Are Thiel-embalmed Cadavers Effective Tools in Educating Medical Students to Perform Knee Arthrocentesis?

INTRODUCTION: The purposes of this study are to determine whether Thiel-embalmed cadavers are an effective educational tool in teaching medical students to perform knee arthrocentesis, to compare the use of Thiel-embalmed cadavers to formalin-embalmed cadavers in arthrocentesis education, and to determine whether the use of Thiel-embalmed cadavers is potentially generalizable to the instruction of other orthopedic procedures. METHODS: Sixty-eight third-year medical students participated in the study. The participants first completed a pre-survey to assess their prior experience with arthrocentesis procedures and Thiel-embalmed cadavers. Participants then attended an instructional session where the knee arthrocentesis procedure was demonstrated on a Thiel-embalmed cadaver. Participants then individually performed the simulated knee arthrocentesis procedure twice: once on a Thiel-embalmed cadaver and once on a formalin-embalmed cadaver. Success of each attempt was determined through the visualization of aspirated joint fluid. Following the laboratory session, each participant completed a post-survey to determine whether the session improved their perceived confidence in performing knee arthrocentesis, if they preferred the use of Thiel-embalmed cadavers or formalin-embalmed cadavers as a teaching tool, and if they believed simulated practice using Thiel-embalmed cadavers would be effective for learning other orthopedic procedural skills. RESULTS: Sixty-eight students participated in the laboratory session and successfully completed both pre- and post-course surveys. 96% of participants reported that they felt confident performing knee arthrocentesis under physician supervision following their participation in the laboratory session (versus 15% of participants in the pre-survey). 96% of participants reported that the Thiel-embalmed cadavers provided a more realistic teaching model than formalin-embalmed cadavers for learning knee arthrocentesis. 100% of participants believed the incorporation of simulated practice using Thiel-embalmed cadavers is an effective method in teaching students to perform knee arthrocentesis. 100% of participants reported that they would participate in future sessions using Thiel-embalmed cadavers to learn and practice other orthopedic procedural techniques. DISCUSSION: This study used a moderate sample size of third-year medical students to provide data regarding the suitability of using Thiel cadavers in arthrocentesis education. Results indicate that Thiel cadavers are effective tools in teaching medical students to perform knee arthrocentesis, that students preferred the Thiel cadavers to the formalin cadavers, and that the use of Thiel cadavers is a safe, engaging, and high-quality teaching modality for demonstrating proper arthrocentesis procedural technique to medical students. Since this study looked specifically at teaching knee arthrocentesis to medical students, it is uncertain whether the benefits of Thiel cadavers are generalizable to the education of other orthopedic procedures and subject groups such as residents, fellows, and practicing physicians. Further studies should be performed to assess whether Thiel cadavers are beneficial in teaching other orthopaedic procedures and if these benefits extend to other subject groups

Invasive Electrical Impedance Tomography for Blood Vessel Detection

We present a novel method for localization of large blood vessels using a bioimpedance based needle positioning system on an array of ten monopolar needle electrodes. The purpose of the study is to develop a portable, low cost tool for rapid vascular access for cooling and controlled reperfusion of cardiac arrest patients. Preliminary results show that localization of blood vessels is feasible with this method, but larger studies are necessary to improve the technology

Public-Access Defibrillation and Survival After Out-of-Hospital Cardiac Arrest

Background The rate of survival after out-of-hospital cardiac arrest is low. It is not known whether this rate will increase if laypersons are trained to attempt defibrillation with the use of automated external defibrillators (AEDs). Methods We conducted a prospective, community-based, multicenter clinical trial in which we randomly assigned community units (e.g., shopping malls and apartment complexes) to a structured and monitored emergency-response system involving lay volunteers trained in cardiopulmonary resuscitation (CPR) alone or in CPR and the use of AEDs. The primary outcome was survival to hospital discharge. Results More than 19,000 volunteer responders from 993 community units in 24 North American regions participated. The two study groups had similar unit and volunteer characteristics. Patients with treated out-of-hospital cardiac arrest in the two groups were similar in age (mean, 69.8 years), proportion of men (67 percent), rate of cardiac arrest in a public location (70 percent), and rate of witnessed cardiac arrest (72 percent). No inappropriate shocks were delivered. There were more survivors to hospital discharge in the units assigned to have volunteers trained in CPR plus the use of AEDs (30 survivors among 128 arrests) than there were in the units assigned to have volunteers trained only in CPR (15 among 107; P=0.03; relative risk, 2.0; 95 percent confidence interval, 1.07 to 3.77); there were only 2 survivors in residential complexes. Functional status at hospital discharge did not differ between the two groups. Conclusions Training and equipping volunteers to attempt early defibrillation within a structured response system can increase the number of survivors to hospital discharge after out-of-hospital cardiac arrest in public locations. Trained laypersons can use AEDs safely and effectively

