Editing Cardiac arrest (section)

==Management==
Sudden cardiac arrest may be treated via attempts at [[resuscitation]]. This is usually carried out based on [[basic life support]], [[advanced cardiac life support]] (ACLS), [[pediatric advanced life support]] (PALS), or [[neonatal resuscitation program]] (NRP) guidelines.<ref name="AHA-2005"/><ref>{{cite journal | title = 2005 American Heart Association (AHA) guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care (ECC) of pediatric and neonatal patients: pediatric advanced life support | journal = Pediatrics | volume = 117 | issue = 5 | pages = e1005–e1028 | date = May 2006 | pmid = 16651281 | doi = 10.1542/peds.2006-0346 | s2cid = 46720891 | author1 = American Heart Association }}</ref>
[[File:CPR training-04.jpg|thumb|CPR training on a mannequin]]

===Cardiopulmonary resuscitation===
{{Main|Cardiopulmonary_resuscitation#Compressions_with_rescue_breaths}}
Early [[cardiopulmonary resuscitation]] (CPR) is essential to surviving cardiac arrest with good neurological function.<ref>{{cite web |title=AHA Releases 2015 Heart and Stroke Statistics {{!}} Sudden Cardiac Arrest Foundation |url=https://www.sca-aware.org/sca-news/aha-releases-2015-heart-and-stroke-statistics |website=www.sca-aware.org |access-date=21 September 2019}}</ref><ref name="Walls-2017">{{Cite book|title=Rosen's emergency medicine : concepts and clinical practice| veditors = Walls RM, Hockberger RS, Gausche-Hill M |isbn=9780323390163|oclc=989157341|date = 2017-03-09| vauthors = Walls R, Hockberger R, Gausche-Hill M | publisher = Elsevier Health Sciences }}</ref> It is recommended that it be started as soon as possible with minimal interruptions once begun. The components of CPR that make the greatest difference in survival are [[chest compressions]] and defibrillating shockable rhythms.<ref name="Wang-2017">{{Cite book|title=Tintinalli's emergency medicine manual|veditors = Cydulka RK |isbn= 9780071837026 |oclc=957505642|date = 2017-08-28| vauthors = Wang VJ, Joing SA, Fitch MT, Cline DM, John Ma O, Cydulka RK |publisher = McGraw-Hill Education }}</ref> After defibrillation, chest compressions should be continued for two minutes before another rhythm check.<ref name="Walls-2017" /> This is based on a compression rate of 100-120 compressions per minute, a compression depth of 5–6 centimeters into the chest, full chest recoil, and a ventilation rate of 10 breath ventilations per minute.<ref name="Walls-2017" /> Mechanical chest compressions (as performed by a machine) are no better than chest compressions performed by hand.<ref name="Neumar-2015">{{cite journal |display-authors=6 |vauthors=Neumar RW, Shuster M, Callaway CW, Gent LM, Atkins DL, Bhanji F, Brooks SC, de Caen AR, Donnino MW, Ferrer JM, Kleinman ME, Kronick SL, Lavonas EJ, Link MS, Mancini ME, Morrison LJ, O'Connor RE, Samson RA, Schexnayder SM, Singletary EM, Sinz EH, Travers AH, Wyckoff MH, Hazinski MF |date=November 2015 |title=Part 1: Executive Summary: 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care |journal=Circulation |volume=132 |issue=18 Suppl 2 |pages=S315–S367 |doi=10.1161/cir.0000000000000252 |pmid=26472989 |doi-access=free}}</ref> It is unclear if a few minutes of CPR before defibrillation results in different outcomes than immediate defibrillation.<ref>{{cite journal |vauthors=Huang Y, He Q, Yang LJ, Liu GJ, Jones A |date=September 2014 |title=Cardiopulmonary resuscitation (CPR) plus delayed defibrillation versus immediate defibrillation for out-of-hospital cardiac arrest |journal=The Cochrane Database of Systematic Reviews |volume=9 |issue=9 |pages=CD009803 |doi=10.1002/14651858.CD009803.pub2 |pmc=6516832 |pmid=25212112}}</ref>

Correctly performed bystander CPR has been shown to increase survival, however it is performed in fewer than 30% of out-of-hospital cardiac arrests (OHCAs) {{as of|2007|lc=y}}.<ref name="Mutchner-2007" /> A 2019 meta-analysis found that use of dispatcher-assisted CPR improved outcomes, including survival, when compared with undirected bystander CPR.<ref>{{cite journal | vauthors = Nikolaou N, Dainty KN, Couper K, Morley P, Tijssen J, Vaillancourt C | title = A systematic review and meta-analysis of the effect of dispatcher-assisted CPR on outcomes from sudden cardiac arrest in adults and children | journal = Resuscitation | volume = 138 | pages = 82–105 | date = May 2019 | pmid = 30853623 | doi = 10.1016/j.resuscitation.2019.02.035 | s2cid = 73727100 | url = http://wrap.warwick.ac.uk/114478/1/WRAP-systematic-review-meta-analysis-effect-dispatcher-assisted-CPR-Couper-2019.pdf }}</ref> Likewise, a 2022 systematic review on exercise-related cardiac arrests supported early intervention of bystander CPR and AED use (for shockable rhythms) as they improve survival outcomes.<ref>{{cite journal | vauthors = Grubic N, Hill B, Phelan D, Baggish A, Dorian P, Johri AM | title = Bystander interventions and survival after exercise-related sudden cardiac arrest: a systematic review | journal = British Journal of Sports Medicine | volume = 56 | issue = 7 | pages = 410–416 | date = April 2022 | pmid = 34853034 | doi = 10.1136/bjsports-2021-104623 | s2cid = 244800392 }}</ref>

