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"Martin, Kyle D."
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Epidemiology and outcomes of critically ill patients in the emergency department of a tertiary teaching hospital in Rwanda
by
Cattermole, Giles N.
,
Martin, Kyle D.
,
Kamunga B., Laurent Gamy
in
Angiology
,
Cardiology
,
Cardiopulmonary resuscitation
2024
Background
The introduction of Emergency Medicine in Rwanda in 2015 has been associated with a mortality reduction in patients presenting to Kigali University Teaching Hospital (KUTH). In the context of increasing numbers of critically ill patients presenting to Emergency Departments (ED) globally, the aim of this study was to describe the characteristics of critically ill patients, the critical care interventions performed, and the outcomes of critically ill patients presenting to the KUTH ED with the goal of informing future research into the root causes of mortality of critically ill ED patients and of identifying high yield topics for didactic and procedural training.
Methods
A descriptive observational prospective cohort pilot study analyzed all patients ≥15 years who presented to KUTH between April and June 2022 with modified South African Triage Scores of Red with alarm, Red without alarm, and Orange.
Results
Of 320 patients, 66.9% were male and median age was 40 years. Patients were triaged as Orange (65.3%), Red without alarm (22.8%), and Red with alarm (11.9%). Presentations were categorized as: medical emergencies (48.0%), traumatic injury (44.5%), and surgical emergencies (7.6%). Median length of stay was 31 h (IQR 28, 56) and boarding was 23 h (IQR 8, 48). Overall mortality was 12.2% and highest among medical emergencies (16.5%,
p
= 0.048) and increased significantly with triage color: Red with alarm (47.4%), Red without alarm (16.4%), and Orange (4.3%,
p
< 0.0001). Cardiopulmonary resuscitation (CPR) (10.3%), endotracheal intubation (8.8%), and vasopressor administration (3.1%) were the most frequent critical interventions performed. Survival after cardiac arrest was 9.1% and 32.1% after intubation. Mortality was associated with the following interventions: CPR, intubation, and use of vasopressors (
p
< 0.05).
Conclusions
This pilot study identified the most common critical care interventions performed and a high mortality among patients who required these interventions in the ED of a tertiary teaching hospital in Rwanda. These findings will inform didactics and procedural training for emergency care providers. Future research should focus on the root causes of mortality in these specific patient populations and identify areas of system strengthening to reduce mortality.
Journal Article
Validation of a wearable biosensor device for vital sign monitoring in septic emergency department patients in Rwanda
by
Umuhoza, Christian
,
Twagirumukiza, Francois R
,
Levine, Adam C
in
Biosensors
,
Heart rate
,
Original Research
2019
Objective
Critical care capabilities needed for the management of septic patients, such as continuous vital sign monitoring, are largely unavailable in most emergency departments (EDs) in low- and middle-income country (LMIC) settings. This study aimed to assess the feasibility and accuracy of using a wireless wearable biosensor device for continuous vital sign monitoring in ED patients with suspected sepsis in an LMIC setting.
Methods
This was a prospective observational study of pediatric (≥2 mon) and adult patients with suspected sepsis at the Kigali University Teaching Hospital ED. Heart rate, respiratory rate and temperature measurements were continuously recorded using a wearable biosensor device for the duration of the patients’ ED course and compared to intermittent manually collected vital signs.
Results
A total of 42 patients had sufficient data for analysis. Mean duration of monitoring was 32.8 h per patient. Biosensor measurements were strongly correlated with manual measurements for heart rate (r = 0.87, p < 0.001) and respiratory rate (r = 0.75, p < 0.001), although were less strong for temperature (r = 0.61, p < 0.001). Mean (SD) differences between biosensor and manual measurements were 1.2 (11.4) beats/min, 2.5 (5.5) breaths/min and 1.4 (1.0)°C. Technical or practical feasibility issues occurred in 12 patients (28.6%) although were minor and included biosensor detachment, connectivity problems, removal for a radiologic study or exam, and patient/parent desire to remove the device.
Conclusions
Wearable biosensor devices can be feasibly implemented and provide accurate continuous heart rate and respiratory rate monitoring in acutely ill pediatric and adult ED patients with sepsis in an LMIC setting.
Journal Article
The financial and environmental impact of unopened medical supplies discarded in the emergency department
2024
Inefficient supply chain management within the US healthcare industry results in significant financial and environmental impact. Unopened medical supplies may routinely be discarded in the Emergency Department (ED), contributing as a source of unnecessary medical waste.
Quantify the financial and environmental impact of unopened medical supplies that are routinely discarded in two EDs.
