This is part 2 of our series on the ACLS Guidelines 2015 Post Arrest Care with Dr. Laurie Morrison and Dr. Steve Lin. After listening to part 1, my friend Scott Weingart of EMCrit asked me if he could chime in to give us his take on the controversies discussed in this series; and of course, I obliged. So in this episode we discuss the controversies in post-arrest care with some of the most important researchers in ACLS and co-authors of The Guidelines as well as one of the most influential critical care educators in the world.
Post-arrest care is as important as intra-arrest care.
Once we’ve achieved ROSC our job is not over. Good post-arrest care involves maintaining blood pressure and cerebral perfusion, adequate sedation, cooling and preventing hyperthermia, considering antiarrhythmic medications, optimization of tissue oxygen delivery while avoiding hyperoxia, getting patients to PCI who need it, and looking for and treating the underlying cause. Dr. Lin and Dr. Morrison offer us their opinion on the new simplified approach to diagnosing the underlying cause of PEA arrests. We’ll also discuss when it’s time to terminate resuscitation or ‘call the code’ as well as some fascinating research on gender differences in cardiac arrest care. These co-authors of the guidelines will give us their vision of the future of cardiac arrest care and we’ll wrap up the episode with a third opinion, so to speak: Dr. Weingart’s take on the whole thing….
Written Summary and blog post prepared by Dr. Anton Helman, November 2015
The Guidelines continue to recommend running through the H’s and T’s in order to arrive at a specific diagnosis and guide treatment in PEA arrest. This approach may not be ideal because the H’s and T’s are difficult to remember in the heat of a stressful resuscitation and some of the H’s and T’s are rare causes of PEA (hypoxia, hypokalemia and hypoglycemia) or are obvious (hypoxia, hypothermia). In contrast, the approach to PEA arrest proposed in the article ‘A simplified and structured teaching tool for the evaluation and management of pulseless electrical activity’ focuses on the more likely diagnoses that require immediate treatment beyond your C-A-Bs to achieve ROSC.
This new way of thinking about PEA combines initial ECG morphology with the clinical scenario to guide the clinician to the most likely causes, and offer further diagnostic certainty using point of care ultrasound (POCUS). The first key step is to distinguish between narrow complex and wide complex PEA, with POCUS being used to help differentiate the causes of narrow complex PEA in particular.
Our experts caution that this approach should be used only when a highly skilled ultrasonographer is present and in a way that does not interrupt high quality chest compressions. Ideally, a designated team member provides the specific POCUS role independent of the other team members.
Update 2016: For a brilliant evidence-based critique of this approach to PEA arrest visit Rory Spiegel’s EM Nerd blog
Antiarryhthmics in Post-Arrest Care
While we know that intra-arrest antiarrhythmic medications may improve rates of ROSC in ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) arrests, there has never been a trial to show improvements in long term survival with any antiarryhthmic medication.
There has never been a trial to show improvements in long term survival with any antiarryhthmic medication in cardiac arrest
When it comes to giving antiarrhythmic medication post-ROSC, there is only one RCT of lidocaine post arrest which showed a decrease in the incidence of recurrent VF. In this study lidocaine was given both intra-arrest and continued post-ROSC. Hence, our experts recommend that if lidocaine is given intra-arrest and ROSC is achieved, then it is reasonable to continue a lidocaine infusion post-ROSC.
The Guidelines state that “there is inadequate evidence to support the routine use of lidocaine after cardiac arrest. However, the initiation or continutation of lidocaine may be considered immediately after ROSC from cardiac arrest due to VFib or pulseless VTach”
We will need to wait for the results of the ROC-ALPS trial to give us a more clear idea of whether or not we should be using antiarrhythmics intra-arrest or post-arrest.
When to Terminate Resuscitation
The only validated rule for termination of resuscitation is for the adult out of hospital cardiac arrest, and it has 3 pre-hospital variables for predicting 30 day mortality after OHCA:
1. No prehospital return of spontaneous circulation
2. Unshockable initial rhythm
3. Unwitnessed by bystanders
In the ED the decision to terminate resuscitation is multi-factorial and there is no absolute time cut off.
Some of the factors to consider are:
- Etco2 < 10 after 20 minutess if high quality CPR (this factor should not be used in isolation for termination of resuscitation decisions)
- Initial VFib or recurrent VFib (our experts recommend activating the cath lab ASAP with ongoing mechanical CPR for patients in recurrent VFib or VFib ‘storm’)
- Hypothermia (‘hypothermic patients are not dead until they are warm and dead’)
Maintaining Adequate Cerebral Perfusion and BP Post Arrest
For patients who receive multiple doses of epinephrine during cardiac arrest resuscitation, if ROSC is achieved, then the patient’s BP tends to be high in the first few minutes. However, when the epinephrine wears off the BP tends to drop precipitously. It is therefore recommended by many critical care experts to start vasopressors early in the post-arrest phase and target a MAP of 65 in order to maintain adequate cerebral perfusion pressure. If a central line has not been placed yet soon after ROSC, it is safe to start vasopressors in a peripheral IV until central access has been obtained.
