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Abstract Background Cardiac dysfunction from pulmonary vascular disease causes characteristic findings on cardiopulmonary exercise testing (CPET). We tested the accuracy of CPET for detecting inadequate stroke volume (SV) augmentation during exercise, a pivotal manifestation of cardiac limitation in patients with pulmonary vascular disease. Methods We reviewed patients with suspected pulmonary vascular disease in whom CPET and right heart catheterization (RHC) measurements were taken at rest and at anaerobic threshold (AT). We correlated CPET-determined O2·pulseAT/O2·pulserest with RHC-determined SVAT/SVrest. We evaluated the sensitivity and specificity of O2·pulseAT/O2·pulserest to detect SVAT/SVrest below the lower limit of normal (LLN). For comparison, we performed similar analyses comparing echocardiographically-measured peak tricuspid regurgitant velocity (TRVpeak) with SVAT/SVrest. Results From July 2018 through February 2023, 83 simultaneous RHC and CPET were performed. Thirty-six studies measured O2·pulse and SV at rest and at AT. O2·pulseAT/O2·pulserest correlated highly with SVAT/SVrest (r = 0.72, 95% CI 0.52, 0.85; p

In some patients with acute respiratory distress syndrome (ARDS), a paradoxical improvement in respiratory system compliance (CRS) has been observed when assuming a supine (head of bed [HOB] 0°) compared with semirecumbent (HOB 35–40°) posture. We sought to test the hypothesis that mechanically ventilated patients with ARDS would have improved CRS, due to changes in ventilation distribution, when moving from the semirecumbent to supine position. We conducted a prospective, observational ICU study including 14 mechanically ventilated patients with ARDS. For each patient, ventilation distribution (assessed by electrical impedance tomography) and pulmonary mechanics were compared in supine versus semirecumbent postures. Compared with semirecumbent, in the supine posture CRS increased (33 ± 21 vs. 26 ± 14 mL/cm H2O, p = 0.005), driving pressure was reduced (14 ± 6 vs. 17 ± 7 cm H2O, p < 0.001), and dorsal fraction of ventilation was decreased (48.5 ± 14.1% vs. 54.5 ± 12.0%, p = 0.003). Posture change from semirecumbent to supine resulted in a favorable physiologic response in terms of improved CRS and reduced driving pressure—with a corresponding increase in ventral ventilation, possibly related to reduced ventral overdistension.

Background and Objective: The COVID-19 pandemic magnified the importance of gas exchange abnormalities in early respiratory failure. Pulse oximetry (SpO2) has not been universally effective for clinical decision-making, possibly because of limitations. The alveolar gas monitor (AGM100) adds exhaled gas tensions to SpO2 to calculate the oxygen deficit (OD). The OD parallels the alveolar-to-arterial oxygen difference (AaDO2) in outpatients with cardiopulmonary disease. We hypothesized that the OD would discriminate between COVID-19 patients who require hospital admission and those who are discharged home, as well as predict need for supplemental oxygen during the index hospitalization. Methods: Patients presenting with dyspnea and COVID-19 were enrolled with informed consent and had OD measured using the AGM100. The OD was then compared between admitted and discharged patients and between patients who required supplemental oxygen and those who did not. The OD was also compared to SpO2 for each of these outcomes using receiver operating characteristic (ROC) curves. Results: Thirty patients were COVID-19 positive and had complete AGM100 data. The mean OD was significantly (p = 0.025) higher among those admitted 50.0 ± 20.6 (mean ± SD) vs. discharged 27.0 ± 14.3 (mean ± SD). The OD was also significantly (p < 0.0001) higher among those requiring supplemental oxygen 60.1 ± 12.9 (mean ± SD) vs. those remaining on room air 25.2 ± 11.9 (mean ± SD). ROC curves for the OD demonstrated very good and excellent sensitivity for predicting hospital admission and supplemental oxygen administration, respectively. The OD performed better than an SpO2 threshold of

OBJECTIVES:. Although proning is beneficial to acute respiratory distress syndrome, impressions vary about its efficacy. Some providers believe that paralysis is required to facilitate proning. We studied impact of paralysis on prone-induced gas exchange improvements and provider attitudes regarding paralytics. DESIGN:. Observational. SETTING:. University of California San Diego. PATIENTS:. Intubated COVID acute respiratory distress syndrome patients. INTERVENTIONS:. None. MEASUREMENTS AND MAIN RESULTS:. 1) Changes in Pao2:Fio2 and Spo2:Fio2 ratios before and after proning with and without paralytics, 2) adverse events during proning with and without paralytics, and 3) nurse and physician attitudes about efficacy/safety of proning with and without paralytics. Gas-exchange improvement with proning was similar with and without paralytics (with no serious adverse events). Survey results showed similar attitudes between nurses and physicians about proning efficacy but differing attitudes about the need for paralytics with proning. CONCLUSIONS:. Findings support use of proning and may help in design of randomized trials to assess paralytics in acute respiratory distress syndrome management.

