written DNAR document. Determine whether the family knows the patient’s resuscitation status. If there is good evidence that the patient’s wishes are not to be resuscitated, then do not start, or stop CPR when this information becomes known. Also, look for clinical indications or signs of death. If present, do not start or stop CPR when this becomes apparent.
Electrical shocks may produce a stunned heart, causing a profound parasympathetic discharge, making resuscitation impossible. Therefore, routine shocking of asystole can worsen a bad situation.
Confirm asystole in more than 1 lead. Fine VF may appear like asystole.
The likelihood that transcutaneous pacing will change the outcome of asystole is rare, and it is not currently recommended.1 Transcutaneous pacing is successful only when performed early in the patient's treatment.
After developing asystole, the heart responds to pacing for only a short time. Patients who develop bradyasystolic arrest, Stokes-Adams attack, asystole following a vagal discharge, or myocardial stunning following defibrillation may respond to transcutaneous pacing if used simultaneously with CPR and medications.
General Approach to Asystole1
Initial Patient
Treatment (Focus on CPR and defibrillation if
indicated)1
Effective CPR with minimal interruption.
Confirm asystole in more than one lead.
Monitor rhythm and O2 saturation
Assess for a reason not to continue resuscitation (ie, DNAR order or signs of death)
Identify reversible causes.
Reversible Causes of Asystole1: 5 Hs and 5 Ts
| Hs | Ts |
| Hypoxia | Tablets/Toxins |
| Hypovolemia | Tamponade |
| Hydrogen ion (acidosis) | Tension pneumothorax |
| Hypo/Hyperthermia | Thrombosis, Coronary (ACS) |
| Hypo/Hyperkalemia | Thrombosis, Pulmonary (embolism) |
Focus on advanced treatment modalities1
Insert an adequate airway (tracheal intubation or equivalent)
Confirm airway device placement (EID, clinical assessment. Note: End-tidal CO2 detector may not be accurate in the arrest situation.)
Secure the airway device. (Consider use of a commercial tube holder.)
Confirm effective oxygenation and ventilation. (Hyperventilation is the best treatment for increased PaCO2 and respiratory acidosis.)
Establish IV access.
Perform a careful search for any treatable cause and, if found, aggressively treat.
Give drugs appropriate for rhythm and conditions.
Consider criteria for stopping resuscitation attempts.
Drugs Used for Asystole Resuscitation1
Epinephrine: The recommended dose is 1 mg IV/IO push every 3 to 5 minutes. PEDS: Epinephrine 0.01 mg/kg IV/IO or 0.1 mg/kg ET; if ET, use 1:1000 preparation.
Vasopressin: One dose of vasopressin (40 units IV) is acceptable in place of first or second dose of epinephrine. PEDS: This treatment is not recommended for pediatric patients.
Atropine: In the past atropine was suggested treatment, but current guidelines discourage its routine use in asystole. Atropine may still be appropriate in very special situations. If used, give 1 mg of atropine IV/IO and repeat at 3- to 5-minute intervals as needed to a total dose of 0.04 mg/kg.1 PEDS: This treatment is also not routinely recommended for pediatric patients but if it is used, give atropine at a dose of 0.02 mg/kg IV/IO repeated at 3 to 5 minute intervals to total dose of 0.04 mg/kg.
Criteria for Stopping Resuscitation Efforts1
Rather than a rhythm to be treated, asystole often represents a confirmation of death. If the patient does not respond to adequate airway management, effective CPR, and appropriate medications, assume the patient is deceased and stop CPR. In special situations of cardiac arrest—such as hypothermia, electrocution, and drug overdoses—prolonged resuscitation is necessary to assure the patient has been adequately treated.
The team leader may cease resuscitation efforts on a patient
in
asystole when the following treatments have been completed:
Administerd effective CPR
Ruled out the presence of VF or treated it if present
Achieved and maintained airway management (tracheal intubation or equivalent) with confirmation of tube placement
Ensured that the best possible oxygenation and ventilation have been achieved by monitoring O2 saturation and end-tidal CO2
Successfully established IV access
Maintained the above interventions for > 10 minutes, during which time the rhythm has been confirmed to be asystole
Administered all rhythm-appropriate drugs
Communicated with available family and friends about the seriousness of the patient’s condition and the lack of response to treatment
Patient has been warmed to 93°F if necessary
Note: Consider the appropriateness of having family members present during the resuscitation attempt.
References
- ECC Committee, Subcommittees and Task Forces of the American Heart Association. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2010;122(18 suppl 3):S735-S746.