Characteristics, Outcomes, and Trends of Patients With COVID-19-Related Critical Illness at a Learning Health System in the United States.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic continues to surge in the United States and globally. OBJECTIVE: To describe the epidemiology of COVID-19-related critical illness, including trends in outcomes and care delivery. DESIGN: Single-health system, multihospital retrospective cohort study. SETTING: 5 hospitals within the University of Pennsylvania Health System. PATIENTS: Adults with COVID-19-related critical illness who were admitted to an intensive care unit (ICU) with acute respiratory failure or shock during the initial surge of the pandemic. MEASUREMENTS: The primary exposure for outcomes and care delivery trend analyses was longitudinal time during the pandemic. The primary outcome was all-cause 28-day in-hospital mortality. Secondary outcomes were all-cause death at any time, receipt of mechanical ventilation (MV), and readmissions. RESULTS: Among 468 patients with COVID-19-related critical illness, 319 (68.2%) were treated with MV and 121 (25.9%) with vasopressors. Outcomes were notable for an all-cause 28-day in-hospital mortality rate of 29.9%, a median ICU stay of 8 days (interquartile range [IQR], 3 to 17 days), a median hospital stay of 13 days (IQR, 7 to 25 days), and an all-cause 30-day readmission rate (among nonhospice survivors) of 10.8%. Mortality decreased over time, from 43.5% (95% CI, 31.3% to 53.8%) to 19.2% (CI, 11.6% to 26.7%) between the first and last 15-day periods in the core adjusted model, whereas patient acuity and other factors did not change. LIMITATIONS: Single-health system study; use of, or highly dynamic trends in, other clinical interventions were not evaluated, nor were complications. CONCLUSION: Among patients with COVID-19-related critical illness admitted to ICUs of a learning health system in the United States, mortality seemed to decrease over time despite stable patient characteristics. Further studies are necessary to confirm this result and to investigate causal mechanisms. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality.

Clinician Perception of a Machine Learning-Based Early Warning System Designed to Predict Severe Sepsis and Septic Shock.

OBJECTIVE: To assess clinician perceptions of a machine learning-based early warning system to predict severe sepsis and septic shock (Early Warning System 2.0). DESIGN: Prospective observational study. SETTING: Tertiary teaching hospital in Philadelphia, PA. PATIENTS: Non-ICU admissions November-December 2016. INTERVENTIONS: During a 6-week study period conducted 5 months after Early Warning System 2.0 alert implementation, nurses and providers were surveyed twice about their perceptions of the alert's helpfulness and impact on care, first within 6 hours of the alert, and again 48 hours after the alert. MEASUREMENTS AND MAIN RESULTS: For the 362 alerts triggered, 180 nurses (50% response rate) and 107 providers (30% response rate) completed the first survey. Of these, 43 nurses (24% response rate) and 44 providers (41% response rate) completed the second survey. Few (24% nurses, 13% providers) identified new clinical findings after responding to the alert. Perceptions of the presence of sepsis at the time of alert were discrepant between nurses (13%) and providers (40%). The majority of clinicians reported no change in perception of the patient's risk for sepsis (55% nurses, 62% providers). A third of nurses (30%) but few providers (9%) reported the alert changed management. Almost half of nurses (42%) but less than a fifth of providers (16%) found the alert helpful at 6 hours. CONCLUSIONS: In general, clinical perceptions of Early Warning System 2.0 were poor. Nurses and providers differed in their perceptions of sepsis and alert benefits. These findings highlight the challenges of achieving acceptance of predictive and machine learning-based sepsis alerts.

A Machine Learning Algorithm to Predict Severe Sepsis and Septic Shock: Development, Implementation, and Impact on Clinical Practice.

