Pulmonary function as a continuum of risk: critical care utilization and survival after allogeneic hematopoietic stem cell transplantation - a multicenter cohort study.

Abnormal pre-transplant pulmonary function tests (PFTs) are associated with reduced survival after allogeneic HCT. Existing scoring systems consider risk dichotomously, attributing risk only to those with abnormal lung function. In a multicenter cohort of 1717 allo-HCT recipients, we examined the association between pre-transplant PFT measures and need for ICU admission (120d), frequency of mechanical ventilation (120d) and overall survival (5 y). Predictive models were developed and validated using Cox proportional hazards, incorporating age, FEV1 (forced expiratory volume in 1-second) and diffusing capacity (DLCO). In univariate analysis, hazard ratios for each outcome (95% CI) were: mechanical ventilation (FEV1: 0.60 [0.52-0.69], DLCO: 0.69 [0.61-0.77], p < 0.001), ICU admission (FEV1: 0.74 [0.67-0.82], DLCO: 0.79 [0.72-0.86], p < 0.001) and overall survival (FEV1: HR 0.87 [0.81-0.94], DLCO: 0.83 [0.77-0.89], p < 0.001). A multivariable Cox model was developed and compared to the HCT-CI Pulmonary score in a validation cohort. This model was better at predicting need for ICU admission and mechanical ventilation, while both models predicted overall survival (p < 0.001). In conclusion, the risk conferred by pre-transplant pulmonary function should be considered in a continuous rather than dichotomous manner. A more granular prognostication system can better inform risk of critical care utilization in the early post-HCT period.

Application of Global Lung Function Initiative Global Spirometry Reference Equations across a Large, Multicenter Pulmonary Function Lab Population.

Rationale: Global Lung Function Initiative (GLI) Global spirometry reference equations were recently derived to offer a "race-neutral" interpretation option. The impact of transitioning from the race-specific GLI-2012 to the GLI Global reference equations is unknown. Objectives: Describe the direction and magnitude of changes in predicted lung function measurements in a population of diverse race and ethnicity using GLI Global in place of GLI-2012 reference equations. Methods: In this multicenter cross-sectional study using a large pulmonary function laboratory database, 109,447 spirometry tests were reanalyzed using GLI Global reference equations and compared with the existing GLI-2012 standard, stratified by self-reported race and ethnicity. Measurements and Main Results: Mean FEV1 and FVC percent predicted increased in the White and Northeast Asian groups and decreased in the Black, Southeast Asian, and mixed/other race groups. The prevalence of obstruction increased by 9.7% in the White group, and prevalences of possible restriction increased by 51.1% and 37.1% in the Black and Southeast Asian groups, respectively. Using GLI Global in a population with equal representation of all five race and ethnicity groups altered the interpretation category for 10.2% of spirometry tests. Subjects who self-identified as Black were the only group with a relative increase in the frequency of abnormal spirometry test results (32.9%). Conclusions: The use of GLI Global reference equations will significantly impact spirometry interpretation. Although GLI Global offers an innovative approach to transition from race-specific reference equations, it is important to recognize the continued need to place these data within an appropriate clinical context.

Implementation of a Virtual Interprofessional ICU Learning Collaborative: Successes, Challenges, and Initial Reactions From the Structured Team-Based Optimal Patient-Centered Care for Virus COVID-19 Collaborators.

