Skip Navigation LinksHome > May 2014 - Volume 42 - Issue 5 > Effectiveness and Safety of the Awakening and Breathing Coor...
Critical Care Medicine:
doi: 10.1097/CCM.0000000000000129
Feature Articles

Effectiveness and Safety of the Awakening and Breathing Coordination, Delirium Monitoring/Management, and Early Exercise/Mobility Bundle*

Balas, Michele C. PhD, RN, APRN-NP, CCRN1; Vasilevskis, Eduard E. MD, MPH2,3,4; Olsen, Keith M. PharmD, FCCP, FCCM5,6; Schmid, Kendra K. PhD7; Shostrom, Valerie MS7; Cohen, Marlene Z. PhD, RN, FAAN8; Peitz, Gregory PharmD, BCPS5,6; Gannon, David E. MD, FACP, FCCP9; Sisson, Joseph MD9; Sullivan, James MD10; Stothert, Joseph C. MD, PhD, FCCM, FACS11; Lazure, Julie BSN, RN12; Nuss, Suzanne L. PhD, RN13; Jawa, Randeep S. MD, FACS, FCCM11; Freihaut, Frank RRT14; Ely, E. Wesley MD, MPH, FCCM3,4,15; Burke, William J. MD16

Free Access
Supplemental Author Material
Article Outline
Collapse Box

Author Information

1Center for Critical and Complex Care, The Ohio State University, College of Nursing, Columbus, OH.

2Department of Medicine, Division of General Internal Medicine and Public Health, Section of Hospital Medicine, Vanderbilt University, Nashville, TN.

3Center for Health Services Research, Vanderbilt University, Nashville, TN.

4Geriatric Research, Education, and Clinical Center, Tennessee Valley VA, Nashville, TN.

5Department of Pharmacy Practice, University of Nebraska Medical Center, College of Pharmacy, Omaha, NE.

6Department of Pharmaceutical and Nutrition Care, The Nebraska Medical Center, Omaha, NE.

7Department of Biostatistics, University of Nebraska Medical Center, College of Public Health, Omaha, NE.

8Department of Adult Health and Illness, University of Nebraska Medical Center, College of Nursing, Omaha, NE.

9Division of Pulmonary, Critical Care, Sleep, and Allergy, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE.

10Department of Anesthesiology, University of Nebraska Medical Center, Omaha, NE.

11Department of Surgery, University of Nebraska Medical Center, Omaha, NE.

12Department of Adult Critical Care Services, The Nebraska Medical Center, Omaha, NE.

13Department of Nursing Research and Quality Outcomes, The Nebraska Medical Center, Omaha, NE.

14Department of Respiratory Care, The Nebraska Medical Center, Omaha, NE.

15Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University, Nashville, TN.

16Department of Psychiatry, University of Nebraska Medical Center, Omaha, NE.


See also p. 1280.

The work was performed at The Nebraska Medical Center.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (

Supported, in part, by the Robert Wood Johnson Foundation Interdisciplinary Nursing Quality Research Initiative and by the National Institute on Aging of the National Institutes of Health (NIH) under award number K23AG040157. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

Dr. Balas is currently a co-investigator on a grant supported by the Alzheimer’s Association and has received honoraria from ProCe, the France Foundation, Hospira, and Hillrom. She received support for article research from the Robert Wood Johnson Foundation (RWJF) Interdisciplinary Nursing Quality Research Initiative (INQRI). Her institution received grant support from the RWJF INQRI and the Alzheimer’s Association (Co-I on mobile monitoring study). Dr. Vasilevskis is currently receiving a Career Development Award from the National Institutes of Health (NIH)-National Institute on Aging (NIA) (5K23AG040157) and received grant support for article research from NIH. Dr. Olsen received support for article research from the RWJF. His institution received grant support from the RWJF (supported, in part, the research related to this manuscript). Dr. Schmid serves as a consultant on the data safety and monitoring board (DSMB) for Puma Biotechnology and, in the past, served as a DSMB consultant for Pfizer and received support for article research from the RWJF. Her institution received grant support from the RWJF INQRI. Dr. Cohen received support for article research from the RWJF. Her institution received grant support from the RWJF. Dr. Sisson is currently receiving a NIH Grant (AA008769-20A1). Dr. Sullivan received support for article research from the RWJF. Dr. Jawa has disclosed that this study was supported by a grant from the RWJF INQRI, but he did not receive any compensation from this grant. Dr. Ely received support from NIA AG-027472 and AG-035117, and he has received honoraria from Hospira, Abbott, and Orion. He consulted for Cumberland and Masimo, received grant support from Lilly, and lectured for Hospira. Dr. Burke has received grant support for clinical studies from the National Institute of Mental Health, NIA, RWJF, Alzheimer Disease Cooperative Studies (ADCS), Forest Laboratories, Astra Zeneca, Vanda Pharmaceuticals, Neosync, Elan/Wyeth/Janssen, Baxter Health Care Corporation, Pfizer, Noven Pharmaceuticals, and Novartis. His institution received support for travel (funds to attend INQRI annual meeting) from the RWJF and grant support from the RWJF (for the research), National Institute of Mental Health (NIMH) (R01 funding), ADCS in collaboration with NIMH and Baxter (grant funds), Pfizer (clinical trial funding), Neosync (clinical trial funding), Vanda Pharmaceuticals (clinical trial funding), Novartis (clinical trial funding), Elan/Wyeth (clinical trial funding), Noven Pharmaceuticals (clinical trial funding), Astra Zeneca (clinical trial funding), and Elan (clinical trial funding). The remaining authors have disclosed that they do not have any potential conflicts of interest.