OBJECTIVES: Develop and implement a machine learning algorithm to predict severe sepsis and septic shock and evaluate the impact on clinical practice and patient outcomes. DESIGN: Retrospective cohort for algorithm derivation and validation, pre-post impact evaluation. SETTING: Tertiary teaching hospital system in Philadelphia, PA. PATIENTS: All non-ICU admissions; algorithm derivation July 2011 to June 2014 (n = 162,212); algorithm validation October to December 2015 (n = 10,448); silent versus alert comparison January 2016 to February 2017 (silent n = 22,280; alert n = 32,184). INTERVENTIONS: A random-forest classifier, derived and validated using electronic health record data, was deployed both silently and later with an alert to notify clinical teams of sepsis prediction. MEASUREMENT AND MAIN RESULT: Patients identified for training the algorithm were required to have International Classification of Diseases, 9th Edition codes for severe sepsis or septic shock and a positive blood culture during their hospital encounter with either a lactate greater than 2.2 mmol/L or a systolic blood pressure less than 90 mm Hg. The algorithm demonstrated a sensitivity of 26% and specificity of 98%, with a positive predictive value of 29% and positive likelihood ratio of 13. The alert resulted in a small statistically significant increase in lactate testing and IV fluid administration. There was no significant difference in mortality, discharge disposition, or transfer to ICU, although there was a reduction in time-to-ICU transfer. CONCLUSIONS: Our machine learning algorithm can predict, with low sensitivity but high specificity, the impending occurrence of severe sepsis and septic shock. Algorithm-generated predictive alerts modestly impacted clinical measures. Next steps include describing clinical perception of this tool and optimizing algorithm design and delivery.

Combined Biomarkers Predict Acute Mortality Among Critically Ill Patients With Suspected Sepsis.

OBJECTIVES: Sepsis is associated with high early and total in-hospital mortality. Despite recent revisions in the diagnostic criteria for sepsis that sought to improve predictive validity for mortality, it remains difficult to identify patients at greatest risk of death. We compared the utility of nine biomarkers to predict mortality in subjects with clinically suspected bacterial sepsis. DESIGN: Cohort study. SETTING: The medical and surgical ICUs at an academic medical center. SUBJECTS: We enrolled 139 subjects who met two or more systemic inflammatory response syndrome (systemic inflammatory response syndrome) criteria and received new broad-spectrum antibacterial therapy. INTERVENTIONS: We assayed nine biomarkers (α-2 macroglobulin, C-reactive protein, ferritin, fibrinogen, haptoglobin, procalcitonin, serum amyloid A, serum amyloid P, and tissue plasminogen activator) at onset of suspected sepsis and 24, 48, and 72 hours thereafter. We compared biomarkers between groups based on both 14-day and total in-hospital mortality and evaluated the predictive validity of single and paired biomarkers via area under the receiver operating characteristic curve. MEASUREMENTS AND MAIN RESULTS: Fourteen-day mortality was 12.9%, and total in-hospital mortality was 29.5%. Serum amyloid P was significantly lower (4/4 timepoints) and tissue plasminogen activator significantly higher (3/4 timepoints) in the 14-day mortality group, and the same pattern held for total in-hospital mortality (Wilcoxon p ≤ 0.046 for all timepoints). Serum amyloid P and tissue plasminogen activator demonstrated the best individual predictive performance for mortality, and combinations of biomarkers including serum amyloid P and tissue plasminogen activator achieved greater predictive performance (area under the receiver operating characteristic curve > 0.76 for 14-d and 0.74 for total mortality). CONCLUSIONS: Combined biomarkers predict risk for 14-day and total mortality among subjects with suspected sepsis. Serum amyloid P and tissue plasminogen activator demonstrated the best discriminatory ability in this cohort.

A randomized trial of nighttime physician staffing in an intensive care unit.

BACKGROUND: Increasing numbers of intensive care units (ICUs) are adopting the practice of nighttime intensivist staffing despite the lack of experimental evidence of its effectiveness. METHODS: We conducted a 1-year randomized trial in an academic medical ICU of the effects of nighttime staffing with in-hospital intensivists (intervention) as compared with nighttime coverage by daytime intensivists who were available for consultation by telephone (control). We randomly assigned blocks of 7 consecutive nights to the intervention or the control strategy. The primary outcome was patients' length of stay in the ICU. Secondary outcomes were patients' length of stay in the hospital, ICU and in-hospital mortality, discharge disposition, and rates of readmission to the ICU. For length-of-stay outcomes, we performed time-to-event analyses, with data censored at the time of a patient's death or transfer to another ICU. RESULTS: A total of 1598 patients were included in the analyses. The median Acute Physiology and Chronic Health Evaluation (APACHE) III score (in which scores range from 0 to 299, with higher scores indicating more severe illness) was 67 (interquartile range, 47 to 91), the median length of stay in the ICU was 52.7 hours (interquartile range, 29.0 to 113.4), and mortality in the ICU was 18%. Patients who were admitted on intervention days were exposed to nighttime intensivists on more nights than were patients admitted on control days (median, 100% of nights [interquartile range, 67 to 100] vs. median, 0% [interquartile range, 0 to 33]; P<0.001). Nonetheless, intensivist staffing on the night of admission did not have a significant effect on the length of stay in the ICU (rate ratio for the time to ICU discharge, 0.98; 95% confidence interval [CI], 0.88 to 1.09; P=0.72), ICU mortality (relative risk, 1.07; 95% CI, 0.90 to 1.28), or any other end point. Analyses restricted to patients who were admitted at night showed similar results, as did sensitivity analyses that used different definitions of exposure and outcome. CONCLUSIONS: In an academic medical ICU in the United States, nighttime in-hospital intensivist staffing did not improve patient outcomes. (Funded by University of Pennsylvania Health System and others; ClinicalTrials.gov number, NCT01434823.).