If high-quality CPR has not resulted in return of spontaneous circulation and the person's heart rhythm is in [[asystole]], stopping CPR and pronouncing the person's death is generally reasonable after 20 minutes.<ref name="Resuscitation Council (UK)" /> Exceptions to this include certain cases with [[hypothermia]] or [[drowning]] victims.<ref name="Wang-2017" /><ref name="Resuscitation Council (UK)">{{cite web |author1=Resuscitation Council (UK) |title=Pre-hospital cardiac arrest |url=https://www.resus.org.uk/pages/prehosca.pdf |url-status=dead |archive-url=https://web.archive.org/web/20150513032323/http://www.resus.org.uk/pages/prehosca.pdf |archive-date=13 May 2015 |access-date=3 September 2014 |website=www.resus.org.uk |page=41}}</ref> Some of these cases should have longer and more sustained CPR until they are nearly [[Normothermia|normothermic]].<ref name="Wang-2017" />

If cardiac arrest occurs after 20 weeks of pregnancy, the uterus should be pulled or pushed to the left during CPR.<ref name="Lavonas-2015" /> If a pulse has not returned by four minutes, an emergency [[Cesarean section]] is recommended.<ref name="Lavonas-2015" />

=== Airway management ===
High levels of oxygen are generally given during CPR.<ref name="Neumar-2015" /> Either a [[bag valve mask]] or an [[advanced airway]] may be used to help with breathing particularly since vomiting and regurgitation are common, especially in OHCA.<ref name="Neumar-2015" /><ref>{{cite journal | vauthors = Simons RW, Rea TD, Becker LJ, Eisenberg MS | title = The incidence and significance of emesis associated with out-of-hospital cardiac arrest | journal = Resuscitation | volume = 74 | issue = 3 | pages = 427–431 | date = September 2007 | pmid = 17433526 | doi = 10.1016/j.resuscitation.2007.01.038 }}</ref><ref>
{{cite journal | vauthors = Voss S, Rhys M, Coates D, Greenwood R, Nolan JP, Thomas M, Benger J | title = How do paramedics manage the airway during out of hospital cardiac arrest? | journal = Resuscitation | volume = 85 | issue = 12 | pages = 1662–1666 | date = December 2014 | pmid = 25260723 | pmc = 4265730 | doi = 10.1016/j.resuscitation.2014.09.008 | eissn = 1873-1570 }}</ref> If this occurs, then modification to existing oropharyngeal suction may be required, such as using [[Suction Assisted Laryngoscopy Airway Decontamination|suction-assisted airway management]].<ref>
{{cite journal | vauthors = Root CW, Mitchell OJ, Brown R, Evers CB, Boyle J, Griffin C, West FM, Gomm E, Miles E, McGuire B, Swaminathan A, St George J, Horowitz JM, DuCanto J | display-authors = 6 | title = Suction Assisted Laryngoscopy and Airway Decontamination (SALAD): A technique for improved emergency airway management | journal = Resuscitation Plus | volume = 1-2 | pages = 100005 | date = 2020-03-01 | pmid = 34223292 | pmc = 8244406 | doi = 10.1016/j.resplu.2020.100005 | doi-access = free }}</ref>

[[Tracheal intubation]] has not been found to improve survival rates or neurological outcomes in cardiac arrest,<ref name="Mutchner-2007">{{cite journal | vauthors = Mutchner L | title = The ABCs of CPR--again | journal = The American Journal of Nursing | volume = 107 | issue = 1 | pages = 60–9; quiz 69–70 | date = January 2007 | pmid = 17200636 | doi = 10.1097/00000446-200701000-00024 }}</ref><ref name="White-2018">{{cite journal | vauthors = White L, Melhuish T, Holyoak R, Ryan T, Kempton H, Vlok R | title = Advanced airway management in out of hospital cardiac arrest: A systematic review and meta-analysis | journal = The American Journal of Emergency Medicine | volume = 36 | issue = 12 | pages = 2298–2306 | date = December 2018 | pmid = 30293843 | doi = 10.1016/j.ajem.2018.09.045 | s2cid = 52931036 | url = https://espace.library.uq.edu.au/view/UQ:4f65350/UQ4f65350_OA.pdf }}</ref> and in the prehospital environment, may worsen it.<ref>{{cite journal | vauthors = Studnek JR, Thestrup L, Vandeventer S, Ward SR, Staley K, Garvey L, Blackwell T | title = The association between prehospital endotracheal intubation attempts and survival to hospital discharge among out-of-hospital cardiac arrest patients | journal = Academic Emergency Medicine | volume = 17 | issue = 9 | pages = 918–925 | date = September 2010 | pmid = 20836771 | doi = 10.1111/j.1553-2712.2010.00827.x | doi-access = free }}</ref> Endotracheal tubes and [[supraglottic airway]]s appear equally useful.<ref name="White-2018" />

