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

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.

Prevalence and Variation of Clinically Recognized Inpatient Alcohol Withdrawal Syndrome in the Veterans Health Administration.

OBJECTIVES: No prior study has evaluated the prevalence or variability of alcohol withdrawal syndrome (AWS) in general hospitals in the United States. METHODS: This retrospective study used secondary data from the Veterans Health Administration (VHA) to estimate the documented prevalence of clinically recognized AWS among patients engaged in VHA care who were hospitalized during fiscal year 2013. We describe variation in documented inpatient AWS by geographic region, hospital, admitting specialty, and inpatient diagnoses using International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis and/or procedure codes recorded at hospital admission, transfer, or discharge. RESULTS: Among 469,082 eligible hospitalizations, the national prevalence of documented inpatient AWS was 5.8% (95% confidence interval [CI] 5.2%-6.4%), but there was marked variation by geographic region (4.3%-11.2%), hospital (1.4%-16.1%), admitting specialty (0.7%-19.0%), and comorbid diagnoses (1.3%-38.3%). AWS affected a high proportion of psychiatric admissions (19.0%, 95% CI 17.5%-20.4%) versus Medical (4.4%, 95% CI 4.0%-4.8%) or surgical (0.7%, 95% CI 0.6%-0.8%); though by volume, medical admissions represented the majority of hospitalizations complicated by AWS (n = 13,478 medical versus n = 12,305 psychiatric and n = 595 surgical). Clinically recognized AWS was also common during hospitalizations involving other alcohol-related disorders (38.3%, 95% CI 35.8%-40.8%), other substance use conditions (19.3%, 95% CI 17.7%-20.9%), attempted suicide (15.3%, 95% CI 13.0%-17.6%), and liver injury (13.9%, 95% CI 12.6%-15.1%). CONCLUSIONS: AWS was commonly recognized and documented during VHA hospitalizations in 2013, but varied considerably across inpatient settings. This clinical variation may, in part, reflect differences in quality of care and warrants further, more rigorous investigation.

The ED-SED Study: A Multicenter, Prospective Cohort Study of Practice Patterns and Clinical Outcomes Associated With Emergency Department SEDation for Mechanically Ventilated Patients.

OBJECTIVES: To characterize emergency department sedation practices in mechanically ventilated patients, and test the hypothesis that deep sedation in the emergency department is associated with worse outcomes. DESIGN: Multicenter, prospective cohort study. SETTING: The emergency department and ICUs of 15 medical centers. PATIENTS: Mechanically ventilated adult emergency department patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All data involving sedation (medications, monitoring) were recorded. Deep sedation was defined as Richmond Agitation-Sedation Scale of -3 to -5 or Sedation-Agitation Scale of 2 or 1. A total of 324 patients were studied. Emergency department deep sedation was observed in 171 patients (52.8%), and was associated with a higher frequency of deep sedation in the ICU on day 1 (53.8% vs 20.3%; p < 0.001) and day 2 (33.3% vs 16.9%; p = 0.001), when compared to light sedation. Mean (SD) ventilator-free days were 18.1 (10.8) in the emergency department deep sedation group compared to 20.0 (9.8) in the light sedation group (mean difference, 1.9; 95% CI, -0.40 to 4.13). Similar results according to emergency department sedation depth existed for ICU-free days (mean difference, 1.6; 95% CI, -0.54 to 3.83) and hospital-free days (mean difference, 2.3; 95% CI, 0.26-4.32). Mortality was 21.1% in the deep sedation group and 17.0% in the light sedation group (between-group difference, 4.1%; odds ratio, 1.30; 0.74-2.28). The occurrence rate of acute brain dysfunction (delirium and coma) was 68.4% in the deep sedation group and 55.6% in the light sedation group (between-group difference, 12.8%; odds ratio, 1.73; 1.10-2.73). CONCLUSIONS: Early deep sedation in the emergency department is common, carries over into the ICU, and may be associated with worse outcomes. Sedation practice in the emergency department and its association with clinical outcomes is in need of further investigation.

One-year mortality after recovery from critical illness: A retrospective cohort study.