Association Between Index Hospitalization and Hospital Readmission in Sepsis Survivors.

OBJECTIVES: Hospital readmission is common after sepsis, yet the relationship between the index admission and readmission remains poorly understood. We sought to examine the relationship between infection during the index acute care hospitalization and readmission and to identify potentially modifiable factors during the index sepsis hospitalization associated with readmission. DESIGN: In a retrospective cohort study, we evaluated 444 sepsis survivors at risk of an unplanned hospital readmission in 2012. The primary outcome was 30-day unplanned hospital readmission. SETTING: Three hospitals within an academic healthcare system. SUBJECTS: Four hundred forty-four sepsis survivors. MEASUREMENTS AND MAIN RESULTS: Of 444 sepsis survivors, 23.4% (95% CI, 19.6-27.6%) experienced an unplanned 30-day readmission compared with 10.1% (95% CI, 9.6-10.7%) among 11,364 nonsepsis survivors over the same time period. The most common cause for readmission after sepsis was infection (69.2%, 72 of 104). Among infection-related readmissions, 51.4% were categorized as recurrent/unresolved. Patients with sepsis present on their index admission who also developed a hospital-acquired infection ("second hit") were nearly twice as likely to have an unplanned 30-day readmission compared with those who presented with sepsis at admission and did not develop a hospital-acquired infection or those who presented without infection and then developed hospital-acquired sepsis (38.6% vs 22.2% vs 20.0%, p = 0.04). Infection-related hospital readmissions, specifically, were more likely in patients with a "second hit" and patients receiving a longer duration of antibiotics. The use of total parenteral nutrition (p = 0.03), longer duration of antibiotics (p = 0.047), prior hospitalizations, and lower discharge hemoglobin (p = 0.04) were independently associated with hospital readmission. CONCLUSIONS: We confirmed that the majority of unplanned hospital readmissions after sepsis are due to an infection. We found that patients with sepsis at admission who developed a hospital-acquired infection, and those who received a longer duration of antibiotics, appear to be high-risk groups for unplanned, all-cause 30-day readmissions and infection-related 30-day readmissions.

Hospital-based acute care use in survivors of septic shock.

OBJECTIVES: Septic shock is associated with increased long-term morbidity and mortality. However, little is known about the use of hospital-based acute care in survivors after hospital discharge. The objectives of the study were to examine the frequency, timing, causes, and risk factors associated with emergency department visits and hospital readmissions within 30 days of discharge. DESIGN: Retrospective cohort study. SETTING: Tertiary, academic hospital in the United States. PATIENTS: Patients admitted with septic shock (serum lactate≥4 mmol/L or refractory hypotension) and discharged alive to a nonhospice setting between 2007 and 2010. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The coprimary outcomes were all-cause hospital readmission and emergency department visits (treat-and-release encounters) within 30 days to any of the three health system hospitals. Of 269 at-risk survivors, 63 (23.4%; 95% CI, 18.2-28.5) were readmitted within 30 days of discharge and another 12 (4.5%; 95% CI, 2.3-7.7) returned to the emergency department for a treat-and-release visit. Readmissions occurred within 15 days of discharge in 75% of cases and were more likely in oncology patients (p=0.001) and patients with a longer hospital length of stay (p=0.04). Readmissions were frequently due to another life-threatening condition and resulted in death or discharge to hospice in 16% of cases. The reasons for readmission were deemed potentially related to the index septic shock hospitalization in 78% (49 of 63) of cases. The most common cause was infection related, accounting for 46% of all 30-day readmissions, followed by cardiovascular or thromboembolic events (18%). CONCLUSIONS: The use of hospital-based acute care appeared to be common in septic shock survivors. Encounters often led to readmission within 15 days of discharge, were frequently due to another acute condition, and appeared to result in substantial morbidity and mortality. Given the potential public health implications of these findings, validation studies are needed.