Abstract Honey bee queens undergo dramatic behavioral (e.g., reduced sexual receptivity), physiological (e.g., ovary activation, ovulation, and modulation of pheromone production) and transcriptional changes after they complete mating. To elucidate how queen post-mating changes are influenced by seminal fluid, the non-spermatozoa-containing component of semen, we injected queens with semen or seminal fluid alone. We assessed queen sexual receptivity (as measured by likelihood to take mating flights), ovary activation, worker retinue response (which is influenced by queen pheromone production), and transcriptional changes in queen abdominal fat body and brain tissues. Injection with either seminal fluid or semen resulted in decreased sexual receptivity, increased attractiveness of queens to workers, and altered expression of several genes that are also regulated by natural mating in queens. The post-mating and transcriptional changes of queens receiving seminal fluid were not significantly different from queens injected with semen, suggesting that components in seminal fluid, such as seminal fluid proteins, are largely responsible for stimulating post-mating changes in queens.

Secondary infections can occur during or after the treatment of an initial infection. Glucocorticoids may decrease mortality in patients with severe COVID-19; however, risk of secondary infection is not well described. Our primary objective was to investigate the risk of secondary infection among critically ill patients with COVID-19 treated with glucocorticoids. We examined patients with COVID-19 being treated in the intensive care unit at two academic medical centers from 1 to 7/2020. One hundred-seven patients were included. Of these, 31 received steroids and 76 patients did not. Analysis of the larger cohort was performed followed by a matched pairs analysis of 22 steroid and 22 non-steroid patients. Secondary infection was seen in 14 patients (45.2%) receiving steroids compared to 35(46.1%) not receiving steroids (p = 0.968). Secondary infections were most frequently encountered in the respiratory tract. Escherichia coli and Staphylococcus aureus were the most frequently identified organisms. Mortality was 16.1% in the steroid-treated group compared to 23.7% in the control group (p = 0.388). After performing matched pairs analysis and multivariable logistic regression there was no significant difference between secondary infection or mortality and steroid receipt. Secondary infections were common among critically ill patients with COVID-19, but the incidence of secondary infection was not significantly impacted by steroid treatment.

Prone Positioning in ARDSCovid-19 has greatly expanded the use of prone positioning for patients with respiratory failure. Pearce and colleagues review the physiology of prone positioning and the evidence for its use, including in nonintubated patients.

Although proning is beneficial to acute respiratory distress syndrome, impressions vary about its efficacy. Some providers believe that paralysis is required to facilitate proning. We studied impact of paralysis on prone-induced gas exchange improvements and provider attitudes regarding paralytics.DesignObservational.SettingUniversity of California San Diego.PatientsIntubated COVID acute respiratory distress syndrome patients.InterventionsNone.Measurements and main results1) Changes in Pao2:Fio2 and Spo2:Fio2 ratios before and after proning with and without paralytics, 2) adverse events during proning with and without paralytics, and 3) nurse and physician attitudes about efficacy/safety of proning with and without paralytics. Gas-exchange improvement with proning was similar with and without paralytics (with no serious adverse events). Survey results showed similar attitudes between nurses and physicians about proning efficacy but differing attitudes about the need for paralytics with proning.ConclusionsFindings support use of proning and may help in design of randomized trials to assess paralytics in acute respiratory distress syndrome management.

BackgroundPatient care ownership improves accountability, clinical skills, and quality of patient care among resident physicians, but appears to be gradually eroding. Research is limited by the lack of a reliable, objective measure of ownership.ObjectiveTo validate the Patient Care Ownership Scale, an instrument that measures decision ownership among internal medicine residents.DesignMulti-institutional, cross-sectional study using a 66-item, online survey that queried residents on ownership's key constructs (advocacy, responsibility, accountability, follow-through, knowledge, communication, initiative, continuity of care, autonomy, self-efficacy, and perceived ownership) as well as mood and burnout.ParticipantsInternal medicine residents in five geographically diverse residency programs completing an inpatient rotation.Main measuresWe performed exploratory and confirmatory factor analysis in two randomly split groups to evaluate for subscales and inform item reduction. We conducted reliability testing with Cronbach's α. We performed bivariate analyses to examine construct validity and identify correlates of ownership.Key resultsOf the 785 eligible residents, 625 completed the survey (80% response rate); we included responses from 563 in the analysis. We identified three factors corresponding to assertiveness, conscientiousness, and confidence or perceived competence. After iterative item reduction, the 13-item ownership scale demonstrated good reliability (Cronbach's α = 0.82). Convergent validity was supported by a significant association with perceived ownership (eliminated from the final scale) (r = 0.67, p < 0.001). There was a positive association between ownership and training level (p < 0.01) and prior experience in the intensive care unit (p < 0.001). There were significant, inverse relationships between ownership and self-defined burnout (r = - 0.24, p < 0.001), depression (r = - 0.22, p < 0.001), detachment (r = - 0.26, p < 0.001), and frustration (r = - 0.15, p = 0.02), and significant positive associations between ownership and feeling energetic (r = 0.29, p < 0.001), happy (r = 0.33, p < 0.001), and fulfilled (r = 0.34, p < 0.001).ConclusionsThe Patient Care Ownership Scale is valid in diverse residency program settings. Medical educators and investigators can use our scale to assess interventions aimed at fostering ownership.

