The Cardiac Arrest Algorithm takes its place as the most important algorithm in the ACLS Protocol. There are 4 rhythms that are seen with pulseless cardiac arrest. They each will be reviewed throughout this section of the course guide. These four rhythms are pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA).
Click below to view the cardiac arrest algorithm diagram. When done click again to close the diagram.
Cardiac Arrest Diagram
The majority of patients that experience sudden cardiac arrest will be treated with the Cardiac Arrest Algorithm. Therefore, mastery of this algorithm is very important. There are 2 branches of the Cardiac Arrest Algorithm, the left, and right branch.
The LEFT BRANCH is used for the treatment of pulseless ventricular tachycardia and ventricular fibrillation,and the RIGHT BRANCH is used for the treatment of PEA and Asystole.
Medications for Cardiac Arrest
There are 3 medications that will be focused on within the Cardiac Arrest Algorithm, epinephrine, amiodarone, and Lidocaine. Magnesium will be mentioned briefly.
Epinephrine
Epinephrine is the primary drug used in the cardiac arrest algorithm. It is used for its potent vasoconstrictive effects and also for its ability to increase cardiac output. Epinephrine is considered a vasopressor.
Indications for Cardiac Arrest
- Vasoconstriction effects: epinephrine binds directly to alpha-1 adrenergic receptors of the blood vessels (arteries and veins) causing direct vasoconstriction, thus, improving perfusion pressure to the brain and heart.
- Cardiac Output: epinephrine also binds to beta-1-adrenergic receptors of the heart. This indirectly improves cardiac output by:
- Increasing heart rate
- Increasing heart muscle contractility
- Increasing conductivity through the AV node
Routes
During ACLS, epinephrine can be given 3 ways: intravenous; intraosseous, and endotracheal tube. The primary method used is intravenous. When given intravenously, always follow the IV push with a 20 ml normal saline flush.
Dosing
Intravenous Push/IO: 1mg epinephrine IV is given every 3-5 minutes.
Note: There is no clinical evidence that the use of epinephrine when used during cardiac arrest, increases rates of survival to discharge from the hospital. However, studies have shown that epinephrine and vasopressin improve rates of ROSC (return of spontaneous circulation).
Amiodarone
Indications for ACLS
Amiodarone is an antiarrhythmic that is used to treat both supraventricular arrhythmias and ventricular arrhythmias.
The mechanism of action of amiodarone remains unknown, but within the framework of ACLS, amiodarone is used primarily to treat ventricular fibrillation and ventricular tachycardia that occurs during cardiac arrest and is unresponsive to shock delivery, CPR, and vasopressors.
Amiodarone should only be used after defibrillation/cardioversion and epinephrine have failed to convert VT/VF.
Route
Amiodarone can be administered by intravenous or intraosseous route.
Dosing
The maximum cumulative dose in a 24 hour period should not exceed 2.2 grams.
Within the VT/VF pulseless arrest algorithm, the dosing is as follows:
300mg IV/IO push → (if no conversion) 150 mg IV/IO push → (after conversion) Infusion #1 360 mg IV over 6 hours (1mg/min) → Infusion #2 540 mg IV over 18 hours (0.5mg/min)
Infusions exceeding 2 hours must be administered in glass or polyolefin bottles containing D5W.
Amiodarone should only be diluted with D5W and given with an in-line filter.
Lidocaine
Lidocaine is an antiarrhythmic that can also be used and is considered equivalent to amiodarone in the treatment of ventricular fibrillation or pulseless ventricular tachycardia.
Dosing
Provide an initial dose of 1-1.5 mg/kg IV or IO. If pVT or VF persists the lidocaine may be repeated at 0.5-0.75 mg/kg over 5 to 10 minute intervals.
The maximum total dosage of lidocaine is 3 mg/kg.
Magnesium Sulfate
Magnesium sulfate can be used during cardiac arrest primaryly to treat torsades de pointes that is caused by a low serum magnesium level.
Dosing
Provide an initial dose of 1-2 grams IV or IO diluted in at least 10 ml of NS. Give the dose over 5 minutes.
Watch Part 1 and Part 2 of the Cardiac Arrest Video Review.
Within ACLS Protocol, there is also a Simplified Cardiac Arrest Algorithm that simplifies and streamlines uncomplicated cardiac arrest. Use this link to watch a short video that reviews the 2015 Simplified Cardiac Arrest Algorithm.
Top Questions Asked on This Page
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Q: Can precordial thump still be used for witnessed arrest?
A: This is the AHA position and it has not changed since 2010. “The precordial thump may be considered for termination of witnessed monitored unstable ventricular tachyarrhythmias when a defibrillator is no immediately ready for use, but should not delay CPR and shock delivery. There is insufficient evidence to recommend for or against the use of the precordial thump for witnessed onset of asystole.
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Q: How fast do you push the Amiodarone 300mg?
A: In a cardiac emergency, you will push amiodarone as fast as you can push the plunder of the syringe. Essentially the same as you would push any drug in a cardiac emergency.