Microbiome Profiling Demonstrates Concordance of Endotracheal Tube Aspirates With Direct Lower Airway Sampling in Intubated Patients.

BACKGROUND: Endotracheal aspirates (ETAs) are widely used for microbiologic studies of the respiratory tract in intubated patients. However, they involve sampling through an established endotracheal tube using suction catheters, both of which can acquire biofilms that may confound results. RESEARCH QUESTION: Does standard clinical ETA in intubated patients accurately reflect the authentic lower airway bacterial microbiome? STUDY DESIGN AND METHODS: Comprehensive quantitative bacterial profiling using 16S rRNA V1-V2 gene sequencing was applied to compare bacterial populations captured by standard clinical ETA vs contemporaneous gold standard samples acquired directly from the lower airways through a freshly placed sterile tracheostomy tube. The study included 13 patients undergoing percutaneous tracheostomy following prolonged (median, 15 days) intubation. Metrics of bacterial composition, diversity, and relative quantification were applied to samples. RESULTS: Pre-tracheostomy ETAs closely resembled the gold standard immediate post-tracheostomy airway microbiomes in bacterial composition and community features of diversity and quantification. Endotracheal tube and suction catheter biofilms also resembled cognate ETA and fresh tracheostomy communities. INTERPRETATION: Unbiased molecular profiling shows that standard clinical ETA sampling has good concordance with the authentic lower airway microbiome in intubated patients.

Severe sepsis cohorts derived from claims-based strategies appear to be biased toward a more severely ill patient population.

OBJECTIVE: The epidemiology of severe sepsis is derived from administrative databases that rely on International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes to select cases. We compared the sensitivity of two code abstraction methods in identifying severe sepsis cases using a severe sepsis registry. DESIGN: Single-center retrospective cohort study. SETTING: Tertiary care, Academic, University Hospital. PATIENTS: One thousand seven hundred thirty-five patients with severe sepsis or septic shock. INTERVENTIONS: None. MEASUREMENTS: Proportion identified as severe sepsis using two code abstraction methods: 1) the new specific ICD-9 codes for severe sepsis and septic shock, and 2) a validated method requiring two ICD-9 codes for infection and end-organ dysfunction. Multivariable logistic regression was performed to determine sociodemographics and clinical characteristics associated with documentation and coding accuracy. MAIN RESULTS: The strategy combining a code for infection and end-organ dysfunction was more sensitive in identifying cases than the method requiring specific ICD-9 codes for severe sepsis or septic shock (47% vs. 21%). Elevated serum lactate level (p<0.001), ICU admission (p<0.001), presence of shock (p<0.001), bacteremia as the source of sepsis (p=0.02), and increased Acute Physiology and Chronic Health Evaluation II score (p<0.001) were independently associated with being appropriately documented and coded. The 28-day mortality was significantly higher in those who were accurately documented/coded (41%, compared with 14% in those who were not, p<0.001), reflective of a more severe presentation on admission. CONCLUSIONS: Patients admitted with severe sepsis and septic shock were incompletely documented and under-coded, using either ICD-9 code abstracting method. Documentation of subsequent coding of severe sepsis was more common in more severely ill patients. These findings are important when evaluating current national estimates and when interpreting epidemiologic studies of severe sepsis as cohorts derived from claims-based strategies appear to be biased toward a more severely ill patient population.

Use of therapeutic hypothermia after in-hospital cardiac arrest.

