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.
rbueno9 says
If you give precordial thump, just once?
Jeff with admin. says
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.
Kind regards,
Jeff
dmckin68 says
I have been enjoying studying for ACLS. I wish you would create the site for PALS.
jonathanjung says
During CPR we use art line pressure readings for compression monitoring and improvement, if the pt has an art line. I have never been in a resuscitation and used cuff pressures during cpr. Would this even work? would it be accurate and would it be useful information? I guess you could autocycle it every 3 min…
Jeff with admin. says
It is going to be very hard to monitor any type of blood pressure whether it is with an arterial line or BP cuff. Both are peripheral blood pressures. I can’t say that I have ever seen a blood pressure watched closely or even recorded until we obtained some type of rhythm change or pulse. Now there have been times in the critical care setting on patient’s with an arterial line when we have watched a patient’s BP tank, responded to the drop in BP, and then the patient coded. In these times it seems that we did use the arterial line BP to watch for any changes in the right direction. Still I would say that the BP is more pre. and post arrest.
Kind regards,
Jeff
jonathanjung says
V tach without a pulse is not considered PEA by academic definition, however, if the V tach is pulseless due to hypovolemia and we are running fluids during the resuscitation we may end up with a pulse. Thus, checking a pulse during your 10 sec rhythm checks (even though we started with pulseless v tach) doesn’t seem unreasonable. Pulse check with V F seems unnecessary and inconsequential ….. any thoughts on that ??
Jeff with admin. says
I agree. IF you are dealing with a pulseless state that is related to hypovolemia, pulse checks WITH the rhythm checks would be wise. However, I would not delay chest compressions for a pulse check. If you have to choose between chest compressions and a pulse check. Choose chest compressions. A few extra chest compressions will not hurt if the patient has a pulse. If the patient does not have a pulse, the chest compressions will most definitely help. Also, you should have some idea whether or not you are dealing with hypovolemia. (usually blood loss).
Kind regards,
Jeff
Michele says
Is there a rule of thumb to remember whether or not a rhythm is shockable? I ask because in the algorhithms it is a step to consider. Thanks for your time.
Jeff with admin. says
There are two types of shock that can be delivered. Unsynchronized shock (defibrillation) and Synchronized shock. For this question, I will assume that you are asking about defibrillation.
Defibrillation is used for Ventricular Fibrillation and Pulseless VT. If you see either of these rhythms and you do not feel a pulse, you will defibrillate.
That is a simple rule of thumb for defibrillation.
Kind regards, Jeff
savvygirl says
Jeff-
Is it advisable to give 2 or 3 doses of Epi with alternating rounds of CPR and shocking prior to the first dose of Amiodarone, or is is up to the code team leader as to how many doses of Epi is given before giving Amiodarone? What is the standard of care?
Jeff with admin. says
According to AHA ACLS Guidelines, the first dose of epinephrine is given after the 2nd shock during CPR. After the first dose, the epinephrine is given every 3-5 minutes. This is because the half-life of epinephrine is 2 minutes.
After the first dose epinephrine is essentially on its own timetable.
The first dose of amiodarone should be administered after the 3rd shock during CPR.
This is per the AHA ACLS guidelines which is considered the standard of care.
Kind regards,
Jeff
KMCOLE says
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?
Jeff with admin. says
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) and 4th (150mg) shock.
Kind regards, Jeff
KMCOLE says
Thanks Jeff, now it is clear.
jwardrn says
How fast do you push the Amiodarone 300mg?
Jeff with admin. says
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.
Kind regards,
Jeff
K R says
Here is a question about the right side of the Pulseless Arrest Algorithm. We know that epinephrine or vasopressin may be used in Asystole/PEA but I made some notes in my 2008 AHA handbook that don’t make sense.
– The handbook states (Pulseless Arrest Algorithm, page 7, box 10): “May give 1 dose of vasopressin 40 U IV/IO to replace first or second dose of epinephrine”
– My handwritten note states: “If vasopressin is used in the first cycle of CPR do not follow with the use of epinephrine in the second round of CPR. Wait four minutes and be sure to use atropine 1mg IV/IO instead.”
What is the reasoning behind not using epinephrine after vasopressin? Why would an ACLS instructor emphasize that? What are the consequences of ignoring that instruction?
Jeff with admin. says
Vasopressin may be given directly as part of the pulseless arrest algorithm. I am not aware of a reason behind not using epinephrine after vasopressin and this is not part of the algorithm. Vasopressin should be used to replace the 1st or 2nd dose of epinephrine.
Also note, atropine is no longer included in the right branch of the pulseless arrest algorithm.
Kind regards,
Jeff
William Womack says
I notice in the video that it emphasizes minimal interruption of compressions yet still states 30/2 as the correct compression/ventilation ratio. Isn’t this a contradiction?
Awesome site. I’m amazed at the logic and thoroughness of it. Thanks for taking our money and giving us a much greater value in return when the opposite is nearly always the case at other sites.
Dwayne
Jeff with admin. says
Hi Dwayne,
Thanks for the encouragement and feedback. With regard to the minimal interruption of chest compressions and the 30/2 compression to ventilation ratio. I would not say this is a contradiction if you have multiple rescuers. Until multiple rescuers are present in the room it would be appropriate to just do compressions according to the guidelines, but once a second rescuer is present, the 30/2 ventilation ratio could be maintained w/o much of an interruption in chest compressions.—regards, Jeff
theresa, rn says
I watched a pt go flat line when he went pale and passed out after a cataract surgery. I called for help, lowered the hob, and while I was lowering the height of the bed, I gave a precordial thump. There was a spike from the thump as witnessed by another nurse and immediate return of pulse. By the time the bed was at a height to do CPR, pt’s color was already returning, and there was a pulse. This precordial thump worked well.
Jessica Callahan says
wow thats great! thanks for sharing
Grape123 says
Is that recommended tho, I don’t see that as a recommended treatment?
Christine Stansberry says
SO VASOPRESSIN IS TO BE GIVEN ONLY ONE TIME DURING THE WHOLE CODE?
Jeff with admin. says
correct
mike says
I really like this site even though all tachycardia algorithms are not done. i do have a question that i could not find. is pre cordial thump still in if wittnessed arrest?
Jeff with admin. says
Hi Mike,
To use precordial thump the arrest must be witness and monitored.
Here is what AHA now says. I could not find any info in the AHA manual about precordial thump, in a review of the following I found this. This information came form the 2010 AHA Highlights found at this link:
http://www.heart.org/idc/groups/heart-public/@wcm/@ecc/documents/downloadabl
e/ucm_317350.pdf
“2010 (New): The precordial thump should not be used for
unwitnessed out-of-hospital cardiac arrest. The precordial
thump may be considered for patients with witnessed,
monitored, unstable VT (including pulseless VT) if a defibrillator
is not immediately ready for use, but it should not delay CPR
and shock delivery.”
(Highlights of the 2010 AHA Guidelines for CPR and ECC; pg. 11)
Kind Regards,
Jeff
acls-algorithms.com
T. Gail Price says
This is a great site, very instructional and easy to follow.
mark odell m.d. says
very conveninet to have available