Struggle for implementation of new strategies in intensive care medicine: anticoagulation, insulin, and lower tidal volumes

Effect of ICU care bundles on long-term patient-relevant outcomes: a scoping review

OBJECTIVE

Care bundles are considered a key tool to improve bedside quality of care in the intensive care unit (ICU). We explored their effect on long-term patient-relevant outcomes.

DESIGN

Systematic literature search and scoping review.

DATA SOURCES

We searched PubMed, Embase, CINAHL, APA PsycInfo, Web of Science, CDSR and CENTRAL for keywords of intensive care, care bundles, patient-relevant outcomes, and follow-up studies.

ELIGIBILITY CRITERIA

Original articles with patients admitted to adult ICUs assessing bundle implementations and measuring long-term (ie, ICU discharge or later) patient-relevant outcomes (ie, mortality, health-related quality of life (HrQoL), post-intensive care syndrome (PICS), care-related outcomes, adverse events, and social health).

DATA EXTRACTION AND SYNTHESIS

After dual, independent, two-stage selection and charting, eligible records were critically appraised and assessed for bundle type, implementation strategies, and effects on long-term patient-relevant outcomes.

RESULTS

Of 2012 records, 38 met inclusion criteria; 55% (n=21) were before-after studies, 21% (n=8) observational cohort studies, 13% (n=5) randomised controlled trials, and 11% (n=4) had other designs. Bundles pertained to sepsis (n=11), neurocognition (n=6), communication (n=4), early rehabilitation (n=3), pharmacological discontinuation (n=3), ventilation (n=2) or combined bundles (n=9). Almost two-thirds of the studies reported on survival (n=24), 45% (n=17) on care-related outcomes (eg, discharge disposition), and 13% (n=5) of studies on HrQoL. Regarding PICS, 24% (n=9) assessed cognition, 13% (n=5) physical health, and 11% (n=4) mental health, up to 1 year after discharge. The effects of bundles on long-term patient-relevant outcomes was inconclusive, except for a positive effect of sepsis bundles on survival. The inconclusive effects may have been due to the high risk of bias in included studies and the variability in implementation strategies, instruments, and follow-up times.

CONCLUSIONS

There is a need to explore the long-term effects of ICU bundles on HrQoL and PICS. Closing this knowledge gap appears vital to determine if there is long-term patient value of ICU bundles.

Low tidal volume ventilation is associated with mortality in COVID-19 patients-Insights from the PRoVENT-COVID study

Purpose

Low tidal volume ventilation (LTVV) is associated with mortality in patients with acute respiratory distress syndrome. We investigated the association of LTVV with mortality in COVID-19 patients.

Methods

Secondary analysis of a national observational study in COVID-19 patients in the first wave of the pandemic. We compared COVID-19 patients that received LTVV, defined as controlled ventilation with a median tidal volume ≤ 6 mL/kg predicted body weight over the first 4 calendar days of ventilation, with patients that did not receive LTVV. The primary endpoint was 28-day mortality. In addition, we identified factors associated with use of LTVV.

Results

Of 903 patients, 294 (32.5%) received LTVV. Disease severity scores and ARDS classification was not different between the two patient groups. The primary endpoint, 28-day mortality, was met in 68 out of 294 patients (23.1%) that received LTVV versus in 193 out of 609 patients (31.7%) that did not receive LTVV (P < 0.001). LTVV was independently associated with 28-day mortality (HR, 0.68 (0.45 to 0.95); P = 0.025). Age, height, the initial tidal volume and continuous muscle paralysis was independently associated with use of LTVV.

Conclusions

In this cohort of invasively ventilated COVID-19 patients, approximately a third of patients received LTVV. Use of LTVV was independently associated with reduced 28-day mortality. The initial tidal volume and continuous muscle paralysis were potentially modifiable factors associated with use of LTVV. These findings are important as they could help clinicians to recognize patients who are at risk of not receiving LTVV.

Promoting Evidence-Based Practice in Acute Respiratory Distress Syndrome: A Systematic Review

Supplemental Digital Content is available in the text.

OBJECTIVE:

Low tidal volume ventilation and prone positioning are recommended therapies yet underused in acute respiratory distress syndrome. We aimed to assess the role of interventions focused on implementation of low tidal volume ventilation and prone positioning in mechanically ventilated adult patients with acute respiratory distress syndrome.

