Years of Potential Life Lost and Mean Age of Adults Experiencing Nontraumatic, Out-of-Hospital Cardiac Arrests - Chicago, 2014-2021.

Approximately 1,000 out-of-hospital cardiac arrests (OHCAs) are assessed by emergency medical services in the United States every day, and approximately 90% of patients do not survive, leading to substantial years of potential life lost (YPLL). Chicago emergency medical services data were used to assess changes in mean age and YPLL from nontraumatic OHCA in adults in biennial cycles during 2014-2021. Among 21,070 reported nontraumatic OHCAs during 2014-2021, approximately 60% occurred among men and 57% among non-Hispanic Black or African American (Black) persons. YPLL increased from 52,044 during 2014-2015 to 88,788 during 2020-2021 (p = 0.002) and mean age decreased from 64.7 years during 2014-2015, to 62.7 years during 2020-2021. Decrease in mean age occurred among both men (p<0.001) and women (p = 0.002) and was largest among Black men. Mean age decreased among patients without presumed cardiac etiology from 56.3 to 52.5 years (p<0.001) and among patients with nonshockable rhythm from 65.5 to 62.7 years (p<0.001). Further study is needed to assess whether similar trends are occurring elsewhere, and to understand the mechanisms that underlie these trends in Chicago because these mechanisms could help guide prevention efforts. Increased public awareness of the risk of cardiac arrest and knowledge of how to intervene as a bystander could help decrease associated mortality.

TeleEMS: An EMS Telemedicine Pilot Program Barriers to Implementation.

INTRODUCTION: In response to the COVID-19 pandemic, emergency medical services (EMS) and hospitals recognized the need for innovative programs addressing 9-1-1 utilization and ambulance transport to provide patient-centered, safe, cost-effective care. The ET3 (Emergency Triage, Treatment, and Transport) model provides flexibility and new payments to ambulance care teams for Medicare beneficiaries for alternate strategies of care. This includes providing treatment in place through telehealth after a 9-1-1 call and ambulance response. Our objective is to evaluate the implementation barriers of a telemedicine service to 9-1-1 responding ambulances providing treatment in place for low-acuity conditions. METHODS: The TeleEMS program was piloted in a large, urban fire-based EMS system with eight ambulances geographically surrounding one hospital. Paramedics received training on the telemedicine software and screening criteria, which were age 1-70 and vital sign parameters. Pregnant, combative, and patients with no clear need for emergency department transport were excluded. Three emergency physicians with additional training in EMS provided the TeleEMS service from 8am to 6 pm on Monday - Friday. The telemedicine software was application-based and provided HIPAA-compliant two-way, real-time audio and video communication through the 4G network on a tablet. The TeleEMS physicians had access to a database of clinics and hospitals that coordinate health care. The TeleEMS physician contacted the patient within 24-72 hours after the encounter for follow-up. RESULTS: The TeleEMS pilot program ran for 12 weeks from April - June 2021. During this time, there were seven completed consults with treatment in place, one completed consult with transport to an emergency department, and five consult attempts that failed due to technological issues with resultant transport. Each of the consults (13/13) met the TeleEMS screening criteria. Post-pilot focus group sessions were held to determine paramedic feedback. Barriers to an EMS telemedicine program include paramedic buy-in, patient expectations for emergency care, technology limitations, and qualified physician resources. CONCLUSIONS: An EMS telemedicine program can be successfully implemented in urban fire-based EMS systems for 9-1-1 responding ambulances. Barriers to implementation should be addressed at the paramedic, patient, technology, and program levels to improve success.

Interhospital variability in Out-of-Hospital cardiac arrest survival in a large metropolitan area.

