Multicenter implementation of a consensus-developed, evidence-based, spontaneous breathing trial protocol

Improving Outcomes for Bronchiolitis Patients After Implementing a High-Flow Nasal Cannula Holiday and Standardizing Discharge Criteria in a PICU

OBJECTIVES

To decrease length of high-flow nasal cannula (HFNC), PICU, and hospital length of stay (LOS).

DESIGN

Quality improvement project.

SETTING

A quaternary academic PICU.

PATIENTS

Patients with bronchiolitis less than 24 months old.

INTERVENTIONS

After initial implementation of a respiratory therapist (RT)-driven HFNC protocol (Plan-Do-Study-Act [PDSA] 1) in October 2017, additional interventions included adjusting HFNC wean rate (PDSA 2) in July 2020, a HFNC holiday (PDSA 3), and standardized discharge criteria (PDSA 4) in October 2021.

MEASUREMENTS AND MAIN RESULTS

Duration of HFNC was used as the primary outcome measure. PICU LOS and hospital LOS were used as secondary outcome measures. Noninvasive ventilation use, invasive mechanical ventilation use, and 7-day PICU and hospital readmission rates were used as balancing measures. A total of 1,310 patients were included in this study. Patients in PDSA 2, PDSA 3 and 4 groups were older compared with pre-intervention and PDSA 1 (median of 9 and 10 mo compared with 8 mo; p = 0.01). HFNC duration decreased from 2.5 to 1.8 days after PDSA 1, then to 1.3 days after PDSA 2. PICU LOS decreased from 2.6 to 2.1 days after PDSA 1, 1.8 days after PDSA 2, and 1.5 days after PDSA 3 and 4. Hospital LOS decreased from 5.7 to 4.5 days after PDSA 1, 3.1 days after PDSA 2, and 2.7 days after PDSA 3 and 4. The use of noninvasive ventilation and invasive mechanical ventilation decreased throughout the study from 23.2% in the pre-intervention group, to 6.9% at the end of the project. The 7-day PICU and hospital readmission rates did not increase after implementation. The percentage of patients discharged from the PICU increased from 6.2% to 21.5%.

CONCLUSIONS

Modifications to an existing RT-driven HFNC protocol and standardization of discharge criteria led to an improvement in outcomes for patients admitted to the PICU with bronchiolitis without an increase in adverse events.

PEEP application during mechanical ventilation contributes to fibrosis in the diaphragm

BACKGROUND

Positive end-expiratory airway pressure (PEEP) is a potent component of management for patients receiving mechanical ventilation (MV). However, PEEP may cause the development of diaphragm remodeling, making it difficult for patients to be weaned from MV. The current study aimed to explore the role of PEEP in VIDD.

METHODS

Eighteen adult male New Zealand rabbits were divided into three groups at random: nonventilated animals (the CON group), animals with volume-assist/control mode without/ with PEEP 8 cmH₂O (the MV group/ the MV + PEEP group) for 48 h with mechanical ventilation. Ventilator parameters and diaphragm were collected during the experiment for further analysis.

RESULTS

There was no difference among the three groups in arterial blood gas and the diaphragmatic excursion during the experiment. The tidal volume, respiratory rate and minute ventilation were similar in MV + PEEP group and MV group. Airway peak pressure in MV + PEEP group was significantly higher than that in MV group (p < 0.001), and mechanical power was significantly higher (p < 0.001). RNA-seq showed that genes associated with fibrosis were enriched in the MV + PEEP group. This results were further confirmed on mRNA expression. As shown by Masson's trichrome staining, there was more collagen fiber in the MV + PEEP group than that in the MV group (p = 0.001). Sirius red staining showed more positive staining of total collagen fibers and type I/III fibers in the MV + PEEP group (p = 0.001; p = 0.001). The western blot results also showed upregulation of collagen types 1A1, III, 6A1 and 6A2 in the MV + PEEP group compared to the MV group (p < 0.001, all). Moreover, the positive immunofluorescence of COL III in the MV + PEEP group was more intense (p = 0.003). Furthermore, the expression of TGF-β1, one of the most potent fibrogenic factors, was upregulated at both the mRNA and protein levels in the MV + PEEP group (mRNA: p = 0.03; protein: p = 0.04).

CONCLUSIONS

We demonstrated that PEEP application for 48 h in mechanically ventilated rabbits will cause collagen deposition and fibrosis in the diaphragm. Moreover, activation of the TGF-β1 signaling pathway and myofibroblast differentiation may be the potential mechanism of this diaphragmatic fibrosis. These findings might provide novel therapeutic targets for PEEP application-induced diaphragm dysfunction.