DATA SOURCES:

PubMed, Excerpta Medica Database, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Central Register of Controlled Trials.

STUDY SELECTION:

We searched the four databases from January 1, 2001, to January 28, 2021, for studies that met the predefined search criteria. Selected studies focused on interventions to improve implementation of low tidal volume ventilation and prone positioning in mechanically ventilated patients with acute respiratory distress syndrome.

DATA EXTRACTION:

Two authors independently performed study selection and data extraction using a standardized form.

DATA SYNTHESIS:

Due to methodological heterogeneity of included studies, meta-analysis was not feasible; thus, we provided a narrative summary and assessment of the literature. Eight nonrandomized studies met our eligibility criteria. Most studies looked at interventions to improve adherence to low tidal volume ventilation. Most interventions focused on education for providers. Studies were primarily conducted in the ICU and involved trainees, intensivists, respiratory therapists, and critical care nurses. Although overall quality of the studies was very low, the primary outcomes of interest suggest that interventions could improve adherence to or implementation of low tidal volume ventilation and prone positioning in acute respiratory distress syndrome.

Measurements and Main Results:

Two authors independently performed study selection and data extraction using a standardized form. Due to methodologic heterogeneity of included studies, meta-analysis was not feasible; thus, we provided a narrative summary and assessment of the literature. Eight nonrandomized studies met our eligibility criteria. Most studies looked at interventions to improve adherence to low tidal volume ventilation. Most interventions focused on education for providers. Studies were primarily conducted in the ICU and involved trainees, intensivists, respiratory therapists, and critical care nurses. Although overall quality of the studies was very low, the primary outcomes of interest suggest that interventions could improve adherence to or implementation of low tidal volume ventilation and prone positioning in acute respiratory distress syndrome.

Conclusions:

There is a dearth of literature addressing interventions to improve implementation of evidence-based practices in acute respiratory distress syndrome. Existing interventions to improve clinician knowledge and facilitate application of low tidal volume ventilation and prone positioning may be effective, but supporting studies have significant limitations.

Ventilator Weaning and Discontinuation Practices for Critically Ill Patients

Importance

Although most critically ill patients receive invasive mechanical ventilation (IMV), few studies have characterized how IMV is discontinued in practice.

Objective

To describe practice variation in IMV discontinuation internationally, associations between initial discontinuation events and outcomes, and factors associated with the use of select discontinuation strategies and failed initial spontaneous breathing trials (SBTs).

Design, Setting, and Participants

Prospective, multinational, observational study of critically ill adults who received IMV for at least 24 hours from 142 intensive care units (ICUs) in 19 countries within 6 regions (27 in Canada, 23 in India, 22 in the UK, 26 in Europe, 21 in Australia/New Zealand, and 23 in the US).

Exposures

Receiving IMV.

Main Outcomes and Measures

Primary analyses characterized types of initial IMV discontinuation events (extubation, SBT, or tracheostomy) and associations with clinical outcomes (including duration of ventilation, ICU and hospital mortality, and ICU and hospital length of stay). Secondary analyses examined the associations between SBT outcome and SBT timing and clinical outcomes.

Results

Among 1868 patients (median [interquartile range] age, 61.8 [48.9-73.1] years; 1173 [62.8%] men) 424 (22.7%) underwent direct extubation, 930 (49.8%) had an initial SBT (761 [81.8%] successful), 150 (8.0%) underwent direct tracheostomy, and 364 (19.5%) died before a weaning attempt. Across regions, there was variation in the use of written directives to guide care, daily screening, SBT techniques, ventilator modes, and the roles played by clinicians involved in weaning. Compared with initial direct extubation, patients who had an initial SBT had higher ICU mortality (20 [4.7%] vs 96 [10.3%]; absolute difference, 5.6% [95% CI, 2.6%-8.6%]), longer duration of ventilation (median of 2.9 vs 4.1 days; absolute difference, 1.2 days [95% CI, 0.7-1.6]), and longer ICU stay (median of 6.7 vs 8.1 days; absolute difference, 1.4 days [95% CI, 0.8-2.4]). Patients whose initial SBT failed (vs passed) had higher ICU mortality (29 [17.2%] vs 67 [8.8%]; absolute difference, 8.4% [95% CI, 2.0%-14.7%]), longer duration of ventilation (median of 6.1 vs 3.5 days; absolute difference, 2.6 days [95% CI, 1.6-3.6]), and longer ICU stay (median of 10.6 vs 7.7 days; absolute difference, 2.8 days [95% CI, 1.1-5.2]). Compared with patients who underwent early initial SBTs, patients who underwent late initial SBTs (>2.3 days after intubation) had longer duration of ventilation (median of 2.1 vs 6.1 days; absolute difference, 4.0 days [95% CI, 3.7-4.5]), longer ICU stay (median of 5.9 vs 10.8 days; absolute difference, 4.9 days [95% CI, 4.0-6.3]), and longer hospital stay (median of 14.3 vs 22.8 days; absolute difference, 8.5 days [95% CI, 6.0-11.0]).