Background: Out-of-hospital cardiac arrest (OHCA) survival varies widely across the United States. The impact of hospital OHCA volume and ST-elevation myocardial infarction (STEMI) Receiving Center (SRC) designation on survival is not fully understood. Methods: This was a retrospective analysis of adult OHCA who survived to hospital admission reported to the Chicago Cardiac Arrest Registry to Enhance Survival (CARES) database from May 1, 2013 to December 31, 2019. Hierarchical logistic regression models were generated and adjusted by hospital characteristics. Survival to hospital discharge (SHD) and cerebral performance category (CPC) 1-2 at each hospital were calculated after adjusting for arrest characteristics. Hospitals were assigned quartiles (Q1-Q4) based on total arrest volume to allow for comparison of SHD and CPC 1-2 between quartiles. Results: 4,020 patients met inclusion criteria. 21 of the 33 Chicago hospitals included in this study were designated SRCs. Adjusted SHD and CPC 1-2 rates ranged from 27.3% to 37.0% and from 8.9% to 25.1%, respectively, by hospital. SRC designation did not significantly affect SHD (OR 0.96; 95% CI, 0.71-1.30) nor CPC 1-2 (OR 1.17; 95% CI, 0.74-1.84). OHCA volume quartiles did not significantly affect SHD (Q2: OR 0.94; 95% CI, 0.54-1.60; Q3: OR 1.30; 95% CI, 0.78-2.16; Q4: OR 1.25; 95% CI, 0.74-2.10) nor CPC 1-2 (Q2: OR 0.75; 95% CI, 0.36-1.54; Q3: OR 0.94; 95% CI, 0.48-1.87; Q4: OR 0.97; 95% CI, 0.48-1.97). Conclusion: Interhospital variability in both SHD and CPC 1-2 cannot be explained by hospital arrest volume nor SRC status. Further research is warranted to explore reasons for interhospital variability.

Prehospital Intranasal Glucagon for Hypoglycemia.

BACKGROUND: Prehospital hypoglycemia is usually treated with oral or intravenous (IV) dextrose in a variety of concentrations. In the absence of vascular access, intramuscular (IM) glucagon is commonly administered. Occupational needle-stick injury remains a significant risk while attempting to obtain vascular access or administer medications intramuscularly in the prehospital setting. We sought to determine if intranasal (IN) glucagon is effective in the prehospital treatment of hypoglycemia. METHODS: We performed a retrospective analysis of all consecutive cases where recombinant glucagon was administered IN by paramedics from January 1, 2015 through December 31, 2020. Excluded were cases without pre or post administration blood glucose documentation, and cases where another form of treatment for hypoglycemia was administered at any time during the EMS encounter. The primary outcome was clinical response to IN glucagon documented by paramedics; secondary outcomes included pre and post administration blood glucose values. RESULTS: Out of 44 cases that met study inclusion criteria, 14 patients (32%) had substantial improvement, 13 patients (30%) had slight improvement, and 17 patients (38%) had no improvement in mental status after administration of IN glucagon. In cases with substantial improvement (n = 14), the mean pre administration blood glucose was 33.8 mg/dl and the mean post administration blood glucose was 87.1 mg/dl (mean increase 53.3 mg/dl, 95% CI: 21.5 to 85.1). In cases with slight improvement (n = 13), the mean pre administration blood glucose was 23.9 mg/dl and the mean post administration blood glucose was 53.8 mg/dl (mean increase 29.9 mg/dl, 95% CI = 2.9 to 56.9). In case with no improvement (n = 17) the mean pre administration blood glucose was 30.1 mg/dl and the mean post administration glucose was 33.1 mg/dl (mean difference 3.1 mg/dl, 95% CI: -10.1 to 3.9). CONCLUSION: Intranasal administration of recombinant glucagon for hypoglycemia resulted in a clinically significant improvement in mental status and a corresponding increase in blood glucose levels in select cases in the prehospital setting.

Fibrous Cap Thickness Predicts Stable Coronary Plaque Progression: Early Clinical Validation of a Semiautomated OCT Technology.