Initial Society of Critical Care Medicine Discovery Viral Infection and Respiratory illness Universal Study (VIRUS) Registry analysis suggested that improvements in critical care processes offered the greatest modifiable opportunity to improve critically ill COVID-19 patient outcomes. OBJECTIVES: The Structured Team-based Optimal Patient-Centered Care for Virus COVID-19 ICU Collaborative was created to identify and speed implementation of best evidence based COVID-19 practices. DESIGN SETTING AND PARTICIPANTS: This 6-month project included volunteer interprofessional teams from VIRUS Registry sites, who received online training on the Checklist for Early Recognition and Treatment of Acute Illness and iNjury approach, a structured and systematic method for delivering evidence based critical care. Collaborators participated in weekly 1-hour videoconference sessions on high impact topics, monthly quality improvement (QI) coaching sessions, and received extensive additional resources for asynchronous learning. MAIN OUTCOMES AND MEASURES: Outcomes included learner engagement, satisfaction, and number of QI projects initiated by participating teams. RESULTS: Eleven of 13 initial sites participated in the Collaborative from March 2, 2021, to September 29, 2021. A total of 67 learners participated in the Collaborative, including 23 nurses, 22 physicians, 10 pharmacists, nine respiratory therapists, and three nonclinicians. Site attendance among the 11 sites in the 25 videoconference sessions ranged between 82% and 100%, with three sites providing at least one team member for 100% of sessions. The majority reported that topics matched their scope of practice (69%) and would highly recommend the program to colleagues (77%). A total of nine QI projects were initiated across three clinical domains and focused on improving adherence to established critical care practice bundles, reducing nosocomial complications, and strengthening patient- and family-centered care in the ICU. Major factors impacting successful Collaborative engagement included an engaged interprofessional team; an established culture of engagement; opportunities to benchmark performance and accelerate institutional innovation, networking, and acclaim; and ready access to data that could be leveraged for QI purposes. CONCLUSIONS AND RELEVANCE: Use of a virtual platform to establish a learning collaborative to accelerate the identification, dissemination, and implementation of critical care best practices for COVID-19 is feasible. Our experience offers important lessons for future collaborative efforts focused on improving ICU processes of care.

The Resident Learning Journey in the Medical Intensive Care Unit.

Background: The medical intensive care unit (MICU) offers rich resident learning opportunities, but traditional teaching strategies can be difficult to employ in this fast-paced, high-acuity environment. Resident perspectives of learning within this environment may improve our understanding of the common challenges residents face and inform novel approaches to transform the MICU educational experience. Objective: We conducted a qualitative study of internal medicine residents to better understand their approach to learning the critical care activities that they are entrusted to perform in the MICU. Methods: Using a thematic analysis approach, we conducted six focus group interviews with 15 internal medicine residents, separated by postgraduate year. A trained investigator led each interview, which was audio-recorded and transcribed verbatim for analysis. Our diverse research team, representing different career stages across the continuum of learning to minimize interpretive bias, identified codes and subsequent themes inductively. We refined these themes through group discussion and sensitizing social learning theory concepts using Wenger's community of practice and organized them to create learner archetypes and a conceptual framework of resident learning in the MICU. Results: We identified three thematic resident learning categories: learning goals and motivation, clinical engagement, and interprofessional collaboration. We distinguished three learner archetypes, the novice, experiential learner, and practicing member, to describe progressive resident development within the interprofessional MICU team, the challenges they frequently encounter, and potential teaching strategies to facilitate learning. Conclusion: We developed a conceptual framework that describes the resident's journey to becoming a trusted, collaborating member of the interprofessional MICU team. We identified common developmental challenges residents face and offer educational strategies that may support their progress. These findings should inform future efforts to develop novel teaching strategies to promote resident learning in the MICU.

Alterations in pulmonary vasomotor modulators post aerobic exercise training in non-alcoholic fatty liver disease.

This study investigated the impact of exercise training on major pulmonary vasomotor mediators and receptors including endothelial nitric oxide synthase (eNOS) inducible NOS (iNOS), endothelin-1 (ET-1), ET-1 receptors A (ETA) and-B (ETB) in high-fat-high-carbohydrate (HFHC) induced non-alcoholic fatty liver disease (NAFLD). NAFLD increased iNOS, ET-1 and ETA (p < 0.05), but not ETB (p > 0.05). Exercise attenuated iNOS, ET-1 and ETA (p < 0.05)., but not ETB (p > 0.05) and eNOS (p > 0.05). Exercise training is beneficial for pulmonary vasculature in NAFLD.

Cardiopulmonary testing in long COVID-19 versus non-COVID-19 patients with undifferentiated Dyspnea on exertion.