The study utilized a waste audit of collection bins targeting unopened medical supplies that would have otherwise been discarded. Associated financial cost was calculated using data from the purchasing department and from an online search. End-of-life (EOL) environmental impact was calculated using the M+ Wastecare calculator. A lifecycle analysis was performed on a supplier-packaged intubation kit, which the study identified as a significant source of waste.
High volumes of unused, unopened supplies (143.48 kg) were collected during the study period with a yearly extrapolated value of 1337 kg. Purchasing costs over 44 days at Hospital A and 37 days at Hospital B for these items amounted to $16,159.71 across both sites with a yearly extrapolated value of $150,631.73. Yearly extrapolated EOL impact yielded 5.79 tons per year of CO2eq. Components from supplier-packaged intubation kits were found to contribute to 45.2% of collected items at one site which purchased them. Lifecycle analysis of an intubation kit yields 23.6 kg of CO2eq.
This study demonstrates that the disposal of unopened medical supplies contributes a significant source of financial and environmental waste in the ED setting. The results continue to support the trend of procedure kits generating significant environmental and financial waste.
Journal Article
Building and Sustaining Partnerships in Health Workforce and Research Capacity in Rwanda
by
Uwamahoro, Doris Lorette
,
Levine, Adam C
,
Garbern, Stephanie C
in
Capacity Building
,
Health Services Accessibility
,
Health Services Research
2019
Rwanda's ambitious Human Resources for Health (HRH) program comes to an end this year, having made great strides towards achieving its aim to create a large, diverse and competent health workforce, and will have graduated over 4,500 healthcare professionals since its inception in 2012. The HRH program was based on strong collaborative relationships between Rwandan and United States academic institutions and faculty and now stands poised to enter a new phase focused on sustaining the many gains achieved. Fostering career development of new Rwandan faculty and building health research capacity are key components to sustaining the mutually beneficial partnerships that have been forged over the past seven years, with the goal of creating strong Rwandan health researchers that can advance knowledge of best practices for patient care and public health, appropriate to the Rwandan context and other resource-limited settings.
Journal Article
Building and Sustaining Partnerships in Health Workforce and Research Capacity in Rwanda
by
Uwamahoro, Doris Lorette
,
Levine, Adam C
,
Garbern, Stephanie C
in
Critical care
,
Emergency medical care
,
Human resources
2019
Rwanda's ambitious Human Resources for Health (HRH) program comes to an end this year, having made great strides towards achieving its aim to create a large, diverse and competent health workforce, and will have graduated over 4,500 healthcare professionals since its inception in 2012. The HRH program was based on strong collaborative relationships between Rwandan and United States academic institutions and faculty and now stands poised to enter a new phase focused on sustaining the many gains achieved. Fostering career development of new Rwandan faculty and building health research capacity are key components to sustaining the mutually beneficial partnerships that have been forged over the past seven years, with the goal of creating strong Rwandan health researchers that can advance knowledge of best practices for patient care and public health, appropriate to the Rwandan context and other resource-limited settings.
Journal Article
Forecasting life expectancy, years of life lost, and all-cause and cause-specific mortality for 250 causes of death: reference and alternative scenarios for 2016–40 for 195 countries and territories
by
Marquez, Neal
,
Brown, Jonathan C
,
Dolgert, Andrew
in
Acquired immune deficiency syndrome
,
Aging
,
AIDS
2018
Understanding potential trajectories in health and drivers of health is crucial to guiding long-term investments and policy implementation. Past work on forecasting has provided an incomplete landscape of future health scenarios, highlighting a need for a more robust modelling platform from which policy options and potential health trajectories can be assessed. This study provides a novel approach to modelling life expectancy, all-cause mortality and cause of death forecasts —and alternative future scenarios—for 250 causes of death from 2016 to 2040 in 195 countries and territories.
We modelled 250 causes and cause groups organised by the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) hierarchical cause structure, using GBD 2016 estimates from 1990–2016, to generate predictions for 2017–40. Our modelling framework used data from the GBD 2016 study to systematically account for the relationships between risk factors and health outcomes for 79 independent drivers of health. We developed a three-component model of cause-specific mortality: a component due to changes in risk factors and select interventions; the underlying mortality rate for each cause that is a function of income per capita, educational attainment, and total fertility rate under 25 years and time; and an autoregressive integrated moving average model for unexplained changes correlated with time. We assessed the performance by fitting models with data from 1990–2006 and using these to forecast for 2007–16. Our final model used for generating forecasts and alternative scenarios was fitted to data from 1990–2016. We used this model for 195 countries and territories to generate a reference scenario or forecast through 2040 for each measure by location. Additionally, we generated better health and worse health scenarios based on the 85th and 15th percentiles, respectively, of annualised rates of change across location-years for all the GBD risk factors, income per person, educational attainment, select intervention coverage, and total fertility rate under 25 years in the past. We used the model to generate all-cause age-sex specific mortality, life expectancy, and years of life lost (YLLs) for 250 causes. Scenarios for fertility were also generated and used in a cohort component model to generate population scenarios. For each reference forecast, better health, and worse health scenarios, we generated estimates of mortality and YLLs attributable to each risk factor in the future.
