Non-VF/VT rhythms in ALS

Pulseless electrical activity (PEA) is defined as cardiac electrical activity in the absence of any palpable pulse. These patients often have some mechanical myocardial contractions but they are too weak to produce a detectable pulse or blood pressure (This is sometimes referred to as Pseudo PEA)

PEA may be caused by reversible conditions that can be treated if they are identified and corrected (4 H's and 4 T's)

• hypoxia
• hypovolaemia
• hyperkalaemia, hypokalaemia, hypocalcaemia, acidaemia, and other metabolic disorders
• hypothermia
• tension pneumothorax
• tamponade
• toxic substances
• thromboembolism (pulmonary embolus/coronary thrombosis)

Survival following cardiac arrest with asystole or PEA is unlikely unless a reversible cause can be found and treated effectively.

Sequence of actions for PEA

• start CPR 30:2
• give adrenaline 1 mg IV as soon as intravascular access is achieved
• continue CPR 30:2 until the airway is secured, then continue chest compressions without pausing during ventilation
• consider possible reversible causes of PEA and correct any that are identified.
• recheck the rhythm after 2 min
  • if there is no change in the ECG appearance:
    • continue CPR
    • recheck the rhythm after 2 min and proceed accordingly
    • give further adrenaline 1 mg IV every 3-5 min (alternate loops)
  • if the ECG changes and organised electrical activity is seen, check for a pulse
    • if a pulse is present, start post-resuscitation care
    • if no pulse is present:
      • continue CPR
      • recheck the rhythm after 2 min and proceed accordingly
      • give further adrenaline 1 mg IV every 3-5 min (alternate loops)

Sequence of actions for asystole and slow PEA (rate < 60 min-1)

• start CPR 30:2
• without stopping CPR, check that the leads are attached correctly
• give adrenaline 1 mg IV as soon as intravascular access is achieved
• continue CPR 30:2 until the airway is secured, then continue chest compression without pausing during ventilation
• consider possible reversible causes of PEA and correct any that are identified.
• recheck the rhythm after 2 min and proceed accordingly
• if VF/VT recurs, change to the shockable rhythm algorithm
• give adrenaline 1 mg IV every 3-5 min (alternate loops)

Reference:

1. Resuscitation Council (UK). Resuscitation Guidelines 2010.