For information regarding this article, E-mail:

Collapse Box



The debilitating and persistent effects of ICU-acquired delirium and weakness warrant testing of prevention strategies. The purpose of this study was to evaluate the effectiveness and safety of implementing the Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle into everyday practice.


Eighteen-month, prospective, cohort, before-after study conducted between November 2010 and May 2012.


Five adult ICUs, one step-down unit, and one oncology/hematology special care unit located in a 624-bed tertiary medical center.


Two hundred ninety-six patients (146 prebundle and 150 postbundle implementation), who are 19 years old or older, managed by the institutions’ medical or surgical critical care service.


Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle.

Measurements and Main Results:

For mechanically ventilated patients (n = 187), we examined the association between bundle implementation and ventilator-free days. For all patients, we used regression models to quantify the relationship between Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle implementation and the prevalence/duration of delirium and coma, early mobilization, mortality, time to discharge, and change in residence. Safety outcomes and bundle adherence were monitored. Patients in the postimplementation period spent three more days breathing without mechanical assistance than did those in the preimplementation period (median [interquartile range], 24 [7–26] vs 21 [0–25]; p = 0.04). After adjusting for age, sex, severity of illness, comorbidity, and mechanical ventilation status, patients managed with the Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle experienced a near halving of the odds of delirium (odds ratio, 0.55; 95% CI, 0.33–0.93; p = 0.03) and increased odds of mobilizing out of bed at least once during an ICU stay (odds ratio, 2.11; 95% CI, 1.29–3.45; p = 0.003). No significant differences were noted in self-extubation or reintubation rates.


Critically ill patients managed with the Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle spent three more days breathing without assistance, experienced less delirium, and were more likely to be mobilized during their ICU stay than patients treated with usual care.

Growing evidence suggests that there is an iatrogenic component to ICU practice that influences critically ill patients’ likelihood of experiencing ICU-acquired delirium and weakness. These comorbidities are common in adult critically ill patients (1–7) and independently predict increased mortality (1, 8–11), mechanical ventilator days (5, 10–12), ICU length of stay (12–14), and use of continuous sedation and physical restraints (15, 16). The effects of both conditions are often persistent and include functional decline (17) and long-term cognitive impairment (18). Strategies are needed to prevent and/or treat ICU-acquired delirium and weakness.

Mechanical ventilation, sedative medications, and immobilization are known risk factors for ICU-acquired delirium and weakness (6, 7, 19). When these factors interact with other known predisposing factors, the likelihood of developing delirium and weakness rises (6, 7, 20). Multicomponent approaches targeted to modifiable risk factors have effectively prevented delirium among older hospitalized medical patients (21). Such multifaceted interventions, however, are understudied in the ICU setting.

A multicomponent liberation and animation strategy aimed at reducing delirium and weakness has recently been proposed (22–25). Liberation refers to reducing exposure to mechanical ventilation and sedative medications through use of coordinated, target-based sedation protocols, spontaneous awakening trials (SATs) (26), and spontaneous breathing trials (SBTs) (27). Animation refers to early mobilization, which reduces delirium (28–30). This evidence-based strategy is referred to as the “Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility” (ABCDE) bundle (22–25).

A bundle is a small set of evidence-based practices that, when performed collectively and reliably, have been proven to improve patient outcomes (31). Bundles are used in the ICU setting to address a number of serious iatrogenic conditions (e.g., ventilator-associated pneumonia and central catheter infections). The use of bundles, as suggested in the study by Barr et al (32), may be similarly beneficial for developing patient-centered protocols for preventing and treating PAD in critically ill patients.

Although many ABCDE bundle components improved important clinical outcomes in rigorously designed randomized controlled trials (RCTs), most of these RCTs evaluated the safety and efficacy of these interventions in isolation, excluded many important ICU populations, and generally relied on research staff to implement the intervention. Additionally, the evidence supporting both the ABCDE bundle and the new PAD guideline recommendations was based predominately on data derived from RCTs in mechanically ventilated patients. Given these circumstances, there is great interest on the part of ICU clinicians to know if the ABCDE approach will improve patient outcomes and which patients the bundle should be applied to (e.g., intubated vs nonintubated patients). These are relevant questions considering that the vast majority of ICU patients are not mechanically ventilated (33).