BACKGROUND: Dyspnea and fatigue are characteristics of long SARS-CoV-2 (COVID)-19. Cardiopulmonary exercise testing (CPET) can be used to better evaluate such patients. RESEARCH QUESTION: How significantly and by what mechanisms is exercise capacity impaired in patients with long COVID who are coming to a specialized clinic for evaluation? STUDY DESIGN AND METHODS: We performed a cohort study using the Mayo Clinic exercise testing database. Subjects included consecutive long COVID patients without prior history of heart or lung disease sent from the Post-COVID Care Clinic for CPET. They were compared to a historical group of non-COVID patients with undifferentiated dyspnea also without known cardiac or pulmonary disease. Statistical comparisons were performed by t-test or Pearson's chi2 test controlling for age, sex, and beta blocker use where appropriate. RESULTS: We found 77 patients with long COVID and 766 control patients. Long COVID patients were younger (47 ± 15 vs 50 ± 10 years, P < .01) and more likely female (70% vs 58%, P < .01). The most prominent difference on CPETs was lower percent predicted peak V̇O2 (73 ± 18 vs 85 ± 23%, p < .0001). Autonomic abnormalities (resting tachycardia, CNS changes, low systolic blood pressure) were seen during CPET more commonly in long COVID patients (34 vs 23%, P < .04), while mild pulmonary abnormalities (mild desaturation, limited breathing reserve, elevated V̇E/V̇CO2) during CPET were similar (19% in both groups) with only 1 long COVID patient showing severe impairment. INTERPRETATION: We identified severe exercise limitation among long COVID patients. Young women may be at higher risk for these complications. Though mild pulmonary and autonomic impairment were common in long COVID patients, marked limitations were uncommon. We hope our observations help to untangle the physiologic abnormalities responsible for the symptomatology of long COVID.

Critical Care Staffing in Pandemics and Disasters: A Consensus Report From a Subcommittee of the Task Force for Mass Critical Care - Systems Strategies to Sustain the Health Care Workforce.

BACKGROUND: The COVID-19 pandemic has led to unprecedented mental health disturbances, burnout, and moral distress among health care workers, affecting their ability to care for themselves and their patients. RESEARCH QUESTION: In health care workers, what are key systemic factors and interventions impacting mental health and burnout? STUDY DESIGN AND METHODS: The Workforce Sustainment subcommittee of the Task Force for Mass Critical Care (TFMCC) utilized a consensus development process, incorporating evidence from literature review with expert opinion through a modified Delphi approach to determine factors affecting mental health, burnout, and moral distress in health care workers, to propose necessary actions to help prevent these issues and enhance workforce resilience, sustainment, and retention. RESULTS: Consolidation of evidence gathered from literature review and expert opinion resulted in 197 total statements that were synthesized into 14 major suggestions. These suggestions were organized into three categories: (1) mental health and well-being for staff in medical settings; (2) system-level support and leadership; and (3) research priorities and gaps. Suggestions include both general and specific occupational interventions to support health care worker basic physical needs, lower psychological distress, reduce moral distress and burnout, and foster mental health and resilience. INTERPRETATION: The Workforce Sustainment subcommittee of the TFMCC offers evidence-informed operational strategies to assist health care workers and hospitals plan, prevent, and treat the factors affecting health care worker mental health, burnout, and moral distress to improve resilience and retention following the COVID-19 pandemic.

Implementation of a Multimodal Knowledge-Exchange Platform to Provide Trauma Critical Care Education During the Ongoing Conflict in Ukraine.

Importance: The conflict in Ukraine has forced civilian hospitals with limited trauma and battlefield medicine experience to care for casualties of war, placing significant strain on the health care system. Using the Checklist for Early Recognition and Treatment of Acute Illness and Injury (CERTAIN) program, a multimodal trauma critical care knowledge-exchange platform was created for clinicians practicing in these institutions. Objectives: To describe the development and implementation of the CERTAIN for Ukraine program and to evaluate the reach of this intervention, together with participant engagement and satisfaction. Design, Setting, and Participants: This quality improvement study included clinicians caring for critically ill patients during the ongoing Ukrainian conflict who were part of a community developed using a messaging app. The program was implemented by a group of international trauma and critical care experts in collaboration with critical care leaders from the Shupyk National Healthcare University in Kyiv, Ukraine. This study evaluates data collected from the CERTAIN for Ukraine program from its launch on April 9, 2022, to August 31, 2022. Interventions: The initiative comprised a longitudinal series of interactive tele-education sessions, a webpage containing the CERTAIN approach and current trauma critical care guidelines translated into Ukrainian and Russian, and a private messaging chat for asynchronous discussion. Main Outcomes and Measures: Participant engagement and satisfaction were tracked using multimedia analytics and a post-session survey. Results: Since program launch, 838 participants have joined the messaging group, and 6 tele-education sessions have been delivered, with 1835 total views. The CERTAIN website has had 3527 visits, mainly from Ukraine (1378 [39%]) and the United States (1060 [30%]). Of the 74 completed postsession surveys, 65 respondents (88%) rated the course content excellent or very good, and 73 (99%) recommended it to others. Conclusions and Relevance: The findings of this quality improvement study indicate that, using widely available and low-cost platforms, knowledge was shared rapidly and efficiently to a large community of clinicians practicing in a wartime environment with broad-based engagement and a high level of learner satisfaction.