Development of a multi-patient ventilator circuit with validation in an ARDS porcine model

Purpose

The COVID-19 pandemic threatens our current ICU capabilities nationwide. As the number of COVID-19 positive patients across the nation continues to increase, the need for options to address ventilator shortages is inevitable. Multi-patient ventilation (MPV), in which more than one patient can use a single ventilator base unit, has been proposed as a potential solution to this problem. To our knowledge, this option has been discussed but remains untested in live patients with differing severity of lung pathology.

Methods

The objective of this study was to address ventilator shortages and patient stacking limitations by developing and validating a modified breathing circuit for two patients with differing lung compliances using simple, off-the-shelf components. A multi-patient ventilator circuit (MPVC) was simulated with a mathematical model and validated with four animal studies. Each animal study had two human-sized pigs: one healthy and one with lipopolysaccharide (LPS) induced ARDS. LPS was chosen because it lowers lung compliance similar to COVID-19. In a previous study, a control group of four pigs was given ARDS and placed on a single patient ventilation circuit (SPVC). The oxygenation of the MPVC ARDS animals was then compared to the oxygenation of the SPVC animals.

Results

Based on the comparisons, similar oxygenation and morbidity rates were observed between the MPVC ARDS animals and the SPVC animals.

Conclusion

As healthcare systems worldwide deal with inundated ICUs and hospitals from pandemics, they could potentially benefit from this approach by providing more patients with respiratory care.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00540-021-02948-2.

Evaluation of the Perceived Barriers and Facilitators to Timely Extubation of Critically Ill Adults: An Interprofessional Survey

BACKGROUND

Spontaneous breathing trials (SBTs) are an evidence-based way of identifying patients ready for mechanical ventilation (MV) liberation. Despite their effectiveness, global SBT performance rates remain suboptimal, and many patients who demonstrate the ability to breathe on their own remain on MV. The factors that influence clinicians' decision to discontinue MV following a successful SBT remain unclear.

AIMS

The aim of this study was to explore the underlying causes of extubation delays in the intensive care unit (ICU) from an interprofessional perspective.

METHODS

An exploratory, descriptive, cross-sectional design was used. An online survey was administered in December 2019 to clinicians practicing in three ICUs at a single medical center in the U.S. Survey questions focused on clinicians' perceptions of current MV liberation practices and perceived barriers or facilitators to timely extubation after a successful SBT.

RESULTS

Of 425 eligible clinicians, 135 completed the survey (31.7% response rate). The majority of clinicians believed the current SBT and extubation process took too long (n = 108; 80.0%) and that this delay negatively affected patient outcomes. While professional groups differed in their rankings of importance, factors perceived to contribute to extubation delays most commonly included SBT timing, low provider confidence levels in making extubation decisions, and patient-specific factors. Potential strategies to overcome these barriers included developing an automated extubation protocol, performing SBTs when the provider responsible for final extubation decisions is physically present, and decreasing clinician perception of reprimand or condemnation for failed extubations.

LINKING EVIDENCE TO ACTION

The MV liberation process is complex and dependent on the decisions of various ICU professionals. Clinicians perceive a number of potentially modifiable provider- and organizational-level factors that cause extubation delays in everyday practice. Understanding and addressing these barriers is essential for improving ICU quality and patient outcomes. Future research should explore the effect of nurse and respiratory therapist-driven extubation protocols on MV liberation rates.

Protocolized ventilator weaning verses usual care: A randomized controlled trial

Background:

Protocolized ventilator weaning (PW) strategies utilizing spontaneous breathing trials (SBTs) result in shorter intubation duration and intensive care unit (ICU) length of stay (LOS). We compared respiratory therapy (RT)-driven PW versus usual care (UC) as it pertains to physiologic respiratory parameters, intubation duration, extubation success/reintubation rates, and ICU LOS.

Methods:

prospective, multicentric, randomized controlled trial was performed in closed medical and surgical ICUs with 24/7 in-house intensivist coverage at six academic medical centers in a resource-limited setting from October 18, 2007, to May 03, 2014. Extubation readiness was determined by the attending physician (UC) or the respiratory therapist (PW) using predefined criteria and SBT. Physiologic variables, serial blood gas measurements, and weaning indices were assessed including the Rapid Shallow Breathing Index (RSBI), negative inspiratory force (NIF), occlusion pressure (P0.1), and dynamic and static compliance (C_dyn and C_s).

