SCCM Pod-521 CCM: Can ICU Liberation Bundle Compliance Impact Post-Intensive Care Syndrome Rates?

Host Kyle B. Enfield, MD, FCCM, is joined by Daisuke Kawakami, MD, to discuss the Critical Care Medicine article, “Evaluation of the Impact of ABCDEF Bundle Compliance Rates on Postintensive Care Syndrome: A Secondary Analysis Study.” (Kawakami D, et al. Crit Care Med. 2023 Dec;51:1685-1696). The study examines how compliance with the ICU Liberation Bundle (A-F) impacts post-intensive care syndrome and intensive care unit mortality rates. Dr. Kawakami is a physician in the Department of Emergency and Critical Care Medicine at St. Marianna University School of Medicine in Kawasaki, Japan. Learn more about the ICU Liberation Bundle at sccm.org/iculiberation.

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Category: CCM Podcast

Transcript:

Dr. Enfield: Hello, and welcome to the Society of Critical Care Medicine Podcast. I’m your host, Kyle Enfield. Today I’m speaking with Dr. Daisuke Kawakami, MD, about the article, “Evaluation of the Impact of ABCDEF Bundle Compliance Rates on Postintensive Care Syndrome: A Secondary Analysis Study,” published in the December 2023 issue of Critical Care Medicine. To access the full article, visit ccmjournal.org. Dr. Kawakami is a physician in the Department of Intensive Care Medicine at the Aso Iizuka Hospital in Iizuka, Japan, and a research student in the Department of Emergency and Critical Medicine at St. Mariana University School of Medicine in Kawasaki, Japan. Welcome Dr. Kawakami. Before we start, do you have any disclosures to report?

Dr. Kawakami: I have no COI to disclose.

Dr. Enfield: I want to thank you for this article. I really enjoyed reading it and you taking the time to meet with me today. I wanted to start with just an understanding of what prompted your group to perform this study.

Dr. Kawakami: In short, it was my interest in PICS. Working as an ICU physician, I witnessed the various patients passing through. I dedicated myself to saving their lives. However, I started questioning whether they were able to return to their lives safely and what their quality of life was like after leaving the ICU and hospital.

When the concept of PICS emerged, I felt it was the perfect thing for me. While existing research had evaluated cognitive, mental, and physical functions separately, there was a notable gap in understanding the overall prevalence of PICS. I was interested in how many ICU patients actually experienced symptoms of PICS.

Moreover, there were almost no data available from Japan. Additionally, I speculated that cultural differences might influence the prevalence of PICS in Japan and other Asian countries. As the A-F Bundle is recommended for preventing PICS, I saw it as a good opportunity to reassess our own practices and evaluate how widely it is implemented.

Furthermore, there was a lack of research on the relationship between bundle compliance and long-term outcomes. When I met with one of the authors, Professor Fujitani, at the 2018 SCCM Congress in San Antonio, we discussed the possibility of conducting a prospective observational study across multiple facilities. Interestingly, the initiative to start the research actually began not in Japan but in the United States.

Dr. Enfield: I know most of our listeners will know a lot about post-intensive care syndrome, but I wondered if you could start with what was known at the time about PICS and interventions in the ICU.

Dr. Kawakami: A substantial amount of data have been accumulated regarding the prevalence of mobility in three domains of physical, mental, and cognitive functioning. However, there is a wide variety of assessment scales used to measure each of these domains. A systematic review in 2016 pointed out that, out of 425 papers, 250 different assessment scales were used.

While there is no gold standard for diagnosing PICS itself, there has been a gradual movement among researchers to examine the prevalence of PICS while defining it. Studies such as Murray et al in 2016 and Muller et al in 2018 have found the prevalence of PICS to be around 60%. PICS has been recognized as a common condition among ICU patients, and it’s understood that its symptoms can persist over the long term.