Mitigating poor quality air is vital for children's health, especially in urban areas. In recent years, attention has been paid on how to improve air quality around schools to reduce children's exposure to airborne pollutants. In this paper, we explore the use of green infrastructure for improving air quality in schools as a multifunctional nature-based solution (green infrastructure for air quality plus, ‘GI4AQ+’); a process that comprises additional (co-)benefits, trade-offs or disbenefits for the school community. We report on a collaborative, action-research project that implements a green fence in a school playground in Sheffield, UK with the specific aim of improving local air quality, but potentially provides other benefits as well as drawbacks. Our results suggest that GI4AQ+ provides multiple social, environmental, and economic co-benefits beyond air quality provisioning. Furthermore, four dimensions (place, physical and biological characteristics, and school-friendly considerations) were identified to facilitate the implementation of this type of project in other schools. Thus, GI4AQ+ appears to be a valuable strategy for school greening. These interventions may also encourage school communities to identify and procure the delivery of other co-benefits from green infrastructure.

ObjectivesTo assess the presence of right-to-left shunting (RLS) in patients with obstructive sleep apnea (OSA), and compare clinical characteristics and parameters of the sleep studies of patients with and without RLS.BackgroundThe most common cause of RLS is due to intermittent flow through a patent foramen ovale (PFO). PFO occurs more frequently in patients with OSA and may be involved in the exacerbation of OSA.MethodsPatients with an abnormal polysomnogram seen at UCLA-Santa Monica Sleep Medicine Clinic were enrolled. A diagnosis of RLS was made using a transcranial Doppler (TCD) bubble study. Gender and age-matched controls were drawn from patients referred for cardiac catheterization who underwent a TCD. The frequency of RLS in OSA patients and the controls was evaluated. Clinical characteristics and polysomnogram parameters were compared between OSA patients with and without a RLS.ResultsA total of 100 OSA patients and 200 controls participated in the study. The prevalence of RLS was higher in patients with OSA compared to the control group (42% versus 19%; p < 0.0001). Patients with OSA and a RLS had a lower apnea-hypopnea index (AHI), less obstructive apnea, and fewer hypopnea episodes than patients with OSA without a RLS. The baseline and nadir SpO2 were similar in both groups and did not correlate with the level of RLS assessed by TCD. The degree of desaturation for a given respiratory disturbance, as measured by oxygen desaturation index (ODI)/AHI ratio, was higher in OSA patients with RLS versus OSA patients without RLS (0.85 ± 0.07 versus 0.68 ± 0.04; p < 0.0001).ConclusionRLS, most commonly due to a PFO, occurs 2.2 times more frequently in OSA patients compared to a control population that was matched for age and gender. The severity of sleep apnea is not greater in OSA patients who have a PFO. However, patients with OSA and a PFO are more likely to become symptomatic at a younger age with an equivalent decrease in nocturnal SpO2, and have greater arterial desaturation in proportion to the frequency of respiratory disturbances.

BackgroundStick and leaf insects (Phasmatodea) are an exclusively leaf-feeding order of insects with no record of omnivory, unlike other "herbivorous" Polyneoptera. They represent an ideal system for investigating the adaptations necessary for obligate folivory, including plant cell wall degrading enzymes (PCWDEs). However, their physiology and internal anatomy is poorly understood, with limited genomic resources available.ResultsWe de novo assembled transcriptomes for the anterior and posterior midguts of six diverse Phasmatodea species, with RNA-Seq on one exemplar species, Peruphasma schultei. The latter's assembly yielded >100,000 transcripts, with over 4000 transcripts uniquely or more highly expressed in specific midgut sections. Two to three dozen PCWDE encoding gene families, including cellulases and pectinases, were differentially expressed in the anterior midgut. These genes were also found in genomic DNA from phasmid brain tissue, suggesting endogenous production. Sequence alignments revealed catalytic sites on most PCWDE transcripts. While most phasmid PCWDE genes showed homology with those of other insects, the pectinases were homologous to bacterial genes.ConclusionsWe identified a large and diverse PCWDE repertoire endogenous to the phasmids. If these expressed genes are translated into active enzymes, then phasmids can theoretically break plant cell walls into their monomer components independently of microbial symbionts. The differential gene expression between the two midgut sections provides the first molecular hints as to their function in living phasmids. Our work expands the resources available for industrial applications of animal-derived PCWDEs, and facilitates evolutionary analysis of lower Polyneopteran digestive enzymes, including the pectinases whose origin in Phasmatodea may have been a horizontal transfer event from bacteria.