OBJECTIVES: Formal guidelines recommend that therapeutic hypothermia be considered after in-hospital cardiac arrest. The rate of therapeutic hypothermia use after in-hospital cardiac arrest and details about its implementation are unknown. We aimed to determine the use of therapeutic hypothermia for adult in-hospital cardiac arrest, whether use has increased over time, and to identify factors associated with its use. DESIGN: Multicenter, prospective cohort study. SETTING: A total of 538 hospitals participating in the Get With the Guidelines-Resuscitation database (2003-2009). PATIENTS: A total of 67,498 patients who had return of spontaneous circulation after in-hospital cardiac arrest. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the initiation of therapeutic hypothermia. We measured the proportion of therapeutic hypothermia patients who achieved target temperature (32-34 °C) and were overcooled. Of 67,498 patients, therapeutic hypothermia was initiated in 1,367 patients (2.0%). The target temperature (32-34 °C) was not achieved in 44.3% of therapeutic hypothermia patients within 24 hours and 17.6% were overcooled. The use of therapeutic hypothermia increased from 0.7% in 2003 to 3.3% in 2009 (p < 0.001). We found that younger age (p < 0.001) and occurrence in a non-ICU location (p < 0.001), on a weekday (p = 0.005), and in a teaching hospital (p = 0.001) were associated with an increased likelihood of therapeutic hypothermia being initiated. CONCLUSIONS: After in-hospital cardiac arrest, therapeutic hypothermia was used rarely. Once initiated, the target temperature was commonly not achieved. The frequency of use increased over time but remained low. Factors associated with therapeutic hypothermia use included patient age, time and location of occurrence, and type of hospital.

The impact of documentation of severe acute kidney injury on mortality.

AIMS: Modification of the mortality risk associated with acute kidney injury (AKI) necessitates recognition of AKI when it occurs. We sought to determine whether formal documentation of AKI in the medical record, assessed by billing codes for AKI, would be associated with improved clinical outcomes. METHODS: Retrospective cohort study conducted at three hospitals within a single university health system. Adults without severe underlying kidney disease who suffered in-hospital AKI as defined by a doubling of baseline creatinine (n = 5,438) were included. Those whose AKI was formally documented according to discharge billing codes were compared to those without such documentation in terms of 30-day mortality. RESULTS: Formal documentation of AKI occurred in 2,325 patients (43%). Higher baseline creatinine, higher peak creatinine, medical admission status, and higher Sequential Organ Failure Assessment (SOFA) score were strongly associated with documentation of AKI. After adjustment for severity of disease, formal AKI documentation was associated with reduced 30-day mortality - OR 0.81 (0.68 - 0.96, p = 0.02). Patients with formal documentation were more likely to receive a nephrology consultation (31% vs. 6%, p < 0.001) and fluid boluses (64% vs. 45%, p < 0.001), and had a more rapid discontinuation of angiotensin-converting enzyme inhibitor and angiotensin-receptor blocker medications (HR 2.04, CI 1.69 - 2.46, p < 0.001). CONCLUSIONS: Formal documentation of AKI is associated with improved survival after adjustment for illness severity among patients with creatinine-defined AKI.

The Mortality Review Committee: a novel and scalable approach to reducing inpatient mortality.

BACKGROUND: Despite the importance of reducing inpatient mortality, little has been reported about establishing a hospitalwide, systematic process to review and address inpatient deaths. In 2006 the University of Pennsylvania Health System's Mortality Review Committee was established and charged with reducing inpatient mortality as measured by the mortality index--observed/expected mortality. METHODS: Between 2006 and 2012, through interdisciplinary meetings and analysis of administrative data and chart reviews, the Mortality Review Committee identified a number of opportunities for improvement in the quality of patient care. Several programmatic interventions, such as those aimed at improving sepsis and delirium recognition and management, were initiated through the committee. RESULTS: During the committee's first six years of activity, the University HealthSystem Consortium (UHC) mortality index decreased from 1.08 to 0.53, with observed mortality decreasing from 2.45% to 1.62%. Interventions aimed at improving sepsis management implemented between 2007 and 2008 were associated with increases in severe sepsis survival from 40% to 56% and septic shock survival from 42% to 54%. The mortality index for sepsis decreased from 2.45 to 0.88. Efforts aimed at improving delirium management implemented between 2008 and 2009 were associated with an increase in the proportion of patients receiving a "timely" intervention from 18% to 57% and with a twofold increase in the percentage of patients discharged to home. DISCUSSION: The establishment of a mortality review committee was associated with a significant reduction in the mortality index. Keys to success include interdisciplinary membership, partnerships with local providers, and a multipronged approach to identifying important clinical opportunities and to implementing effective interventions.