Conclusions and Relevance

In this observational study of invasive mechanical ventilation discontinuation in 142 ICUs in Canada, India, the UK, Europe, Australia/New Zealand, and the US from 2013 to 2016, weaning practices varied internationally.

Trial Registration

ClinicalTrials.gov Identifier: NCT03955874.

Low tidal volume ventilation use remains low in patients with acute respiratory distress syndrome at a single center

PURPOSE

Low tidal volume ventilation (LTVV) reduces mortality in acute respiratory distress syndrome (ARDS) patients. Understanding local barriers to LTVV use at a former ARDS Network hospital may provide new insight to improve LTVV implementation.

METHODS

A cohort of 214 randomly selected adults met the Berlin definition of ARDS at Harborview Medical Center between 2008 and 2012. The primary outcome was the receipt of LTVV (tidal volume of ≤6.5mL/kg predicted body weight) within 48h of ARDS onset. We constructed a multivariable logistic regression model to identify factors associated with the outcome.

RESULTS

Only 27% of patients received tidal volumes of ≤6.5mL/kg PBW within 48h of ARDS onset. Increasing plateau pressure (OR 1.11; 95% CI 1.03 to 1.19; p-value<0.01) was positively associated with LTVV use while increasing PaO₂:F_IO₂ ratio was negatively associated (OR 0.75; 95% CI 0.57 to 0.98; p-value 0.03). Physicians documented an ARDS diagnosis in only 21% of the cohort. Neither patient height nor gender was associated with LTVV use.

CONCLUSIONS

Most ARDS patients did not receive LTVV despite implementation of a protocol. ARDS was also recognized in a minority of patients, suggesting an opportunity for improvement of care.

Frequency of adoption of practice management guidelines at trauma centers

Evidence-based management guidelines have been shown to improve patient outcomes, yet their utilization by trauma centers remains unknown. This study measured adoption of practice management guidelines or protocols by trauma centers. A survey of 228 trauma centers was conducted over 1 year; 55 completed the survey. Centers were classified into three groups: noncompliant, partially compliant, and compliant with adoption of management protocols. Characteristics of compliant centers were compared with those of the other two groups. Most centers were Level I (58%) not-for-profit (67%) teaching hospitals (84%) with a surgical residency (74%). One-third of centers had an accredited fellowship in surgical critical care (37%). Only one center was compliant with all 32 management protocols. Half of the centers were compliant with 14 of 32 protocols studied (range, 4 to 32). Of the 21 trauma center characteristics studied, only two were independently associated with compliant centers: use of physician extenders and daily attending rounds (both P < .0001). Adoption of management guidelines by trauma centers is inconsistent, with wide variations in practices across centers.

The epidemiology of acute respiratory failure in hospitalized patients: a Brazilian prospective cohort study

PURPOSE

The purpose of this study was to assess risk factors associated with the development of acute respiratory failure (ARF) and death in a general intensive care unit (ICU).

MATERIALS AND METHODS

Adults who were hospitalized at 12 surgical and nonsurgical ICUs were prospectively followed up. Multivariable analyses were realized to determine the risk factors for ARF and point out the prognostic factors for mortality in these patients.

RESULTS

A total of 1732 patients were evaluated, with an ARF prevalence of 57%. Of the 889 patients who were admitted without ARF, 141 (16%) developed this syndrome in the ICU. The independent risk factors for developing ARF were 64 years of age or older, longer time between hospital and ICU admission, unscheduled surgical or clinical reason for ICU admission, and severity of illness. Of the 984 patients with ARF, 475 (48%) died during the ICU stay. Independent prognostic factors for death were age older than 64 years, time between hospital and ICU admission of more than 4 days, history of hematologic malignancy or AIDS, the development of ARF in ICU, acute lung injury, and severity of illness.