Immune cell expression patterns of CD39/CD73 ectonucleotidases in rodent models of cardiac arrest and resuscitation

BackgroundCardiac arrest (CA) is a significant public health concern. There is the high imminent mortality and survival in those who are resuscitated is substantively compromised by the post-CA syndrome (PCAS), characterized by multiorgan ischemia–reperfusion injury (IRI). The inflammatory response in PCAS is complex and involves various immune cell types, including lymphocytes and myeloid cells that have been shown to exacerbate organ IRI, such as myocardial infarction. Purinergic signaling, as regulated by CD39 and CD73, has emerged as centrally important in the context of organ-specific IRI. Hence, comprehensive understanding of such purinergic responses may be likewise imperative for improving outcomes in PCAS.MethodsWe have investigated alterations of immune cell populations after CA by utilizing rodent models of PCAS. Blood and spleen were collected after CA and resuscitation and underwent flow cytometry analysis to evaluate shifts in CD3+CD4+ helper T cells, CD3+CD8a+ cytotoxic T cells, and CD4/CD8a ratios. We then examined the expression of CD39 and CD73 across diverse cell types, including myeloid cells, T lymphocytes, and B lymphocytes.ResultsIn both rat and mouse models, there were significant increases in the frequency of CD3+CD4+ T lymphocytes in PCAS (rat, P < 0.01; mouse, P < 0.001), with consequently elevated CD4/CD8a ratios in whole blood (both, P < 0.001). Moreover, CD39 and CD73 expression on blood leukocytes were markedly increased (rat, P < 0.05; mouse, P < 0.01 at 24h). Further analysis in the experimental mouse model revealed that CD11b+ myeloid cells, with significant increase in their population (P < 0.01), had high level of CD39 (88.80 ± 2.05 %) and increased expression of CD73 (P < 0.05). CD19+ B lymphocytes showed slight increases of CD39 (P < 0.05 at 2h) and CD73 (P < 0.05 at 2h), while, CD3+ T lymphocytes had decreased levels of them. These findings suggested a distinct patterns of expression of CD39 and CD73 in these specific immune cell populations after CA.ConclusionsThese data have provided comprehensive insights into the immune response after CA, highlighting high-level expressions of CD39 and CD73 in myeloid cells

Quantitative estimation of nerve fiber engagement by vagus nerve stimulation using physiological markers

Background Cervical vagus nerve stimulation (VNS) is a rapidly emerging bioelectronic treatment for brain, metabolic, cardiovascular and immune disorders. Its desired and off-target effects are mediated by different nerve fiber populations and knowledge of their engagement could guide calibration and monitoring of VNS therapies. Objective /Hypothesis: Stimulus-evoked compound action potentials (eCAPs) directly provide fiber engagement information but are currently not feasible in humans. A method to estimate fiber engagement through common, noninvasive physiological readouts could be used instead of eCAP measurements. Methods In anesthetized rats, we recorded eCAPs while registering acute physiological response markers to VNS: cervical electromyography (EMG), changes in heart rate (ΔHR) and breathing interval (ΔBI). Quantitative models were established to capture the relationship between A-, B- and C-fiber type activation and those markers, and to quantitatively estimate fiber activation from physiological markers and stimulation parameters. Results In bivariate analyses, we found that EMG correlates with A-fiber, ΔHR with B-fiber and ΔBI with C-fiber activation, in agreement with known physiological functions of the vagus. We compiled multivariate models for quantitative estimation of fiber engagement from these markers and stimulation parameters. Finally, we compiled frequency gain models that allow estimation of fiber engagement at a wide range of VNS frequencies. Our models, after calibration in humans, could provide noninvasive estimation of fiber engagement in current and future therapeutic applications of VNS