Mouth-to-mouth as a means of providing respirations to the person has been phased out due to the risk of contracting infectious diseases from the affected person.<ref>{{cite journal |vauthors=Hallstrom A, Cobb L, Johnson E, Copass M |date=May 2000 |title=Cardiopulmonary resuscitation by chest compression alone or with mouth-to-mouth ventilation |journal=The New England Journal of Medicine |volume=342 |issue=21 |pages=1546–1553 |doi=10.1056/NEJM200005253422101 |pmid=10824072 |doi-access=free}}</ref>

When done by emergency medical personnel, 30 compressions followed by two breaths appear to be better than continuous chest compressions and breaths being given while compressions are ongoing.<ref name="Zhan-2017" /> For bystanders, CPR that involves only chest compressions results in better outcomes as compared to standard CPR for those who have gone into cardiac arrest due to heart issues.<ref name="Zhan-2017">{{cite journal | vauthors = Zhan L, Yang LJ, Huang Y, He Q, Liu GJ | title = Continuous chest compression versus interrupted chest compression for cardiopulmonary resuscitation of non-asphyxial out-of-hospital cardiac arrest | journal = The Cochrane Database of Systematic Reviews | volume = 3 | issue = 12 | pages = CD010134 | date = March 2017 | pmid = 28349529 | pmc = 6464160 | doi = 10.1002/14651858.CD010134.pub2 }}</ref>

===Defibrillation===
[[File:Defibrillator-809447 1920.jpg|thumb|upright=1.3|An automated external defibrillator stored in a visible orange mural support]]
Defibrillation is indicated if an shockable rhythm is present; the two shockable rhythms are [[ventricular fibrillation]] and [[ventricular tachycardia]]. These shockable rhythms have a 25-40% likelihood of survival, compared with a significantly lower rate (less than 5%) in non-shockable rhythms.<ref>{{cite journal | vauthors = Woolcott OO, Reinier K, Uy-Evanado A, Nichols GA, Stecker EC, Jui J, Chugh SS | title = Sudden cardiac arrest with shockable rhythm in patients with heart failure | journal = Heart Rhythm | volume = 17 | issue = 10 | pages = 1672–1678 | date = October 2020 | pmid = 32504821 | pmc = 7541513 | doi = 10.1016/j.hrthm.2020.05.038 }}</ref> The non-shockable rhythms include [[asystole]] and pulseless electrical activity.

Ventricular fibrillation involves the [[Ventricle (heart)|ventricles]] of the heart rapidly contracting in an disorganized pattern, and thereby limiting blood flow from the heart. This is due to an uncoordinated electrical activity.<ref>{{Cite web |date=2022-03-24 |title=Arrhythmias - What Is an Arrhythmia? {{!}} NHLBI, NIH |url=https://www.nhlbi.nih.gov/health/arrhythmias |url-status=live |archive-url=https://web.archive.org/web/20240926180105/https://www.nhlbi.nih.gov/health/arrhythmias |archive-date=2024-09-26 |access-date=2024-01-31 |website=www.nhlbi.nih.gov |language=en}}</ref> The electrocardiogram (ECG) shows irregular QRS complexes at a very high rate (>300  beats per minute).<ref>{{cite book | vauthors = Ludhwani D, Goayal A, Jagtap M | chapter = Ventricular Fibrillation |date=2024 | title = StatPearls | chapter-url= http://www.ncbi.nlm.nih.gov/books/NBK537120/ |access-date=2024-01-31 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=30725805 }}</ref> In ventricular tachycardia, the ECG will show a wide complex rhythm at a rate higher than 100 beats per minute.<ref>{{cite book | vauthors = Foth C, Gangwani MK, Ahmed I, Alvey H | chapter = Ventricular Tachycardia |date=2024 | title = StatPearls | chapter-url=http://www.ncbi.nlm.nih.gov/books/NBK532954/ |access-date=2024-01-31 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=30422549 }}</ref> These two rhythm lead to hemodynamic instability and compromise, resulting in poor perfusion to vital organs (including the heart itself).

[[File:Defibrillation Electrode Position.jpg|thumb|Demonstration of electrode pad placement for defibrillation]]
A defibrillator — either implanted or external — delivers an electrical current that results in the entire myocardium simultaneously depolarized thereby stopping the arrhythmia.<ref>{{Cite web | vauthors = Knight BP | date = 23 January 2023 | veditors = Page RL, Dardas TF | title = Basic principles and technique of external electrical cardioversion and defibrillation | work = UpToDate |url=https://www.uptodate.com/contents/basic-principles-and-technique-of-external-electrical-cardioversion-and-defibrillation |access-date=2024-01-18 }}</ref> Defibrillators can deliver energy as monophasic or biphasic waveforms, although biphasic defibrillators are now the most common.<ref>{{cite journal | vauthors = Leng CT, Paradis NA, Calkins H, Berger RD, Lardo AC, Rent KC, Halperin HR | title = Resuscitation after prolonged ventricular fibrillation with use of monophasic and biphasic waveform pulses for external defibrillation | journal = Circulation | volume = 101 | issue = 25 | pages = 2968–2974 | date = June 2000 | pmid = 10869271 | doi = 10.1161/01.CIR.101.25.2968 }}</ref><ref name="Schneider 1780–1787">{{cite journal | vauthors = Schneider T, Martens PR, Paschen H, Kuisma M, Wolcke B, Gliner BE, Russell JK, Weaver WD, Bossaert L, Chamberlain D | display-authors = 6 | title = Multicenter, randomized, controlled trial of 150-J biphasic shocks compared with 200- to 360-J monophasic shocks in the resuscitation of out-of-hospital cardiac arrest victims. Optimized Response to Cardiac Arrest (ORCA) Investigators | journal = Circulation | volume = 102 | issue = 15 | pages = 1780–1787 | date = October 2000 | pmid = 11023932 | doi = 10.1161/01.CIR.102.15.1780 }}</ref> Prior studies suggest that biphasic shock is more likely to produce successful defibrillation after a single shock, however rate of survival is comparable between the methods.<ref name="Schneider 1780–1787"/>