This study was designed to better understand these important aspects of the ABCDE management strategy. Our goal was to determine if implementing the ABCDE components as a bundle would prove safe and effective if applied to every critically ill patient, every day, regardless of mechanical ventilation status, as well as to identify successes and pitfalls in bundle implementation. Some results of this study have been previously reported in abstract form (34–36).

Back to Top | Article Outline


Additional information about the methods is provided in the online supplement (Supplemental Digital Content 1,

Back to Top | Article Outline
Overview of Study Development and Adoption of ABCDE Bundle Policy

We recently described in detail our experience implementing the ABCDE management strategy into everyday practice (37). In brief, over an 18-month period, members of the research team and study site collaborated on the development of an institutional ABCDE bundle policy and numerous ABCDE bundle-related educational opportunities (Table E1, Supplemental Digital Content 1, The ABCDE bundle was officially implemented on October 3, 2011.

Back to Top | Article Outline
Usual Care (Pre-ABCDE Bundle Implementation)

Prior to ABCDE bundle implementation, clinicians at the participating institution had some experience with SATs and SBTs. The performance of both procedures, however, was inconsistent and identified as a needed area of quality improvement. There were no official policies in place to guide the SAT or SBT process (e.g., no checks to see if it was safe to perform a SAT or SBT, no guidance as to what defined success or failure). Additionally, SATs and SBTs were rarely coordinated and interprofessional rounding depended on the individual ICU physicians’ practice. No delirium monitoring or management policies were in place. One ICU was in the beginning phase of an early mobility program, but patients were not routinely assisted out of bed in the ICU setting.

Back to Top | Article Outline
ABCDE Bundle Intervention (Post-ABCDE Bundle Implementation)

In the postimplementation period, the stated institutional policy was that the ABCDE bundle was to be applied to every adult patient receiving ICU level of care. All patients were to receive the intervention on a daily basis unless a licensed prescriber wrote an order not to have the patient participate in certain components of the ABCDE bundle (opt-out method). The five distinct components of the ABCDE bundle, along with safety screen and success failure criteria used in this study, are provided in Figure 1 and Table 1.

Image Tools
Figure 1.
Figure 1.
Image Tools
Back to Top | Article Outline
Study Design, Setting, and Participants

This prospective before-after study was conducted at a 624-bed tertiary medical center. Eligible patients included adult patients (≥ 19 yr old) admitted to the institution’s medical or surgical critical care service, regardless of mechanical ventilation status. Critically ill patients were recruited consecutively from five adult ICUs, one step down unit, and an oncology/hematology special care unit. Patients were excluded if they did not have a legally authorized representative (LAR) to provide consent within 48 hours of ICU admission. “Pre” patients were enrolled from February to October 2011 and received “usual care.” “Post” patients were enrolled from October 2011 to April 2012. The institutional review board approved the study protocol, and written informed consent was obtained from all patients’ LAR.

Back to Top | Article Outline
Study Procedures

To ensure reliability of outcomes assessment in the pre- and postimplementation period, trained research personnel (all registered nurses [RNs]) were hired to enroll patients, perform daily sedation/agitation and delirium assessments, and conduct standardized medical record reviews. Interrater reliability checks for delirium and sedation/agitation screenings were 100% for all four research personnel. The research personnel had no role in administering any parts of the ABCDE bundle. The decision to perform daily SATs, SBTs, delirium monitoring/management, and early exercise/mobility was made solely by the ICU team.

At enrollment, we collected demographic data, admission source, and primary diagnosis. Severity of illness and comorbidity were measured by the Acute Physiology and Chronic Health Evaluation II (APACHE II) (38) score and Charlson Comorbidity Index (39), respectively. We recorded the cumulative amount of sedative medications administered from ICU admission until study enrollment, including operating room, postanesthesia care unit, and procedural sedation.

Back to Top | Article Outline
Awakening and Breathing Coordination.

We recorded daily the total 24-hour dose of sedative medications as we did at study enrollment. If a patient received a continuous infusion of sedative medications and/or mechanical ventilation within the preceding 24-hour period, we recorded whether that patient received a SAT/SBT and the documented reasons for safety screen or trial failure. We recorded the date and time of intubation and extubation, any unplanned extubations, reintubations, new tracheostomies, and any hospital discharges on mechanical ventilation.

Back to Top | Article Outline
Delirium Monitoring/Management.