The Importance of an Arterial Line Early in Cardiac Arrest Care
- As an adjunct or replacement of manual pulse checks: rather than depending on manual pulse checks (which have been shown to be inaccurate) to determine ROSC, an arterial line placed early after cardiac arrest can instantly determine whether ROSC is present or not and hence minimize the chest compression pause time.
- Early detection of loss of pulse or hypotension after ROSC is achieved: one of the goals in post-arrest care is to maintain adequate cerebral perfusion pressure; after ROSC has been achieved, many patients will lose their pulse again or become hypotensive once the epinephrine has worn off. Having an arterial line in place will detect this loss of circulation sooner than standard BP monitors or manual pulse checks.
What are the Indications for Cath Lab Activation in Post Arrest Care?
The literature clearly shows that patients with an initial rhythm of Vfib or showing ongoing signs of STEMI on ECG should be considered for emergency PCI. Our experts believe that it is especially important to advocate for PCI in patients who suffer from recurrent VFib or Vfib ‘storm’.
For all other patients (those without VFib or STEMI), it is unclear which patients should be transferred for PCI.
Again, similar to the decision to terminate resuscitation, multiple factors should be taken into consideration in deciding whether or not to activate the cath lab.
Favorable Factors include:
An elevated Troponin: A ROC paper that is currently under peer review as of November 2015 shows a clear association between a higher serum troponin level and a PCI amenable lesion as well as improved outcomes.
Unfavorable Factors derived from The Utstein Factors:
1. Non-VFib arrest
2. Unwitnessed arrest
3. No ROSC in the field
5. Clearly no cardiac cause – eg overdose, drowning
6. >30 minutes to ROSC
7. Long resuscitation time without ROSC as indicated by acidosis (pH<7.2) and elevated lactate >7
Targeted Temperature Management in Post Arrest Care
The Guidelines stipulate that Targeted Temperature Management (TTM) should be initiated for ALL post arrest patients who achieve a ROSC, and it’s up to your intensivist what the target temperature should be between 32 and 36 degrees.
TTM. . . Just Do It
It is important to understand that the control arm in the TTM trial still actively cooled patients, just not to the same degree as the 32 degree arm.
A pre-hospital RCT in 2013 compared immediate 2L boluses of cooled saline vs in-hospital cooling and showed an increased rate of re-arrest and acute heart failure in the pre-hospital group that received immediate large boluses of cooled NS. Therefore, in terms of when and how to start cooling, Dr. Morrison recommends to wait a few minutes after ROSC to let the heart settle and then start cooled IV saline in small boluses.
The relative contraindications to TTM (exluded in clinical trials)
1. Intracranial event
Littmann L, Bustin DJ, Haley MW. A simplified and structured teaching tool for the evaluation and management of pulseless electrical activity. Med Princ Pract. 2014;23(1):1-6.
Kudenchuk PJ, Brown SP, Daya M, et al. Resuscitation Outcomes Consortium-Amiodarone, Lidocaine or Placebo Study (ROC-ALPS): Rationale and methodology behind an out-of-hospital cardiac arrest antiarrhythmic drug trial. Am Heart J.2014;167(5):653-9.e4.
Goto Y, Maeda T, Goto YN. Termination-of-resuscitation rule for emergency department physicians treating out-of-hospital cardiac arrest patients: an observational cohort study. Crit Care. 2013;17(5):R235.
Jacobs I, Nadkarni V, Bahr J, et al. Cardiac arrest and cardiopulmonary resuscitation outcome reports: update and simplification of the Utstein templates for resuscitation registries. A statement for healthcare professionals from a task force of the international liaison committee on resuscitation (American Heart Association, European Resuscitation Council, Australian Resuscitation Council, New Zealand Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Southern Africa). Resuscitation. 2004;63(3):233-49. Full PDF
Maynard C, Longstreth WT, Nichol G, et al. Effect of prehospital induction of mild hypothermia on 3-month neurological status and 1-year survival among adults with cardiac arrest: long-term follow-up of a randomized, clinical trial. J Am Heart Assoc. 2015;4(3):e001693. Full Article
Dr. Helman, Dr. Morrison & Dr. Lin have no conflicts of interest to declare
Additional FOAMed Resources on Post Arrest Care
New PEA Algorithm on RebelEM
Simplified approach to PEA on First10EM
Post Cardiac Arrest Care on EMCrit
Author of TTM trial speaks with Scott Weingart on EMCrit