Adjusting diffusing capacity for anemia in patients undergoing allogeneic HCT: a comparison of two methodologies.

BACKGROUND: Diffusing capacity (DLCO) measurements are affected by hemoglobin. Two adjustment equations are used: Cotes (recommended by ATS/ERS) and Dinakara (used in the hematopoietic stem cell transplantation comorbidity index [HCT-CI]). It is unknown how these methods compare, and which is better from a prognostication standpoint. STUDY DESIGN: This is a retrospective cohort of 1273 adult patients who underwent allogeneic HCT, completed a pre-transplant DLCO and had a concurrent hemoglobin measurement. Non-relapse mortality was measured using competing risk analysis. RESULTS: Patients had normal spirometry (FEV1 99.7% [IQR: 89.4-109.8%; FVC 100.1% [IQR: 91.0-109.6%] predicted), left ventricular ejection fraction (57.2[6.7]%) and right ventricular systolic pressure (30.1[7.0] mmHg). Cotes-DLCO was 85.6% (IQR: 76.5-95.7%) and Dinakara-DLCO was 103.6% (IQR: 90.7-117.2%) predicted. For anemic patients (Hb<10g/dL), Cotes-DLCO was 84.2% (IQR: 73.9-94.1%) while Dinakara-DLCO 111.0% (97.3-124.7%) predicted. Cotes-DLCO increased HCT-CI score for 323 (25.4%) and decreased for 4 (0.3%) patients. Cotes-DLCO was superior for predicting non-relapse mortality: for both mild (66-80% predicted, HR 1.55 [95%CI: 1.26-1.92, p < 0.001]) and moderate (<65% predicted, HR 2.11 [95%CI: 1.55-2.87, p<0.001]) impairment. In contrast, for Dinakara-DLCO, only mild impairment (HR 1.69 [95%CI 1.26-2.27, p < 0.001]) was associated with lower survival while moderate impairment was not (HR 1.44 [95%CI: 0.64-3.21, p = 0.4]). In multivariable analyses, after adjusting for demographics, hematologic variables, cardiac function and FEV1, Cotes-DLCO was predictive of overall survival at 1-year (OR 0.98 [95%CI: 0.97-1.00], p = 0.01), but Dinakara-DLCO was not (OR 1.00 [95%CI: 0.98-1.00], p = 0.20). CONCLUSION: The ERS/ATS recommended Cotes method likely underestimates DLCO in patients with anemia, whereas the Dinakara (used in the HCT-CI score) overestimates DLCO. The Cotes method is superior to the Dinakara method score in predicting overall survival and relapse-free survival in patients undergoing allogeneic HCT.

Development and usability testing of a patient digital twin for critical care education: a mixed methods study.

