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BACKGROUND: Transpulmonary pressure (PL) is used to assess pulmonary mechanics and guide lung-protective mechanical ventilation (LPV). PL is recommended to individualize LPV settings for patients with high pleural pressures and hypoxemia. We aimed to determine whether PL-guided LPV settings, pulmonary mechanics, and oxygenation improve and differ from non-PL-guided LPV among obese patients after 24 h on mechanical ventilation. Secondary outcomes included classification of hypoxemia severity, count of ventilator-free days, ICU length of stay, and overall ICU mortality. METHODS: This is a retrospective analysis of data. Ventilator settings, pulmonary mechanics, and oxygenation were recorded on the initial day of PL measurement and 24 h later. PL-guided LPV targeted inspiratory PL < 20 cm H2O and expiratory PL of 0--6 cm H2O. Comparisons were made to repeat measurements. RESULTS: Twenty subjects (13 male) with median age of 49 y, body mass index 47.5 kg/m², and SOFA score of 8 were included in our analysis. Fourteen subjects received care in a medical ICU. PL measurement occurred 16 h after initiating non-PL-guided LPV. PL-guided LPV resulted in higher median PEEP (14 vs 18 cm H2O, P = .009), expiratory PL (--3 vs 1 cm H2O, P = .02), respiratory system compliance (30.7 vs 44.6 mL/cm H2O, P = .001), and PaO2/FIO2 (156 vs 240 mm Hg, P = .002) at 24 h. PL-guided LPV resulted in lower FIO2 (0.53 vs 0.33, P < .001) and lower PL driving pressure (10 vs 6 cm H2O, P = .001). Tidal volume (420 vs 435 mL, P = .64) and inspiratory PL (7 vs 7 cm H2O, P = .90) were similar. Subjects had a median of 7 ventilator-free days, and median ICU length of stay was 14 d. Three of 20 subjects died within 28 d after ICU admission. CONCLUSIONS: PL-guided LPV resulted in higher PEEP, lower FIO2, improved pulmonary mechanics, and greater oxygenation when compared to non-PL-guided LPV settings in adult obese subjects. Key words: mechanical ventilation; obesity; respiratory mechanics; esophageal pressure; [ABSTRACT FROM AUTHOR]

The article discusses the impact of heat waves on emergency department visits in Roanoke, Virgin. Topics discussed include Prior heat-related research has emphasized the impact of heat events on mortality, but there is a growing interest in understanding the influence of heat on emergency department (ED) visits; and potential cause of morbidity, traditional data set filtering by heat stress codes results in a significant underestimate of the actual heat impact.

In most midlatitude locations, human morbidity and mortality are highly seasonal, with winter peaks driven by respiratory disease and associated comorbidities. But the transition between high and low mortality/morbidity months varies spatially. We use a measure of the thermal biophysical strain imposed on the respiratory system—the Acclimatization Thermal Strain Index (ATSI)—to examine respiratory hospital admissions in Charlottesville, VA. Daily respiratory admissions to the University of Virginia over a 19-year period are compared to ATSI values derived from hourly surface weather data acquired from the Charlottesville airport. Negative ATSI values (associated with transitions from warm (and humid) to cold (and dry) conditions) are related to admission peaks at seasonal and weekly timescales, whereas positive ATSI values (cold to warm) exhibit weaker relationships. This research marks the first application of the ATSI to human morbidity, and results suggest that respiratory strain may account for how people who are acclimated to different climates respond to short-term weather changes. [ABSTRACT FROM AUTHOR]

The substantial winter influenza peak in temperate climates has lead to the hypothesis that cold and/or dry air is a causal factor in influenza variability. We examined the relationship between cold and/or dry air and daily influenza and pneumonia mortality in the cold season in the New York metropolitan area from 1975-2002. We conducted a retrospective study relating daily pneumonia and influenza mortality for New York City and surroundings from 1975-2002 to daily air temperature, dew point temperature (a measure of atmospheric humidity), and daily air mass type. We identified high mortality days and periods and employed temporal smoothers and lags to account for the latency period and the time between infection and death. Unpaired t-tests were used to compare high mortality events to non-events and nonparametric bootstrapped regression analysis was used to examine the characteristics of longer mortality episodes. We found a statistically significant (p = 0.003) association between periods of low dew point temperature and above normal pneumonia and influenza mortality 17 days later. The duration (r =20.61) and severity (r =20.56) of high mortality episodes was inversely correlated with morning dew point temperature prior to and during the episodes. Weeks in which moist polar air masses were common (air masses characterized by low dew point temperatures) were likewise followed by above normal mortality 17 days later (p = 0.019). This research supports the contention that cold, dry air may be related to influenza mortality and suggests that warning systems could provide enough lead time to be effective in mitigating the effects. [ABSTRACT FROM AUTHOR]

Objectives: Patients in ICUs are susceptible to subacute potentially catastrophic illnesses such as respiratory failure, sepsis, and hemorrhage that present as severe derangements of vital signs. More subtle physiologic signatures may be present before clinical deterioration, when treatment might be more effective. We performed multivariate statistical analyses of bedside physiologic monitoring data to identify such early subclinical signatures of incipient life-threatening illness.Design: We report a study of model development and validation of a retrospective observational cohort using resampling (Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis type 1b internal validation) and a study of model validation using separate data (type 2b internal/external validation).Setting: University of Virginia Health System (Charlottesville), a tertiary-care, academic medical center.Patients: Critically ill patients consecutively admitted between January 2009 and June 2015 to either the neonatal, surgical/trauma/burn, or medical ICUs with available physiologic monitoring data.Interventions: None.Measurements and Main Results: We analyzed 146 patient-years of vital sign and electrocardiography waveform time series from the bedside monitors of 9,232 ICU admissions. Calculations from 30-minute windows of the physiologic monitoring data were made every 15 minutes. Clinicians identified 1,206 episodes of respiratory failure leading to urgent unplanned intubation, sepsis, or hemorrhage leading to multi-unit transfusions from systematic individual chart reviews. Multivariate models to predict events up to 24 hours prior had internally validated C-statistics of 0.61-0.88. In adults, physiologic signatures of respiratory failure and hemorrhage were distinct from each other but externally consistent across ICUs. Sepsis, on the other hand, demonstrated less distinct and inconsistent signatures. Physiologic signatures of all neonatal illnesses were similar.Conclusions: Subacute potentially catastrophic illnesses in three diverse ICU populations have physiologic signatures that are detectable in the hours preceding clinical detection and intervention. Detection of such signatures can draw attention to patients at highest risk, potentially enabling earlier intervention and better outcomes. [ABSTRACT FROM AUTHOR]