Cardiopulmonary exercise test to detect cardiac dysfunction from pulmonary vascular disease.

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 < 0.0001), whereas TRVpeak did not (r = -0.09, 95% CI -0.47, 0.33; p = 0.69). The AUROC to detect SVAT/SVrest below the LLN was significantly higher for O2·pulseAT/O2·pulserest (0.92, SE 0.04; p = 0.0002) than for TRVpeak (0.69, SE 0.10; p = 0.12). O2·pulseAT/O2·pulserest of less than 2.6 was 92.6% sensitive (95% CI 76.6%, 98.7%) and 66.7% specific (95% CI 35.2%, 87.9%) for deficient SVAT/SVrest. CONCLUSIONS: CPET detected deficient SV augmentation more accurately than echocardiography. CPET-determined O2·pulseAT/O2·pulserest may have a prominent role for noninvasive screening of patients at risk for pulmonary vascular disease, such as patients with persistent dyspnea after pulmonary embolism.

Impact of Supine Versus Semirecumbent Body Posture on the Distribution of Ventilation in Acute Respiratory Distress Syndrome.

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.

Noninvasive Assessment of Impaired Gas Exchange with the Alveolar Gas Monitor Predicts Clinical Deterioration in COVID-19 Patients.

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 <94%. CONCLUSIONS: The AGM100 is a novel, noninvasive way of measuring impaired gas exchange for clinically important endpoints in COVID-19.

Secondary infections in critically ill patients with COVID-19 receiving steroid therapy.

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.

Observational cohort study to validate SEARCH, a novel hierarchical algorithm to define long-term outcomes after pulmonary embolism.

BACKGROUND: Chronic dyspnoea and exercise impairment are common after acute pulmonary embolism (PE) but are not defined and quantified sufficiently to serve as outcomes in clinical trials. The planned project will clinically validate a novel method to determine discrete, clinically meaningful diagnoses after acute PE. The method uses an algorithm entitled SEARCH, for symptom screen, exercise testing, arterial perfusion, resting echocardiography, confirmatory imaging and haemodynamic measurements. SEARCH is a stepwise algorithm that sorts patients by a hierarchical series of dichotomous tests into discreet categories of long-term outcomes after PE: asymptomatic, post-PE deconditioning, symptoms from other causes, chronic thromboembolism with ventilatory inefficiency, chronic thromboembolism with small stroke volume augmentation, chronic thromboembolic disease and chronic thromboembolic pulmonary hypertension. METHODS: The project will test the inter-rater reliability of the SEARCH algorithm by determining whether it will yield concordant post-PE diagnoses when six independent reviewers review the same diagnostic data on 150 patients evaluated at two time points after PE. The project will also determine whether the post-PE diagnoses are stable, according to the SEARCH algorithm, between the first evaluation and the subsequent one 6 months later. IMPLICATIONS: Validation of the SEARCH algorithm would offer clinicians a straightforward method to diagnose post-PE conditions that are rarely distinguished clinically. Their categorisation and definition will allow post-PE conditions to be used as endpoints in clinical trials of acute PE treatment. TRIAL REGISTRATION NUMBER: NCT05568927.

Proning in COVID-19 Acute Respiratory Distress Syndrome: Role of Paralytics.

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.

Prone Positioning in Acute Respiratory Distress Syndrome.

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.

An International Virtual COVID-19 Critical Care Training Forum for Healthcare Workers.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic resulted in redeployment of non-critical care-trained providers to intensive care units across the world. Concurrently, traditional venues for delivery of medical education faced major disruptions. The need for a virtual forum to fill knowledge gaps for healthcare workers caring for patients with coronavirus disease (COVID-19) was apparent in the early stages of the pandemic. Objective: The weekly, open-access COVID-19 Critical Care Training Forum (CCCTF) organized by the American Thoracic Society (ATS) provided a global audience access to timely content relevant to their learning needs. The goals of the forum were threefold: to aid healthcare providers in assessment and treatment of patients with COVID-19, to reduce provider anxiety, and to disseminate best practices. Methods: The first 13 ATS CCCTF sessions streamed live from April to July 2020. Structured debriefs followed each session and participant feedback was evaluated in planning of subsequent sessions. A second set of 14 sessions streamed from August to November 2020. Content experts were recruited from academic institutions across the United States. Results: As of July 2020, the ATS CCCTF had 2,494 live participants and 7,687 downloads for a total of 10,181 views. The majority of participants had both completed training (58.6%) and trained in critical care (53.8%). Physicians made up a majority (82.2%) of the audience that spanned the globe (61% were international attendees). Conclusion: We describe the rapid and successful implementation of an open-access medical education forum to address training and knowledge gaps among healthcare personnel caring for patients with COVID-19.