For instance, the BRAIN-ICU study in 2013 revealed that 40% of patients with respiratory failure or shock had cognitive function equivalent to moderate traumatic brain injury three months after ICU discharge, and 26% had cognitive function equivalent to mild Alzheimer’s disease. This level of function remained largely unchanged even after 12 months. Furthermore, studies examining the rate of return to work for ICU patients have shown that, although there is a recovery rate of approximately 36% in the first three months, about 60% after six months, there has been no further improvement thereafter.

It’s also been demonstrated that PICS affects not only patients but also the environment status of their family members, indicating significant socioeconomic implications. Efforts have been made to detect and intervene early with PICS through outpatient follow-up but, as evidenced by systematic reviews and meta-analyses, effective intervention methods are not yet clearly understood. This underscores the importance of the concept of prevention in reducing PICS.

In terms of PICS prevention, the ABCDEF Bundle is crucial. This bundle is based on two guidelines, the PADIS guidelines and the family-centered care guidelines from SCCM. The ABCDEF Bundle, along with its predecessor, the ABCDE Bundle, has been shown to reduce ICU and in-hospital mortality, decrease ICU length of stay and duration of mechanical ventilation, lower sedative dose, reduce delirium and the use of restraints, decrease ICU readmission rates, and lower cost. However, these outcomes are all short term. Therefore, we conducted a study focusing on the implementation of the A-to-F Bundle and its association with long-term outcomes.

Dr. Enfield: It’s a great summary of what we’ve learned in the past and some of the outcomes associated and how the A-to-F Bundle impacts them. Are there other reasons that ICU providers should be concerned about PICS?

Dr. Kawakami: There are barriers because there are various causes of PICS. Patient factors, disease-related factors, and interventional environmental factors are the three main categories with physiologic conditions such as delirium, pain, and nutritional status contributing to the development of PICS. While controlling patient and disease-related factors may be challenging, interventional environmental factors in the ICU such as immobility, invasive procedures, light and noise environment, and sedative use can be addressed by ICU providers.

Post-intensive care syndrome, as its name suggests, refers to symptoms occurring after ICU intensive care, but it actually begins during the ICU stay. ICU providers have a duty to prevent PICS through the practice of the A-to-F Bundle. Thinking about PICS is about being aware of the goal of patient care.

ICU providers shouldn’t just focus on saving patients’ lives during their stay. They must also safeguard the patient’s post-ICU life. Being aware of this is crucial. Furthermore, by following up on PICS even after ICU discharge, not only does it serve as a safety net for patients, but it also enhances job satisfaction for ICU providers, prevents burnout, and allows for feedback on daily clinical practice. Making PICS an outcome measure in research will likely become increasingly important in the future.

Dr. Enfield: In this study, you did a secondary analysis of work that you had previously done. Can you tell us a little bit about the first study and why it was performed?

Dr. Kawakami: Our initial study focused on the epidemiology of PICS. Previously there had been few studies examining the overall prevalence of PICS, especially considering the cultural differences between Japan and Asia and the West. Additionally, around 70% of PICS studies didn’t compare against the baseline, which led us to consider evaluating PICS more accurately by comparing it to baseline.

It was a multicenter prospective observational study conducted at 14 centers and 16 ICUs in Japan for six months starting in 2019. The subjects were adult ICU patients expected to be on mechanical ventilation for 40 hours or longer. We conducted surveys via mail regarding PICS at six months post-ICU admission.

Among 947 individuals, cases expected to have primary brain injury or die within 12 to 24 hours, as well as those lacking next of kin, making follow-up difficult, were excluded, leaving 192 subjects for the study. There were 33 in-hospital deaths, which corresponded to about 70% of the total, and 48 deaths at six months, making up around 30% of the total. The survey response rate was 80%, and we analyzed the six-month outcomes of 96 individuals. PICS occurred in 63.5% of cases, with 17.8% of patients experiencing overlapping symptoms in two or more domains.

It is very interesting that all of the studies that looked at the prevalence of PICS were roughly 60%, although there are differences in the scales on which they were measured. Fewer years of education was identified as a risk factor for PICS. Such socioeconomic factors were believed to be associated with baseline conditions, like smoking and exercise habits, as well as diminished utilization of resources during the recovery phase.