Background: Digital twins are computerized patient replicas that allow clinical interventions testing in silico to minimize preventable patient harm. Our group has developed a novel application software utilizing a digital twin patient model based on electronic health record (EHR) variables to simulate clinical trajectories during the initial 6 h of critical illness. This study aimed to assess the usability, workload, and acceptance of the digital twin application as an educational tool in critical care. Methods: A mixed methods study was conducted during seven user testing sessions of the digital twin application with thirty-five first-year internal medicine residents. Qualitative data were collected using a think-aloud and semi-structured interview format, while quantitative measurements included the System Usability Scale (SUS), NASA Task Load Index (NASA-TLX), and a short survey. Results: Median SUS scores and NASA-TLX were 70 (IQR 62.5-82.5) and 29.2 (IQR 22.5-34.2), consistent with good software usability and low to moderate workload, respectively. Residents expressed interest in using the digital twin application for ICU rotations and identified five themes for software improvement: clinical fidelity, interface organization, learning experience, serious gaming, and implementation strategies. Conclusion: A digital twin application based on EHR clinical variables showed good usability and high acceptance for critical care education.

Exercise training attenuates pulmonary inflammation and mitochondrial dysfunction in a mouse model of high-fat high-carbohydrate-induced NAFLD.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) can lead to pulmonary dysfunction that is associated with pulmonary inflammation. Moreover, little is known regarding the therapeutic role of exercise training on pulmonary pathophysiology in NAFLD. The present study aimed to investigate the effect of exercise training on high-fat high-carbohydrate (HFHC)-induced pulmonary dysfunction in C57BL/6 mice. METHODS: Male C57BL/6 mice (N = 40) were fed a standard Chow (n = 20) or an HFHC (n = 20) diet for 15 weeks. After 8 weeks of dietary treatment, they were further assigned to 4 subgroups for the remaining 7 weeks: Chow (n = 10), Chow plus exercise (Chow+EX, n = 10), HFHC (n = 10), or HFHC plus exercise (HFHC+EX, n = 10). Both Chow+EX and HFHC+EX mice were subjected to treadmill running. RESULTS: Chronic exposure to the HFHC diet resulted in obesity with hepatic steatosis, impaired glucose tolerance, and elevated liver enzymes. The HFHC significantly increased fibrotic area (p < 0.001), increased the mRNA expression of TNF-α (4.1-fold, p < 0.001), IL-1ß (5.0-fold, p < 0.001), col1a1 (8.1-fold, p < 0.001), and Timp1 (6.0-fold, p < 0.001) in the lung tissue. In addition, the HFHC significantly altered mitochondrial function (p < 0.05) along with decreased Mfn1 protein levels (1.8-fold, p < 0.01) and increased Fis1 protein levels (1.9-fold, p < 0.001). However, aerobic exercise training significantly attenuated these pathophysiologies in the lungs in terms of ameliorating inflammatory and fibrogenic effects by enhancing mitochondrial function in lung tissue (p < 0.001). CONCLUSIONS: The current findings suggest that exercise training has a beneficial effect against pulmonary abnormalities in HFHC-induced NAFLD through improved mitochondrial function.

Supporting Professionals in Critical Care Medicine: Burnout, Resiliency, and System-Level Change.

Burnout is occurring in epidemic proportions among intensive care unit physicians and other health-care professionals-accelerated by pandemic-driven stress. The impact of burnout is far-reaching, threatening the health of individual workers, the safety and quality of care our patients receive, and eroding the infrastructure of health care in general. Drivers of burnout include excessive quantity of work (nights, weekends, and acuity surges); excessive menial tasks; incivility, poor communication, and challenges to team success; and frequent moral distress and end-of-life issues. This article provides system-based practice and individual strategies to address these drivers and improve the well-being of our team and our patients.

Paroxysmal supine hypoxaemia with hyperthyroidism and atrial fibrillation: a case report of a diagnostic challenge.