The patients’ level of arousal was assessed daily by research personnel with the Richmond Agitation-Sedation Scale (RASS) (40, 41). Subjects with a RASS score of –3 or higher underwent delirium screening with the Confusion Assessment Method for the ICU (CAM-ICU) (2, 42). If the subject was unavailable, additional attempts were made to evaluate their neurologic status that day. We also recorded the results of the ICU clinicians’ every 8-hour CAM-ICU and RASS assessments.

Back to Top | Article Outline
Early Exercise/Mobility.

We recorded daily whether patients received physical therapy consultation and if they were mobilized out of bed anytime in the previous 24 hours.

Back to Top | Article Outline
Outcome Definitions

Our primary outcome for mechanically ventilated patients was ventilator-free days (VFDs). We defined VFDs as the number of days patients were breathing without mechanical ventilator assistance during a 28-day period which began at the time of study enrollment. A period of unassisted breathing began with extubation (or removal of mechanical ventilation support for patients with tracheostomies) if the period of unassisted breathing lasted at least 48 consecutive hours. Patients who died during the study period were assigned 0 VFDs.

We secondarily examined outcomes across the entire ICU population (i.e., mechanically ventilated and nonmechanically ventilated patients), including the prevalence, duration, and percent of ICU days of delirium and coma. Duration of delirium was defined as the number of ICU days in which patients were CAM-ICU-positive and not comatose. Duration of coma was defined as the number of ICU days that patients had a RASS score of –4 or –5. We additionally explored the number of patients mobilized out of bed during their ICU stay. Finally, we examined 28-day ICU and total hospital mortality, time to discharge from the ICU and hospital, and the number of patients who experienced a change in residence. Change in residence was defined as discharge from the hospital to a place other than home in subjects residing at home prior to admission. Unplanned extubations, reintubations, tracheostomy placement, percent of ICU time in physical restraints, and the use of imaging for “changes in mental status” were tracked as safety endpoints. Reintubation was defined as a second intubation that occurred during the patient’s initial ICU stay.

Back to Top | Article Outline
Statistical Analysis

Demographic and clinical characteristics were compared between both sets of subjects and by mechanical ventilation status. Mean and sd (median and interquartile range [IQR] for skewed distributions) or frequencies and percentages are presented for continuous or categorical variables, respectively. Initial comparisons between pre and post groups were made using t tests (or Wilcoxon test) for continuous variables, chi-square test (or Fisher exact test) for categorical variables, and log-rank tests for time-to-event variables. Differences in outcomes between pre and post groups were analyzed after adjusting for age, sex, mechanical ventilation status, APACHE II, and Charlson Comorbidity Index using logistic regression for binary outcomes and Cox regression for time-to-event outcomes. SAS version 9.2 (SAS Institute, Inc. Cary, NC) was used for all summaries and analyses. The statistical level of significance was set at less than 0.05 (two-sided α).

Back to Top | Article Outline


Patient Characteristics

A total of 146 patients were enrolled before ABCDE bundle implementation (“pre” group) and 150 after implementation (“post” group) (Fig. 2). Patients in the preimplementation phase were older (pre-age mean 59.2 ± 16.1 vs post-age mean 55.6 ± 14.9; p = 0.05), but otherwise they shared similar baseline characteristics to patients in the postimplementation period (Table 2). Patients in both groups were lightly sedated at the time of study enrollment (median RASS score of –1) and received similar doses and types of sedative medications prior to study enrollment. Patients were admitted to the ICUs with a variety of medical and surgical diagnoses, with more than 40% of the sample having surgery on or during their ICU admission. When we examined baseline characteristics by mechanical ventilation status, no significant differences between pre- and postimplementation groups were noted (Table E2, Supplemental Digital Content 1,

Image Tools
Figure 2.
Figure 2.
Image Tools
Back to Top | Article Outline
Outcome Effectiveness

Mechanically ventilated patients in postimplementation group spent more days breathing without mechanical ventilator assistance than those in preimplementation group (pre-median 21 d [IQR, 0–25] vs post-median 24 d [IQR, 7–26]; p = 0.04) (Table 3). Three patients in the postimplementation and five in the preimplementation period were discharged from the hospital on mechanical ventilation (p = 0.50).

Image Tools

Fewer patients treated with the ABCDE bundle experienced delirium (pre 62.3% vs post 48.7%; p = 0.02) (Table 3). Delirium duration was reduced by 1 day in the postimplementation period, and the percent of ICU days spent delirious decreased by 17% (pre 50% [IQR, 30–64.3] vs post 33.3% [IQR, 18.8–50]; p = 0.003). After adjusting for age, APACHE II score, sex, Charlson Comorbidity Index, and mechanical ventilation, there continued to be a significant effect of the ABCDE bundle on prevalence of delirium (p = 0.03), and the odds of delirium were reduced by almost half (odds ratio, 0.55; 95% CI, 0.33–0.93). No significant difference was noted in coma prevalence, coma duration, percentage of ICU days spent in coma, or mean RASS score between the pre- and postimplementation period in unadjusted or adjusted analyses.

