ABCDEF (A2F) Overview

Delirium Prevention and Safety: Starting with the ABCDEF’s

It is essential to consider delirium management in the broader picture of ICU patient care as a major piece of the current guidelines for Pain, Agitation, Delirium, Immobility, and Sleep Disruption (PADIS) from the Society of Critical Care Medicine (SCCM). Advancements in research and technology are resulting in higher acuity and increased complexity of care, which is resulting in drastic increases in workload and demands on staff. More than ever, there is a great need to develop simpler ways of implementing safer and better care into practice for our sickest patients.

The ABCDEF (A2F) bundle is one way to align and coordinate care, which includes specific focus on delirium as a component of the overall care patients receive including sedation and pain medications, breathing machines, and mobilization.

What are the components of the A2F bundle?

Think of the ABCDEFs as a means of putting best practice into the real world of your ICU. Why use a mnemonic? Because it provides a sticky (i.e., easy to remember) message, and it is evidence based (all created from data published in high impact journals such as JAMA, Lancet, and NEJM). The use of the A2F bundle is associated with clinically meaningful improvements in outcomes including survival, mechanical ventilation use, coma, delirium, restraint-free care, ICU readmissions, and post-ICU discharge disposition (B Pun CCM 2018, M.A. Barnes-Daly CCM 2017, M Balas CCM 2014). To ensure that bundles remain scientifically credible and have the maximum possible impact on outcomes, periodic updating based on new evidence is critical. The A2F bundle, in accordance with the Society of Critical Care Medicine’s 2018 Clinical Practice Guidelines for the Management of Pain, Agitation, Delirium, Immobility, and Sleep Disruption (PADIS) in Adult ICU Patients, must include routine pain, agitation, and delirium screening and management through the use of valid and reliable tools. These tools are well outlined in the PADIS Guidelines and many are available on this website.

So what is a BUNDLE anyway?

This is a published conversation that took place within the largest quality improvement organization in the U.S. called the Institute for Healthcare Improvement (IHI). The IHI's Rethinking Critical Care program has incorporated concepts related to the ABCDEFs and the PADIS Guidelines that can be found on their website.

Commonly misunderstood aspects of the ABCDEFs are as follows:

• MYTH: The ABCDEFs and PADIS are advocating different things.
• TRUTH: These are similar constructs. As noted above, think of the ABCDEFs as a way of operationalizing the PADIS guidelines. There are many ways of going about this; the A2F Bundle is just one way of talking about and organizing this “new culture” of lighter sedation, attention to delirium, and early mobility. Just like the PADIS does advocate early mobility even though mobility is not explicitly stated in the title, so Pain is also included in the ABCDEFs even though that mnemonic doesn’t include a “P.”
• MYTH: If an ICU is not completely turning off sedative medications, it is not embracing SATs or the ABCDEFs.
• TRUTH: The original ABC study, as well as other subsequent publications and quality improvement projects have prioritized the concept of a “complete shut off” of sedation and analgesia once the patient is felt to be pain free and passes the SAT safety screen. However, there are hospitals in general or specific patients in whom a reduction in sedative dose without a complete shut-off is indicated for safety reasons. This SAT and SBT approach supported by the NEJM and Lancet studies is not a “one shoe fits all.” We must use clinical judgment. If the reason we are leaving the potent sedative medications going in our patients is mostly because “that is our culture” or the staff are too busy to deal with an interactive patient, then that likely needs to be re-evaluated and solutions found.

ABCDEF Bundle and ICU Liberation

The SCCM’s ICU Liberation program centers on the concept that patients can achieve superior outcomes when we are thorough not only in starting the right treatments but also in determining when those same “once helpful” treatments should be stopped.  The ABCDEF bundle is the central framework of the ICU liberation program and it  helps drive those treatment decisions. As a medical community, we now have published data on over 25,000 patients in ICUs all over North America that there is a dose-response relationship between higher compliance with the ABCEDF bundle and higher survival, shorter time on mechanical ventilation, earlier discharge from the ICU and hospital, fewer bounce backs to the ICU, less delirium and coma, less use of restraints, lower cost of care, and lower rates of discharge to nursing homes and rehabilitation facilities. 

What is this Bundle? 

It is a bundle of 6 safety elements built from the global literature representing original randomized controlled trials from over 35 NEJM, JAMA, and Lancet investigations.  Together, these have been constructed into the ABCDEF Bundle, which was adopted by the SCCM as the foundation of the ICU Liberation collaborative.  This was initially tested in single center studies, then in 6,000 patients at many ICUs in California, subsequently in 15,000 patients at 70 ICUs in the US and Puerto Rico, and most recently in thousands of patients in New York.  These same concepts were also developed and used in IHI Collaboratives over a 5-year period at dozens of international institutions.

The ABCDEF Bundle, which is easier to write merely as the A2F Bundle, is now being implemented, studied and adopted by ICU teams around the world and has been translated into over 20 languages.  Does this mean it’s a total success and adopted by all? Absolutely not.  There are so many human factors and cultural boundaries to change that we must all figure out exactly how we want to accomplish this basic take home about ICU Liberation: What is the most efficient and sustainable way to change the antiquated and harmful culture of deep sedation and immobilization into one of awake and mobile patients spending more time cognitively engaged with their loved ones and able to understand the plan outlined by the ICU team?  Ultimately, what we want is for the world’s sickest patients and their families is to see this goal realized.  As of 2020, by far the most evidence-based way shown to date to accomplish this goal is by achieving your centers “best” at accomplishing the A2F bundle for each and every patient every day they are in the ICU.

It is worthwhile to note that the A2F bundle is also about ushering in a good dying process for those patients who will succumb to their critical illness. The elements in the bundle help navigate towards less suffering for both patients and families and optimizing meaningful time with the people most important to our patients.

There is room for each center to adapt the bundle using the experts in their institution.  No program like this should ever be adopted as a one-shoe-fits-all protocol. Such an approach of PDSA cycles and small tests of change over weeks and months is much more appropriate and successful in changing culture in a sustainable fashion than an “all at once” large roll-out implementation approach. However, it is essential to include the concept that these elements are interdependent and synergistic and thus roll them out as a bundle, even if your current implementation plan focuses on one piece.  That is perhaps the most important lesson learned in the ICU Liberation collaborative.