Background: Imaging-based characteristics associated with the progression of stable coronary atherosclerotic lesions are poorly defined. Utilizing a combination of optical coherence tomography (OCT) and intravascular ultrasound (IVUS) imaging, we aimed to characterize the lesions prone to progression through clinical validation of a semiautomated OCT computational program. Methods: Patients with stable coronary artery disease underwent nonculprit vessel imaging with IVUS and OCT at baseline and IVUS at the 12-month follow-up. After coregistration of baseline and follow-up IVUS images, paired 5-mm segments from each patient were identified, demonstrating the greatest plaque progression and regression as measured by the change in plaque burden. Experienced readers identified plaque features on corresponding baseline OCT segments, and predictors of plaque progression were assessed by multivariable analysis. Each segment then underwent volumetric assessment of the fibrous cap (FC) using proprietary software. Results: Among 23 patients (70% men; median age, 67 years), experienced-reader analysis demonstrated that for every 100 µm increase in mean FC thickness, plaques were 87% less likely to progress (P = .01), which persisted on multivariable analysis controlling for baseline plaque burden (P = .05). Automated FC analysis (n = 17 paired segments) confirmed this finding (P = .01) and found thinner minimal FC thickness (P = .01) and larger FC surface area of <65 µm (P = .02) and <100 µm (P = .04) in progressing segments than in regressing segments. No additional imaging features predicted plaque progression. Conclusions: A semiautomated FC analysis tool confirmed the significant association between thinner FC and stable coronary plaque progression along entire vessel segments, illustrating the diffuse nature of FC thinning and suggesting a future clinical role in predicting the progression of stable coronary artery disease.

Immersive educational curriculum on intracoronary optical coherence tomography image analysis among naïve readers.

BACKGROUND: Optical coherence tomography (OCT) is an intravascular imaging modality for analysing coronary vessels. Image interpretation remains an obstacle for novice readers due to technical artefacts and uncertainty in tissue characterization. Despite an expanding clinical and research role for OCT, few training efforts exist, and there is an absence of a national standardized educational curriculum. We sought to determine whether an interactive, feedback-based OCT curriculum improved image interpretation among naive readers. METHODS: Naive OCT readers completed both a Standard curriculum, comprised of self-directed didactics and consensus statements, and an Augmented curriculum, which provided real-time digital feedback of feature identification and measurements. Modules were separated by a minimum one-week washout period. After each module, and blinded to the exam answers, subjects completed an identical expert-designed 413-item exam to assess technical knowledge and ability to identify and measure vessel features. Performances were compared using Exact Wilcoxon signed-rank tests. RESULTS: Among the 7 included subjects were 3 medical students, 3 internal medicine residents, and 1 cardiovascular medicine fellow with no prior OCT experience. The technical knowledge score (maximum 13) was significantly higher with the Augmented compared with the Standard curriculum (median 11 vs. 7, p = 0.03). After undergoing the Augmented curriculum, all 7 subjects were able to identify features of plaque rupture (Standard curriculum: 5/7 subjects, p = 0.5) and macrophages (Standard curriculum: 6/7 subjects, p = 0.99), differentiate the components between red and white thrombus (Standard curriculum: 6/7 subjects, p = 0.99), and characterize lipid plaque by attenuation, signal, homogeneity, and borders (Standard curriculum: 5/7 subjects, p = 0.5). Performances on the remaining exam portions did not differ between curricula. CONCLUSIONS: The need for standardized, effective training in OCT image interpretation is increasingly essential as the intravascular imaging modality becomes widely utilized among interventional cardiologists and trainees. A novel interactive OCT curriculum enhanced naive readers' technical knowledge and may supplement traditional self-learning in refining analytic skills.

Utilizing community level factors to improve prediction of out of hospital cardiac arrest outcome using machine learning.

OBJECTIVES: To evaluate the impact of community level information on the predictability of out-of-hospital cardiac arrest (OHCA) survival. METHODS: We used the Cardiac Arrest Registry to Enhance Survival (CARES) to geocode 9,595 Chicago incidents from 2014 to 2019 into community areas. Community variables including crime, healthcare, and economic factors from public data were merged with CARES. The merged data were used to develop ML models for OHCA survival. Models were evaluated using Area Under the Receiver Operating Characteristic curve (AUROC) and features were analyzed using SHapley Additive exPansion (SHAP) values. RESULTS: Baseline results using CARES data achieved an AUROC of 84%. The final model utilizing community variables increased the AUROC to 88%. A SHAP analysis between high and low performing community area clusters showed the high performing cluster is positively impacted by good health related features and good community safety features positively impact the low performing cluster. CONCLUSION: Utilizing community variables helps predict neurologic outcomes with better performance than only CARES data. Future studies will use this model to perform simulations to identify interventions to improve OHCA survival.