Results:

total of 5502 patients were randomized (PW 2787; UC 2715), of which 167 patients died without ventilator weaning (PW 90; UC 77) and 645 patients were excluded (PW 365; UC 280). Finally, a total of 4200 patients were analyzed (PW 2075; UC 2125). The PW group displayed improvements in minute ventilation (P < 0.001), C_s and C_dyn(both P < 0.05), P0.1 (P < 0.001), NIF (P < 0.001), and RSBI (P < 0.001). Early re-intubation (≤48 h) rates were lower in the PW group (16.7% vs. 24.8%; P < 0.0001), as were late re-intubation rates (5.2% vs. 25.8%; P < 0.0001). Intubation duration was longer in the PW group (P < 0.001), however, hospital LOS was shorter (P < 0.001). Mortality was unchanged (P = 0.19).

Conclusion:

PW with RT-driven extubation decisions is safe, effective, and associated with decreased re-intubation (early and late), shorter hospital stays, increased intubation duration (statistically but not clinically significant), and unchanged in-patient mortality.

Compliance With Evidence-Based Processes of Care After Transitions Between Staff Intensivists

OBJECTIVES

We sought to evaluate the impact of transitions of care among staff intensivists on the compliance with evidence-based processes of care.

DESIGN

Cohort study using data from the Toronto Intensive Care Observational Registry.

SETTING

Seven academic ICUs in Toronto, Ontario.

PATIENTS

Critically ill mechanically ventilated adult patients.

INTERVENTIONS

We explored the effects of the weekly transition of care among staff intensivists on compliance with three evidence-based processes of care (spontaneous breathing trials, lung-protective ventilation, and neuromuscular blocking agents). Two practices that are less guided by evidence (early discontinuation of antibiotics and extubation attempts) served as positive controls. We conducted the analysis using generalized estimating equations to account for clustering at the patient level.

MEASUREMENTS AND MAIN RESULTS

The cohort consisted of 10,570 patients admitted between June 2014 and August 2018. Compliance varied for each practice (63.6%, 42.5%, and 21.1% for lung-protective ventilation, spontaneous breathing trials, and neuromuscular blockade, respectively). There was no effect of transitions of care on compliance with spontaneous breathing trials (odds ratio, 1.00; 95% CI, 0.95-1.07), lung-protective ventilation (odds ratio, 1.07, 95% CI, 0.90-1.26), or neuromuscular blockade use (odds ratio, 0.95; 95% CI, 0.75-1.20). However, early antibiotic discontinuation was more likely (odds ratio, 1.23; 95% CI, 1.06-1.42) and extubation attempts were less frequent (odds ratio, 0.77; 95% CI, 0.65-0.93) after a transition of care.

CONCLUSIONS

We observed no significant impact of transitions of care between individual staff physicians on evidence-based processes of care for mechanically ventilated adult patients. However, transitions were associated with a lower likelihood of extubation and higher odds of earlier discontinuation of antibiotics.

Effect of Using the Rapid Shallow Breathing Index as Readiness Criterion for Spontaneous Breathing Trials in a Weaning Protocol

BACKGROUND

This study aimed to compare the effect of using versus not using the Rapid-Shallow Breathing Index (RSBI) as a readiness criterion for Spontaneous Breathing Trials (SBT) on SBT success.

MATERIALS AND METHODS

Daily readiness screens were performed within a respiratory therapist-driven weaning protocol. Patients who passed these screens underwent a one-time measurement of the RSBI and then a SBT regardless of RSBI result. The proportion of passed readiness screens reaching SBT success was compared to the proportion that would have been obtained if RSBI ≤ 105 br/min/L had been used as an additional screen criterion.

RESULTS

Two hundred and fifty SBTs performed on 157 patients were analyzed. The sensitivity of RSBI ≤ 105 br/min/L to predict SBT success was 94.8% (95% CI 90.6-97.5). Relative to potentially using RSBI, 14.4% additional SBTs were performed. A third of these were successful, and no complications were detected in the rest that failed. The proportion of passed readiness screens reaching SBT success would have been 4% (95% CI 1.2-6.8) (P = 0.002) lower if RSBI had been used.

CONCLUSIONS

The inclusion of the RSBI in a readiness screen may not be useful in a weaning protocol.

