What Are They & How To Get Them

Building Better Cardiac Arrest Care – Part 3

High-quality CPR is the primary component influencing survival from cardiac arrest, but there is considerable variation in monitoring, implementation, and quality improvement. – The AHA

Overview

The phrase “high quality” chest compressions has taken center stage in cardiac arrest care. Research providing insights into coronary perfusion during chest compressions (and its central importance in achieving ROSC) makes them the foundation that all other cardiac arrest care is build upon. This post is all about what they are, and how to get them in the current real world of cardiac arrest care.

But what does “high quality” really mean? And how can we tell if we’re achieving our goal? Without being able to identify and correct the factors intrinsic to good chest compressions during an arrest, the phrase “high quality” remains merely a slogan, and leaves us with the traditional algorithmic model of: chest compressions, meds, pulse check, repeat. A combination of new tools, physiologic markers, and crisis resource management techniques are needed to improve the current delivery of this central piece of cardiac arrest care, and give the phrase “high quality” real meaning.

Identifying the Challenges

Chest compressions, more than any other procedure physicians are trained in, appear to be one of the easiest and most basic skills we learn.  It’s a common mistake made by providers early in their training to believe that being “certified” in the mechanics of chest compressions and the required ACLS algorithms, will equate with providing good cardiac arrest care (I know, I was one of them).  Nothing could be further from the truth, and here’s why.

Even If You’re Doing It Right, You Might Be Doing It Wrong

Anyone who participates in cardiac arrest care knows the innumerable barriers to good chest compressions: start with patient clothing, and body habitus, poor external landmarks, blood, sweat, other secretions all mixed in with a squirt of ultrasound gel to get things nice and slippery. Add space restrictions, poor working surfaces, bed height, stool placement, provider fatigue, and variability in chest compression skills along with a chaotic environment and competing distractions such as distraught family members, airway management, vascular access, medication dosing, and you have just some of the many issues that translate into generally ineffective chest compressions during an  arrest.

To make matters worse, even if we achieve “ideal” chest compressions based on current guidelines, we may still be doing it wrong. Studies using transesophageal echo (TEE) during cardiac arrest find that the area of maximal compression during standard CPR can often significantly obstruct forward flow, and that initial hand placement based only on standard external landmarks are frequently sub-optimal.

We’re Not That Good At Self-Correcting 

“Providers are notoriously poor at estimating whether their own compressions are too fast, too slow, too deep etc”  Excerpts From: “Cardiac Arrest.” Oren Friedman, 2016. iBooks. 

When it comes to providers assessing the quality of their own chest compressions, the truth is we’re bad at it. Combine this with the other barriers to effective CC’s mentioned above, and the resulting ubiquity of bad chest compressions (or at least inconsistently good ones) in cardiac arrest care is not such a mystery.

“The code leader needs to continuously monitor the overall quality of compressions, and ensure proper rotation of providers” Excerpt From: “Cardiac Arrest.” Oren Friedman, 2016. iBooks.

To overcome this problem, it has traditionally been the responsibility of the team leader to constantly monitor and direct the details of this essential element of cardiac arrest care, in addition to maintaining focused on the big picture: gathering information, managing the rest of the team, and all other aspects of resuscitation care. Even with task delegation, this approach to crisis resource management in a cardiac arrest can allow focus on chest compressions to dissipate, negatively impacting overall chest compression delivery.

We Can’t Fix it if We Don’t Know it’s Broken 

Finally, what we really want to know during CPR is how effective our efforts are in improving coronary perfusion pressure (CPP). Real-time, physiology-driven decisions during CPR makes sense, but as yet there are no simple methods of directly measuring CPP during most cardiac arrests. For now, how well we’re actually doing with CPP in our patients is anyone’s guess, but there are surrogate  physiologic markers of CPP that can give us some guidance. In addition, there are tools that can guide chest compressions and improve the mechanics of delivery.

So What Can You Do?

In part one of this series, I broke down cardiac arrest care into two core goals:

1. Rapidly optimizing cardio-cerebral perfusion.
2. Finding and treating reversible causes of cardiac arrest.

When the multiple demands of these goals compete or interfere with each other, even an experienced code leader can become distracted or overwhelmed: loss of focus on CPR, even for a short time, can rapidly lead to inadequate coronary perfusion and a diminishing likelihood of achieving ROSC. Complete focus lock on good CPR can delay potential life-saving treatment of reversible causes of cardiac arrest.

Even brief interruptions in chest compressions can negatively impact CPP

Managing these competing demands in cardiac arrest care is a crisis resource management issue, and should be no different from managing any other critical action in resuscitation care.

To me it makes sense (when possible) to divide these roles and assign a chest compression leader (CC leader) with the responsibility of optimizing and maintaining coronary perfusion. This CC leader should be told that their sole focus is orchestrating and maintaining high quality, uninterrupted chest compressions.

To be effective, this role should be clearly defined within your team training prior to a cardiac arrest, and a qualified provider should be identified early on within the resuscitation. Ideally this person should have a clear grasp of all the factors that determine good chest compressions:

• Proper hand placement, rate, depth, and recoil.
• Height of the stretcher & stool placement
• Proper rigid board placement if needed
• Monitoring for fatigue and CC team rotation
• Placement and managing of mechanical devices
• Understanding of chest compression fraction

The “CC leader” can then independently direct the “CC providers” to improve their performance and adjust their efforts appropriately based on the available real-time feedback tools.

