asystole

Introduction

Asystole generally occurs as a terminal rhythm in a patient with severe underlying cardiac disease.

Likelihood of resuscitation is low. (also see sinus arrest)

Etiology

• hypoxia
• hyperkalemia, hypokalemia
• pre-existing acidosis
• drug overdose*
• hypothermia

* patient's medications not of immediate importance

Diagnostic procedures

• electrocardiogram
• point-of-care ultrasound
  • lack of cardiac activity portends poor prognosis

Management

• CPR until defibrillator is available
• confirm asystole in more than one lead
• if rhythm is unclear, possibly VF, defibrillation
• if asystole is confirmed, continue CPR
• intubate, establish IV access (IV access takes precedence)
• consider possible causes & initiate appropriate treatment
• consider immediate transcutaneous pacing
  • considered a class IIb intervention
• epinephrine*, 1 mg IV push, repeat every 3-5 minutes
  • administration of 1st dose within 1 to 3 minutes
  • vasopressin 40 IU IV may be better than epinephrine
• atropine 1 mg IV push, repeat every 3-5 minutes up to 3 mg
• if no response, consider
  • high dose epinephrine 2-5 mg IV push every 3-5 min; 1 mg, 3 mg, 5 mg 3 minutes apart; 0.1 mg/kg every 3-5 min
  • NaHCO3 if appropriate
    • NaHCO3 not indicated early in resuscitation
    • acidosis is generally secondary to inadequate ventilation,
    • dose is 1 meq/kg IV followed by 0.5 meq/kg every 0 min
  • termination of efforts

* closed-loop communication employed

More general terms

• bradyarrhythmia (bradycardia)

Additional terms

• sinus arrest/pause