Video-Only Cardiopulmonary Resuscitation Education for High-Risk Families Before Hospital Discharge: A Multicenter Pragmatic Trial

BACKGROUND: Cardiopulmonary resuscitation (CPR) training rates in the United States are low, highlighting the need to develop CPR educational approaches that are simpler, with broader dissemination potential. The minimum training required to ensure long-term skill retention remains poorly characterized. We compared CPR skill retention among laypersons randomized to training with video-only (VO; no manikin) with those trained with a video self-instruction kit (VSI; with manikin). We hypothesized that VO training would be noninferior to the VSI approach with respect to chest compression (CC) rate. METHODS AND RESULTS: We performed a prospective, cluster randomized trial of CPR education for family members of patients with high-risk cardiac conditions on hospital cardiac units, using a multicenter pragmatic design. Eight hospitals were randomized to offer either VO or VSI training before discharge using volunteer trainers. CPR skills were assessed 6 months post training. Mean CC rate among those trained with VO compared with those trained with VSI was assessed with a noninferiority margin set at 8 CC per min; as a secondary outcome, mean differences in CC depth were assessed. From February 2012 to May 2015, 1464 subjects were enrolled and 522 subjects completed a skills assessment. The mean CC rates were 87.7 (VO) CC per min and 89.3 (VSI) CC per min; we concluded noninferiority for VO based on a mean difference of -1.6 (90% confidence interval, -5.2 to 2.1). The mean CC depth was 40.2 mm (VO) and 45.8 mm (VSI) with a mean difference of -5.6 (95% confidence interval, -7.6 to -3.7). Results were similar after multivariate regression adjustment. CONCLUSIONS: In this large, prospective trial of CPR skill retention, VO training yielded a noninferior difference in CC rate compared with VSI training. CC depth was greater in the VSI group. These findings suggest a potential trade-off in efforts for broad dissemination of basic CPR skills; VO training might allow for greater scalability and dissemination, but with a potential reduction in CC depth. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01514656

The Responses of Tissues from the Brain, Heart, Kidney, and Liver to Resuscitation following Prolonged Cardiac Arrest by Examining Mitochondrial Respiration in Rats

Cardiac arrest induces whole-body ischemia, which causes damage to multiple organs. Understanding how each organ responds to ischemia/reperfusion is important to develop better resuscitation strategies. Because direct measurement of organ function is not practicable in most animal models, we attempt to use mitochondrial respiration to test efficacy of resuscitation on the brain, heart, kidney, and liver following prolonged cardiac arrest. Male Sprague-Dawley rats are subjected to asphyxia-induced cardiac arrest for 30 min or 45 min, or 30 min cardiac arrest followed by 60 min cardiopulmonary bypass resuscitation. Mitochondria are isolated from brain, heart, kidney, and liver tissues and examined for respiration activity. Following cardiac arrest, a time-dependent decrease in state-3 respiration is observed in mitochondria from all four tissues. Following 60 min resuscitation, the respiration activity of brain mitochondria varies greatly in different animals. The activity after resuscitation remains the same in heart mitochondria and significantly increases in kidney and liver mitochondria. The result shows that inhibition of state-3 respiration is a good marker to evaluate the efficacy of resuscitation for each organ. The resulting state-3 respiration of brain and heart mitochondria following resuscitation reenforces the need for developing better strategies to resuscitate these critical organs following prolonged cardiac arrest

Race differences in interventions and survival after Out-of-Hospital Cardiac Arrest in North Carolina, 2010 to 2014