RATIONALE: Factors associated with one-year mortality after recovery from critical illness are not well understood. Clinicians generally lack information regarding post-hospital discharge outcomes of patients from the intensive care unit, which may be important when counseling patients and families. OBJECTIVE: We sought to determine which factors among patients who survived for at least 30 days post-ICU admission are associated with one-year mortality. METHODS: Single-center, longitudinal retrospective cohort study of all ICU patients admitted to a tertiary-care academic medical center from 2001-2012 who survived ≥30 days from ICU admission. Cox's proportional hazards model was used to identify the variables that are associated with one-year mortality. The primary outcome was one-year mortality. RESULTS: 32,420 patients met the inclusion criteria and were included in the study. Among patients who survived to ≥30 days, 28,583 (88.2%) survived for greater than one year, whereas 3,837 (11.8%) did not. Variables associated with decreased one-year survival include: increased age, malignancy, number of hospital admissions within the prior year, duration of mechanical ventilation and vasoactive agent use, sepsis, history of congestive heart failure, end-stage renal disease, cirrhosis, chronic obstructive pulmonary disease, and the need for renal replacement therapy. Numerous effect modifications between these factors were found. CONCLUSION: Among survivors of critical illness, a significant number survive less than one year. More research is needed to help clinicians accurately identify those patients who, despite surviving their acute illness, are likely to suffer one-year mortality, and thereby to improve the quality of the decisions and care that impact this outcome.

Phenotyping Hypotensive Patients in Critical Care Using Hospital Discharge Summaries.

Among critically-ill patients, hypotension represents a failure in compensatory mechanisms and may lead to organ hypoperfusion and failure. In this work, we adopt a data-driven approach for phenotype discovery and visualization of patient similarity and cohort structure in the intensive care unit (ICU). We used Hierarchical Dirichlet Process (HDP) as a nonparametric topic modeling technique to automatically learn a d-dimensional feature representation of patients that captures the latent "topic" structure of diseases, symptoms, medications, and findings documented in hospital discharge summaries. We then used the t-Distributed Stochastic Neighbor Embedding (t-SNE) algorithm to convert the d-dimensional latent structure learned from HDP into a matrix of pairwise similarities for visualizing patient similarity and cohort structure. Using discharge summaries of a large patient cohort from the MIMIC II database, we evaluated the clinical utility of the discovered topic structure in phenotyping critically-ill patients who experienced hypotensive episodes. Our results indicate that the approach is able to reveal clinically interpretable clustering structure within our cohort and may potentially provide valuable insights to better understand the association between disease phenotypes and outcomes.

Reasons for death in patients with sepsis and septic shock.

PURPOSE: Understanding the underlying cause of mortality in sepsis has broad implications for both clinical care and interventional trial design. However, reasons for death in sepsis remain poorly understood. We sought to characterize reasons for in-hospital mortality in a population of patients with sepsis or septic shock. MATERIALS AND METHODS: We performed a retrospective review of patients admitted to the intensive care unit with sepsis or septic shock who died during their index admission. Reasons for death were classified into 6 categories determined a priori by group consensus. Interrater reliability was calculated and Fleiss κ reported. The associations between selected patient characteristics (eg, serum lactate) and reason for death were also assessed. RESULTS: One hundred fifteen patients were included. Refractory shock (40%) and comorbid withdrawal of care (44%) were the most common reasons for death. Overall interrater agreement was substantial (κ = 0.61, P<.01). Lactate was higher in patients who died because of refractory shock as compared with those who died for other reasons (4.7 vs 2.8 mmol/L, P<.01). CONCLUSION: In this retrospective cohort, refractory shock and comorbid withdrawal of care were the most common reasons for death. Following prospective validation, the classification methodology presented here may be useful in the design/interpretation of trials in sepsis.

Absolute lactate value vs relative reduction as a predictor of mortality in severe sepsis and septic shock.