Effects of an extubation readiness test protocol at a tertiary care fully outborn neonatal intensive care unit

Background and objectives

Extubation readiness testing (ERT) in the Neonatal Intensive Care Unit (NICU) is highly variable and lacking standardized criteria. To address this gap, an evidence-based, inter-professionally developed ERT protocol was implemented to assess effectiveness on extubation failure within 72 h and on duration of intubation (DOI).

Methods

A longitudinal retrospective chart review in a level III, fully outborn NICU, of intubated infants admitted 1-year prior (Group 1), and 1 year after implementation (Group 2). Patients were extubated if they passed a 2-stage ERT protocol (3 min continuous positive airway pressure (CPAP) followed by 7 min CPAP + pressure support). Descriptive, comparative statistics, and univariate and multiple logistic regression were completed on all patients and a ≤32 6/7 weeks subgroup (intubated at day-of-life 1); p < 0.05 is considered significant.

Results

All patients (n = 589 (n = 294 Group 1, n = 295 Group 2)) were included (preterm, intubated day of life one subgroup: n = 42 Group 1, n = 38 Group 2). For all patients, extubation failure decreased significantly from 9.9% to 4.1% (p = 0.006); Group 1 patients were 2.42 times more likely to experience extubation failure compared with Group 2. Extubation failure in the preterm subgroup decreased from 21.7% to 2.6% (p = 0.01); Group 1 patients were 10.71 times more likely to experience extubation failure. Median DOI was similar in both groups for all patients and in the preterm subgroup.

Conclusions

A unique two-stage ERT protocol was effective at reducing extubation failure rate, without increasing DOI, largely in preterm infants. The evidence-based, interprofessionally developed ERT protocol and its integration into the NICU culture largely contributed to its success.

Lung-thorax compliance measured during a spontaneous breathing trial is a good index of extubation failure in the surgical intensive care unit: a retrospective cohort study

Background

Extubation failure is associated with mortality and morbidity in the intensive care unit. Ventilator weaning protocols have been introduced, and extubation is conducted based on the results of a spontaneous breathing trial. Room for improvement still exists in extubation management, and additional objective indices may improve the safety of the weaning and extubation process. Static lung-thorax compliance reflects lung expansion difficulty that is caused by several conditions, such as atelectasis, fibrosis, and pleural effusion. Nevertheless, it is not used commonly in the weaning and extubation process. In this study, we investigated whether lung-thorax compliance is a good index of extubation failure in adults even when patients pass a spontaneous breathing trial.

Methods

In a single-center, retrospective cohort study, patients over 18 years of age were mechanically ventilated, weaned with proportional assist ventilation, and underwent a spontaneous breathing trial process in surgical intensive care units of Kagawa University Hospital from July 2014 to June 2016. Extubation failure was the outcome measure of the study. We defined extubation failures as when patients were reintubated or underwent non-invasive positive-pressure ventilation within 24 h after extubation. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the clinical involvement of several parameters. The area under the curve (AUC) was calculated to assess the discriminative power of the parameters.

Results

We analyzed 173 patients and compared the success and failure groups. Most patients (162, 93.6%) were extubated successfully, and extubation failed in 11 patients (6.4%). The averages of lung-thorax compliance values in the success and failure groups were 71.9 ± 23.0 and 43.3 ± 14.6 mL/cmH₂O, respectively, and were significantly different (p < 0.0001). In the ROC curve analysis, the AUC was highest for lung-thorax compliance (0.862), followed by the respiratory rate (0.821), rapid shallow breathing index (0.781), Acute Physiology and Chronic Health Evaluation II score (0.72), heart rate (0.715), and tidal volume (0.695).

Conclusions

Lung-thorax compliance measured during a spontaneous breathing trial is a potential indicator of extubation failure in postoperative patients.

Dynamic data monitoring improves predictive analytics for failed extubation in the ICU

OBJECTIVE

Predictive analytics monitoring that informs clinicians of the risk for failed extubation would help minimize both the duration of mechanical ventilation and the risk of emergency re-intubation in ICU patients. We hypothesized that dynamic monitoring of cardiorespiratory data, vital signs, and lab test results would add information to standard clinical risk factors.

METHODS

We report model development in a retrospective observational cohort admitted to either the medical or surgical/trauma ICU that were intubated during their ICU stay and had available physiologic monitoring data (n  =  1202). The primary outcome was removal of endotracheal intubation (i.e. extubation) followed within 48 h by reintubation or death (i.e. failed extubation). We developed a standard risk marker model based on demographic and clinical data. We also developed a novel risk marker model using dynamic data elements-continuous cardiorespiratory monitoring, vital signs, and lab values.