In out-of-hospital arrests (OHA), the defibrillation is made by an [[automated external defibrillator]] (AED), a portable machine that can be used by any user. The AED provides voice instructions that guide the process, automatically checks the person's condition, and applies the appropriate electric shocks. Some defibrillators even provide feedback on the quality of [[cardiopulmonary resuscitation|CPR]] compressions, encouraging the lay rescuer to press the person's chest hard enough to circulate blood.<ref>{{cite web|title=Zoll Automated External Defibrillator (AED) Plus|url=http://www.lifeassisttraining.com/zollaedplus.html|archive-url=https://web.archive.org/web/20110621004342/http://www.lifeassisttraining.com/zollaedplus.html|archive-date=2011-06-21|work=Life Assistance Training}}</ref>

There is increasing use of public access to defibrillators. This typically involves placing AEDs in publicly-accessible places and training staff in these areas on how to use them. This allows defibrillation to occur prior to the arrival of emergency services, which has been shown to increase the chances of survival. People who have cardiac arrests in remote locations have worse outcomes.<ref name="Lyon-2004">{{cite journal | vauthors = Lyon RM, Cobbe SM, Bradley JM, Grubb NR | title = Surviving out of hospital cardiac arrest at home: a postcode lottery? | journal = Emergency Medicine Journal | volume = 21 | issue = 5 | pages = 619–624 | date = September 2004 | pmid = 15333549 | pmc = 1726412 | doi = 10.1136/emj.2003.010363 }}</ref>

Defibrillation cannot be applied to asystole and CPR must be initiated first in this case. A similar concept, [[cardioversion]], utilizes the same defibrillation machine but is used for other rhythms such as [[atrial fibrillation]] and [[supraventricular tachycardia]]. In these rhythms, the machine is "synchronized" to the QRS complex to avoid shocking on the T wave (and inducing VT or VF). Cardioversion can be done electively for rhythm control, or urgently if the rhythm is unstable.

===Medications===
Medications recommended in the ACLS protocol include [[epinephrine]], [[amiodarone]], and [[lidocaine]].<ref name="Kronick-2015" /> The timing and administration of these medications depends on the underlying arrhythmia of the arrest.

Epinephrine acts on the alpha-1 receptor, which in turn increases the blood flow that supplies the heart.<ref>{{Cite web |title=Deep Dive into the Evidence: Epinephrine in Cardiac Arrest |url=http://www.emra.org/emresident/article/deep-dive-epi/ |access-date=2021-11-12 |website=www.emra.org |language=en}}</ref> Epinephrine in adults improves survival<ref>{{cite journal |vauthors=Vargas M, Buonanno P, Iacovazzo C, Servillo G |date=March 2019 |title=Epinephrine for out of hospital cardiac arrest: A systematic review and meta-analysis of randomized controlled trials |journal=Resuscitation |volume=136 |pages=54–60 |doi=10.1016/j.resuscitation.2019.10.026 |pmid=30685547 |s2cid=207940828}}</ref> but does not appear to improve neurologically normal survival.<ref>{{cite journal |vauthors=Aves T, Chopra A, Patel M, Lin S |date=27 November 2019 |title=Epinephrine for Out-of-Hospital Cardiac Arrest: An Updated Systematic Review and Meta-Analysis. |journal=Critical Care Medicine |volume=48 |issue=2 |pages=225–229 |doi=10.1097/CCM.0000000000004130 |pmid=31789700 |s2cid=208537959}}</ref> In ventricular fibrillation and pulseless ventricular tachycardia, 1&nbsp;mg of epinephrine is given every 3–5 minutes, following an initial round of CPR and defibrillation.<ref name="Neumar-2015" /> Doses higher than 1&nbsp;mg of epinephrine are not recommended for routine use in cardiac arrest. If the person has a non-shockable rhythm, such as asystole, following an initial round of CPR, 1&nbsp;mg of epinephrine should be given every 3–5 minutes, with the goal of obtaining a shockable rhythm.<ref>{{cite journal | vauthors = Panchal AR, Berg KM, Hirsch KG, Kudenchuk PJ, Del Rios M, Cabañas JG, Link MS, Kurz MC, Chan PS, Morley PT, Hazinski MF, Donnino MW | display-authors = 6 | title = 2019 American Heart Association Focused Update on Advanced Cardiovascular Life Support: Use of Advanced Airways, Vasopressors, and Extracorporeal Cardiopulmonary Resuscitation During Cardiac Arrest: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care | journal = Circulation | volume = 140 | issue = 24 | pages = e881–e894 | date = December 2019 | pmid = 31722552 | doi = 10.1161/CIR.0000000000000732 | s2cid = 208019248 | doi-access = free }}</ref>