Background: A patent foramen ovale (PFO) is a persistent embryonic defect in the interatrial septum. Platypnoea-orthodeoxia syndrome is characterized by positional hypoxaemia that is most commonly due to right-to-left shunting through a PFO. Dynamic right-to-left shunting through a PFO can also exacerbate positional hypoxaemia without platypnea-orthodeoxia syndrome. Case summary: A 78-year-old woman with hyperthyroidism and paroxysmal atrial fibrillation (AF) presented with positional hypoxaemia exacerbated by supine positioning. Diagnostic testing revealed intermittent right-to-left shunting through a PFO triggered by worsening atrial functional tricuspid regurgitation and elevated right atrial pressures. Diuresis, rate control, and thyroidectomy initially led to resolution of positional hypoxaemia, but recurrent AF episodes triggered right-to-left shunting with recurrent desaturation. Left atrial and cavo-tricuspid isthmus ablation led to restoration of normal sinus rhythm and resolution of positional hypoxaemia without PFO closure. Discussion: The clinical presentation of intermittent intracardiac right-to-left shunting can mimic decompensated heart failure with pulmonary oedema. Persistent hypoxaemia out of proportion to the degree of pulmonary oedema and minimally responsive to supplemental O2 should raise suspicion for right-to-left shunt aetiology. Positional arterial blood gases can facilitate the diagnostic evaluation of refractory hypoxaemia in cases of suspected shunting. Diagnostic imaging for PFO detection includes both transthoracic and transesophageal echocardiography with Valsalva manoeuver and agitated saline injection. Closure of a PFO for management of arterial deoxygenation syndromes should not be performed before treating other causes of arterial deoxygenation and optimizing factors that may exacerbate shunting across the PFO.

Use of a Viral Filter to Reduce Exposure to Exhaled Aerosol Does Not Affect Methacholine Dose Delivery During Bronchoprovocation Testing.

BACKGROUND: Methacholine challenge testing (MCT) is a common bronchoprovocation technique used to assess airway hyper-responsiveness. We previously demonstrated that the addition of a viral filter to the nebulizer exhalation limb substantially reduced expelled particles during MCT. Our aim was to evaluate whether this modification affects the delivered dose of methacholine. METHODS: A mechanical ventilator was connected to a lung simulator with breathing frequency 15 breaths/min, tidal volume 500 mL, inspiratory-expiratory ratio 1:1, with a sinusoidal waveform. We compared methacholine dose delivery using the Hudson Micro Mist or AeroEclipse II BAN nebulizers powered by either a dry gas source or a compressor system. A filter placed in line between the nebulizer and test lung was weighed before and after 1 min of nebulized methacholine delivery. Mean inhaled mass was measured with and without a viral filter on the exhalation limb. Dose delivery was calculated by multiplying the mean inhaled mass by the respirable fraction (particles < 5 µm) and inhalation time. Unpaired t test was used to compare methacholine dose delivery with and without viral filter placement. RESULTS: The addition of a viral filter did not significantly affect methacholine dose delivery across all devices tested. Using a 50-psi dry gas source, dose delivered with or without a viral filter did not differ with the Hudson (422.3 µg vs 282.0 µg, P = .11) or the AeroEclipse nebulizer (563.0 µg vs 657.6 µg, P = .59). Using the compressor, dose delivered with and without a viral filter did not differ with the Hudson (974.0 µg vs 868.0 µg, P = .03) or the AeroEclipse nebulizer (818.0 µg vs 628.5 µg, P = .42). CONCLUSIONS: The addition of a viral filter to the nebulizer exhalation limb did not affect methacholine dose during bronchoprovocation testing. Routine use of a viral filter should be considered to improve pulmonary function technician safety and infection control measures during the ongoing COVID-19 pandemic.

International Virtual Simulation Education in Critical Care During COVID-19 Pandemic: Preliminary Description of the Virtual Checklist for Early Recognition and Treatment of Acute Illness and iNjury Program.

SUMMARY STATEMENT: The Checklist for Early Recognition and Treatment of Acute Illness and iNjury program is a well-established, interactive, and simulation-based program designed to improve the quality of care delivered in intensive care units. The COVID-19 pandemic created an overwhelming surge of critically ill patients worldwide, and infection control concerns limited healthcare providers' access to in-person and hands-on simulation training when they needed it the most. Virtual simulation offers an alternative to in-person training but is often complex and expensive. We describe our successful development and initial implementation of an inexpensive, simulation-based virtual Checklist for Early Recognition and Treatment of Acute Illness and iNjury program to address the pressing need for effective critical care training in various resource-limited settings both within and outside of the United States. The overall satisfaction rate ("excellent" or "very good" responses) was 94.4% after the virtual simulation workshop. Our initial experience suggests that virtual interactions can be engaging and build strong relationships, like in-person continuing professional education, even using relatively simple technology. This knowledge-to-practice improvement platform can be readily adapted to other disciplines beyond critical care medicine.