If possible, identify and assign a chest compression quality leader early on in your resuscitation.

I’m unsure why, in my experience this is done so infrequently. Perhaps it’s an integral part of cardiac arrest care in other places. If so, please share your experience with me. My belief is that this is another unintended consequence of algorithmic care in cardiac arrest training: where most code leaders feel they need to be in charge of the resuscitation based on the requirements of ACLS, where “running the code” means CPR.

Whatever the historical reason for this, assigning someone to manage the procedure of chest compressions during a code should be no different from assigning a qualified provider to manage the airway, or place a central line. All successful resuscitation care starts with getting control of the room: by assigning critical roles to team members and communicating effectively the chaos is reduced and the cognitive noise is subdued.

This model also fits smartly with the concept of cognitive offloading (presented so well recently by Salim Rezaie MD @srrezaie) during cardiac arrest care. An idea that was also highlighted in the first post of this series. Assigning this first core goal of cardiac arrest care (the optimization and maintenance of cardio-cerebral perfusion) in the same manner that airway management and other critical roles are assigned, frees the team leader to focus on the second core goal: finding and treating reversible causes.

Do I Really Have “High Quality” Chest Compressions? Getting Real-Time Feedback

Without the arrest team being able to identify and correct the factors intrinsic to good chest compressions in real-time, most CPR delivery during a resuscitation will be bad – or at least inconsistently good. 

Assigning a CC leader early in the resuscitation addresses the crisis resource management issues of delivering high quality chest compression, but how can we know if our “high quality” work is translating into improved coronary perfusion?

While there’s no way to directly measure CPP, there are several tools that can be employed to assess the effectiveness of our efforts.  The ones listed below are easily integrated int current cardiac arrest care, are readily available and accessible for most providers, and may already be in your department.  Being able to use these tools effectively to assess “quality” and adjust your approach accordingly should be an important skill for the experienced CC leader, and become a larger focus of advanced cardiac arrest training in the future.

The CPR Dashboard (feedback for the CC provider)

The Zoll-R now has a dashboard that provides detailed real-time visual feedback on CPR quality. The rate, depth, and release of each compression is captured with a sensor which is built into the pads. The system then gives visual and audio prompts to guide chest compressions.

While this tool can be fooled by factors like soft hospital bed surfaces, it’s a welcome addition in giving the code leader, the cc leader and the active cc provider real-time feedback on how well they’re doing.

ETCO2 (feedback on perfusion)

The best tool we have currently for assessing coronary perfusion is the use of ETCO2 as a marker of blood flow through the lungs during CPR. This tool is now widely available and a realistic option for most providers. Along with the chest compression quality dashboard, the CC leader can use this information to guide the teams attempts at improving coronary perfusion.

In much the same way we’re trained to adjust something in our approach to a difficult intubation  after our first attempt fails, ETCO2 in cardiac arrest can give us real-time feedback on the quality of our CPR.  If ETCO2 is not rising above 15-20 mmHg or more, change what you’re doing! For example. larger patients may need deeper compressions; backboard placement may give added efficiency to your CPR and adjustment of hand placement may change the point of maximal compression to align better with the ventricles.

Ultrasound ( feedback on hand positioning)

TEE is not yet a realistic option for most emergency departments or in hospital cardiac arrests, but bedside TTE (beyond the extended FAST exam to search for reversible causes of PEA arrest) may be a useful adjunct to give the team feedback on the quality of chest compressions. (For more on TEE and its potential use in physiology-driven cardiac arrest care, I highly recommend viewing this wonderful presentation by Felipe Teran MD @FTeranmd)

TTE ultrasound for this reason during cardiac arrest should never take priority over uninterrupted chest compressions, but probe placement in the sub-xiphoid or apical view may help optimize hand placement by assessing the area of maximum compression. Compressions that clearly land on the aortic root or LVOT should be moved caudally over the ventricles. I add this to my cardiac arrest care when, despite optimizing chest compressions, the ETCO2 does not rise.

Chest Compression Fraction

Chest compression fraction is a relatively new term in the CA world to describe the proportion of time chest compressions are done by providers during a cardiac arrest. This is also integrated into the CPR dashboard, and may be the most important real-time feedback tool the new system offers, because it’s a measure of how well your team is doing in minimizing chest compression interruptions.

Increased chest compression fraction is independently predictive of better survival in patients suffering a prehospital ventricular fibrillation/tachycardia cardiac arrest. Circulation. 2009 Sep 29; 120(13): 1241–1247.

This is FOAMtastic

Finally this is a great place for me to introduce you to another fantastic FOAM resource on cardiac arrest care by Dr. Oren Friedman @OrenFriedman. It’s geared toward the expert resuscitationist, and covers the latest thinking on everything from chest compressions to ECMO. Oren also addresses much of the teamwork and communication skills required to turn the ABCs of cardiac arrest care into high level resuscitation skills. It’s an incredible new resource and a great jumping off point for the many of the posts in this series, including this one. So go ahead, read it.  I’ll wait…

That’s it for now. Our next topic in this series will be on how to minimize interruptions in chest compressions during a cardiac arrest.

Watch this space