Niven, Alexander S

Acute respiratory distress syndrome (ARDS) is a common and highly heterogeneous condition in the critically ill. The association between hyper- and hypo-inflammatory subphenotypes and clinical outcomes has generated significant interest in precise ARDS management. The value of identifying biomarkers to guide treatment and enrollment in future ARDS trials is undisputable. We describe multiple factors complicating the search for subphenotypes and their treatable traits. The observed heterogeneity seen in the clinical course of ARDS is dynamic and influenced by factors beyond lung pathophysiology, including variations in the delivery of best critical care practices, patient comorbidities, and functional status, and patient or family preferences. Current subphenotype definitions lack strong biological plausibility and without clear evidence of benefit from targeted treatments, their use in clinical practice is currently unwarranted.

Abstract 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.

Abstract Background CERTAIN (Checklist for Early Recognition and Treatment of Acute Illness and iNjury) education program was developed to accelerate the global dissemination of a standardized, systemic, structured approach to critical care delivery. The coronavirus disease (COVID-19) pandemic prompted the evolution of this program from a live in-person course to a blended synchronous and asynchronous learning experience, including virtual simulation. Objectives We describe our experience and insights gained through this digital program transformation and highlight areas in need of further research to advance the delivery of high-quality online education offerings to global interprofessional audiences. Methods The CERTAIN education program was delivered to a broad international audience first in person (2016–2019) and then virtually during the COVID-19 global pandemic (2020–present). During this transition, we adopted a flipped classroom model to deliver the core content asynchronously using an online learning management system, supplemented by a novel synchronous online experience to provide learners with the opportunity to apply these concepts using a series of simulated clinical cases. Results A total of 400 participants attended 11 CERTAIN courses. We transitioned our 10-hour live course to a 3-hour virtual workshop. The duration of simulation activities (admission, rounding, and shared decision-making) remained constant. Didactic lectures were eliminated from the synchronous online course and presented as recorded videos in precourse materials. We collected 306 postcourse surveys (response rate, 76.5%). The majority of the overall course ratings were excellent (147 [49.5%]) and very good (97 [32.7%]), and learner responses were similar to live and online courses. Simulation activities were consistently the most popular elements of our program. Access to digital learning platforms and language barriers during simulation activities proved to be the greatest challenges during our transition. Delivering mobile-friendly online content and close coordination between dedicated bilingual faculty and local champions helped overcome these challenges. Conclusion Critical care education and case-based simulation workshops can be delivered to international interprofessional audiences with similar, high degrees of learner satisfaction to in-person offerings.

Abstract 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.

Abstract 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.