CONCLUSIONS

Acute respiratory failure represents a large percentage of all ICU patients, and the high mortality is related to some preventable factors such as the time to ICU admission.

Implementation of tight glucose control for critically ill surgical patients: a process improvement analysis

BACKGROUND

Tight glucose control has been advocated as a method to improve outcomes of surgical critical care. However, continuous infusion of insulin has potential morbidity (e.g., neurologic consequences of hypoglycemia), and it remains unclear to what degree the glucose concentration must be controlled. We examined our performance in instituting a protocol for tight glucose control in our surgical intensive care unit (ICU).

METHODS

Prospective study of 220 consecutive patients (February, 2003-March, 2006) who received an infusion of insulin for glucose control for >24 h by protocol. Data collected included age, acuity (Acute Physiology and Chronic Health Evaluation [APACHE] III) score, sex, history of diabetes mellitus, organ dysfunction (Marshall), and death or survival. Infusion-related data included initial glucose concentration, time to glucose <120 mg/dL, h/day of glucose <110 mg/dL and <140 mg/dL, duration of infusion (days), insulin units/day, year of therapy, and complications. Analysis was performed by chi(2), analysis of variance, and logistic regression, with p < 0.05 considered significant.

RESULTS

Insulin drips were required by 10.2% of patients (287/2,804); 29 of these (10.1%) had diabetes mellitus. The mean APACHE III score for the treated patients was 77 +/- 2 (standard deviation), and the mortality rate was 24%. Hypoglycemia (<60 mg/dL) occurred in 4.2% of patients. The trigger insulin concentration decreased over time (2003 vs. 2005) from 249 +/- 14 to 160 +/- 5 mg/dL, and the h/day of glucose <140 increased from 11 +/- 1 to 16 +/- 1. However, age, acuity, APACHE III, days of insulin, time to achieve glucose <120, h/day of glucose <110, and mortality rate were unchanged. By logistic regression, only the year of treatment (odds ratio [OR] 1.871; 95% confidence interval [CI] 1.177, 2.972; p = 0.008] predicted success in controlling the blood glucose concentration to <140 mg/dL; age, illness severity, diabetes history, and trigger glucose concentration [OR 0.996; 95% CI 0.992, 1.001; p = 0.11] did not.

CONCLUSIONS

Success in implementing tight glucose control was modest, albeit improving, despite a specific protocol for administration. No medical reason could be identified for inability to achieve tight glucose control; therefore, successful implementation must be volitional. Education, particularly regarding hypoglycemia, and possible refinement of our protocol may improve our ability to control blood glucose in our ICU.

Has mortality from sepsis improved and what to expect from new treatment modalities: review of current insights

BACKGROUND

The incidence of sepsis is increasing continuously, making mortality rate reduction through improved intensive care unit (ICU) care and new treatment modalities a pressing issue. This study aimed to provide insight into the effects of modern ICU care on mortality trends from severe sepsis and to provide a quantitative review of the relative effectiveness of new treatment modalities in reducing deaths.

METHODS

Mortality data from severe sepsis were extracted from the control arms of several large randomized trials of sepsis treatment published within the last two decades. The effectiveness of recent treatment strategies was expressed as the number of patients it is necessary to treat by that method to save one life (number needed to treat: NNT).

RESULTS

Death from severe sepsis showed a decline from 44% to 35% between 1990 and 2000. The two most effective strategies in critically ill patients are early appropriate antibiotics (NNT 3; 95% confidence interval [CI] 2, 4) and early goal-directed therapy (NNT 6; 95% CI 4, 24). Infusion of recombinant human activated protein C is the most effective anticoagulant therapy (NNT 15; 95% CI 10, 27). Intensive insulin therapy is only moderately effective (NNT 27; 95% CI 15, 124).

CONCLUSIONS

The mortality rate from severe sepsis has decreased significantly with modernization of ICU care. New therapeutic strategies may reduce further the mortality rate. However, focused implementation of these new strategies in accordance with their relative effectiveness is needed before we can expect to see their true effect on mortality rates.

