Pulseless Arrest Algorithm

Pulseless Arrest (Cardiac Arrest) Algorithm

The Pulseless Arrest Algorithm which is now known as 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. These four rhythms are pulseless ventricular tachycardia (VT), ventricular fibrillation (VF), asystole, and pulseless electrical activity (PEA). Visit the links above for detailed information about each of the rhythms and their treatment in the ACLS protocol.

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 to 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. Watch Part 1 and Part 2 of the Cardiac Arrest Video Review.

Also, In 2010 the AHA released new ACLS guidelines that simplified the pulseless arrest algorithm. Use this link to watch a short video that reviews the 2010 Simplified Pulseless Arrest Algorithm.


  1. Chritina says

    I would like to know when a patient is coding and goes in and out of PEA and V fib arrest, and has no pulse throughout the code, how long to run the code? And should code end only with asystole or can v fib can be the end rhythm? Thanks. I work in ICU.

    • says

      There is a lot of variability as to how long a code can go on before it is stopped and a patient pronounced deceased. Usually, this will be at some point when the patient has been asystole rather than a shockable rhythm. Vfib and pulseless VT indicate electrical activity in the heart and as such can be treated with the hopes of conversion to an organized electrical impulse and rhythm.
      There is not a cut and dry rule for stopping a code and the team running the code should work together to decide when all best efforts have been put forward in an attempt to reverse cardiac arrest. In my experience, the max code time is somewhere around 20-30 minutes. I have never seen a good outcome with a code lasting longer than 15 minutes. I have had several people on this site comment about codes with good outcomes that lasted longer than 15 minutes, but they are rare. I would say that the best suggestion is for the code team to put forth their best effort to reverse cardiac arrest and maintain ongoing dialog about when to stop resuscitative efforts.

      Kind regards,

  2. Sherry Hess says

    Hi Jeff,
    I wanted to say thank you so much for this site. I’m a new graduate RN and just passed my first ever ACLS course. I rocked my megacode, but couldn’t have done it without your site. A great prep/review for anyone! Thanks again

  3. Mike says

    My only complaint is that I didn’t find your site sooner…I’m due to take the ACLS recert this Sunday.

    I’ll be returning, though.



  4. says

    Hi, Jeff.
    I’d like to ask about the pediatric cardiac arrest algorithm. In AHA 2010, box 8, it is said to give amiodarone (which is an adrenergic inhibitor), whereas the epinephrine (adrenergic) was the drug of choice for cardiac arrest. Any rationale about that?

    • says

      Amiodarone is used in this case for its antiarrhythmic properties. As with the adult cardiac arrest algorithm, amiodarone is the preferred antiarrhythmic that can be used for cardiac arrest. Epinephrine is included in box 6 of the pediatric cardiac arrest algorithm and is give very 3-5 minutes after the first dose. As with adult cardiac arrest, epinephrine is given in pediatric cardiac arrest for its vasopressor affects.

      Kind regards,

  5. goar0701 says

    Is there a specific length of time when resuscitation maneuvers have to be stopped because the patient didn’t response to the protocols of cardiac arrest?

    • says

      First I will give you my thoughts: In my experience, the length of time to continue a code can vary widely and is mostly dependent on the physician running the code. I have seen them last 15 minutes (which is reasonable) and I have seen them last 45 minutes (45 min. which is entirely to long). I have never seen anyone successfully resuscitated past about 18 minutes and I have not seen a good outcome for anyone who was resuscitated past about 15 minutes.
      Now Here is what AHA says about Termination of resuscitation:
      (from Circulation 2010, 122:S665-S675)
      “Terminating Cardiac Arrest Resuscitative Efforts in Adult IHCA”
      In the hospital the decision to terminate resuscitative efforts rests
      with the treating physician and is based on consideration of
      many factors, including witnessed versus unwitnessed arrest,
      time to CPR, initial arrest rhythm, time to defibrillation, comorbid
      disease, pre-arrest state, and whether there is ROSC at some
      point during the resuscitative efforts. Clinical decision rules for
      in-hospital termination of resuscitation may be helpful in reducing
      variability in decision making; however, the evidence for
      their reliability is limited, and rules should be prospectively
      validated before adoption.”
      Hope this helps.
      Kind regards,

      • Erin Burnham, MD says

        I disagree with your assessment that 45 minutes is too long to resuscitate Vfib. We had a recent witnessed arrest in the hospital that received 45 minutes of ACLS including about 20 shocks, multiple doses of epinephrine, full dose of amiodarone who ultimately had ROSC and survived neurologically intact. Vfib is a resuscitatable rhythm, and with high quality CPR it is reasonable to continue efforts. If it were you or your family member, you would be very grateful for the effort.

      • says

        Wow! That is very impressive, and very rare. This is why the AHA just makes guidelines and a physician has the discretion to diverge away from the guidelines if they deem it necessary. I’m also glad the physician in this case continued. Kind regards, Jeff

  6. julezzz26 says

    I absolutely love your site, it is terrific. I have a few questions.
    1.A pt is in pulseless v tach or in v fib and are shocked at 120 and 200 and then convert to wide complex regular monomorphic vtach with a pulse do we synch cardiovert at 100 or would it be a higher synch dose? Would you want to give adenosine at this time as well?

    2. How fast can you push magnesium?

    Thank you so much!

    • says

      1. Since the patient is already connected to the defibrillator and is unstable, you would use cardioversion. You can start with the lower dose and increase in a step-wise fashion. Many providers would probably opt for the higher initial synchronized dose and that would be ok. As well. (since this started as an unstable situation, adenosine would not be indicated.)
      2. When magnesium is given during cardiac arrest for the treatment of Torsades, it should be started as soon as possible, AHA recommendations are over 5-20 minutes but it can be rapid pushed. It can be pushed rapidly over 60 seconds, but may cause hypotension due to a direct vasodilating effect.

      Kind regards,

  7. 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

    • 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,

  8. 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.

    • 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.”

      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,

    • 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,

  9. 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.

  10. says

    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,

    • 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,

  11. 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.

    • 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,

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