RESULTS

Risk estimates from multivariate predictive models in the 24 h preceding extubation were significantly higher for patients that failed. Combined standard and novel risk markers demonstrated good predictive performance in leave-one-out validation: AUC of 0.64 (95% CI: 0.57-0.69) and 1.6 alerts per week to identify 32% of extubations that will fail. Novel risk factors added significantly to the standard model.

CONCLUSION

Predictive analytics monitoring models can detect changes in vital signs, continuous cardiorespiratory monitoring, and laboratory measurements in both the hours preceding and following extubation for those patients destined for extubation failure.

Effects of Physician-targeted Pay for Performance on Use of Spontaneous Breathing Trials in Mechanically Ventilated Patients

RATIONALE

Pay for performance is an increasingly common quality improvement strategy despite the absence of robust supporting evidence.

OBJECTIVES

To determine the impact of a financial incentive program rewarding physicians for the completion of daily spontaneous breathing trials (SBTs) in three academic hospitals.

METHODS

We compared data from mechanically ventilated patients from 6 months before to 2 years after introduction of a financial incentive program that provided annual payments to critical care physicians contingent on unit-level SBT completion rates. We used Poisson regression to compare the frequency of days on which SBTs were completed among eligible patients and days on which patients were excluded from SBT eligibility among all mechanically ventilated patients. We used multivariate regression to compare risk-adjusted duration of mechanical ventilation and in-hospital mortality.

MEASUREMENTS AND MAIN RESULTS

The cohort included 7,291 mechanically ventilated patients with 75,621 ventilator days. Baseline daily SBT rates were 96.8% (hospital A), 16.4% (hospital B), and 74.7% (hospital C). In hospital A, with the best baseline performance, there was no change in SBT rates, exclusion rates, or duration of mechanical ventilation across time periods. In hospitals B and C, with lower SBT completion rates at baseline, there was an increase in daily SBT completion rates and a concomitant increase in exclusions from eligibility. Duration of mechanical ventilation decreased in hospital C but not in hospital B. Mortality was unchanged for all hospitals.

CONCLUSIONS

In hospitals with low baseline SBT completion, physician-targeted financial incentives were associated with increased SBT rates driven in part by increased exclusion rates, without consistent improvements in outcome.

Practice Variation in Spontaneous Breathing Trial Performance and Reporting

Background. Spontaneous breathing trials (SBTs) are standard of care in assessing extubation readiness; however, there are no universally accepted guidelines regarding their precise performance and reporting. Objective. To investigate variability in SBT practice across centres. Methods. Data from 680 patients undergoing 931 SBTs from eight North American centres from the Weaning and Variability Evaluation (WAVE) observational study were examined. SBT performance was analyzed with respect to ventilatory support, oxygen requirements, and sedation level using the Richmond Agitation Scale Score (RASS). The incidence of use of clinical extubation criteria and changes in physiologic parameters during an SBT were assessed. Results. The majority (80% and 78%) of SBTs used 5 cmH₂O of ventilator support, although there was variability. A significant range in oxygenation was observed. RASS scores were variable, with RASS 0 ranging from 29% to 86% and 22% of SBTs performed in sedated patients (RASS < −2). Clinical extubation criteria were heterogeneous among centres. On average, there was no change in physiological variables during SBTs. Conclusion. The present study highlights variation in SBT performance and documentation across and within sites. With their impact on the accuracy of outcome prediction, these results support efforts to further clarify and standardize optimal SBT technique.

Mobilizing outcomes: implementation of a nurse-led multidisciplinary mobility program

The safety and efficacy of mobility programs for the ventilated patient and the ability to improve outcomes related to immobility of the critically ill are well documented in the literature. Early mobility programs have been proven safe and effective in study. However, a lack of literature describing application of the therapy and integration at the bedside exists. This article describes the multidisciplinary change process and partnerships necessary to provide the innovation of early mobility to ventilated intensive care unit patients. Early mobility targets ventilated patients upon admission to ensure that interventions are performed that promote physical therapy at first possible moment. In order to accomplish this innovation, evidence-based practice was used to guide culture change in an intensive care unit and build partnerships among disciplines that worked to achieve the same goals independently.

