Improving Cardiac Arrest Survival With Post-Event Reviews

I was recently on the EMS Nation (@EMS_Nation) podcast discussing Pit Crew / High Performance CPR and Systems of Care with Faizan H. Arshad, MD (@emscritcare). You can listen to the podcast in iTunes or Libsyn.

We talked about QA/QI of cardiac arrest calls and the importance of providing non-punitive feedback to crews. As a supplement to that discussion, I thought I would provide an example of how we review these calls in my EMS system.

This is a recent case that is presented with the patient’s permission (although identifiers have been removed).


  • 66 year-old-male
  • Spouse woken up by patient’s agonal breathing
  • CPR instructions provided by dispatchers
  • Initial rhythm of ventricular fibrillation (VF)
  • Return of spontaneous circulation (ROSC) after 3 shocks
  • Post-conversion 12-lead ECG shows posterolateral STEMI
  • Angiography reveals chronically occluded circumflex with good collateral circulation
  • LV ejection fraction normal
  • Patient managed medically
  • Discharged alive with a CPC score of 1

One of the first things I do when I review a cardiac arrest call is put a timeline together with information from the NFIRS report, the dispatch record, PCR, and CODE-STAT. It’s time consuming but it gives me a good feel for how we performed on the call from a system standpoint.


  • 05:50:28 – Call Received
  • 05:52:29 – Initial Dispatch
  • 05:53:00 – Dispatchers providing CPR instructions
  • 05:54:00 – Medic 3 En Route
  • 05:54:53 – Medic 5 En Route
  • 05:55:04 – Truck 6 En Route
  • 05:55:11 – Battalion 1 En Route
  • 05:55:32 – Engine 5 En Route
  • 05:55:49 – Loss Prevention Advised to Bring AED
  • 05:56:44 – Medic 3 Arrival Curbside
  • 05:58:44 – Medic 3 At Patient
  • 05:59:46 – Medic 5 Arrival Curbside
  • 06:00:03 – Truck 6 Arrival Curbside
  • 06:00:25 – Shock 1
  • 06:02:17 – Engine 5 Arrival Curbside
  • 06:02:58 – Shock 2
  • 06:05:07 – Shock 3
  • 06:05:53 – Battalion 1 Arrival Curbside
  • 06:05:56 – ROSC
  • 06:07:00 – Post Resuscitation Care Checklist
  • 06:15:59 – 12-Lead 1
  • 06:19:59 – 12-Lead 2
  • 06:21:11 – Code STEMI
  • 06:29:24 – Medic 3 En Route Hospital
  • 06:38:20 – Medic 3 Arrived Hospital

Compression Rate

Next I look at the rate of compressions in CODE-STAT. This is something my department struggled with after the 2010 AHA ECC Guidelines were published. We “pushed hard and fast” at rates that sometimes exceeded 140-160 per minute. Now we know that this is too fast.

compression rate

In this particular call we were right in the “sweet spot” which is between 100 and 120. This is where metronomes are extremely helpful! I personally use the CPR Tempo app with the compression rate programmed to 110, the shock timer programmed to 2 minutes, and the epinephrine timer programmed to 5 minutes.

Chest Compression Fraction

Next I look at the compression fraction (also called the “CPR fraction time”) which is the percentage of time that chest compressions were ongoing during the resuscitation.

compression fraction

On this call the compression fractions were excellent. I don’t see any significant gaps in chest compressions (small vertical red lines) that would indicate a prolonged intubation attempt, for example.

Timing and Appropriateness of Shocks

Because all of these calls go into the CARES Registry, I verify the patient’s initial heart rhythm with my own eyes. I also look at each shock with and without CPR Events (the impedance channel that the computer uses to determine whether or not chest compressions were being performed).

Studies suggest that inappropriate shocks are relatively common during resuscitation attempts. They are probably not harmful but it is best to avoid them. With the current emphasis on immediate post-shock compressions, it is usually not obvious (in real-time) whether our shocks are successfully terminating VF.

In this case the patient was experiencing recurrent VF as opposed to shock-resistant or refractory VF. This is important if you work in a system that allows double sequential defibrillation.

Shock 1

shock 1

Shock 2

shock 2

Shock 3

shock 3

Perishock Pauses

We know that shocking is one of the major reasons we interrupt chest compressions so it’s desirable to: 1.) perform chest compressions while the capacitor is charging, and 2.) perform immediate post-shock compressions.  The pre-shock pause plus the post-shock pause is the total perishock pause.

perishock pauses

In this case all of the perishock pauses were 5 seconds or less which is our goal.


I also find it interesting to look at the capnography histogram.

capnography histogram

When this patient experienced return of spontaneous circulation (ROSC) there was a sudden rise in ETCO2 from < 25 mmHg to > 50 mmHg.

Trend Summary

The first thing we do after confirming that we have a return of pulses is attach pulse oximetry. The SpO2 is often low initially (in this case the low 70s). Our goal is to bring up the SpO2 without blowing off all the patient’s CO2.

trend summary

In this case the ventilation rate was determined by the patient’s spontaneous breathing. In other words, we gave a gentle bag squeeze when he took a breath. He had been gasping throughout the code (not uncommon in the era of high performance CPR).

12-Lead ECG Interpretation

After obtaining a full set of vital signs (including temperature) we obtain a 12-lead ECG. I review them to assess the accuracy of the paramedic’s interpretation and whether or not Code STEMI was appropriately called from the field.

The medical literature tells us that a very high percentage of patients resuscitated from out-of-hospital cardiac arrest have coronary artery disease (97%) with a 50% incidence of coronary occlusion.

In addition, “the absence of ST elevation on a surface 12-lead electrocardiogram after resuscitation of circulation from cardiac arrest is not strongly predictive of the absence of coronary occlusion on acute angiography.”

12-Lead 1

12-Lead 1

12-Lead 2

12-Lead 2

In this case the paramedics had difficulty locating the precordial leads initially (one of the few hiccups on the call). It was interpreted as acute posterolateral STEMI and “Code STEMI” was announced on the radio.


The angiograms were requested from our receiving hospital.

The circumflex (LCX) was found to be 100% occluded but they were unable to cross the lesion with a wire. The cardiologist felt that it was chronically occluded considering the amount of collateral circulation coming off the right coronary artery (RCA).

lcx and rca


When time allows I create a PowerPoint presentation with all of this information and email it out to the crews who responded to the call. It helps identify opportunities for improvement and recognize a job well done.

Further Reading

High Performance CPR – Performance Not Protocol! 

Ten Steps for Improving Survival from Sudden Cardiac Arrest

Telecommunicator CPR (T-CPR) Certificate Course


About author

Tom Bouthillet
Tom Bouthillet - 25 posts

Tom Bouthillet (@tbouthillet) is Editor-in-Chief of (@ECGTraining) and Fire Captain/Paramedic in South Carolina where he is the Emergency Cardiac Care Program Manager and the STEMI and CARES Site Coordinator of his fire department.

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