Globally, most independent drivers of health were forecast to improve by 2040, but 36 were forecast to worsen. As shown by the better health scenarios, greater progress might be possible, yet for some drivers such as high body-mass index (BMI), their toll will rise in the absence of intervention. We forecasted global life expectancy to increase by 4·4 years (95% UI 2·2 to 6·4) for men and 4·4 years (2·1 to 6·4) for women by 2040, but based on better and worse health scenarios, trajectories could range from a gain of 7·8 years (5·9 to 9·8) to a non-significant loss of 0·4 years (–2·8 to 2·2) for men, and an increase of 7·2 years (5·3 to 9·1) to essentially no change (0·1 years [–2·7 to 2·5]) for women. In 2040, Japan, Singapore, Spain, and Switzerland had a forecasted life expectancy exceeding 85 years for both sexes, and 59 countries including China were projected to surpass a life expectancy of 80 years by 2040. At the same time, Central African Republic, Lesotho, Somalia, and Zimbabwe had projected life expectancies below 65 years in 2040, indicating global disparities in survival are likely to persist if current trends hold. Forecasted YLLs showed a rising toll from several non-communicable diseases (NCDs), partly driven by population growth and ageing. Differences between the reference forecast and alternative scenarios were most striking for HIV/AIDS, for which a potential increase of 120·2% (95% UI 67·2–190·3) in YLLs (nearly 118 million) was projected globally from 2016–40 under the worse health scenario. Compared with 2016, NCDs were forecast to account for a greater proportion of YLLs in all GBD regions by 2040 (67·3% of YLLs [95% UI 61·9–72·3] globally); nonetheless, in many lower-income countries, communicable, maternal, neonatal, and nutritional (CMNN) diseases still accounted for a large share of YLLs in 2040 (eg, 53·5% of YLLs [95% UI 48·3–58·5] in Sub-Saharan Africa). There were large gaps for many health risks between the reference forecast and better health scenario for attributable YLLs. In most countries, metabolic risks amenable to health care (eg, high blood pressure and high plasma fasting glucose) and risks best targeted by population-level or intersectoral interventions (eg, tobacco, high BMI, and ambient particulate matter pollution) had some of the largest differences between reference and better health scenarios. The main exception was sub-Saharan Africa, where many risks associated with poverty and lower levels of development (eg, unsafe water and sanitation, household air pollution, and child malnutrition) were projected to still account for substantive disparities between reference and better health scenarios in 2040.
With the present study, we provide a robust, flexible forecasting platform from which reference forecasts and alternative health scenarios can be explored in relation to a wide range of independent drivers of health. Our reference forecast points to overall improvements through 2040 in most countries, yet the range found across better and worse health scenarios renders a precarious vision of the future—a world with accelerating progress from technical innovation but with the potential for worsening health outcomes in the absence of deliberate policy action. For some causes of YLLs, large differences between the reference forecast and alternative scenarios reflect the opportunity to accelerate gains if countries move their trajectories toward better health scenarios—or alarming challenges if countries fall behind their reference forecasts. Generally, decision makers should plan for the likely continued shift toward NCDs and target resources toward the modifiable risks that drive substantial premature mortality. If such modifiable risks are prioritised today, there is opportunity to reduce avoidable mortality in the future. However, CMNN causes and related risks will remain the predominant health priority among lower-income countries. Based on our 2040 worse health scenario, there is a real risk of HIV mortality rebounding if countries lose momentum against the HIV epidemic, jeopardising decades of progress against the disease. Continued technical innovation and increased health spending, including development assistance for health targeted to the world's poorest people, are likely to remain vital components to charting a future where all populations can live full, healthy lives.
Bill & Melinda Gates Foundation.