Improving physician clinical documentation quality: evaluating two self-efficacy-based training programs.

BACKGROUND: Clinical documentation is critical to health care quality and cost. The generally poor quality of such documentation has been well recognized, yet medical students, residents, and physicians receive little or no training in it. When clinical documentation quality (CDQ) training for residents and/or physicians is provided, it excludes key constructs of self-efficacy: vicarious learning (e.g., peer demonstration) and mastery (i.e., practice). CDQ training that incorporates these key self-efficacy constructs is more resource intensive. If such training could be shown to be more effective at enhancing clinician performance, it would support the investment of the additional resources required by health care systems and residency training programs. PURPOSES: The aim of this study was to test the impact of CDQ training on clinician self-efficacy and performance and the relative efficacy of intervention designs employing two versus all four self-efficacy constructs. METHODOLOGY/APPROACH: Ninety-one internal medicine residents at a major academic medical center in the northeastern United States were assigned to one of two self-efficacy-based training groups or a control group, with CDQ and clinical documentation self-efficacy measured before and after the interventions. A structural equation model (AMOS) allowed for testing the six hypotheses in the context of the whole study, and findings were cross-validated using traditional regression. FINDINGS: Although both interventions increased CDQ, the training designed to include all four self-efficacy constructs had a significantly greater impact on improving CDQ. It also increased self-efficacy. PRACTICE IMPLICATIONS: CDQ may be significantly improved and sustained by (a) training physicians in clinical documentation and (b) employing all four self-efficacy constructs in such training designs.

Timing of neuroprognostication in postcardiac arrest therapeutic hypothermia*.

OBJECTIVE: Early assessment of neurologic recovery is often challenging in survivors of cardiac arrest. Further, little is known about when to assess neurologic status in comatose, postarrest patients receiving therapeutic hypothermia. We sought to evaluate timing of prognostication in cardiac arrest survivors who received therapeutic hypothermia. DESIGN: A retrospective chart review of consecutive postarrest patients receiving therapeutic hypothermia (protocol: 24-hr maintenance at target temperature followed by rewarming over 8 hrs). Data were abstracted from the medical chart, including documentation during the first 96 hrs post arrest of "poor" prognosis, diagnostic tests for neuroprognostication, consultations used for determination of prognosis, and outcome at discharge. SETTING: Two academic urban emergency departments. PATIENTS: A total of 55 consecutive patients who underwent therapeutic hypothermia were reviewed between September 2005 and April 2009. INTERVENTION: None. RESULTS: Of our cohort of comatose postarrest patients, 59% (29 of 49) were male, and the mean age was 56 ± 16 yrs. Chart documentation of "poor" or "grave" prognosis occurred "early": during induction, maintenance of cooling, rewarming, or within 15 hrs after normothermia in 57% (28 of 49) of cases. Of patients with early documentation of poor prognosis, 25% (seven of 28) had care withdrawn within 72 hrs post arrest, and 21% (six of 28) survived to discharge with favorable neurologic recovery. In the first 96 hrs post arrest: 88% (43 of 49) of patients received a head computed tomography, 90% (44 of 49) received electroencephalography, 2% (one of 49) received somatosensory evoked potential testing, and 71% (35 of 49) received neurology consultation. CONCLUSIONS: Documentation of "poor prognosis" occurred during therapeutic hypothermia in more than half of patients in our cohort. Premature documentation of poor prognosis may contribute to early decisions to withdraw care. Future guidelines should address when to best prognosticate in postarrest patients receiving therapeutic hypothermia.

ANGPT2 genetic variant is associated with trauma-associated acute lung injury and altered plasma angiopoietin-2 isoform ratio.