Background Following the implementation of the HeartRescue project, with interventions in the community, emergency medical services, and hospitals to improve care and outcomes for out‐of‐hospital cardiac arrests (OHCA) in North Carolina, improved bystander and first responder treatments as well as survival were observed. This study aimed to determine whether these improvements were consistent across Black versus White individuals. Methods and Results Using the Cardiac Arrest Registry to Enhance Survival (CARES), we identified OHCA from 16 counties in North Carolina (population 3 million) from 2010 to 2014. Temporal changes in interventions and outcomes were assessed using multilevel multivariable logistic regression, adjusted for patient and socioeconomic neighborhood‐level factors. Of 7091 patients with OHCA, 36.5% were Black and 63.5% were White. Black patients were younger, more females, had more unwitnessed arrests and non‐shockable rhythm (Black: 81.0%; White: 75.4%). From 2010 to 2014, the adjusted probabilities of bystander cardiopulmonary resuscitation (CPR) went from 38.5% to 51.2% in White, P<0.001; and 36.9% to 45.6% in Black, P=0.002, and first‐responder defibrillation went from 13.2% to 17.2% in White, P=0.002; and 14.7% to 17.3% in Black, P=0.16. From 2010 to 2014, survival to discharge only increased in White (8.0% to 11.4%, P=0.004; Black 8.9% to 9.5%, P=0.60), though, in shockable patients the probability of survival to discharge went from 24.8% to 34.6% in White, P=0.02; and 21.7% to 29.0% in Black, P=0. 10. Conclusions After the HeartRescue program, bystander CPR and first‐responder defibrillation increased in both patient groups; however, survival only increased significantly for White patients

Infidelity of SARS-CoV Nsp14-Exonuclease Mutant Virus Replication Is Revealed by Complete Genome Sequencing

Most RNA viruses lack the mechanisms to recognize and correct mutations that arise during genome replication, resulting in quasispecies diversity that is required for pathogenesis and adaptation. However, it is not known how viruses encoding large viral RNA genomes such as the Coronaviridae (26 to 32 kb) balance the requirements for genome stability and quasispecies diversity. Further, the limits of replication infidelity during replication of large RNA genomes and how decreased fidelity impacts virus fitness over time are not known. Our previous work demonstrated that genetic inactivation of the coronavirus exoribonuclease (ExoN) in nonstructural protein 14 (nsp14) of murine hepatitis virus results in a 15-fold decrease in replication fidelity. However, it is not known whether nsp14-ExoN is required for replication fidelity of all coronaviruses, nor the impact of decreased fidelity on genome diversity and fitness during replication and passage. We report here the engineering and recovery of nsp14-ExoN mutant viruses of severe acute respiratory syndrome coronavirus (SARS-CoV) that have stable growth defects and demonstrate a 21-fold increase in mutation frequency during replication in culture. Analysis of complete genome sequences from SARS-ExoN mutant viral clones revealed unique mutation sets in every genome examined from the same round of replication and a total of 100 unique mutations across the genome. Using novel bioinformatic tools and deep sequencing across the full-length genome following 10 population passages in vitro, we demonstrate retention of ExoN mutations and continued increased diversity and mutational load compared to wild-type SARS-CoV. The results define a novel genetic and bioinformatics model for introduction and identification of multi-allelic mutations in replication competent viruses that will be powerful tools for testing the effects of decreased fidelity and increased quasispecies diversity on viral replication, pathogenesis, and evolution

Interactions between cigarette and alcohol consumption in rural China

The objective of this paper is to analyze interdependencies between cigarette and alcohol consumption in rural China, using panel data for 10 years (1994–2003) for rural areas of 26 Chinese provinces. There have been many studies in which cigarette and alcohol consumption have been considered separately but few to date for China on interactions between the consumption of these two products. Taxes are often recommended as a tool to reduce alcohol and cigarette consumption. If cigarettes and alcohol are complements, taxing one will reduce the consumption of both and thus achieve a double public health dividend. However, if they are substitutes, taxing one will induce consumers to increase consumption of the other, offsetting the public health benefits of the tax. Our results indicate that the demands for both cigarettes and alcohol are very sensitive to the price of alcohol, but not to the price of cigarettes or to income. This suggests that taxes on alcohol can have a double dividend. On the other hand, an increase in cigarette taxes may not be effective in curbing cigarette or alcohol consumption in rural China