Journal Article
Oligodendrocyte precursor cells present antigen and are cytotoxic targets in inflammatory demyelination
2019
Oligodendrocyte precursor cells (OPCs) are abundant in the adult central nervous system, and have the capacity to regenerate oligodendrocytes and myelin. However, in inflammatory diseases such as multiple sclerosis (MS) remyelination is often incomplete. To investigate how neuroinflammation influences OPCs, we perform in vivo fate-tracing in an inflammatory demyelinating mouse model. Here we report that OPC differentiation is inhibited by both effector T cells and IFNγ overexpression by astrocytes. IFNγ also reduces the absolute number of OPCs and alters remaining OPCs by inducing the immunoproteasome and MHC class I. In vitro, OPCs exposed to IFNγ cross-present antigen to cytotoxic CD8 T cells, resulting in OPC death. In human demyelinated MS brain lesions, but not normal appearing white matter, oligodendroglia exhibit enhanced expression of the immunoproteasome subunit PSMB8. Therefore, OPCs may be co-opted by the immune system in MS to perpetuate the autoimmune response, suggesting that inhibiting immune activation of OPCs may facilitate remyelination.
In multiple sclerosis (MS), antigen-presenting cells inducing cytotoxic T cell response against mature oligodendrocytes remain to be identified. Here the authors show that oligodendrocyte precursors cross-present antigen taken up from mature oligodendrocytes, and are targeted by cytotoxic T cells in cell culture and in an animal model of MS.
Journal Article
Climate change effects on agriculture: Economic responses to biophysical shocks
by
Deryng, Delphine
,
Müller, Christoph
,
Kyle, Page
in
Agricultural land
,
Agricultural production
,
Agriculture
2014
Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change’s representative concentration pathway with end-of-century radiative forcing of 8.5 W/m2. The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change.
Journal Article
Decarboxylative alkenylation
by
Knouse, Kyle W.
,
Vokits, Benjamin
,
Qin, Tian
in
639/638/403/933
,
639/638/403/977
,
639/638/77/888
2017
Starting with alkyl carboxylic acids, a simple olefin synthesis using any substitution pattern or geometry, based on amide-bond synthesis with nickel- or iron-based catalysis, is described.
Simplified olefin synthesis
Olefins are ubiquitous functional groups in organic chemistry and are typically installed in small molecules by the formation of a carbon–carbon double bond. Here, Phil Baran and colleagues report a decarboxylative alkyl-vinyl cross-coupling that offers a cheap and simple route to olefins with defined geometry and substitution pattern. The nickel or iron catalysts extract carbon dioxide from the carboxylic acid, which is activated in a similar way to peptide-bond formation. The alkene is then attached with a vinyl zinc reagent. The authors exemplify their method by preparing more than 60 olefins and synthesizing 16 natural products. One such example offers a short route to macrocyclic polyketides from the commodity chemical diethyl tartrate.
Olefin chemistry, through pericyclic reactions, polymerizations, oxidations, or reductions, has an essential role in the manipulation of organic matter
1
. Despite its importance, olefin synthesis still relies largely on chemistry introduced more than three decades ago, with metathesis
2
being the most recent addition. Here we describe a simple method of accessing olefins with any substitution pattern or geometry from one of the most ubiquitous and variegated building blocks of chemistry: alkyl carboxylic acids. The activating principles used in amide-bond synthesis can therefore be used, with nickel- or iron-based catalysis, to extract carbon dioxide from a carboxylic acid and economically replace it with an organozinc-derived olefin on a molar scale. We prepare more than 60 olefins across a range of substrate classes, and the ability to simplify retrosynthetic analysis is exemplified with the preparation of 16 different natural products across 10 different families.
Journal Article
Measurement of Optical Rubidium Clock Frequency Spanning 65 Days
by
Lemke, Nathan D.
,
Elgin, John D.
,
Martin, Kyle W.
in
atomic clock
,
Calibration
,
Clocks & watches
2022
Optical clocks are emerging as next-generation timekeeping devices with technological and scientific use cases. Simplified atomic sources such as vapor cells may offer a straightforward path to field use, but suffer from long-term frequency drifts and environmental sensitivities. Here, we measure a laboratory optical clock based on warm rubidium atoms and find low levels of drift on the month-long timescale. We observe and quantify helium contamination inside the glass vapor cell by gradually removing the helium via a vacuum apparatus. We quantify a drift rate of 4×10−15/day, a 10 day Allan deviation less than 5×10−15, and an absolute frequency of the Rb-87 two-photon clock transition of 385,284,566,371,190(1970) Hz. These results support the premise that optical vapor cell clocks will be able to meet future technology needs in navigation and communications as sensors of time and frequency.
Journal Article