Pulseless electrical activity
| Pulseless electrical activity |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords: PEA; electromechanical dissociation; non-perfusing rhythm
Overview
Pulseless electrical activity refers to any heart rhythm observed on the electrocardiogram that should be producing a pulse, but is not. The condition may or may not be caused by electromechanical dissociation. The most common cause is hypovolemia.
Pathophysiology
The normal condition when electrical activation of muscle cells precedes mechanical contraction is known as Electromechanical Coupling.
Causes
The goal of treatment of PEA is to treat the underlying cause. These possible causes are remembered as the Hs and Ts.[1][2][3]
- Hypovolemia
- Hypoxia
- Hydrogen ions (Acidosis)
- Hypothermia
- Hyperkalemia or Hypokalemia
- Hypoglycemia
- Tablets or Toxins (Drug overdose) such as beta blockers, tricyclic antidepressants, or calcium channel blockers
- Cardiac Tamponade
- Tension pneumothorax
- Thrombosis (Myocardial infarction)
- Thrombosis (Pulmonary embolism)
- Trauma (Hypovolemia from blood loss)
In those cases in which an underlying systemic cause is unable to be immediately identified, the patient should be treated as if they were in asystole: intravenous Epinephrine 1 mg every 3-5 minutes, and, if the underlying rhythm is bradycardia, Atropine 1 mg IV up to .04 mg/kg (varies with regional protocols). Both these drugs should be administered along with appropriate CPR techniques. Defibrillationis not used for this rhythm, as the problem lies in the response of the myocardial tissue to electrical impulses.
Natural History, Complications, Prognosis
Diagnosis
Electrocardiogram
The appearance of the electrocardiogram varies, but several common patterns exist. There may be a normal sinus rhythm or sinus tachycardia, with discernible P waves and QRS complexes. Sometimes there is a bradycardia, with or without P waves, and often with wide QRS complexes.[4]
Treatment
The mainstay of treatment is to reverse the underlying cause of PEA.
If an underlying cause for PEA cannot be determined and/or reversed, the treatment of pulseless electrical activity is similar to that for asystole.[5]
The mainstay of drug therapy for PEA is epinephrine 1 mg every 3–5 minutes. Although previously the use of atropine was recommended in the treatment of PEA/asystole, this recommendation was withdrawn in 2010 by the American Heart Association due to lack of evidence for therapeutic benefit.[5]
Sodium bicarbonate at a dose of 1 meq per kilogram may be considered in this rhythm as well, although there is little evidence to support this practice. Its routine use is not recommended for patients in this context, except in special situations (e.g. preexisting metabolic acidosis, hyperkalemia, tricyclic antidepressant overdose).[5]
All of these drugs should be administered along with appropriate CPR techniques. Defibrillators are not used for this rhythm, as the problem lies in the response of the myocardial tissue to electrical impulses.
References
- ↑ ACLS: Principles and Practice. p. 71-87. Dallas: American Heart Association, 2003. ISBN 0-87493-341-2.
- ↑ ACLS for Experienced Providers. p. 3-5. Dallas: American Heart Association, 2003. ISBN 0-87493-424-9.
- ↑ "2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - Part 7.2: Management of Cardiac Arrest." Circulation 2005; 112: IV-58 - IV-66.
- ↑ Foster B, Twelve Lead Electrocardiography, 2nd edition, 2007
- ↑ 5.0 5.1 5.2 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care (2010). "Part 8: Adult Advanced Cardiovascular Life Support". Circulation. 122 (18 Suppl): S729–S767. doi:10.1161/CIRCULATIONAHA.110.970988. PMID 20956224. Unknown parameter
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