A Statewide Approach to Reducing Re-excision Rates for Women With Breast-conserving Surgery.

OBJECTIVE: Test the effectiveness of benchmarked performance reports based on existing discharge data paired with a statewide intervention to implement evidence-based strategies on breast re-excision rates. BACKGROUND: Breast-conserving surgery (BCS) is a common breast cancer surgery performed in a range of hospital settings. Studies have demonstrated variations in post-BCS re-excision rates, identifying it as a high-value improvement target. METHODS: Wisconsin Hospital Association discharge data (2017-2019) were used to compare 60-day re-excision rates following BCS for breast cancer. The analysis estimated the difference in the average change preintervention to postintervention between Surgical Collaborative of Wisconsin (SCW) and nonparticipating hospitals using a logistic mixed-effects model with repeated measures, adjusting for age, payer, and hospital volume, including hospitals as random effects. The intervention included 5 collaborative meetings in 2018 to 2019 where surgeon champions shared guideline updates, best practices/challenges, and facilitated action planning. Confidential benchmarked performance reports were provided. RESULTS: In 2017, there were 3692 breast procedures in SCW and 1279 in nonparticipating hospitals; hospital-level re-excision rates ranged from 5% to >50%. There was no statistically significant baseline difference in re-excision rates between SCW and nonparticipating hospitals (16.1% vs. 17.1%, P =0.47). Re-excision significantly decreased for SCW but not for nonparticipating hospitals (odds ratio=0.69, 95% confidence interval=0.52-0.91). CONCLUSIONS: Benchmarked performance reports and collaborative quality improvement can decrease post-BCS re-excisions, increase quality, and decrease costs. Our study demonstrates the effective use of administrative data as a platform for statewide quality collaboratives. Using existing data requires fewer resources and offers a new paradigm that promotes participation across practice settings.

A machine learning approach for modeling decisions in the out of hospital cardiac arrest care workflow.

BACKGROUND: A growing body of research has shown that machine learning (ML) can be a useful tool to predict how different variable combinations affect out-of-hospital cardiac arrest (OHCA) survival outcomes. However, there remain significant research gaps on the utilization of ML models for decision-making and their impact on survival outcomes. The purpose of this study was to develop ML models that effectively predict hospital's practice to perform coronary angiography (CA) in adult patients after OHCA and subsequent neurologic outcomes. METHODS: We utilized all (N = 2398) patients treated by the Chicago Fire Department Emergency Medical Services included in the Cardiac Arrest Registry to Enhance Survival (CARES) between 2013 and 2018 who survived to hospital admission to develop, test, and analyze ML models for decisions after return of spontaneous circulation (ROSC) and patient survival. ML classification models, including the Embedded Fully Convolutional Network (EFCN) model, were compared based on their ability to predict post-ROSC decisions and survival. RESULTS: The EFCN classification model achieved the best results across tested ML algorithms. The area under the receiver operating characteristic curve (AUROC) for CA and Survival were 0.908 and 0.896 respectively. Through cohort analyses, our model predicts that 18.3% (CI 16.4-20.2) of patients should receive a CA that did not originally, and 30.1% (CI 28.5-31.7) of these would experience improved survival outcomes. CONCLUSION: ML modeling effectively predicted hospital decisions and neurologic outcomes. ML modeling may serve as a quality improvement tool to inform system level OHCA policies and treatment protocols.

Prehospital Comprehensive Stroke Center vs Primary Stroke Center Triage in Patients With Suspected Large Vessel Occlusion Stroke.