Amiodarone and lidocaine are anti-arrhythmic medications. Amiodarone is a [[class III antiarrhythmic]]. Amiodarone may be used in cases of [[ventricular fibrillation]], [[ventricular tachycardia]], and [[wide complex tachycardia]].<ref>{{cite book | vauthors = Florek JB, Lucas A, Girzadas D | chapter = Amiodarone |date=2024 | title = StatPearls | chapter-url=http://www.ncbi.nlm.nih.gov/books/NBK482154/ |access-date=2024-01-31 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=29489285 }}</ref> Lidocaine is a [[Class IB anti-arrhythmic]], also used to manage acute arrhythmias.<ref>{{cite book | vauthors = Beecham GB, Nessel TA, Goyal A | chapter = Lidocaine |date=2024 | title = StatPearls | chapter-url = http://www.ncbi.nlm.nih.gov/books/NBK539881/ |access-date=2024-01-31 |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=30969703 }}</ref> Anti-arrhythmic medications may be used after an unsuccessful defibrillation attempt. However, neither lidocaine nor amiodarone improves survival to hospital discharge, despite both equally improving survival to hospital admission.<ref>{{cite journal |vauthors=Sanfilippo F, Corredor C, Santonocito C, Panarello G, Arcadipane A, Ristagno G, Pellis T |date=October 2016 |title=Amiodarone or lidocaine for cardiac arrest: A systematic review and meta-analysis |journal=Resuscitation |volume=107 |pages=31–37 |doi=10.1016/j.resuscitation.2016.07.235 |pmid=27496262 |doi-access=free}}</ref> The first dose is given as a 300&nbsp;mg bolus. The second dose is given as a 600&nbsp;mg bolus.<ref name="Neumar-2015" />

=== Additional medications ===

[[Sodium bicarbonate|Bicarbonate]], given as sodium bicarbonate, works to stabilize [[Metabolic acidosis|acidosis]] and [[hyperkalemia]], both of which can contribute to and exacerbate cardiac arrest. If acid-base or electrolyte disturbance is evident, bicarbonate may be used. However, if there is little suspicion that these imbalances are occurring and contributing to the arrest, routine use of bicarbonate is not recommended as it does not provide additional benefit.<ref>{{cite journal | vauthors = Xu T, Wu C, Shen Q, Xu H, Huang H | title = The effect of sodium bicarbonate on OHCA patients: A systematic review and meta-analysis of RCT and propensity score studies | journal = The American Journal of Emergency Medicine | volume = 73 | pages = 40–46 | date = November 2023 | pmid = 37611525 | doi = 10.1016/j.ajem.2023.08.020 | s2cid = 260893519 }}</ref>

[[Calcium chloride|Calcium]], given as calcium chloride, works as an [[inotrope]] and [[vasopressor]]. Calcium is used in specific circumstances such as electrolyte disturbances (hyperkalemia) and [[Calcium channel blocker toxicity|calcium-channel blocker toxicity]]. Overall, calcium is not routinely used during cardiac arrest as it does not provide additional benefit (compared to non-use) and may even cause harm (poor neurologic outcomes).<ref>{{cite journal | vauthors = Messias Hirano Padrao E, Bustos B, Mahesh A, de Almeida Castro M, Randhawa R, John Dipollina C, Cardoso R, Grover P, Adler Maccagnan Pinheiro Besen B | display-authors = 6 | title = Calcium use during cardiac arrest: A systematic review | journal = Resuscitation Plus | volume = 12 | pages = 100315 | date = December 2022 | pmid = 36238582 | pmc = 9550532 | doi = 10.1016/j.resplu.2022.100315 }}</ref>

[[Vasopressin]] overall does not improve or worsen outcomes compared to epinephrine.<ref name="Neumar-2015" /> The combination of epinephrine, vasopressin, and [[methylprednisolone]] appears to improve outcomes.<ref>{{cite journal | vauthors = Belletti A, Benedetto U, Putzu A, Martino EA, Biondi-Zoccai G, Angelini GD, Zangrillo A, Landoni G | display-authors = 6 | title = Vasopressors During Cardiopulmonary Resuscitation. A Network Meta-Analysis of Randomized Trials | journal = Critical Care Medicine | volume = 46 | issue = 5 | pages = e443–e451 | date = May 2018 | pmid = 29652719 | doi = 10.1097/CCM.0000000000003049 | url = https://www.zora.uzh.ch/id/eprint/162689/1/document%282%29.pdf | url-status = live | s2cid = 4851288 | archive-date = 5 March 2020 | archive-url = https://web.archive.org/web/20200305002245/https://www.zora.uzh.ch/id/eprint/162689/1/document%282%29.pdf | hdl = 1983/d002beb9-1298-4134-b062-c617f3df43f2 }}</ref> 

