Second victim experiences and moral injury as predictors of hospitalist burnout before and during the COVID-19 pandemic.

BACKGROUND: The increasing number of physicians leaving practice, especially hospitalists, has been well-documented. The most commonly examined factor associated with this exodus has been burnout. The COVID-19 pandemic has put a unique and unprecedented stress on hospitalists who have been at the front lines of patient care. Therefore, the investigation of burnout and its related factors in hospitalists is essential to preventing future physician shortages. OBJECTIVE: This study examined the relationship between burnout, second victim, and moral injury experiences before and during the COVID-19 pandemic among hospitalists. METHODS: Two anonymous cross-sectional surveys of hospitalists from a community hospital in the metropolitan Washington, DC area were conducted. One was conducted pre-COVID-19 (September-November 2019) and one was conducted during COVID-19 (July-August 2020). The surveys were sent to all full-time hospitalists via an online survey platform. A variety of areas were assessed including demographic (e.g., age, gender), work information (e.g., hours per week, years of experience), burnout, second victim experiences, well-being, and moral injury. RESULTS: Burnout rates among providers during these two time periods were similar. Second victim experiences remained prevalent in those who experienced burnout both pre and during COVID-19, but interestingly the prevalence increased in those without burnout during COVID-19. Moral injury was predictive of burnout during COVID-19. CONCLUSION: While there were some factors that predicted burnout that were similar both pre- and during-pandemic, moral injury was unique to predicting burnout during COVID-19. With burnout as a contributing factor to future physician shortages, it is imperative that predictive factors in a variety of different environments are well understood to prevent future shortages. Hospitalists may be an excellent barometer of these factors given their presence on the front line during the pandemic, and their experiences need to be further explored so that targeted interventions aimed at addressing those factors may be created.

High throughput single cell bioinformatics.

Advances in systems biology and bioinformatics have highlighted that no cell population is truly uniform and that stochastic behavior is an inherent property of many biological systems. As a result, bulk measurements can be misleading even when particular care has been taken to isolate a single cell type, and measurements averaged over multiple cell populations in a tissue can be as misleading as the average height at an elementary school. There is a growing need for experimental techniques that can provide a combination of single cell resolution, large cell populations, and the ability to track cells over multiple time points. In this article, a microwell array cytometry platform was developed to meet this need and investigate the heterogeneity and stochasticity of cell behavior on a single cell basis. The platform consisted of a microfabricated device with high-density arrays of cell-sized microwells and custom software for automated image processing and data analysis. As a model experimental system, we used primary hepatocytes labeled with fluorescent probes sensitive to mitochondrial membrane potential and free radical generation. The cells were exposed to oxidative stress and the responses were dynamically monitored for each cell. The resulting data was then analyzed using bioinformatics techniques such as hierarchical and k-means clustering to visualize the data and identify interesting features. The results showed that clustering of the dynamic data not only enhanced comparisons between the treatment groups but also revealed a number of distinct response patterns within each treatment group. Heatmaps with hierarchical clustering also provided a data-rich complement to survival curves in a dose response experiment. The microwell array cytometry platform was shown to be powerful, easy to use, and able to provide a detailed picture of the heterogeneity present in cell responses to oxidative stress. We believe that our microwell array cytometry platform will have general utility for a wide range of questions related to cell population heterogeneity, biological stochasticity, and cell behavior under stress conditions.

High-throughput single cell arrays as a novel tool in biopreservation.

Microwell array cytometry is a novel high-throughput experimental technique that makes it possible to correlate pre-stress cell phenotypes and post-stress outcomes with single cell resolution. Because the cells are seeded in a high density grid of cell-sized microwells, thousands of individual cells can be tracked and imaged through manipulations as extreme as freezing or drying. Unlike flow cytometry, measurements can be made at multiple time points for the same set of cells. Unlike conventional image cytometry, image analysis is greatly simplified by arranging the cells in a spatially defined pattern and physically separating them from one another. To demonstrate the utility of microwell array cytometry in the field of biopreservation, we have used it to investigate the role of mitochondrial membrane potential in the cryopreservation of primary hepatocytes. Even with optimized cryopreservation protocols, the stress of freezing almost always leads to dysfunction or death in part of the cell population. To a large extent, cell fate is dominated by the stochastic nature of ice crystal nucleation, membrane rupture, and other biophysical processes, but natural variation in the initial cell population almost certainly plays an important and under-studied role. Understanding why some cells in a population are more likely to survive preservation will be invaluable for the development of new approaches to improve preservation yields. For this paper, primary hepatocytes were seeded in microwell array devices, imaged using the mitochondrial dyes Rh123 or JC-1, cryopreserved for up to a week, rapidly thawed, and checked for viability after a short recovery period. Cells with a high mitochondrial membrane potential before freezing were significantly less likely to survive the freezing process, though the difference in short term viability was fairly small. The results demonstrate that intrinsic cell factors do play an important role in cryopreservation survival, even in the short term where extrinsic biophysical factors would be expected to dominate. We believe that microwell array cytometry will be an important tool for a wide range of studies in biopreservation and stress biology.

Nonmetabolizable glucose compounds impart cryotolerance to primary rat hepatocytes.

We herein report a novel method for the cryopreservation of hepatocytes using a non-metabolizable glucose derivative in an attempt to mimic the natural cryoprotective adaptations observed in freeze-tolerant frogs. Primary rat hepatocytes were loaded with 3-O-methyl glucose (3OMG) through endogenous glucose transporters without evident toxicity. The 3OMG-loaded hepatocytes were then frozen in a controlled rate freezer down to -80 degrees C and stored in liquid nitrogen at -196 degrees C. Hepatocytes cryopreserved with a relatively small amount of intracellular 3OMG (<0.2 M) showed high post-thaw viability and maintained long-term hepatospecific functions, including synthesis, metabolism, and detoxification. Metabolite uptake and secretion rates were also largely preserved in the cryopreserved hepatocytes. This is the first study to demonstrate the use of the non-metabolizable glucose derivative 3OMG in hepatocyte cryopreservation.