RATIONALE: Acute lung injury (ALI) acts as a complex genetic trait, yet its genetic risk factors remain incompletely understood. Large-scale genotyping has not previously been reported for ALI. OBJECTIVES: To identify ALI risk variants after major trauma using a large-scale candidate gene approach. METHODS: We performed a two-stage genetic association study. We derived findings in an African American cohort (n = 222) using a cardiopulmonary disease-centric 50K single nucleotide polymorphism (SNP) array. Genotype and haplotype distributions were compared between subjects with ALI and without ALI, with adjustment for clinical factors. Top performing SNPs (P < 10(-4)) were tested in a multicenter European American trauma-associated ALI case-control population (n = 600 ALI; n = 2,266 population-based control subjects) for replication. The ALI-associated genomic region was sequenced, analyzed for in silico prediction of function, and plasma was assayed by ELISA and immunoblot. MEASUREMENTS AND MAIN RESULTS: Five SNPs demonstrated a significant association with ALI after adjustment for covariates in Stage I. Two SNPs in ANGPT2 (rs1868554 and rs2442598) replicated their significant association with ALI in Stage II. rs1868554 was robust to multiple comparison correction: odds ratio 1.22 (1.06-1.40), P = 0.0047. Resequencing identified predicted novel splice sites in linkage disequilibrium with rs1868554, and immunoblots showed higher proportion of variant angiopoietin-2 (ANG2) isoform associated with rs1868554T (0.81 vs. 0.48; P = 0.038). CONCLUSIONS: An ANGPT2 region is associated with both ALI and variation in plasma angiopoietin-2 isoforms. Characterization of the variant isoform and its genetic regulation may yield important insights about ALI pathogenesis and susceptibility.

Racial Disparities in Occult Hypoxemia and Clinically Based Mitigation Strategies to Apply in Advance of Technological Advancements.

BACKGROUND: Pulse oximetry is the mainstay of patient oxygen monitoring. Measurement error from pulse oximetry is more common for those with darker skin pigmentation, yet this topic remains understudied, and evidence-based clinical mitigation strategies do not currently exist. Our objectives were to measure the rate of occult hypoxemia, defined as arterial oxygen saturation (SaO2 ) < 88% when pulse oximeter oxygen saturation was between 92-96%, in a racially diverse critically ill population; to analyze degree, direction, and consistency of measurement error; and to develop a mitigation strategy that minimizes occult hypoxemia in advance of technological advancements. METHODS: We performed a multi-center retrospective cohort study of critically ill subjects. RESULTS: Among 105,467 paired observations from 7,693 subjects, we found occult hypoxemia was more common among minority subjects. The frequency of occult hypoxemia was 7.9% versus 2.9% between Black and white subjects, respectively, (P < .001). Pulse oximeter measurement errors were inconsistent throughout a patient encounter, with 67% of encounters having a range of intra-subject measurement errors > 4 percentage points. In 75% of encounters, the intra-subject errors were bidirectional. SaO2 < 88% was less common at higher pulse oximeter oxygenation ranges (4.1% and 1.8% of observations among Black and white subjects at a pulse oximeter threshold of 94-98%). Although occult hypoxemia was further reduced at oxygenation saturation range 95-100%, the frequency of hyperoxemia (partial pressure of arterial oxygen > 110 mm Hg) became more common, occurring in 42.3% of Black and 46.0% of white observations. CONCLUSIONS: Measurement error in pulse oximetry is common for all racial groups, but occult hypoxemia occurred most commonly in Black subjects. The highly variable magnitude and direction of measurement error preclude an individualized mitigation approach. In advance of technological advancements, we recommend targeting a pulse oximetry saturation goal of 94-98% for all patients.

Well-Being Among Respiratory Therapists in an Academic Medical Center During the COVID-19 Pandemic.

BACKGROUND: Recent studies have revealed high rates of burnout among respiratory therapists (RTs), which has implications for patient care and outcomes as well as for the health care workforce. We sought to better understand RT well-being during the COVID-19 pandemic. The purpose of this study was to determine rates and identify determinants of well-being, including burnout and professional fulfillment, among RTs in ICUs. METHODS: We conducted a mixed-methods study comprised of a survey administered quarterly from July 2020-May 2021 to critical-care health care professionals and semi-structured interviews from April-May 2021 with 10 ICU RTs within a single health center. We performed multivariable analyses to compare RT well-being to other professional groups and to evaluate changes in well-being over time. We analyzed qualitative interview data using thematic analysis, followed by mapping themes to the Maslow needs hierarchy. RESULTS: One hundred eight RTs responded to at least one quarterly survey. Eighty-two (75%) experienced burnout; 39 (36%) experienced professional fulfillment, and 62 (58%) reported symptoms of depression. Compared to clinicians of other professions in multivariable analyses, RTs were significantly more likely to experience burnout (odds ratio 2.32 [95% CI 1.41-3.81]) and depression (odds ratio 2.73 [95% CI 1.65-4.51]) and less likely to experience fulfillment (odds ratio 0.51 [95% CI 0.31-0.85]). We found that staffing challenges, safety concerns, workplace conflict, and lack of work-life balance led to burnout. Patient care, use of specialized skills, appreciation and a sense of community at work, and purpose fostered professional fulfillment. Themes identified were mapped to Maslow's hierarchy of needs; met needs led to professional fulfillment, and unmet needs led to burnout. CONCLUSIONS: ICU RTs experienced burnout during the pandemic at rates higher than other professions. To address RT needs, institutions should design and implement strategies to reduce burnout across all levels.