The use of atropine, lidocaine, and amiodarone have not been shown to improve survival from cardiac arrest.<ref>{{cite journal | vauthors = McLeod SL, Brignardello-Petersen R, Worster A, You J, Iansavichene A, Guyatt G, Cheskes S | title = Comparative effectiveness of antiarrhythmics for out-of-hospital cardiac arrest: A systematic review and network meta-analysis | journal = Resuscitation | volume = 121 | pages = 90–97 | date = December 2017 | pmid = 29037886 | doi = 10.1016/j.resuscitation.2017.10.012 }}</ref><ref>{{cite journal | vauthors = Ali MU, Fitzpatrick-Lewis D, Kenny M, Raina P, Atkins DL, Soar J, Nolan J, Ristagno G, Sherifali D | display-authors = 6 | title = Effectiveness of antiarrhythmic drugs for shockable cardiac arrest: A systematic review | journal = Resuscitation | volume = 132 | pages = 63–72 | date = November 2018 | pmid = 30179691 | doi = 10.1016/j.resuscitation.2018.08.025 | url = http://wrap.warwick.ac.uk/113491/1/WRAP-effectiveness-antiarrhythmic-drugs-cardiac-review-Nolan-2018.pdf | url-status = live | s2cid = 52154562 | archive-url = https://web.archive.org/web/20200305122730/http://wrap.warwick.ac.uk/113491/1/WRAP-effectiveness-antiarrhythmic-drugs-cardiac-review-Nolan-2018.pdf | archive-date = 5 March 2020 }}</ref><ref name="Wang-2017" />

Atropine is used for symptomatic [[bradycardia]]. It is given at a dose of 1&nbsp;mg (iv), and additional 1&nbsp;mg (iv) doses can be given every 3–5 minutes for a total of 3&nbsp;mg. However, the 2010 guidelines from the American Heart Association removed the recommendation for atropine use in pulseless electrical activity and asystole for lack of evidence supporting its use.<ref>{{cite journal | vauthors = Neumar RW, Otto CW, Link MS, Kronick SL, Shuster M, Callaway CW, Kudenchuk PJ, Ornato JP, McNally B, Silvers SM, Passman RS, White RD, Hess EP, Tang W, Davis D, Sinz E, Morrison LJ | display-authors = 6 | title = Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care | journal = Circulation | volume = 122 | issue = 18 Suppl 3 | pages = S729–S767 | date = November 2010 | pmid = 20956224 | doi = 10.1161/CIRCULATIONAHA.110.970988 | doi-access = free }}</ref><ref name="Wang-2017" />

=== Special considerations ===

Hemodialysis patients carry a greater risk of cardiac arrest events. Multiple factors contribute including increased cardiovascular risk factors, electrolyte disturbances (calcium and potassium, caused by accumulation and aggressive removal), and acid-base disturbances.<ref>{{cite journal | vauthors = Makar MS, Pun PH | title = Sudden Cardiac Death Among Hemodialysis Patients | journal = American Journal of Kidney Diseases | volume = 69 | issue = 5 | pages = 684–695 | date = May 2017 | pmid = 28223004 | pmc = 5457912 | doi = 10.1053/j.ajkd.2016.12.006 }}</ref> Calcium levels are considered a key factor contributing to cardiac arrests in this population.<ref>{{cite journal | vauthors = Kim ED, Parekh RS | title = Calcium and Sudden Cardiac Death in End-Stage Renal Disease | journal = Seminars in Dialysis | volume = 28 | issue = 6 | pages = 624–635 | date = November 2015 | pmid = 26257009 | doi = 10.1111/sdi.12419 | s2cid = 5503149 }}</ref>

[[Tricyclic antidepressant overdose|Tricyclic antidepressant (TCA) overdose]] can lead to cardiac arrest with typical ECG findings including wide QRS and prolonged QTc. Treatment for this condition includes [[Activated carbon|activated charcoal]] and sodium bicarbonate.<ref>{{cite journal | vauthors = Woolf AD, Erdman AR, Nelson LS, Caravati EM, Cobaugh DJ, Booze LL, Wax PM, Manoguerra AS, Scharman EJ, Olson KR, Chyka PA, Christianson G, Troutman WG | display-authors = 6 | title = Tricyclic antidepressant poisoning: an evidence-based consensus guideline for out-of-hospital management | journal = Clinical Toxicology | volume = 45 | issue = 3 | pages = 203–233 | date = January 2007 | pmid = 17453872 | doi = 10.1080/15563650701226192 }}</ref>