Cost-effectiveness of implementing low-tidal volume ventilation in patients with acute lung injury

BACKGROUND

Despite widespread guidelines recommending the use of lung-protective ventilation (LPV) in patients with acute lung injury (ALI), many patients do not receive this lifesaving therapy. We sought to estimate the incremental clinical and economic outcomes associated with LPV and determined the maximum cost of a hypothetical intervention to improve adherence with LPV that remained cost-effective.

METHODS

Adopting a societal perspective, we developed a theoretical decision model to determine the cost-effectiveness of LPV compared to non-LPV care. Model inputs were derived from the literature and a large population-based cohort of patients with ALI. Cost-effectiveness was determined as the cost per life saved and the cost per quality-adjusted life-years (QALYs) gained.

RESULTS

Application of LPV resulted in an increase in QALYs gained by 15% (4.21 years for non-LPV vs 4.83 years for LPV), and an increase in lifetime costs of $7,233 per patient with ALI ($99,588 for non-LPV vs $106,821 for LPV). The incremental cost-effectiveness ratios for LPV were $22,566 per life saved at hospital discharge and $11,690 per QALY gained. The maximum, cost-effective, per patient investment in a hypothetical program to improve LPV adherence from 50 to 90% was $9,482. Results were robust to a wide range of economic and patient parameter assumptions.

CONCLUSIONS

Even a costly intervention to improve adherence with low-tidal volume ventilation in patients with ALI reduces death and is cost-effective by current societal standards.

Why are clinicians not embracing the results from pivotal clinical trials in severe sepsis? A bayesian analysis

BACKGROUND

Five pivotal clinical trials (Intensive Insulin Therapy; Recombinant Human Activated Protein C [rhAPC]; Low-Tidal Volume; Low-Dose Steroid; Early Goal-Directed Therapy [EGDT]) demonstrated mortality reduction in patients with severe sepsis and expert guidelines have recommended them to clinical practice. Yet, the adoption of these therapies remains low among clinicians.

OBJECTIVES

We selected these five trials and asked: Question 1--What is the current probability that the new therapy is not better than the standard of care in my patient with severe sepsis? Question 2--What is the current probability of reducing the relative risk of death (RRR) of my patient with severe sepsis by meaningful clinical thresholds (RRR >15%; >20%; >25%)?

METHODS

Bayesian methodologies were applied to this study. Odds ratio (OR) was considered for Question 1, and RRR was used for Question 2. We constructed prior distributions (enthusiastic; mild, moderate, and severe skeptic) based on various effective sample sizes of other relevant clinical trials (unfavorable evidence). Posterior distributions were calculated by combining the prior distributions and the data from pivotal trials (favorable evidence).

MAIN FINDINGS

Answer 1--The analysis based on mild skeptic prior shows beneficial results with the Intensive Insulin, rhAPC, and Low-Tidal Volume trials, but not with the Low-Dose Steroid and EGDT trials. All trials' results become unacceptable by the analyses using moderate or severe skeptic priors. Answer 2--If we aim for a RRR>15%, the mild skeptic analysis shows that the current probability of reducing death by this clinical threshold is 88% for the Intensive Insulin, 62-65% for the Low-Tidal Volume, rhAPC, EGDT trials, and 17% for the Low-Dose Steroid trial. The moderate and severe skeptic analyses show no clinically meaningful reduction in the risk of death for all trials. If we aim for a RRR >20% or >25%, all probabilities of benefits become lower independent of the degree of skepticism.

CONCLUSIONS

Our clinical threshold analysis offers a new bedside tool to be directly applied to the care of patients with severe sepsis. Our results demonstrate that the strength of evidence (statistical and clinical) is weak for all trials, particularly for the Low-Dose Steroid and EGDT trials. It is essential to replicate the results of each of these five clinical trials in confirmatory studies if we want to provide patient care based on scientifically sound evidence.

How many patients with severe sepsis are needed to confirm the efficacy of drotrecogin alfa activated? A Bayesian design

OBJECTIVES

Controversies concerning the pivotal trial and negative results from other Drotrecogin alfa activated (DAA) trials have raised questions about its efficacy in severe sepsis patients. Based on all available evidence, our study aimed to respond to: (1) What is the current probability that DAA is not better than the control? If the current probability is not small, e.g. greater than 0.05, then (2) How many patients will be needed for the DAA confirmatory trial?