Dr. Enfield: That is a great summary of that study, and it sounds like a lot of work to do all that. But implementing bundles like the A-to-F Bundle is also very difficult, and I think it’s important for us to understand how you measured bundle compliance as we interpret these results.

Dr. Kawakami: After admission to the ICU, the bundle compliance rate over the past 24 hours was checked by the intensivist or nurse using a checklist at 8 a.m. on the second, third, and fourth days. This method was used to check bundle compliance for the first three days of ICU admissions. While it is a limitation that bundle compliance was measured only during the first three days, there is a study indicating that higher sedation intensity during the initial 48 hours after ICU admission is associated with increased risk of mortality and delirium as well as prolonged duration of mechanical ventilation.

It was deemed meaningful to check whether the bundle was strictly adhered to during the first three days. The A-to-F Bundle items were divided into a total of 12 items. The average bundle compliance during the first three days was defined as bundle compliance rate.

Dr. Enfield: What did you find when you looked at the correlations between the A-to-F Bundle and long-term outcomes, specifically those PICS outcomes that you’ve been talking about?

Dr. Kawakami: Total bundle compliance rate was 69.8%. The bundle compliance rates for the PICS and non-PICS groups were 71.3% and 69.9%, respectively. Contrary to expectations, no statistically significant difference was found, as the results were similar after adjusting for age, aptitude score, Charlson comorbidity index, and educational level.

Dr. Enfield: I can imagine you guys were a little bit disappointed with those initial findings. What did you find in your secondary outcomes, particularly those findings associated with mortality?

Dr. Kawakami: The bundle compliance rates for the in-hospital mortality and survival groups were 65.8% and 70.6%, respectively, with no statistically significant difference. However, the bundle compliance rates for the 60-month mortality and survival groups were 66.6% and 71.6%, respectively. With higher bundle compliance rates resulting in significantly fewer six-month deaths, a different definition of bundle compliance rate was also examined using the patient-day bundle compliance rate used in the previous study by Pan et al.

Using this definition, a three-day bundle compliance rate measurement would count as three patient days, increasing the number of cases. When examined by patient-day compliance rate, significantly lower bundle compliance rates were found for hospital deaths as well as six-month deaths. These results suggest that bundle compliance may improve the outcome of short- and long-term mortality.

Dr. Enfield: So the PICS assessment here is really important for us to understand. You highlighted the importance of pre-knowledge of patients and post-knowledge of patients. How did you all identify and define PICS in this case?

Dr. Kawakami: We conducted the survey by mailing questionnaires six months later. In case of no response, we followed up with two phone calls to encourage participation. The definition of PICS does not have a gold standard and, for this study, we adapted the definition as I’m about to explain. We defined physical function impairment as a decline of 10 or more from the baseline of the SF-36 physical component score, and mental function impairment as a decline of 10 or more from the baseline of the SF-36 mental component score.

SF-36 is one of the most commonly used scales in PICS research, consisting of 36 questions. From the obtained responses, component summary scores PCS and MCS are calculated. The national standard value is set at 50 points out of 100, with 10 points representing one standard deviation.

In previous studies, a 10-point change has been considered a minimally clinical important difference, and similar results were obtained in our initial study. Additionally, cognitive function was defined as a short memory questionnaire score of less than 40 and deterioration from the baseline. The short memory questionnaire is a dementia screening scale consisting of 14 questions with a maximum score of 46 points. It is notable for being accessible through caregiver input and is similar to the IQCODE scale. We defined PICS as meeting criteria for impairment in any one of physical function, mental function, or cognitive function.

Dr. Enfield: I can imagine a lot of people questioning at this point in time if you think your sample size is part of the reason you didn’t find a significant difference between bundle compliance and PICS prevalence.