Magnesium can be given at a does of 2 g (iv or oral bolus) to manage [[Torsades de pointes|torsades de points]]. However, without specific indication, magnesium is not generally given in cardiac arrest.<ref>{{Cite journal | vauthors = Ludwin K, Smereka J, Jaguszewski MJ, Filipiak KJ, Ladny JR, Szarpak L, Wozniak S, Evrin T |date=2020-10-28 |title=Place of magnesium sulfate in cardiopulmonary resuscitation. A systematic review and meta-analysis |url=https://journals.viamedica.pl/disaster_and_emergency_medicine/article/view/70952 |journal=Disaster and Emergency Medicine Journal |volume=5 |issue=4 |pages=182–189 |doi=10.5603/DEMJ.a2020.0041 |issn=2543-5957|doi-access=free }}</ref> In people with a confirmed [[pulmonary embolism]] as the cause of arrest, [[thrombolytics]] may be of benefit.<ref>{{cite journal | vauthors = Perrott J, Henneberry RJ, Zed PJ | title = Thrombolytics for cardiac arrest: case report and systematic review of controlled trials | journal = The Annals of Pharmacotherapy | volume = 44 | issue = 12 | pages = 2007–2013 | date = December 2010 | pmid = 21119096 | doi = 10.1345/aph.1P364 | s2cid = 11006778 }}</ref><ref name="Lavonas-2015" /> Evidence for use of [[naloxone]] in those with cardiac arrest due to [[opioid]]s is unclear, but it may still be used.<ref name="Lavonas-2015" /> In people with cardiac arrest due to a local anesthetic, [[lipid emulsion]] may be used.<ref name="Lavonas-2015" />

===Targeted temperature management===
Current international guidelines suggest cooling adults after cardiac arrest using [[targeted temperature management]] (TTM) with the goal of improving neurological outcomes.<ref name="Lindsay-2018">{{cite journal | vauthors = Lindsay PJ, Buell D, Scales DC | title = The efficacy and safety of pre-hospital cooling after out-of-hospital cardiac arrest: a systematic review and meta-analysis | journal = Critical Care | volume = 22 | issue = 1 | pages = 66 | date = March 2018 | pmid = 29534742 | pmc = 5850970 | doi = 10.1186/s13054-018-1984-2 | doi-access = free }}</ref> The process involves cooling for a 24-hour period, with a target temperature of {{convert|32|-|36|C|F|abbr=}}, followed by gradual rewarming over the next 12 to 24 hrs.<ref name="Neumar-2015-3">{{cite journal | vauthors = Neumar RW, Shuster M, Callaway CW, Gent LM, Atkins DL, Bhanji F, Brooks SC, de Caen AR, Donnino MW, Ferrer JM, Kleinman ME, Kronick SL, Lavonas EJ, Link MS, Mancini ME, Morrison LJ, O'Connor RE, Samson RA, Schexnayder SM, Singletary EM, Sinz EH, Travers AH, Wyckoff MH, Hazinski MF | display-authors = 6 | title = Part 1: Executive Summary: 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care | journal = Circulation | volume = 132 | issue = 18 Suppl 2 | pages = S315–S367 | date = November 2015 | pmid = 26472989 | doi = 10.1161/cir.0000000000000252 | doi-access = free }}</ref><ref>{{cite book |title=Therapeutic hypothermia after cardiac arrest : clinical application and management |vauthors=Lundbye JB |date=2012 |publisher=Springer |isbn=9781447129509 |location=London |oclc=802346256}}</ref> There are several methods used to lower the body temperature, such as applying ice packs or cold-water circulating pads directly to the body or infusing cold saline.

The effectiveness of TTM after OHCA is an area of ongoing study. Several recent reviews have found that patients treated with TTM have more favorable neurological outcomes.<ref name="Arrich_2023" /><ref name="Schenone-2016" /> However, pre-hospital TTM after OHCA has been shown to increase the risk of adverse outcomes.<ref name="Lindsay-2018" /> The rates of re-arrest may be higher in people who were treated with pre-hospital TTM.<ref name="Lindsay-2018" /> Moreover, TTM may have adverse neurological effects in people who survive post-cardiac arrest''.''<ref>{{cite journal | vauthors = Kalra R, Arora G, Patel N, Doshi R, Berra L, Arora P, Bajaj NS | title = Targeted Temperature Management After Cardiac Arrest: Systematic Review and Meta-analyses | language = en-US | journal = Anesthesia and Analgesia | volume = 126 | issue = 3 | pages = 867–875 | date = March 2018 | pmid = 29239942 | doi = 10.1213/ANE.0000000000002646 | pmc = 5820193 }}</ref> [[Osborn wave|Osborn waves]] on [[ECG]] are frequent during TTM, particularly in patients treated with 33 °C.<ref name="Hadziselimovic_2018">{{cite journal | vauthors = Hadziselimovic E, Thomsen JH, Kjaergaard J, Køber L, Graff C, Pehrson S, Nielsen N, Erlinge D, Frydland M, Wiberg S, Hassager C | display-authors = 6 | title = Osborn waves following out-of-hospital cardiac arrest-Effect of level of temperature management and risk of arrhythmia and death | journal = Resuscitation | volume = 128 | pages = 119–125 | date = July 2018 | pmid = 29723608 | doi = 10.1016/j.resuscitation.2018.04.037 | s2cid = 19236851 | url = https://vbn.aau.dk/da/publications/3ba7eb92-0d81-45fe-8fec-02db97a5f08e }}</ref> [[J wave|Osborn waves]] are not associated with increased risk of ventricular arrhythmia, and may be considered a benign physiological phenomenon, associated with lower mortality in univariable analyses.<ref name="Hadziselimovic_2018" />