DESIGN

We applied the Bayesian methodology to all randomized trials which tested anti-thrombotic therapies for severe sepsis. Prior distributions were defined as severe skeptic (all anti-thrombotic trials or DAA trials); moderate skeptic (anti-thrombotic trials with high risk of death); mild skeptic (DAA trials only); enthusiastic (DAA trials with high risk of death).

RESULTS

The total study sample includes 7,683 patients: DAA (N = 3,143); Anti-thrombin-III (N = 2,581); tissue factor pathway inhibitor (N = 1,959). Answer 1: All current probabilities that DAA is not better than the control (except for the enthusiastic analysis) range from 0.14 to 0.48, which strongly suggest the need for a confirmatory trial. Answer 2: The number of patients necessary for the DAA confirmatory trial ranges up to 8,350 for the severe skeptic; 730-810 for moderate skeptic; 550-685 for mild skeptic; and zero for enthusiastic analysis.

CONCLUSIONS

A confirmatory trial with approximately 600 patients with severe sepsis and high risk of death can provide a convincing answer for both the mild and moderate skeptic physicians concerning the efficacy of DAA in severe sepsis.

Barriers to low tidal volume ventilation in acute respiratory distress syndrome: survey development, validation, and results

OBJECTIVE

To evaluate perceived attitudes, knowledge, and behaviors regarding the use of low tidal volume ventilation in acute respiratory distress syndrome among physicians, nurses, and respiratory therapists in intensive care units.

DESIGN

Cross-sectional, self-administered survey.

SETTING

Large Acute Respiratory Distress Syndrome Network teaching hospital in Baltimore, MD.

PARTICIPANTS

Attending, fellow, and resident physicians; staff nurses; and respiratory therapists in three intensive care units.

INTERVENTIONS

A survey was designed to assess barriers related to clinicians' perceived attitudes, knowledge, and behaviors related to low tidal volume ventilation in acute respiratory distress syndrome and intensive care unit organization-related barriers. Survey development was guided by a published framework of barriers to clinician adherence to practice guidelines; individual items were derived through literature review and refined through pilot testing. Content validity, face validity, and ease of use were verified by local clinicians. Psychometric properties were assessed and regression analyses were conducted to examine differences in perceptions and knowledge level by provider discipline and training level.

MEASUREMENTS AND MAIN RESULTS

There were 291 completed surveys with a response rate of 84%. Validity and acceptable psychometric properties were demonstrated. Barriers related to clinician attitudes, behaviors, and intensive care unit organization were significantly higher among nurses and respiratory therapists vs. physicians. Knowledge-related barriers also were significantly higher among nurses vs. physicians and respiratory therapists. Barriers were lower and knowledge test scores higher among fellows and attending physicians vs. residents. Similarly, barriers were lower and knowledge test scores higher among nurses with >10 yrs of experience vs. <10 yrs of experience.

CONCLUSIONS

Important organizational and clinician barriers, including knowledge deficits, regarding low tidal volume ventilation were reported, particularly among nurses and resident physicians. Addressing these barriers may be important for increasing implementation of low tidal volume ventilation.

Evolution of mechanical ventilation in response to clinical research

RATIONALE

Recent literature in mechanical ventilation includes strong evidence from randomized trials. Little information is available regarding the influence of these trials on usual clinical practice.

OBJECTIVES

To describe current mechanical ventilation practices and to assess the influence of interval randomized trials when compared with findings from a 1998 cohort.

METHODS

A prospective international observational cohort study, with a nested comparative study performed in 349 intensive care units in 23 countries. We enrolled 4,968 consecutive patients receiving mechanical ventilation over a 1-month period. We recorded demographics and daily data related to mechanical ventilation for the duration of ventilation. We systematically reviewed the literature and developed 11 practice-change hypotheses for the comparative cohort study before seeing these results. In assessing practice changes, we only compared data from the 107 intensive care units (1,675 patients) that also participated in the 1998 cohort (1,383 patients).

MEASUREMENTS AND MAIN RESULTS

In 2004 compared with 1998, the use of noninvasive ventilation increased (11.1 vs. 4.4%, P < 0.001). Among patients with acute respiratory distress syndrome, tidal volumes decreased (7.4 vs. 9.1 ml/kg, P < 0.001) and positive end-expiratory pressure levels increased slightly (8.7 vs. 7.7 cm H(2)O, P = 0.02). More patients were successfully extubated after their first attempt of spontaneous breathing (77 vs. 62%, P < 0.001). Use of synchronized intermittent mandatory ventilation fell dramatically (1.6 vs. 11%, P < 0.001). Observations confirmed 10 of our 11 practice-change hypotheses.