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

OBJECTIVE

The awakening and breathing coordination, delirium monitoring/management, and early exercise/mobility bundle is an evidence-based interprofessional multicomponent strategy for minimizing sedative exposure, reducing duration of mechanical ventilation, and managing ICU-acquired delirium and weakness. The purpose of this study was to identify facilitators and barriers to awakening and breathing coordination, delirium monitoring/management, and early exercise/mobility bundle adoption and to evaluate the extent to which bundle implementation was effective, sustainable, and conducive to dissemination.

DESIGN

Prospective, before-after, mixed-methods study.

SETTING

Five adult ICUs, one step-down unit, and a special care unit located in a 624-bed academic medical center

SUBJECTS

: Interprofessional ICU team members at participating institution.

INTERVENTIONS AND MEASUREMENTS

In collaboration with the participating institution, we developed, implemented, and refined an awakening and breathing coordination, delirium monitoring/management, and early exercise/mobility bundle policy. Over the course of an 18-month period, all ICU team members were offered the opportunity to participate in numerous multimodal educational efforts. Three focus group sessions, three online surveys, and one educational evaluation were administered in an attempt to identify facilitators and barriers to bundle adoption.

MAIN RESULTS

Factors believed to facilitate bundle implementation included: 1) the performance of daily, interdisciplinary, rounds; 2) engagement of key implementation leaders; 3) sustained and diverse educational efforts; and 4) the bundle's quality and strength. Barriers identified included: 1) intervention-related issues (e.g., timing of trials, fear of adverse events), 2) communication and care coordination challenges, 3) knowledge deficits, 4) workload concerns, and 5) documentation burden. Despite these challenges, participants believed implementation ultimately benefited patients, improved interdisciplinary communication, and empowered nurses and other ICU team members.

CONCLUSIONS

In this study of the implementation of the awakening and breathing coordination, delirium monitoring/management, and early exercise/mobility bundle in a tertiary care setting, clear factors were identified that both advanced and impeded adoption of this complex intervention that requires interprofessional education, coordination, and cooperation. Focusing on these factors preemptively should enable a more effective and lasting implementation of the bundle and better care for critically ill patients. Lessons learned from this study will also help healthcare providers optimize implementation of the recent ICU pain, agitation, and delirium guidelines, which has many similarities but also some important differences as compared with the awakening and breathing coordination, delirium monitoring/management, and early exercise/mobility bundle.

Nurse-driven, protocol-directed weaning from mechanical ventilation improves clinical outcomes and is well accepted by intensive care unit physicians

PURPOSE

Ventilator weaning protocols can improve clinical outcomes, but their impact may vary depending on intensive care unit (ICU) structure, staffing, and acceptability by ICU physicians. This study was undertaken to examine their relationship.

DESIGN/METHODS

We prospectively examined outcomes of 102 mechanically ventilated patients for more than 24 hours and weaned using nurse-driven protocol-directed approach (nurse-driven group) in an intensivist-led ICU with low respiratory therapist staffing and compared them with a historic control of 100 patients who received conventional physician-driven weaning (physician-driven group). We administered a survey to assess ICU physicians' attitude.

RESULTS

Median durations of mechanical ventilation (MV) in the nurse-driven and physician-driven groups were 2 and 4 days, respectively (P = .001). Median durations of ICU length of stay (LOS) in the nurse-driven and physician-driven groups were 5 and 7 days, respectively (P = .01). Time of extubation was 2 hours and 13 minutes earlier in the nurse-driven group (P < .001). There was no difference in hospital LOS, hospital mortality, rates of ventilator-associated pneumonia, or reintubation rates between the 2 groups. We identified 4 independent predictors of weaning duration: nurse-driven weaning, Acute Physiology and Chronic Health Evaluation II score, vasoactive medications use, and blood transfusion. Intensive care unit physicians viewed this protocol implementation positively (mean scores, 1.59-1.87 on a 5-point Likert scale).

CONCLUSIONS

A protocol for liberation from MV driven by ICU nurses decreased the duration of MV and ICU LOS in mechanically ventilated patients for more than 24 hours without adverse effects and was well accepted by ICU physicians.

Surgical prophylaxis and other complication avoidance care bundles

Individual health care quality measures that have been shown to improve outcome can be combined together into what are called care bundles, with the expectation that this set of practices produces further improvements in outcome. Prevention of surgical site infection is the focus of several quality measures put forward by the Surgical Care Improvement Project; these can collectively be considered a bundle as well. Whether these process measures, which include several components related to the administration of antibiotic prophylaxis, are effective in decreasing rates of surgical site infection has come under considerable debate recently.