===Do not resuscitate===
Some people choose to avoid aggressive measures at the end of life. A [[do not resuscitate]] order (DNR) in the form of an [[advance health care directive]] makes it clear that in the event of cardiac arrest, the person does not wish to receive [[cardiopulmonary resuscitation]].<ref>{{cite journal | vauthors = Loertscher L, Reed DA, Bannon MP, Mueller PS | title = Cardiopulmonary resuscitation and do-not-resuscitate orders: a guide for clinicians | journal = The American Journal of Medicine | volume = 123 | issue = 1 | pages = 4–9 | date = January 2010 | pmid = 20102982 | doi = 10.1016/j.amjmed.2009.05.029 }}</ref> Other directives may be made to stipulate the desire for [[intubation]] in the event of [[respiratory failure]] or, if comfort measures are all that are desired, by stipulating that healthcare providers should "allow natural death".<ref>{{cite journal | vauthors = Knox C, Vereb JA | title = Allow natural death: a more humane approach to discussing end-of-life directives | journal = Journal of Emergency Nursing | volume = 31 | issue = 6 | pages = 560–561 | date = December 2005 | pmid = 16308044 | doi = 10.1016/j.jen.2005.06.020 }}</ref>

===Chain of survival===
Several organizations promote the idea of a [[chain of survival]]. The chain consists of the following "links":
* Early recognition. If possible, recognition of illness before the person develops a cardiac arrest will allow the rescuer to prevent its occurrence. Early recognition that a cardiac arrest has occurred is key to survival, for every minute a patient stays in cardiac arrest, their chances of survival drop by roughly 10%.<ref name="Resuscitation Council"/>
* Early CPR improves the flow of blood and of oxygen to vital organs, an essential component of treating a cardiac arrest. In particular, by keeping the brain supplied with oxygenated blood, the chances of neurological damage are decreased.
* Early defibrillation is effective for the management of [[ventricular fibrillation]] and pulseless [[ventricular tachycardia]].<ref name="Resuscitation Council"/>
* Early advanced care.
* Early post-resuscitation care, which may include [[percutaneous coronary intervention]].<ref>{{cite journal | vauthors = Millin MG, Comer AC, Nable JV, Johnston PV, Lawner BJ, Woltman N, Levy MJ, Seaman KG, Hirshon JM | display-authors = 6 | title = Patients without ST elevation after return of spontaneous circulation may benefit from emergent percutaneous intervention: A systematic review and meta-analysis | journal = Resuscitation | volume = 108 | pages = 54–60 | date = November 2016 | pmid = 27640933 | doi = 10.1016/j.resuscitation.2016.09.004 }}</ref>

If one or more links in the chain are missing or delayed, then the chances of survival drop significantly.

These protocols are often initiated by a [[Code Blue (emergency code)|code blue]], which usually denotes impending or acute onset of cardiac arrest or [[respiratory failure]].<ref>{{cite journal | vauthors = Eroglu SE, Onur O, Urgan O, Denizbasi A, Akoglu H | title = Blue code: Is it a real emergency? | journal = World Journal of Emergency Medicine | volume = 5 | issue = 1 | pages = 20–23 | date = 2014 | pmid = 25215142 | pmc = 4129865 | doi = 10.5847/wjem.j.issn.1920-8642.2014.01.003 }}</ref>

===Other===
Resuscitation with [[extracorporeal membrane oxygenation]] devices has been attempted with better results for in-hospital cardiac arrest (29% survival) than OHCA (4% survival) in populations selected to benefit most.<ref>{{cite journal | vauthors = Lehot JJ, Long-Him-Nam N, Bastien O | title = [Extracorporeal life support for treating cardiac arrest] | journal = Bulletin de l'Académie Nationale de Médecine | volume = 195 | issue = 9 | pages = 2025–33; discussion 2033–6 | date = December 2011 | pmid = 22930866 | doi = 10.1016/S0001-4079(19)31894-1 | doi-access = free }}</ref>

[[Cardiac catheterization]] in those who have survived an OHCA appears to improve outcomes, although high-quality evidence is lacking.<ref>{{cite journal | vauthors = Camuglia AC, Randhawa VK, Lavi S, Walters DL | title = Cardiac catheterization is associated with superior outcomes for survivors of out of hospital cardiac arrest: review and meta-analysis | journal = Resuscitation | volume = 85 | issue = 11 | pages = 1533–1540 | date = November 2014 | pmid = 25195073 | doi = 10.1016/j.resuscitation.2014.08.025 | s2cid = 207517242 }}</ref> It is recommended to be done as soon as possible in those who have had a cardiac arrest with [[ST elevation]] due to underlying heart problems.<ref name="Neumar-2015" />

The [[precordial thump]] may be considered in those with witnessed, monitored, unstable ventricular tachycardia (including pulseless VT) if a defibrillator is not immediately ready for use, but it should not delay CPR and shock delivery or be used in those with unwitnessed OHCA.<ref>{{cite journal | vauthors = Cave DM, Gazmuri RJ, Otto CW, Nadkarni VM, Cheng A, Brooks SC, Daya M, Sutton RM, Branson R, Hazinski MF | display-authors = 6 | title = Part 7: CPR techniques and devices: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care | journal = Circulation | volume = 122 | issue = 18 Suppl 3 | pages = S720–S728 | date = November 2010 | pmid = 20956223 | pmc = 3741663 | doi = 10.1161/CIRCULATIONAHA.110.970970 }}</ref>