Performance of an automated electronic acute lung injury screening system in intensive care unit patients.

OBJECTIVE: Lung protective ventilation reduces mortality in patients with acute lung injury, but underrecognition of acute lung injury has limited its use. We recently validated an automated electronic acute lung injury surveillance system in patients with major trauma in a single intensive care unit. In this study, we assessed the system's performance as a prospective acute lung injury screening tool in a diverse population of intensive care unit patients. DESIGN: Patients were screened prospectively for acute lung injury over 21 wks by the automated system and by an experienced research coordinator who manually screened subjects for enrollment in Acute Respiratory Distress Syndrome Clinical Trials Network (ARDSNet) trials. Performance of the automated system was assessed by comparing its results with the manual screening process. Discordant results were adjudicated blindly by two physician reviewers. In addition, a sensitivity analysis using a range of assumptions was conducted to better estimate the system's performance. SETTING: The Hospital of the University of Pennsylvania, an academic medical center and ARDSNet center (1994-2006). PATIENTS: Intubated patients in medical and surgical intensive care units. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 1270 patients screened, 84 were identified with acute lung injury (incidence of 6.6%). The automated screening system had a sensitivity of 97.6% (95% confidence interval, 96.8-98.4%) and a specificity of 97.6% (95% confidence interval, 96.8-98.4%). The manual screening algorithm had a sensitivity of 57.1% (95% confidence interval, 54.5-59.8%) and a specificity of 99.7% (95% confidence interval, 99.4-100%). Sensitivity analysis demonstrated a range for sensitivity of 75.0-97.6% of the automated system under varying assumptions. Under all assumptions, the automated system demonstrated higher sensitivity than and comparable specificity to the manual screening method. CONCLUSIONS: An automated electronic system identified patients with acute lung injury with high sensitivity and specificity in diverse intensive care units of a large academic medical center. Further studies are needed to evaluate the effect of automated prompts that such a system can initiate on the use of lung protective ventilation in patients with acute lung injury.

Evaluation of Respiratory Therapist Extender Comfort With Mechanical Ventilation During COVID-19 Pandemic.

BACKGROUND: Staffing strategies used to meet the needs of respiratory care departments during the COVID-19 pandemic included the deployment of respiratory therapist extenders. The purpose of this study was to evaluate respiratory therapist extenders' comfort level with critical care ventilators while caring for patients with COVID-19. To our knowledge, this is the first study to evaluate the deployment of certified registered nurse anesthetists (CRNAs) in a critical care setting. METHODS: A qualitative survey method was used to assess CRNA experience with critical care ventilators. Prior to deployment in the ICU, CRNAs were trained by clinical lead respiratory therapists. Education included respiratory clinical practices and ventilator management. Sixty-minute sessions were held with demonstration stations set up in ICUs for hands-on experience. RESULTS: Fifty-six CRNAs responded to our survey (63%). A mean ± SD of 9.48 ± 12.27 h was spent training prior to deployment in the ICU. CRNAs were at the bedside a mean ± SD of 73.0 ± 40.6 h during the pandemic. While CRNA comfort level with critical care ventilators increased significantly (P < .001) from the beginning to the end of their work experience, no statistically significant differences were found between CRNA comfort based on years of experience. Differences in comfort level were not found after training (chi-squared test 23.82, P = .09) or after ICU experience was completed (chi-squared test = 15.99, P = .45). Similarly, mean comfort level did not increase based on the number of hours spent working in the ICU (chi-squared test = 13.67, P = .55). CONCLUSIONS: Comfort level with mechanical ventilation increased for CRNAs working alongside respiratory therapists during the COVID-19 pandemic.