CONCLUSIONS

The strong concordance of predicted and observed practice changes suggests that randomized trial results have advanced mechanical ventilation practices internationally.

Impact of introducing multiple evidence-based clinical practice protocols in a medical intensive care unit: a retrospective cohort study

BACKGROUND

Recently completed clinical trials have shown that certain interventions improve the outcome of the critically ill. To facilitate the implementation of these interventions, professional organizations have developed guidelines. Although the impacts of the individual evidence-based interventions have been well described, the overall impact on outcome of introducing multiple evidence-based protocols has not been well studied. The objective of this study was to determine the impact of introducing multiple evidence-based protocols on patient outcome.

METHODS

A retrospective, cohort study of 8,386 patients admitted to the medical intensive care unit (MICU) of an academic, tertiary medical center, from January 2000 through June 2005 was performed. Four evidence-based protocols (lung protective strategy for acute lung injury, activated protein C for severe sepsis/septic shock, intravenous insulin for hyperglycemia control and a protocol for sedation/analgesia) were introduced in the MICU between February 2002 and April 2004. We considered the time from January 2000 through January 2002 as the pre-protocol period, from February 2002 through March 2004 as the transition period and from April 2004 through June 2005 as the protocol period. We retrieved data including demographics, severity of illness as measured by the Acute Physiology and Chronic Health Evaluation (APACHE) III, MICU length of stay and hospital mortality. Student's t, Kruskal-Wallis, Mann-Whitney U, chi square and multiple logistic regression analyses were used to compare differences between groups. P-values < 0.05 were considered significant.

RESULTS

The predicted mean mortality rates were 20.7%, 21.1% and 21.8%, with the observed mortality rates of 19.3%, 18.0% and 16.9% during the pre-protocol, transition and protocol periods, respectively. Using the pre-protocol period as a reference, the severity-adjusted risk (95% confidence interval) of dying was 0.777 (0.655-0.922) during the protocol period (P = 0.0038). The average 28-day MICU free days improved during the protocol period compared to the pre-protocol period. The benefit was limited to sicker patients and those who stayed in the MICU longer.

CONCLUSION

The introduction of multiple evidence-based protocols is associated with improved outcome in critically ill medical patients.

Intensive care unit exposures for long-term outcomes research: development and description of exposures for 150 patients with acute lung injury

PURPOSE

Long-term follow-up studies in critical care have described survivors' outcomes, but provided less insight into the patient/disease characteristics and intensive care therapies ("exposures") associated with these outcomes. Such insights are essential for improving patients' long-term outcomes. This report describes the development of a strategy for comprehensively measuring relevant exposures for long-term outcomes research, and presents empiric results from its implementation.

MATERIALS AND METHODS

A multistep, iterative process was used to develop the exposures strategy. First, a comprehensive list of potential exposures was generated and subsequently reduced based on feasibility, redundancy, and relevance criteria. Next, data abstraction methods were designed and tested. Finally, the strategy was implemented in 150 patients with acute lung injury with iterative refinement.

RESULTS

The strategy resulted in the development of more than 60 unique exposures requiring less than 45 minutes per patient-day for data collection. Most exposures had minimal missing data and adequate reliability. These data revealed that evidence-based practices including lower tidal volume ventilation, spontaneous breathing trials, sedation interruption, adequate nutrition, and blood glucose of less than 6.1 mmol/L (110 mg/dL) occurred in only 23% to 50% of assessments.

CONCLUSIONS

Using a multistep, iterative process, a comprehensive and feasible exposure measurement strategy for long-term outcomes research was successfully developed and implemented.

Physiology of mechanical ventilation

Mechanical ventilation, although essential in taking care of acute lung injury and widely used during surgical procedures worldwide, remains a highly debated field. Clinical trials in the last decade have shown convincingly that mechanical ventilation can result in additional mortality in patients with acute lung injury. This understanding has resulted in a resurged interest in mechanical ventilation, and especially in techniques and strategies to further improve mechanical ventilation. This article discusses physiological principles to improve the understanding of mechanical ventilation.

Intensive insulin therapy in intensive care: an example of the struggle to implement evidence-based medicine

Schultz and colleagues discuss the factors hindering implementation of intensive insulin therapy.