Importance: Endovascular therapy (EVT) improves functional outcomes in acute ischemic stroke (AIS) with large vessel occlusion (LVO). Whether implementation of a regional prehospital transport policy for comprehensive stroke center triage increases use of EVT is uncertain. Objective: To evaluate the association of a regional prehospital transport policy that directly triages patients with suspected LVO stroke to the nearest comprehensive stroke center with rates of EVT. Design, Setting, and Participants: This retrospective, multicenter preimplementation-postimplementation study used an interrupted time series analysis to compare treatment rates before and after implementation in patients with AIS arriving at 15 primary stroke centers and 8 comprehensive stroke centers in Chicago, Illinois, via emergency medical services (EMS) transport from December 1, 2017, to May 31, 2019 (9 months before and after implementation in September 2018). Data were analyzed from December 1, 2017, to May 31, 2019. Interventions: Prehospital EMS transport policy to triage patients with suspected LVO stroke, using a 3-item stroke scale, to comprehensive stroke centers. Main Outcomes and Measures: Rates of EVT before and after implementation among EMS-transported patients within 6 hours of AIS onset. Results: Among 7709 patients with stroke, 663 (mean [SD] age, 68.5 [14.9] years; 342 women [51.6%] and 321 men [48.4%]; and 348 Black individuals [52.5%]) with AIS arrived within 6 hours of stroke onset by EMS transport: 310 of 2603 (11.9%) in the preimplementation period and 353 of 2637 (13.4%) in the postimplementation period. The EVT rate increased overall among all patients with AIS (preimplementation, 4.9% [95% CI, 4.1%-5.8%]; postimplementation, 7.4% [95% CI, 7.5%-8.5%]; P < .001) and among EMS-transported patients with AIS within 6 hours of onset (preimplementation, 4.8% [95% CI, 3.0%-7.8%]; postimplementation, 13.6% [95% CI, 10.4%-17.6%]; P < .001). On interrupted time series analysis among EMS-transported patients, the level change within 1 month of implementation was 7.15% (P = .04) with no slope change before (0.16%; P = .71) or after (0.08%; P = .89), which indicates a step rather than gradual change. No change in time to thrombolysis or rate of thrombolysis was observed (step change, 1.42%; P = .82). There were no differences in EVT rates in patients not arriving by EMS in the 6- to 24-hour window or by interhospital transfer or walk-in, irrespective of time window. Conclusions and Relevance: Implementation of a prehospital transport policy for comprehensive stroke center triage in Chicago was associated with a significant, rapid, and sustained increase in EVT rate for patients with AIS without deleterious associations with thrombolysis rates or times.

In Vivo Entombment of Bacteria and Fungi during Calcium Oxalate, Brushite, and Struvite Urolithiasis.

Background: Human kidney stones form via repeated events of mineral precipitation, partial dissolution, and reprecipitation, which are directly analogous to similar processes in other natural and manmade environments, where resident microbiomes strongly influence biomineralization. High-resolution microscopy and high-fidelity metagenomic (microscopy-to-omics) analyses, applicable to all forms of biomineralization, have been applied to assemble definitive evidence of in vivo microbiome entombment during urolithiasis. Methods: Stone fragments were collected from a randomly chosen cohort of 20 patients using standard percutaneous nephrolithotomy (PCNL). Fourier transform infrared (FTIR) spectroscopy indicated that 18 of these patients were calcium oxalate (CaOx) stone formers, whereas one patient formed each formed brushite and struvite stones. This apportionment is consistent with global stone mineralogy distributions. Stone fragments from seven of these 20 patients (five CaOx, one brushite, and one struvite) were thin sectioned and analyzed using brightfield (BF), polarization (POL), confocal, super-resolution autofluorescence (SRAF), and Raman techniques. DNA from remaining fragments, grouped according to each of the 20 patients, were analyzed with amplicon sequencing of 16S rRNA gene sequences (V1-V3, V3-V5) and internal transcribed spacer (ITS1, ITS2) regions. Results: Bulk-entombed DNA was sequenced from stone fragments in 11 of the 18 patients who formed CaOx stones, and the patients who formed brushite and struvite stones. These analyses confirmed the presence of an entombed low-diversity community of bacteria and fungi, including Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria, and Aspergillus niger. Bacterial cells approximately 1 µm in diameter were also optically observed to be entombed and well preserved in amorphous hydroxyapatite spherules and fans of needle-like crystals of brushite and struvite. Conclusions: These results indicate a microbiome is entombed during in vivo CaOx stone formation. Similar processes are implied for brushite and struvite stones. This evidence lays the groundwork for future in vitro and in vivo experimentation to determine how the microbiome may actively and/or passively influence kidney stone biomineralization.