Following multivariable adjustment, a significant effect of the ABCDE bundle was observed on the percentage of patients (pre 48% vs post 66%; p = 0.002) who were mobilized during their ICU stay. Patients treated with the ABCDE bundle had twice the odds (95% CI, 1.30–3.45; p = 0.003) of mobilizing out of bed at least once during their ICU stay compared with patients in the ICU prior to bundle implementation (Table 3).

Unadjusted hospital mortality was significantly lower in the postimplementation group (p = 0.04), while ICU mortality showed a nonstatistically significant reduction (p = 0.07). The hospital mortality rate was 19.9% in the preimplementation period versus 11.3% in the postimplementation period, yielding an odds ratio of 0.56 (95% CI, 0.28–1.10; p = 0.09) after adjustment for age, APACHE II score, sex, and comorbidity (Table 3).

No significant difference was observed in the time to ICU or hospital discharge between the pre- and postimplementation periods (Table 3). Few ICU patients who were admitted from home returned to this setting at hospital discharge in either the pre- or postimplementation period. No significant differences, however, were noted in change in residence in either the unadjusted or adjusted analysis.

Back to Top | Article Outline
Outcome Safety

No significant differences were found in unplanned extubations, reintubation rates, tracheostomy placements, percent time spent in physical restraints, or the use of imaging for mental status changes pre- versus post-ABCDE bundle implementation (Table 4).

Image Tools
Back to Top | Article Outline
ABCDE Bundle Compliance and Sedative Medication Use

Most patients requiring mechanical ventilation received a continuous infusion of either sedative or opioid medications sometime during their ICU stay (pre 77.4% vs post 70.2%, p = 0.26) (Table 5). Post-ABCDE bundle implementation, there was a significant increase in the number of patients who had their continuously infused sedative medication held at least once for a SAT (pre 53% vs post 71%; p = 0.04). The percentage of ICU days on which patients received a SAT while on a continuously infused opioid medication also doubled in the postimplementation period (pre 25% vs post 50%; p = 0.001). Patients in the postimplementation period were significantly more likely to undergo a SBT at least once during their ICU stay (pre 71% vs post 84%; p = 0.03). In the postimplementation period, clinicians documented a variety of reasons for not performing both SATs and SBTs (Table E3, Supplemental Digital Content 1,

Image Tools

Although there was a trend toward decreased benzodiazepine use and increased opiate use in the postintervention period, the number of patients treated and total average daily doses of these medications did not differ significantly in pre- and postimplementation (Table 6). CAM-ICU and RASS score were documented in the postimplementation period every 8 hours by bedside nurses 50% and 68% of the time, respectively (Table 6). Delirium was identified as present by bedside nurses in 51% of patients in the postimplementation period. Although nearly two thirds of the patients received a physical therapy consultation while they were in the ICU, approximately one third of ICU days were spent out of bed.

Image Tools
Back to Top | Article Outline


We explored the effectiveness and safety of implementing into everyday clinical care an interprofessional, multicomponent, bundle of evidence-based interventions directed at reducing the harmful effects of oversedation, mechanical ventilation, and immobility. In this prospective before-after study, implementation of the ABCDE bundle resulted in patients spending an additional 3 days breathing without mechanical ventilator assistance compared with patients treated with usual care. After adjusting for important covariates, the ABCDE bundle was found to be an important independent predictor of reduced delirium rates and increased likelihood of mobilizing out of bed. Implementation of the ABCDE bundle was also found to be safe and well tolerated. These efficacy and safety findings were present despite a lower than anticipated compliance with the ABCDE bundle.

Our results are consistent with RCTs that studied the individual components of the ABCDE bundle. Girard et al (43) found that a ventilator liberation strategy pairing daily SATs and SBTs resulted in three more VFDs and less time in coma compared with usual care consisting of daily SBTs and patient-targeted sedation. We found a similar reduction in VFDs but not in coma days. This may be due to deeper sedation levels at enrollment in the study by Girard et al (43) (RASS of –4 compared with RASS of –1). Our findings are also consistent with randomized trial evidence from Schweickert et al (30) that found a rehabilitation strategy consisting of SATs and physical and occupational therapy resulted in more VFDs and shorter duration of delirium for mechanically ventilated patients who were functionally independent prior to hospitalization.

In the current and previous investigations (30, 43), improvements in outcomes occurred despite the fact that the overall number of patients treated with sedative and opioid medications did not significantly differ between groups. This suggests (but does not prove) the potential benefit from the “act” of awakening. This awakening strategy ensures a period of maximum wakefulness that may mitigate harm through a variety of potential mechanisms. For example, daily awakenings may reduce the risks of prolonged deep sedation (44), provide beneficial effects of higher peak stimulations (45), and/or allow for patients to engage in physical and cognitive activity (46) that may be independently protective. It is equally plausible that observed improvements were due to other factors such as active care coordination or more intense delirium monitoring.