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Q: I keep getting confused about when to return to administration of epinephrine following the initial dose and admin of 300/150 amiodarone…is it based on time (q 3-5 min)? Any suggestions on how to keep this straight?
A: After the first dose of epinephrine, it is essentially on its own time table. Just remember to give epinephrine every 3-5 minutes after the first dose. Amiodarone is given after the 3rd (300mg) shock and any time after 4th (150mg) shock.
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Q: If you give precordial thump, is it given just once?
A: Yes, the precordial thump is attempted only one time. it is effective only if used near the onset of VF or pulseless VT, and so should be used only when the arrest is witnessed or monitored and only at the outset. . About 25% of patients in cardiac arrest who received a thump on the precordium regained cardiac function according to one study. There is no evidence that the precordial thump improves recovery in unwitnessed cardiac arrest.
Kayode says
Jeff, I’d like to commend for your contributions. I enjoyed your explanations.
Jeff with admin. says
Thank you. It is my privilege to help. Kind regards, Jeff
ahmed rashwan says
what is the king airway?
Jeff with admin. says
Here is some information about the King Airway: King Airway Explained.
ramon says
What is the difference between witnessed and unwitnessed arrest? Do you check the rhythm right away after hooking to cardiac monitor in both cases? If yes, do you defib right away if the rhythm is V.fib or you have to finish the 2min CPR cycle in the unwitnessed arrest then do rhythm check to see if the rhythm is shockable?
Thanks Jeff
Jeff with admin. says
The difference between witness and unwitnessed arrest is that you know when the arrest occurred. For witnessed arrest, the cardiovascular compromise will be less and therefore defibrillation should be done as soon as a defibrillator is available.
With witness arrest, you would stop CPR to check the rhythm after the defibrillator is hooked. For unwitnessed arrest, you would finish the 5 cycles (2 minutes) of CPR before the rhythm check.
Kind regards,
Jeff
Ramon says
I was currently taught in a recent intensive course that we should give epinephrine during the first CPR cycle. They said that it is more helpful and “synergistic” if you would give it during the first cycle of CPR whether it be PEA, Asystole, VFIB or Pulseless V-tach. Is this true? They stated that the Defibrillation is still carried out the same (rapid defib on the first cycle) as before but the epinephrine administration should be given during the first cycle. Do you have any reference for this? Thanks.
Jeff with admin. says
Hi Ramon,
Thanks for the question. You asked:”I was currently taught in a recent intensive course that we should give epinephrine during the first CPR cycle. They said that it is more helpful and “synergistic” if you would give it during the first cycle of CPR whether it be PEA, Asystole, VFIB or Pulseless V-tach. Is this true? They stated that the Defibrillation is still carried out the same (rapid defib on the first cycle) as before but the epinephrine administration should be given during the first cycle. Do you have any reference for this? Thanks.”
Reply:
There is no evidence to support that epinephrine is more synergistic or more effective when given during the first cycle of CPR. There is also no evidence to show that it is more effective when given during the second cycle of CPR.
In fact, there is no evidence that epinephrine or vasopressin improve survival to hospital discharge inpatients that experience cardiac arrest.
Epinephrine is used in ACLS simply because we know how epinephrine affects the cardiovascular system, and because of this we continue to use it for its ability to reduce peripheral circulation and increase coronary and cerebral perfusion pressures and therefore increase oxygen exchange at the cellular level.
It is my experience in codes that we give epinephrine as soon as we can. If we have time, we usually give epinephrine before the first shock is given. While CPR is being performed and the defibrillator is being attached, somebody is usually pushing epinephrine. This is my experience.
This would not be the same as the American Heart Association guidelines, but guidelines are just guidelines. You would not be breaking any rules by giving epinephrine during the first cycle of CPR, but there is no clinical evidence to support that it is somehow better.
Kind regards,
Jeff
tamer says
Hi I would ask about the role of Magnesium and Calcium in ACLS
Jeff with admin. says
Here is a quote from AHA about Calcium:
“Although calcium ions play a critical role in myocardial contractile performance and impulse formation, retrospective and prospective studies in the cardiac arrest setting have not shown benefit from the use of calcium. In addition, there is concern on a theoretical basis that the high blood levels induced by calcium administration may be detrimental. When hyperkalemia, hypocalcemia (eg, after multiple blood transfusions), or calcium channel blocker toxicity is present, use of calcium is probably helpful (Class IIb). Otherwise, calcium should not be used (Class III). When necessary, a 10% solution of calcium chloride can be given in a dose of 2 to 4 mg/kg and repeated as necessary at 10-minute intervals. (The 10% solution contains 1.36 mEq of calcium per 100 mg of salt per milliliter.) Calcium gluceptate can be given in a dose of 5 to 7 mL and calcium gluconate in a dose of 5 to 8 mL.” AHA Website Source
Here is a quote from AHA about Magnesium:
“Two observational studies showed that IV magnesium can effectively terminate torsades de pointes (irregular/polymorphic VT associated with prolonged QT interval). One small adult case series in adults showed that isoproterenol or ventricular pacing can be effective in terminating torsades de pointes associated with bradycardia and drug-induced QT prolongation. Magnesium is not likely to be effective in terminating irregular/polymorphic VT in patients with a normal QT interval.
