Editing Defibrillation (section)

== Use of defibrillators ==
{{Main|Cardiopulmonary resuscitation#Defibrillators}}

=== Indications ===
Defibrillation is often an important step in [[cardiopulmonary resuscitation]] (CPR).<ref name="CriticalCare" /><ref name="Marenco" /> CPR is an algorithm-based intervention aimed to restore cardiac and pulmonary function.<ref name="CriticalCare" /> Defibrillation is indicated only in certain types of [[cardiac dysrhythmias]], specifically [[ventricular fibrillation]] (VF) and [[ventricular tachycardia#Classification|pulseless ventricular tachycardia]].<ref name="Tintinalli" /><ref name="Kerber" /> If the heart has completely stopped, as in [[asystole]] or [[pulseless electrical activity|pulseless electrical activity (PEA)]], defibrillation is not indicated. Defibrillation is also not indicated if the patient is conscious or has a pulse. Improperly given electrical shocks can cause dangerous dysrhythmias, such as ventricular fibrillation.<ref name="Tintinalli" />

=== Application method ===
A defibrillation device that is often available outside of medical centers is the automated external defibrillator (AED),<ref>{{Cite web|date=2011-06-23|title=What is an automated external defibrillator? Defibrillators, cardiac arrest|url=http://nhlbi.nih.gov/health/dci/Diseases/aed/aed_whatis.html|access-date=2021-11-08 |archive-url=https://web.archive.org/web/20110623091319/http://nhlbi.nih.gov/health/dci/Diseases/aed/aed_whatis.html |archive-date=2011-06-23}}</ref> a portable machine that can be used with no previous training. That is possible because the machine produces pre-recorded voice instructions that guide the user. The device automatically checks the patient's condition and applies the correct electric shocks. There also exist written instructions that explain the procedure step-by-step.<ref>{{Cite web |date=2011-06-23 |title=How to use an automated external defibrillator |url=http://nhlbi.nih.gov/health/dci/Diseases/aed/aed_use.html |archive-url=https://web.archive.org/web/20110623095339/http://nhlbi.nih.gov/health/dci/Diseases/aed/aed_use.html |url-status=dead |archive-date=2011-06-23 |access-date=2024-05-09 }}</ref>

=== Outcomes ===
{{Globalize|section|North America|date=December 2023}}

Survival rates for out-of-hospital [[cardiac arrest]]s in North America are poor, often less than 10%.<ref name="medscape" /> Outcome for in-hospital cardiac arrests are higher at 20%.<ref name="medscape" /> Within the group of people presenting with cardiac arrest, the specific cardiac rhythm can significantly impact survival rates. Compared to people presenting with a non-shockable rhythm (such as asystole or PEA), people with a shockable rhythm (such as VF or pulseless ventricular tachycardia) have improved survival rates, ranging between 21 and 50%.<ref name="CriticalCare" /><ref name="Nadkarni" /><ref name="Nichol" />