Despite intense education regarding the hazards of continuously infused sedation, more than two thirds of the patients in the current study were treated with this sedation strategy. Although clinicians in this study were more likely to discontinue sedative drips for a SAT after ABCDE bundle implementation, there was no difference in SAT performance for patients receiving opioid infusions, suggesting that clinicians may not view opioids as potentially harmful, or alternatively, believe the need for pain medication outweighs the need to discontinue sedation.

Similarly, despite the known benefits of early mobilization in mechanically ventilated patients (28–30), patients spent more than 65% of their ICU days in bed. This finding may be due to a number of factors, including the method by which early mobilization was conducted (i.e., primarily by ICU RNs without additional staffing), the patients to which it was applied (i.e., prehospitalization functional status not considered), and the outcomes that were used to evaluate effectiveness. Patient outcomes, however, were significantly improved despite lower-than-desired bundle adherence. Therefore, the current study may underrepresent the potential impact with ABCDE bundle implementation, considering that we did not reach the goal of “applying it to every patient every day.” This also highlights the need for rigorously designed research to understand best practices for applying evidence to the bedside.

A major strength of this study was the daily assessment of patients’ sedation/agitation level and delirium status by trained study staff using valid and reliable screening instruments. Enhancing the applicability and feasibility for other ICUs, this study also included the results of bedside RNs’ assessment of sedation levels and delirium status, demonstrating good agreement between clinician and research personnel. In contrast to previous RCTs, our study had few exclusion criteria. We included a diverse patient population (e.g., intubated and nonintubated) and relied on clinicians to implement the interventions and monitor the patients, suggesting that the ABCDE bundle could be applied widely across ICUs. We also followed adherence to the individual components of the ABCDE bundle, critical to understanding effectiveness trial results. Finally, study focus was on knowledge translation, or applying research findings into everyday practice, an important yet understudied subject area in critical care.

There are several important limitations to this investigation. Because of the study’s design, relatively small sample size, and the fact that there was a delay in study enrollment until consent was obtained, our results are susceptible to both temporal changes and the impact of important unbalanced (or missing) confounders not included in our multivariable adjustment. The fact that most ABCDE bundle-related educational efforts took place during the preimplementation period may have also influenced study findings. Although we attempted to track the number of patients who received individual components of the ABCDE bundle each day, we were unable to determine the cause of coma (i.e., structural or drug-induced) and relied on medical record reviews, which limited our ability to determine definitively the reasons for withholding specific interventions. This was particularly true in the preimplementation period, when there were no SAT or SBT safety screen criteria. Finally, we also did not follow pain levels using a valid and reliable tool as suggested in the new PAD guidelines. These limitations, in balance with the observed intervention benefit, suggest the value of confirmative trials.

Although we followed a number of important effectiveness and safety outcomes, some applied to only to a segment of the ICU population (e.g., VFDs to mechanically ventilated patients), whereas others could be interpreted as either an outcome or compliance measure (e.g., mobilized out of bed anytime). Future studies would be strengthened by the use of a validated functional outcome measure. We also did not explore the role that specific sedative medications had on patient outcomes, but this is an appropriate direction for future analysis. Finally, it is important to reiterate that nearly all the evidence supporting the ABCDE bundle (and new PAD guidelines) was derived from RCTs that included only mechanically ventilated patients. Our inclusion of nonintubated patients extrapolated evidence derived from one population (mechanically ventilated patients) to a population less well studied (nonmechanically ventilated patients). Although we found benefits and no obvious harm applying the ABCDE bundle to nonintubated patients, we believe that individual ICUs should explore their own epidemiology/patient mix, culture, and staffing levels before they decide whether to apply the ABCDE bundle to their entire ICU population. Our data also suggest that RCTs may be warranted in nonmechanically ventilated patients to strengthen the PAD evidence base.

Back to Top | Article Outline


This prospective study explored the effectiveness and safety of the ABCDE bundle, an evidence-based, interprofessional, multicomponent ICU management strategy that promotes early liberation and animation of critically ill patients. In a diverse group of critically ill patients, implementation of the ABCDE bundle resulted in reduced time on the ventilator, less delirium, and more time spent out of bed compared with patients not treated with the bundle. These improvements were achieved despite little difference in medication exposure and incomplete bundle adherence. The ABCDE bundle appears to be a valuable tool in the management of critically ill patients.

Back to Top | Article Outline


We are grateful for all the support provided by nurses, respiratory therapists, pharmacists, physical therapists, physicians, and administrative leadership at the Nebraska Medical Center. We are also deeply appreciative of the patients, families, and research staff who made this study possible.