Noninvasive work of breathing improves prediction of post-extubation outcome

PURPOSE

We hypothesized that non-invasively determined work of breathing per minute (WOB(N)/min) (esophageal balloon not required) may be useful for predicting extubation outcome, i.e., appropriate work of breathing values may be associated with extubation success, while inappropriately increased values may be associated with failure.

METHODS

Adult candidates for extubation were divided into a training set (n = 38) to determine threshold values of indices for assessing extubation and a prospective validation set (n = 59) to determine the predictive power of the threshold values for patients successfully extubated and those who failed extubation. All were evaluated for extubation during a spontaneous breathing trial (5 cmH(2)O pressure support ventilation, 5 cmH(2)O positive end expiratory pressure) using routine clinical practice standards. WOB(N)/min data were blinded to attending physicians. Area under the receiver operating characteristic curves (AUC), sensitivity, specificity, and positive and negative predictive values of all extubation indices were determined.

RESULTS

AUC for WOB(N)/min was 0.96 and significantly greater (p < 0.05) than AUC for breathing frequency at 0.81, tidal volume at 0.61, breathing frequency-to-tidal volume ratio at 0.73, and other traditionally used indices. WOB(N)/min had a specificity of 0.83, the highest sensitivity at 0.96, positive predictive value at 0.84, and negative predictive value at 0.96 compared to all indices. For 95% of those successfully extubated, WOB(N)/min was ≤10 J/min.

CONCLUSIONS

WOB(N)/min had the greatest overall predictive accuracy for extubation compared to traditional indices. WOB(N)/min warrants consideration for use in a complementary manner with spontaneous breathing pattern data for predicting extubation outcome.

Using "off-the-shelf" tools for terabyte-scale waveform recording in intensive care: computer system design, database description and lessons learned

Until now, the creation of massive (long-term and multichannel) waveform databases in intensive care required an interdisciplinary team of clinicians, engineers and informaticians and, in most cases, also design-specific software and hardware development. Recently, several commercial software tools for waveform acquisition became available. Although commercial products and even turnkey systems are now being marketed as simple and effective, the performance of those solutions is not known. The additional expense upfront may be worthwhile if commercial software can eliminate the need for custom software and hardware systems and the associated investment in teams and development. We report the development of a computer system for long-term large-scale recording and storage of multichannel physiologic signals that was built using commercial solutions (software and hardware) and existing hospital IT infrastructure. Both numeric (1 Hz) and waveform (62.5-500 Hz) data were captured from 24 SICU bedside monitors simultaneously and stored in a file-based vital sign data bank (VSDB) during one-year period (total DB size is 4.21TB). In total, vital signs were recorded from 1,175 critically ill patients. Up to six ECG leads, all other monitored waveforms, and all monitored numeric data were recorded in most of the cases. We describe the details of building blocks of our system, provide description of three datasets exported from our VSDB and compare the contents of our VSDB with other available waveform databases. Finally, we summarize lessons learned during recording, storage, and pre-processing of physiologic signals.

Clinical Prediction of Weaning and Extubation in Australian and New Zealand Intensive Care Units

Our objective was to describe, in Australian and New Zealand adult intensive care units, the relative frequency in which various clinical criteria were used to predict weaning and extubation, and the weaning methods employed.

Participant intensivists at 55 intensive care units completed a self-administered questionnaire, using visual analogue scales (0=not at all predictive, 10=perfectly predictive, not used=null score) to record the perceived utility of 30 potential predictors.

Survey response rate was 71% (164/230). Those variables thought most predictive of weaning readiness were respiratory rate (median score 8.0, interquartile range 7.0 to 8.6) effective cough (7.3, 5.9 to 8.2) and pressure support setting (7.2, 6.0 to 8.0). The most highly rated predictors of extubation success were effective cough (8.0, 7.0 to 9.0), respiratory rate (8.0, 7.0 to 8.5) and Glasgow Coma Score (7.9, 6.1 to 8.3). Variables perceived least predictive of weaning and extubation success were P0.1, Acute Physiological and Chronic Health Evaluation score II, mean arterial pressure, electrolytes and maximum inspiratory pressure (individual median scores <5). Most popular clinical criteria were those perceived to have high predictive accuracy, both for weaning (respiratory rate 96%, pressure support setting 94% and Glasgow coma score 91%) and extubation readiness (respiratory rate 98%, effective cough 94% and Glasgow Coma Score 92%). Weaning mostly employed pressure support ventilation (55%), with less use of synchronised intermittent mandatory ventilation (32%) and spontaneous breathing trials (13%).