PURPOSE: Lactate reduction, a common method of risk stratification, has been variably defined. Among patients with an initial lactate >4mmol/L, we compared mortality prediction between a subsequent lactate ≥4mmol/L to a <10% and <20% decrease between initial and subsequent lactate values. MATERIALS AND METHODS: We performed a single-center retrospective study of patients presenting to the emergency department with an initial lactate ≥4mmol/L and suspected infection. Patients were stratified by lactate reduction using 3 previously identified definitions (subsequent lactate ≥4mmol/L, and <10% and <20% relative decrease in lactate) and compared using multivariable logistic regression. Sensitivity and specificity were compared using McNemar test. RESULTS: A subsequent lactate ≥4mmol/L and a lactate reduction <20% were associated with increased in-hospital mortality (odds ratio [OR], 3.18; 95% confidence interval [CI], 1.24-8.16; P=.02 and OR, 3.11; 95% CI, 1.39-6.96; P=.006, respectively), whereas a lactate reduction <10% was not (OR, 1.13; 95% CI, 0.94-1.34; P=.11). A subsequent lactate ≥4mmol/L and a lactate reduction <20% were more sensitive than a lactate reduction <10% (72% vs 41%, P=.002 and 62% vs 41%, P=.008, respectively) but less specific (57% vs 76%, P<.001 and 67% vs 76%, P=.002, respectively). CONCLUSIONS: A subsequent lactate ≥4mmol/L and lactate reduction <20% were associated with increased in-hospital mortality, whereas a lactate reduction <10% was not. Sensitivity and specificity are different between these parameters.

Datathons and Software to Promote Reproducible Research.

BACKGROUND: Datathons facilitate collaboration between clinicians, statisticians, and data scientists in order to answer important clinical questions. Previous datathons have resulted in numerous publications of interest to the critical care community and serve as a viable model for interdisciplinary collaboration. OBJECTIVE: We report on an open-source software called Chatto that was created by members of our group, in the context of the second international Critical Care Datathon, held in September 2015. METHODS: Datathon participants formed teams to discuss potential research questions and the methods required to address them. They were provided with the Chatto suite of tools to facilitate their teamwork. Each multidisciplinary team spent the next 2 days with clinicians working alongside data scientists to write code, extract and analyze data, and reformulate their queries in real time as needed. All projects were then presented on the last day of the datathon to a panel of judges that consisted of clinicians and scientists. RESULTS: Use of Chatto was particularly effective in the datathon setting, enabling teams to reduce the time spent configuring their research environments to just a few minutes-a process that would normally take hours to days. Chatto continued to serve as a useful research tool after the conclusion of the datathon. CONCLUSIONS: This suite of tools fulfills two purposes: (1) facilitation of interdisciplinary teamwork through archiving and version control of datasets, analytical code, and team discussions, and (2) advancement of research reproducibility by functioning postpublication as an online environment in which independent investigators can rerun or modify analyses with relative ease. With the introduction of Chatto, we hope to solve a variety of challenges presented by collaborative data mining projects while improving research reproducibility.

Disease heterogeneity and risk stratification in sepsis-related occult hypoperfusion: A retrospective cohort study.

PURPOSE: Occult hypoperfusion is associated with increased mortality in patients with sepsis. We sought to determine the practice patterns and outcomes of patients with sepsis-related occult hypoperfusion and introduce a potential method for risk stratification. MATERIALS AND METHODS: Single-center retrospective study of normotensive patients presenting to an urban tertiary care emergency department with lactate greater than or equal to 4 mmol/L and suspected infection. χ(2) Testing, Spearman, and Wilcoxon coefficients were used to compare binary, parametric, and nonparametric data, respectively. Patients were divided into 4 groups based on lactate clearance (<4 mmol/L) and the presence of respiratory distress while in the emergency department; outcomes were compared using χ(2) test and analysis of variance. RESULTS: Median initial lactate was 4.7 mmol/L (interquartile range, 4.2-6.4), and 34 (45.2%) of 73 exhibited respiratory distress. Hyperlactatemia resolved in 67.1% (49/73) of patients. Mortality was 23.3% (17/73), and 19.1% (14/73) required vasopressors. In patients with lactate clearance and without respiratory distress (n = 27), mortality was 0%, and none required vasopressors. In patients with persistent hyperlactatemia and/or respiratory distress (n = 46), 30.4% required vasopressors, and the mortality was 37.0% (P < .01 and P < .01, respectively). CONCLUSIONS: Patients defined as having occult hypoperfusion comprise a heterogeneous group with a varied degree of illness severity. Identifying those with low risk of clinical deterioration may be important for titration of care.