The Patient Care Ownership Scale: External Validation of an Instrument that Measures Patient Care Ownership Among Internal Medicine Trainees-a Multi-Institutional Study.

BACKGROUND: Patient 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. OBJECTIVE: To validate the Patient Care Ownership Scale, an instrument that measures decision ownership among internal medicine residents. DESIGN: Multi-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. PARTICIPANTS: Internal medicine residents in five geographically diverse residency programs completing an inpatient rotation. MAIN MEASURES: We 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 RESULTS: Of 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). CONCLUSIONS: The 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.

Removing Barriers: A Confidential Opt-Out Mental Health Pilot Program for Internal Medicine Interns.

PROBLEM: There are significant barriers for resident physicians seeking mental health care, including lack of time, cost, and concerns about confidentiality. The authors sought to improve access to mental health resources by addressing these barriers through the development of a confidential opt-out mental health pilot program for interns and to assess the feasibility, acceptability, and resident satisfaction with the program. APPROACH: All internal medicine and internal medicine-pediatrics interns in the 2017-2018 residency class at the University of Colorado were enrolled in the confidential opt-out mental health program. Each intern was provided with an additional half-day off during their continuity clinic week, during which a mental health screening appointment at the campus health center with an in-network mental health provider was scheduled. All costs were covered by the residency program. An anonymous follow-up survey was sent to all interns to assess participation in the program and its perceived impact on their wellness. OUTCOMES: Appointments were made for 80 interns: 23 (29%) attended the appointment, 45 (56%) opted out in advance, and 12 (15%) were no-shows. The total cost of the program was $940 or $11.75 per intern. Of the 41 interns who responded to the survey, 35 (85%) agreed the program should continue next year. The majority of interns felt the program positively affected their wellness regardless of whether they attended the appointment. Of the 16 interns who attended the appointment and completed the survey, 4 (25%) reported receiving additional mental health referrals or follow-up appointments. NEXT STEPS: This confidential opt-out mental health pilot program for interns was feasible, relatively low cost and simple to implement, and had positive impacts on self-reported wellness. Further study of interventions that remove barriers to accessing mental health care for residents is urgently needed.

Brain-derived neurotrophic factor modulates antiretroviral-induced mechanical allodynia in the mouse.

Nucleoside reverse transcriptase inhibitors (NRTIs) are key components of HIV/AIDS treatment to reduce viral load. However, these drugs can induce chronic neuropathic pain, leading to increased morbidity in HIV patients. This study examines the role of brain-derived neurotrophic factor (BDNF) in the spinal dorsal horn (SDH) in development of mechanical allodynia in male C57BL/6J mice treated with the NRTI stavudine (d4T). After d4T administration, mice developed increased neuronal activity and BDNF expression in the SDH and hind paw mechanical allodynia that was exacerbated by intrathecal BDNF administration. Intrathecal BDNF alone also increased neuronal activity and caused mechanical allodynia. Because excess BDNF amplified d4T-induced mechanical allodynia and neuronal activity, the impact of decreasing BDNF in the SDH was investigated. After d4T, BDNF heterozygous mice were less allodynic than wild-type littermates, which was negated by intrathecal BDNF administration. Finally, pretreatment with intrathecal trkB-Fc chimera prior to d4T or administration of the tyrosine kinase inhibitor K252a 3 days after d4T blocked BDNF-mediated signaling, significantly attenuated the development of mechanical allodynia (trkB-Fc), and decreased neuronal activity (trkB-Fc and K252a). Taken together, these findings provide evidence that BDNF in the SDH contributes to the development of NRTI-induced painful peripheral neuropathy and may represent a new therapeutic opportunity.