Dr. Kawakami: This is a very important point. While there wasn’t significant correlation observed between bundle compliance and PICS, as you rightly point out, the sample size issue is the first possibility. I think there are three other possible causes.

First, I think it is possible that PICS occurred more often in patients who could have survived with bundle compliance. To give a similar example, there is a New England Journal of Medicine study that looked at the effectiveness of cranial decompression or intracranial hypertension in head trauma and found that surgery improved mortality but had a worse neurologic prognosis. Similar reasoning could apply here.

Secondly, the high implementation rates of SAT and SBT in this study could be a factor. Combining SAT and SBT has been found to improve ventilator days and mortality, and it’s considered a strong component of the A-to-F Bundle. Previous studies on bundles have shown SAT and SBT implementation rates of around 30% to 60%. So the high rates in these studies at participating facilities might have made it difficult to observe differences in PICS occurrence.

Thirdly, related to the issue of raw sample size, in the multivariate analysis examining the relationship between bundle compliance and PICS, the inability to include facility differences as variables due to the issue of case numbers could be a factor. When evaluating each facility separately, a strong negative correlation was found between bundle compliance and PICS occurrence, particularly when limited to high-volume centers.

Dr. Enfield: Speaking of high-volume centers, you highlight some significant negative correlations indicating that there was a trend toward lower PICS and higher compliance in those centers with higher volumes of patients.

Dr. Kawakami: Due to the issue of low case numbers, we didn’t include facilities as variables in the multivariate analysis. Instead, we separately examined the association between bundle compliance rates and PICS occurrence of each facility. In facilities with low case numbers, both bundle compliance rate and PICS occurrence rate can take extremely high or low values, making it a challenge to draw meaningful conclusions. Therefore, we categorized facilities with bundle evaluation counts of 10 or more and PICS evaluation counts of five or more as high-volume centers. We restricted our analysis to these facilities.

The rationale behind these numbers was that average bundle measurement count for facilities was 11 and the PICS evaluation count was six. Hence, facilities with case numbers exceeding 10 and five, respectively, were classified as high-volume centers. When restricted to high-volume centers, we observed a strong negative correlation between facilities’ basic bundle compliance rates and PICS occurrence rates. Higher bundle compliance rates in facilities were associated with lower incidence of PICS.

Dr. Enfield: Of all these findings, what surprised you?

Dr. Kawakami: Even though we did not find a statistically significant association between bundle compliance and PICS, it’s interesting that facilities with higher bundle compliance rates tend to have lower incidence of PICS. This suggests that, while we can’t definitively say that bundle compliance directly impacts PICS, it could imply that facilities adhering to recommended practice, such as the A-to-F Bundle outlined in guidelines, are achieving better outcomes.

Dr. Enfield: As you look back at this study, what do you see as the key takeaways for our listeners today?

Dr. Kawakami: In this study, there was suggestive evidence that the A-to-F Bundle could improve long-term outcomes. In the field of quality of medical care, the Donabedian model, which divides quality into structure, process, and outcomes, is well known. The A-to-F Bundle falls under the process category. By implementing and benchmarking compliance rates of the ABCDEF Bundle, we can observe and strive for high-quality healthcare delivery. It’s crucial for ICU staff to focus on the long-term prognosis of ICU patients and to prevent PICS.

Dr. Enfield: Dr. Kawakami, I want to thank you for getting up early this morning to record with me. I know that our listeners will appreciate you really diving into this article, which had a lot to unpack, and for your team and all the work that you guys did to give us more information on how the A-to-F Bundle is improving outcomes for our patients. I think it’ll open up several questions that people are going to want to do research on in the future. This concludes another episode of the Society of Critical Care Medicine Podcast. If you’re listening on your favorite podcast app and liked what you heard, consider rating and leaving a review. For the Society of Critical Care Medicine Podcast, I’m Kyle Enfield.

Announcer: Kyle B. Enfield, MD, is an associate professor of medicine in the Division of Pulmonary and Critical Care at the University of Virginia. He received his undergraduate degree from the University of Oklahoma.

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