Back to Top | Article Outline


1. Ely EW, Shintani A, Truman B, et al. Delirium as a predictor of mortality in mechanically ventilated patients in the intensive care unit. JAMA. 2004; 291:1753–1762

2. Ely EW, Inouye SK, Bernard GR, et al. Delirium in mechanically ventilated patients: Validity and reliability of the confusion assessment method for the intensive care unit (CAM-ICU). JAMA. 2001; 286:2703–2710

3. Witt NJ, Zochodne DW, Bolton CF, et al. Peripheral nerve function in sepsis and multiple organ failure. Chest. 1991; 99:176–184

4. Berek K, Margreiter J, Willeit J, et al. Polyneuropathies in critically ill patients: A prospective evaluation. Intensive Care Med. 1996; 22:849–855

5. De Jonghe B, Bastuji-Garin S, Sharshar T, et al. Does ICU-acquired paresis lengthen weaning from mechanical ventilation? Intensive Care Med. 2004; 30:1117–1121

6. Mendez-Tellez PA, Needham DM. Early physical rehabilitation in the ICU and ventilator liberation. Respir Care. 2012; 57:1663–1669

7. Schweickert WD, Hall J. ICU-acquired weakness. Chest. 2007; 131:1541–1549

8. Lin SM, Liu CY, Wang CH, et al. The impact of delirium on the survival of mechanically ventilated patients. Crit Care Med. 2004; 32:2254–2259

9. Pisani MA, Kong SY, Kasl SV, et al. Days of delirium are associated with 1-year mortality in an older intensive care unit population. Am J Respir Crit Care Med. 2009; 180:1092–1097

10. Shehabi Y, Riker RR, Bokesch PM, et al. SEDCOM (Safety and Efficacy of Dexmedetomidine Compared With Midazolam) Study Group Delirium duration and mortality in lightly sedated, mechanically ventilated intensive care patients. Crit Care Med. 2010; 38:2311–2318

11. Garnacho-Montero J, Madrazo-Osuna J, García-Garmendia JL, et al. Critical illness polyneuropathy: Risk factors and clinical consequences. A cohort study in septic patients. Intensive Care Med. 2001; 27:1288–1296

12. Lat I, McMillian W, Taylor S, et al. The impact of delirium on clinical outcomes in mechanically ventilated surgical and trauma patients. Crit Care Med. 2009; 37:1898–1905

13. Thomason JW, Shintani A, Peterson JF, et al. Intensive care unit delirium is an independent predictor of longer hospital stay: A prospective analysis of 261 non-ventilated patients. Crit Care. 2005; 9:R375–R381

14. Ely EW, Gautam S, Margolin R, et al. The impact of delirium in the intensive care unit on hospital length of stay. Intensive Care Med. 2001; 27:1892–1900

15. Micek ST, Anand NJ, Laible BR, et al. Delirium as detected by the CAM-ICU predicts restraint use among mechanically ventilated medical patients. Crit Care Med. 2005; 33:1260–1265

16. Van Rompaey B, Elseviers MM, Schuurmans MJ, et al. Risk factors for delirium in intensive care patients: A prospective cohort study. Crit Care. 2009; 13:R77

17. Balas MC, Happ MB, Yang W, et al. Outcomes associated with delirium in older patients in surgical ICUs. Chest. 2009; 135:18–25

18. Girard TD, Jackson JC, Pandharipande PP, et al. Delirium as a predictor of long-term cognitive impairment in survivors of critical illness. Crit Care Med. 2010; 38:1513–1520

19. Girard TD, Pandharipande PP, Ely EW. Delirium in the intensive care unit. Crit Care. 2008; 12:(Suppl 3)S3

20. Inouye SK. Predisposing and precipitating factors for delirium in hospitalized older patients. Dement Geriatr Cogn Disord. 1999; 10:393–400

21. Inouye SK, Bogardus ST Jr, Charpentier PA, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. N Engl J Med. 1999; 340:669–676

22. Morandi A, Brummel NE, Ely EW. Sedation, delirium and mechanical ventilation: The ‘ABCDE’ approach. Curr Opin Crit Care. 2011; 17:43–49

23. Vasilevskis EE, Ely EW, Speroff T, et al. Reducing iatrogenic risks: ICU-acquired delirium and weakness–crossing the quality chasm. Chest. 2010; 138:1224–1233

24. Vasilevskis EE, Pandharipande PP, Girard TD, et al. A screening, prevention, and restoration model for saving the injured brain in intensive care unit survivors. Crit Care Med. 2010; 38:S683–S691

25. Balas MC, Vasilevskis EE, Burke WJ, et al. Critical care nurses’ role in implementing the “ABCDE bundle” into practice. Crit Care Nurse. 2012; 32:35–38, 40–47; quiz 48