When VF/pulseless VT cardiac arrest is associated with torsades de pointes, providers may administer magnesium sulfate at a dose of 1 to 2 g diluted in 10 mL D5W IV/IO push, typically over 5 to 20 minutes (Class IIa for torsades). When torsades is present in the patient with pulses, the same 1 to 2 g is mixed in 50 to 100 mL of D5W and given as a loading dose. It can be given more slowly (eg, over 5 to 60 minutes IV) under these conditions. See Part 7.3: “Management of Symptomatic Bradycardia and Tachycardia” for additional information about management of torsades de pointes not associated with cardiac arrest.” AHA Source
Kind regards,
Jeff
tamer says
i need the ACLS Algorithm & ACLS Drugs (recent changes) thanks
Jeff with admin. says
Everything on this site is up to date with the most recent guidelines. Kind regards, Jeff
smmendoza58@yahoo.com says
Hi Jeff. This will be my first time to do ACLS. My question is: Are there ACLS drugs that are not to be used during a cardiac arrest of a pregnant patient. Thank you.
Jeff with admin. says
During pregnancy, the medications used to treat cardiac arrest are the same. Kind regards, Jeff
Audra says
Hi!
First of all i would like to say that this website is amazing. Thank you for the endless resources! I just have a quick question in regards to your answer to the above question. I thought that VT with a pulse would warrant using the other side of the Cardiac Arrest algorithm (shock, CPR, epi, amiodarone,etc.) instead of just treating with the tachycardia algorithm which I take to mean treating with vagal maneuvers, beta blockers, and adenosine depending on how high the heart rate is. Was just wondering if you could clarify your answer.
Thanks again,
Audra
Jeff with admin. says
If a person has VT with a pulse then the treatment would being using the tachycardia algorithm. If they are unstable but have a pulse, the tachycardia algorithm would call for synchronized cardioversion.
The tachycardia algorithm deals with both narrow and wide QRS tachycardia and both unstable and stable tachycardia.
The pulseless arrest algorithm deals with the treatment of pulseless arrest.
Hope this makes sense,
Kind regards,
Jeff
Joan says
Is there a ventricular tachycardia with a pulse?
Jeff with admin. says
Yes, you can have VT with a pulse. This is treated with the tachycardia algorithm.
Kind regards,
Jeff
Yemi13 says
Hi Jeff,
Thank you so much for the endless effort you are making on this site to help people so that ACLS is easily understandable. I build up my confidence since I join your site!!!
I have one Q… If the only choice we have is Vasopressin during adult cardiac arrest algorism managing VT/VF , can we administer Vasopressin every 3-5 minutes as much as we needed? or is there any max dose we have to administer like Epinephrine.
Jeff with admin. says
Vasopressin should only be administered once because, the half-life of vasopressin is 10-35 minutes. This means that it will remain in the system for at least 20 minutes.
The reason why epinephrine is give every 3-5 minutes is that the half-life of is 2-3 minutes. This means that it will remain in the system for at least 4 minutes.
Vasopressin should only need to be given once during a code.
Kind regards,
Jeff
emily allison rogers says
this site is fantastic!
gail1 says
do I stay with 200j defib (after the initial 120j) when using Biphasic?
Jeff with admin. says
You could continue to increase incrementally. Like this: 120 – 200 – 300 – 360
Kind regards,
Jeff
Bonnie says
When your patient is in pulse less vib or vtach do you do a pulse check before or after a shock 2 years sgo I failed and had to redo my mega c ode because the ER RN who was doing it said always after not before shocking. When I redid the mega code the next day the instructor said always before not after so what is it? I was always told to do a quick less then 10 sec after the shock
Jeff with admin. says
You would not do a pulse check unless you see a rhythm that could be a perfusing rhythm. Rhythm checks are always performed after 5 cycles of cpr. So if you perform a shock, you would then complete 5 cycles (2 min.) of CPR before checking a rhythm and if needed a pulse check.
example: Patient with VF has just been shocked. ALWAYS Perform 5 cycles of CPR then do a rhythm check. If you see a change to a rhythm that could be a perfusing rhythm, then you would perform a pulse check.
Many times providers make the mistake of looking at the monitor just after shocking. If they see a rhythm change, they check a pulse. This is incorrect because there is a good chance that the patient will have no pulse. Chest compressions should continue for 2 minutes after the shock. This increases the likelihood of return of spontaneous circulation.
Kind regards,
Jeff
vincent paul says
In a pulseless state, (pre and post CPR) no BP reading can be recorded??
Gigo George says
What is the maxium dose of of atropine given during cpr
Jeff with admin. says
You would not give atropine during CPR to treat pulseless arrest. Atropine is given for symptomatic bradycardia.
The maximum total dosage to be given when treating bradycardia is 3mg.
Kind regards,
Jeff
shackelfordk says
3 mg.