Mitochondria interaction networks show altered topological patterns in Parkinson's disease.

Mitochondrial dysfunction is linked to pathogenesis of Parkinson's disease (PD). However, individual mitochondria-based analyses do not show a uniform feature in PD patients. Since mitochondria interact with each other, we hypothesize that PD-related features might exist in topological patterns of mitochondria interaction networks (MINs). Here we show that MINs formed nonclassical scale-free supernetworks in colonic ganglia both from healthy controls and PD patients; however, altered network topological patterns were observed in PD patients. These patterns were highly correlated with PD clinical scores and a machine-learning approach based on the MIN features alone accurately distinguished between patients and controls with an area-under-curve value of 0.989. The MINs of midbrain dopaminergic neurons (mDANs) derived from several genetic PD patients also displayed specific changes. CRISPR/CAS9-based genome correction of alpha-synuclein point mutations reversed the changes in MINs of mDANs. Our organelle-interaction network analysis opens another critical dimension for a deeper characterization of various complex diseases with mitochondrial dysregulation.

An optical coherence tomography comparison of coronary arterial plaque calcification in patients with end-stage renal disease and diabetes mellitus.

BACKGROUND: Coronary arterial plaques in patients with end-stage renal disease (ESRD) are assumed to have increased calcification due to underlying renal disease or initiation of dialysis. This relationship may be confounded by comorbid type 2 diabetes mellitus (DM). METHODS: From a single-center OCT registry, 60 patients were analyzed. Twenty patients with ESRD and diabetes (ESRD-DM) were compared to 2 groups of non-ESRD patients: 20 with and 20 without diabetes. In each patient, one 20 mm segment within the culprit vessel was analyzed. RESULTS: ESRD-DM patients exhibited similar calcium burden, arc, and area compared to patients with diabetes alone. When compared to patients without diabetes, patients with diabetes exhibited a greater summed area of calcium (DM: Median 9.0, IQR [5.3-28] mm2 vs Non-DM: 3.5 [0.1-14] mm2, p = 0.04) and larger calcium deposits by arc (DM: Mean 45 ± SE 6.2° vs Non-DM: 21 ± 6.2°, p = 0.01) and area (DM: 0.58 ± 0.10 mm2 vs Non-DM: 0.26 ± 0.10 mm2, p = 0.03). Calcification deposits in ESRD-DM patients (0.14 ± 0.02 mm) and patients with diabetes (0.14 ± 0.02 mm) were more superficially located relative to patients without diabetes (0.21 ± 0.02 mm), p = 0.01 for both. CONCLUSIONS: Coronary calcification in DM and ESRD-DM groups exhibited similar burden, deposit size, and depth within the arterial wall. The increase in coronary calcification and cardiovascular disease events seen in ESRD-DM patients may not be secondary to ESRD and dialysis, but instead due to a combination of declining renal function and diabetes.

Retrospective Study of Midazolam Protocol for Prehospital Behavioral Emergencies.