26. Kress JP, Pohlman AS, O’Connor MF, et al. Daily interruption of sedative infusions in critically ill patients undergoing mechanical ventilation. N Engl J Med. 2000; 342:1471–1477

27. Ely EW, Baker AM, Dunagan DP, et al. Effect on the duration of mechanical ventilation of identifying patients capable of breathing spontaneously. N Engl J Med. 1996; 335:1864–1869

28. Needham DM, Korupolu R, Zanni JM, et al. Early physical medicine and rehabilitation for patients with acute respiratory failure: A quality improvement project. Arch Phys Med Rehabil. 2010; 91:536–542

29. Needham DM. Mobilizing patients in the intensive care unit: Improving neuromuscular weakness and physical function. JAMA. 2008; 300:1685–1690

30. Schweickert WD, Pohlman MC, Pohlman AS, et al. Early physical and occupational therapy in mechanically ventilated, critically ill patients: A randomised controlled trial. Lancet. 2009; 373:1874–1882

31. Resar R, Pronovost P, Haraden C, et al. Using a bundle approach to improve ventilator care processes and reduce ventilator-associated pneumonia. Jt Comm J Qual Patient Saf. 2005; 31:243–248

32. Barr J, Fraser GL, Puntillo K, et al. American College of Critical Care Medicine Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit. Crit Care Med. 2013; 41:263–306

33. Wunsch H, Wagner J, Herlim M, et al. ICU occupancy and mechanical ventilator use in the United States. Crit Care Med. 2013; 41:2712–2719

34. Balas M, Olsen K, Gannon D, et al. Safety and efficacy of the ABCDE bundle in critically-ill patients receiving mechanical ventilation. Crit Care Med. 2012; 40:(12S)1–328

35. Olsen K, Burke W, Peitz G, et al. The ABCDE bundle reduces the incidence of delirium in non-mechanically ventilated patients. Crit Care Med. 2012; 40:(12S)1–328

36. Jawa RS, Thorell W, Stothert J, et al. Delirium is prevalent in the ICU: A call for implementation of evidence-based guidelines. Paper presented at American Association for the Surgery of Trauma Meeting 2012 Kauai, HI

37. Balas MC, Burke WJ, Gannon D, et al. Implementing the awakening and breathing coordination, delirium monitoring/management, and early exercise/mobility bundle into everyday care: Opportunities, challenges, and lessons learned for implementing the ICU Pain, Agitation, and Delirium Guidelines. Crit Care Med. 2013; 41:S116–S127

38. Knaus WA, Draper EA, Wagner DP, et al. APACHE II: A severity of disease classification system. Crit Care Med. 1985; 13:818–829

39. Charlson ME, Pompei P, Ales KL, et al. A new method of classifying prognostic comorbidity in longitudinal studies: Development and validation. J Chronic Dis. 1987; 40:373–383

40. Ely EW, Truman B, Shintani A, et al. Monitoring sedation status over time in ICU patients: Reliability and validity of the Richmond Agitation-Sedation Scale (RASS). JAMA. 2003; 289:2983–2991

41. Sessler CN, Gosnell MS, Grap MJ, et al. The Richmond Agitation-Sedation Scale: Validity and reliability in adult intensive care unit patients. Am J Respir Crit Care Med. 2002; 166:1338–1344

42. Ely EW, Margolin R, Francis J, et al. Evaluation of delirium in critically ill patients: Validation of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Crit Care Med. 2001; 29:1370–1379

43. Girard TD, Kress JP, Fuchs BD, et al. Efficacy and safety of a paired sedation and ventilator weaning protocol for mechanically ventilated patients in intensive care (Awakening and Breathing Controlled trial): A randomised controlled trial. Lancet. 2008; 371:126–134

44. Shehabi Y, Bellomo R, Reade MC, et al. Sedation Practice in Intensive Care Evaluation (SPICE) Study Investigators; ANZICS Clinical Trials Group Early intensive care sedation predicts long-term mortality in ventilated critically ill patients. Am J Respir Crit Care Med. 2012; 186:724–731

45. Seymour CW, Pandharipande PP, Koestner T, et al. Diurnal sedative changes during intensive care: Impact on liberation from mechanical ventilation and delirium. Crit Care Med. 2012; 40:2788–2796

46. Brummel NE, Jackson JC, Girard TD, et al. A combined early cognitive and physical rehabilitation program for people who are critically ill: The activity and cognitive therapy in the intensive care unit (ACT-ICU) trial. Phys Ther. 2012; 92:1580–1592


Awakening and Breathing Coordination, Delirium monitoring/management, and Early exercise/mobility bundle; delirium; intensive care unit; ventilator-free days

Back to Top | Article Outline

Supplemental Digital Content

Copyright © 2014 by the Society of Critical Care Medicine and Lippincott Williams & Wilkins

Article Tools



Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.