A pilot study of trained ICU doulas providing early psychological support to critically ill patients.

BACKGROUND: Over a third of critical illness survivors suffer from mental health problems following hospitalization. Memories of delusional experiences are a major risk factor. In this project, ICU doulas delivered a unique positive suggestion intervention targeting the vulnerable time period during critical illness when these memories are formed. METHODS: Adult critically ill patients were recruited for this single-arm, prospective pilot study. These ICU patients received a positive suggestion intervention daily during their ICU stay in parallel with their medical treatment. The intervention was designed to be delivered over a minimum of two sessions. Feasibility was defined as intervention delivery on ≥ 70% of ICU days after patient enrollment. As a secondary analysis, psychometric questionnaires were compared to those of a historic control cohort of patients receiving standard care in the ICU using adjusted linear regression models. RESULTS: Of the 97 patients who received the intervention and were alive at the end of their ICU course, 54 were excluded from analyses mostly for having received only one session because of a short ICU length of stay of < 2 days, transitioning to comfort care or not wanting to answer the study questionnaires. Forty-three patients who completed 2 or more sessions of the positive therapeutic suggestion intervention provided by two trained ICU doulas received it for a median of 4 days (IQR 3, 5), with each session lasting for a median of 20 min (IQR 14, 25). The intervention was delivered on 71% of days, meeting our pre-determined feasibility goal. Compared to historical controls (N = 299), patients receiving the intervention had higher severity of illness and longer length of stay. When adjusted for baseline differences, patients both with and without mechanical ventilation who received the intervention scored lower on the Hospital Anxiety and Depression Scale (HADS)-Depression subscale. The intervention was also associated with reduced HADS-Anxiety subscale among ventilated patients. CONCLUSIONS: Positive therapeutic suggestion delivered by ICU doulas is feasible in the ICU setting. A randomized trial is warranted to better delineate the role that positive suggestion and ICU doulas may play in ongoing interprofessional efforts to humanize critical care medicine. The study was registered on clinicaltrials.gov (NCT03736954) on 03/14/2018 prior to the first patient enrollment https://clinicaltrials.gov/ct2/show/NCT03736954?cond=ICU+Doulas+Providing+Psychological+Support&draw=2&rank=1 .

Aerosol Generation and Mitigation During Methacholine Bronchoprovocation Testing: Infection Control Implications in the Era of COVID-19.

BACKGROUND: Methacholine bronchoprovocation or challenge testing (MCT) is commonly performed to assess airway hyper-responsiveness in the setting of suspected asthma. Nebulization is an aerosol-generating procedure, but little is known about the risks of MCT in the context of the ongoing coronavirus disease 2019 (COVID-19) pandemic. We aimed to quantify and characterize aerosol generation during MCT by using different delivery methods and to assess the impact of adding a viral filter. METHODS: Seven healthy subjects performed simulated MCT in a near particle-free laboratory space with 4 different nebulizers and with a dosimeter. Two devices continuously sampled the ambient air during the procedure, which detected ultrafine particles, from 0.02-1 µm, and particles of sizes 0.3, 0.5, 1.0, 2.0, 5.0, and 10 µm, respectively. Particle generation was compared among all the devices, with and without viral filter placement. RESULTS: Ultrafine-particle generation during simulated MCT was significant across all the devices. Ultrafine-particle (0.02-1 µm) concentrations decreased 77%-91% with the addition of a viral filter and varied significantly between unfiltered (P < .001) and filtered devices (P < .001). Ultrafine-particle generation was lowest when using the dosimeter with filtered Hudson nebulizer (1,258 ± 1,644 particle/mL). Ultrafine-particle concentrations with the filtered nebulizer devices using a compressor were higher than particle concentrations detected when using the dosimeter: Monaghan (3,472 ± 1,794 particles/mL), PARI (4,403 ± 2,948), Hudson (6,320 ± 1,787) and AirLife (9,523 ± 5,098). CONCLUSIONS: The high particle concentrations generated during MCT pose significant infection control concerns during the COVID-19 pandemic. Particle generation during MCT was significantly reduced by using breath-actuated delivery and a viral filter, which offers an effective mitigation strategy.