INTRODUCTION: Agitated patients in the prehospital setting pose challenges for both patient care and emergency medical services (EMS) provider safety. Midazolam is frequently used to control agitation in the emergency department setting; however, limited data exist in the prehospital setting. We describe our experience treating patients with midazolam for behavioral emergencies in a large urban EMS system. We hypothesized that using midazolam for acute agitation leads to improved clinical conditions without causing significant clinical deterioration. METHODS: We performed a retrospective review of EMS patient care reports following implementation of a behavioral emergencies protocol in a large urban EMS system from February 2014-June 2016. For acute agitation, paramedics administered midazolam 1 milligram (mg) intravenous (IV), 5 mg intramuscular (IM), or 5 mg intranasal (IN). Results were analyzed using descriptive statistics, Levene's test for assessing variance among study groups, and t-test to evaluate effectiveness based on route. RESULTS: In total, midazolam was administered 294 times to 257 patients. Median age was 30 (interquartile range 24-42) years, and 66.5% were male. Doses administered were 1 mg (7.1%) and 5 mg (92.9%). Routes were IM (52.0%), IN (40.8%), and IV (7.1%). A second dose was administered to 37 patients. In the majority of administrations, midazolam improved the patient's condition (73.5%) with infrequent adverse events (3.4%). There was no significant difference between the effectiveness of IM and IN midazolam (71.0% vs 75.4%; p = 0.24). CONCLUSION: A midazolam protocol for prehospital agitation was associated with reduced agitation and a low rate of adverse events.

A novel approach to rapid rewarming of a frostbitten extremity: The sous vide method.

BACKGROUND: Rapid rewarming of an acutely frostbitten extremity has been the standard treatment for nearly 60 years, however, there are no existing practical recommendations to create a warm water bath. Our study describes a novel approach to rapid rewarming using a sous vide cooking device to create and maintain a circulating warm water bath at a desired set temperature. METHODS: A series of in vitro experiments were performed to assess the efficacy of different methods of maintaining constant water temperature while rapidly rewarming a simulated frostbitten extremity (frozen pig's foot). An Anova Sous Vide Precision Cooker® was attached to a 5 gallon bucket and used to circulate and maintain the water at 104 °F while rewarming a frozen pig's foot. This method was compared to manual exchange of water to maintain the temperature at 104 °F and to a control with no water exchanged. During each experiment, the temperature of the water was recorded every 2 min and the pliability of the pig's foot was assessed after 30 min. RESULTS: The sous vide method maintained circulating water at a constant temperature of 104 °F for 30 min. At 30 min the frozen pig's foot was warm, soft, and pliable. The manual method resulted in temperature fluctuations requiring frequent large volume water exchanges. When no water was exchanged, the water cooled quickly and the pig's foot remained partially frozen. CONCLUSION: Sous vide rewarming is a novel method that easily creates and maintains a warm water bath ideal for rapid rewarming of a frostbitten extremity.

Physiology, Metabolism, and Fossilization of Hot-Spring Filamentous Microbial Mats.

The evolutionarily ancient Aquificales bacterium Sulfurihydrogenibium spp. dominates filamentous microbial mat communities in shallow, fast-flowing, and dysoxic hot-spring drainage systems around the world. In the present study, field observations of these fettuccini-like microbial mats at Mammoth Hot Springs in Yellowstone National Park are integrated with geology, geochemistry, hydrology, microscopy, and multi-omic molecular biology analyses. Strategic sampling of living filamentous mats along with the hot-spring CaCO3 (travertine) in which they are actively being entombed and fossilized has permitted the first direct linkage of Sulfurihydrogenibium spp. physiology and metabolism with the formation of distinct travertine streamer microbial biomarkers. Results indicate that, during chemoautotrophy and CO2 carbon fixation, the 87-98% Sulfurihydrogenibium-dominated mats utilize chaperons to facilitate enzyme stability and function. High-abundance transcripts and proteins for type IV pili and extracellular polymeric substances (EPSs) are consistent with their strong mucus-rich filaments tens of centimeters long that withstand hydrodynamic shear as they become encrusted by more than 5 mm of travertine per day. Their primary energy source is the oxidation of reduced sulfur (e.g., sulfide, sulfur, or thiosulfate) and the simultaneous uptake of extremely low concentrations of dissolved O2 facilitated by bd-type cytochromes. The formation of elevated travertine ridges permits the Sulfurihydrogenibium-dominated mats to create a shallow platform from which to access low levels of dissolved oxygen at the virtual exclusion of other microorganisms. These ridged travertine streamer microbial biomarkers are well preserved and create a robust fossil record of microbial physiological and metabolic activities in modern and ancient hot-spring ecosystems.