Classic ventilatory performance predictors including respiratory rate and effective cough were reported to be of greater clinical utility than other more recently proposed measures.

Reducing iatrogenic risks: ICU-acquired delirium and weakness--crossing the quality chasm

ICUs are experiencing an epidemic of patients with acute brain dysfunction (delirium) and weakness, both associated with increased mortality and long-term disability. These conditions are commonly acquired in the ICU and are often initiated or exacerbated by sedation and ventilation decisions and management. Despite > 10 years of evidence revealing the hazards of delirium, the quality chasm between current and ideal processes of care continues to exist. Monitoring of delirium and sedation levels remains inconsistent. In addition, sedation, ventilation, and physical therapy practices proven successful at reducing the frequency and severity of adverse outcomes are not routinely practiced. In this article, we advocate for the adoption and implementation of a standard bundle of ICU measures with great potential to reduce the burden of ICU-acquired delirium and weakness. Individual components of this bundle are evidence based and can help standardize communication, improve interdisciplinary care, reduce mortality, and improve cognitive and functional outcomes. We refer to this as the "ABCDE bundle," for awakening and breathing coordination, delirium monitoring, and exercise/early mobility. This evidence-based bundle of practices will build a bridge across the current quality chasm from the "front end" to the "back end" of critical care and toward improved cognitive and functional outcomes for ICU survivors.

Predicting clinical physiology: a Markov chain model of heart rate recovery after spontaneous breathing trials in mechanically ventilated patients

Analysis of heart rate (HR) dynamics before, during, and after a physiologic stress has clinical importance. For example, the celerity of heart rate recovery (HRR) after a cardiac stress test (eg, treadmill exercise test) has been shown to be an independent predictor of all-cause mortality. Heart rate dynamics are modulated, in part, by the autonomic nervous system. These dynamics are commonly abstracted using metrics of heart rate variability (HRV), which are known to be sensitive to the influence of the autonomic nervous system on HR. The patient-specific modulators of HR should be reflected both in the response to stress as well as in the recovery from stress. We therefore hypothesized that the patient-specific HR response to stress could be used to predict the HRR after the stress. We devised a Markov chain model to predict the poststress HRR dynamics using the parameters (transition matrix) calculated from HR data during the stress. The model correctly predicts the exponential shape of poststress HRR. This model features a simple analytical relationship linking poststress HRR time constant (T(off)) with a standard measure of HRV, namely the correlation coefficient of the Poincaré plot (first return map) of the HR recorded during the stress. A corresponding relationship exists between the time constant (T(on)) of R-R interval decrease at the onset of stress and the correlation coefficient of the Poincaré plot of prestress R-R intervals. Consequently, the model can be used for the prediction of poststress HRR using the HRV measured during the stress. This direct relationship between the event-to-event microscopic fluctuations (HRV) during the stress and the macroscopic response (HRR) after the stress terminates can be interpreted as an instance of a fluctuation-dissipation relationship. We have thus applied the fluctuation-dissipation theorem to the analysis of heart rate dynamics. The approach is specific neither to cardiac physiology nor to transitions between mechanical and free ventilation as a specific stress. It may therefore have wider applicability to physiologic systems subject to modest stresses.

Implementation of the enteral nutrition practice recommendations

In developing the evidence-based Enteral Nutrition Practice Recommendations, the American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) formed a task force to address the many aspects of safety in the delivery and provision of enteral nutrition support. This recently published document provides healthcare professionals with recommendations that are derived from evidence-based practice. The development and use of clinical practice guidelines (CPGs) is a recent, significant contribution for the dissemination of evidence-based medicine. This involves the review of scientific literature along with clinical skill and knowledge to generate specific recommendations assisting healthcare providers and patients with decisions regarding appropriate healthcare. A primary opportunity to improve patient outcomes will come from the effective delivery of existing therapies rather than from the new development of treatment modalities. Compliance with CPGs is challenging because it depends on a variety of factors. Both general and specific strategies have been devised with the expansion of the new discipline of implementation science. The high degree of evidence now available in medicine gives clinicians more opportunity to improve patient outcomes and quality of care. It remains for clinicians to evaluate their institutional mission and goals, and to investigate those CPGs appropriate to improve patient care in that setting.