Large urban center improves out-of-hospital cardiac arrest survival.

BACKGROUND: Large cities pose unique challenges that limit the effectiveness of system improvement interventions. Successful implementation of integrated cardiac resuscitation systems of care can serve as a model for other urban centers. METHODS: This was a retrospective analysis of prospectively collected data of adult cases of non-traumatic cardiac arrest who received treatment by Chicago Fire Department EMS from September 1, 2013 through December 31, 2016. We measured temporal OHCA outcomes during implementation of system-wide initiatives including telephone-assisted and community CPR training programs; high performance CPR and team based simulation training; new post resuscitation care and destination protocols; and case review for EMS providers. Outcomes measured included bystander CPR rates, return of spontaneous circulation (ROSC), hospital admission and survival, and favorable neurologic outcomes (CPC 1-2). Relative risk was determined by logistic regression model where observed group-specific outcomes are expressed as odds ratios (OR). RESULTS: We included 6103 adult OHCA cases occurring outside of health care facilities from September 1, 2013 through December 31, 2016. Significantly improved outcomes (p < 0.05) were observed between 2013 and 2016 for bystander CPR (11.6% vs 19.4%), ROSC (28.6% vs 36.9%), hospital admission (22.5% vs 29.4%), survival (7.3% vs 9.9%), and CPC 1-2 (4.3% vs 6.4%). Utstein survival increased from 16.3%-35.4% and CPC 1-2 survival from 11.6%-29.1% (p < 0.05). After adjustment for OHCA characteristics, survival with CPC 1-2 increased over time (OR 1.15, p = 0.0277). CONCLUSIONS: Densely populated cities with low survival rates can overcome systematic challenges and improve OHCA survival.

Cincinnati Prehospital Stroke Scale Can Identify Large Vessel Occlusion Stroke.

OBJECTIVE: Accurate prehospital identification of patients with acute ischemic stroke (AIS) from large vessel occlusion (LVO) facilitates direct transport to hospitals that perform endovascular thrombectomy. We hypothesize that a cut-off score of the Cincinnati Prehospital Stroke Scale (CPSS), a simple assessment tool currently used by emergency medical services (EMS) providers, can be used to identify LVO. METHODS: Consecutively enrolled, confirmed AIS patients arriving via EMS between August 2012 and April 2014 at a high-volume stroke center in a large city with a single municipal EMS provider agency were identified in a prospective, single-center registry. Head and neck vessel imaging confirmed LVO. CPSS scores were abstracted from prehospital EMS records. Spearman's rank correlation, Wilcoxon rank-sum test, and Student's t-test were performed. Cohen's kappa was calculated between CPSS abstractors. The Youden index identified the optimal CPSS cut-off. Multivariate logistic regression controlling for age, sex, and race determined the odds ratio (OR) for LVO. RESULTS: Of 144 eligible patients, 138 (95.8%) had CPSS scores in the EMS record and were included for analysis. The median age was 69 (IQR 58-81) years. Vessel imaging was performed in 97.9% of patients at a median of 5.9 (IQR 3.6-10.2) hours from hospital arrival, and 43.7% had an LVO. Intravenous tissue plasminogen activator was administered to 29 patients, in whom 12 had no LVO on subsequent vessel imaging. The optimal CPSS cut-off predicting LVO was 3, with a Youden index of 0.29, sensitivity of 0.41, and specificity of 0.88. The adjusted OR for LVO with CPSS = 3 was 5.7 (95% CI 2.3-14.1). Among patients with CPSS = 3, 72.7% had an LVO, compared with 34.3% of patients with CPSS ≤ 2 (p < 0.0001). CONCLUSIONS: A CPSS score of 3 reliably identifies LVO in AIS patients. EMS providers may be able to use the CPSS, a simple, widely adopted prehospital stroke assessment tool, with a cut-off score to screen for patients with suspected LVO.