An evaluation of the usability and durability of 3D printed versus standard suture materials

The capability to produce suture material using three-dimensional (3D) printing technology may have applications in remote health facilities where rapid restocking of supplies is not an option. This is a feasibility study evaluating the usability of 3D-printed sutures in the repair of a laceration wound when compared with standard suture material. The 3D-printed suture material was manufactured using a fused deposition modelling 3D printer and nylon 3D printing filament. Study participants were tasked with performing laceration repairs on the pigs' feet, first with 3-0 WeGo nylon suture material, followed by the 3D-printed nylon suture material. Twenty-six participants were enrolled in the study. Survey data demonstrated statistical significance with how well the 3D suture material performed with knot tying, 8.9 versus 7.5 (p = 0.0018). Statistical significance was observed in the 3D-printed suture's ultimate tensile strength when compared to the 3-0 Novafil suture (274.8 vs. 199.8 MPa, p = 0.0096). The 3D-printed suture also demonstrated statistical significance in ultimate extension when compared to commercial 3-0 WeGo nylon suture (49% vs. 37%, p = 0.0215). This study was successful in using 3D printing technology to manufacture suture material and provided insight into its usability when compared to standard suture material.

Incidence of unknown COVID-19 infection in a cohort of emergency physicians and advance practice providers

INTRODUCTION

In United States, health care workers have been immersed in the COVID-19 pandemic since February 2020. Since availability of COVID-19 vaccines, there is limited literature investigating the incidence of unknown COVID-19 infections in physicians and Advanced Practitioner Providers (APPs) working in emergency departments (EDs). The primary objective is to determine the incidence unknown COVID-19 infection within a cohort of emergency physicians (EPs) and APPs.

METHODS

Prospective observational study at a tertiary academic center with emergency medicine residency and 64,000 annual ED visits. EPs/APPs providing care to ED patients over the prior 12 months were eligible. Serum samples were collected between May 1 and June 30, 2022. Analysis utilized Luminex xMAP® SARS-CoV-2 Multi-Antigen IgG Assay for antibodies to Nucleocapsid, Receptor-binding domain, and Spike subunit 1. Mean Fluorescent Intensity (MFI) ≥ 700 was considered positive. Subjects completed 12 question survey assessing demographics and previously confirmed COVID-19 infection. Fisher's exact test evaluated associations of demographics and clinical characteristics with confirmed COVID-19 status. Analyses performed using SAS, Version 9.4. P < 0.05 considered statistically significant.

RESULTS

Sixty-nine of 81 eligible subjects (85.2%) participated, 58.0% were male, 97.1% white, with mean age of 37. Eighteen subjects had MFI ≥ 700 strongly suggestive of prior infection, with 17.7% unknown. No statistically significant difference between age, gender, race, children in home, or household member with previously COVID-19 infection.

CONCLUSION

Unknown previous COVID-19 infection was less then expected in this cohort of EPs/APPs, and no association with individual characteristics, previously infected household member, or children in the home.

Different responses of skeletal muscles to femoral artery ligation-induced ischemia identified in BABL/c and C57BL/6 mice

Peripheral arterial disease (PAD) is a common circulatory problem in lower extremities, and the murine ischemic model is used to reproduce human PAD. To compare strain differences of skeletal muscle responses to ischemia, the left femoral artery was blocked by ligation to reduce blood flow to the limb of BALB/c and C57BL/6 mice. After 6 weeks of the femoral artery ligation, the functional and morphological changes of the gastrocnemius muscle were evaluated. BALB/c mice displayed serious muscular dystrophy, including smaller myofibers (524.3 ± 66 µM²), accumulation of adipose-liked tissue (17.8 ± 0.9%), and fibrosis (6.0 ± 0.5%), compared to C57BL/6 mice (1,328.3 ± 76.3 µM², 0.27 ± 0.09%, and 1.56 ± 0.06%, respectively; p < 0.05). About neuromuscular junctions (NMJs) in the gastrocnemius muscle, 6 weeks of the femoral artery ligation induced more damage in BALB/c mice than that in C57BL/6 mice, demonstrated by the fragment number of nicotinic acetylcholine receptor (nAChR) clusters (8.8 ± 1.3 in BALB/c vs. 2.5 ± 0.7 in C57BL/6 mice, p < 0.05) and amplitude of sciatic nerve stimulated-endplate potentials (EPPs) (9.29 ± 1.34 mV in BALB/c vs. 20.28 ± 1.42 mV in C57BL/6 mice, p < 0.05). More importantly, 6 weeks of the femoral artery ligation significantly weakened sciatic nerve-stimulated skeletal muscle contraction in BALB/c mice, whereas it didn’t alter the skeletal muscle contraction in C57BL/6 mice. These results suggest that the femoral artery ligation in BALB/c mice is a useful animal model to develop new therapeutic approaches to improve limb structure and function in PAD, although the mechanisms about strain differences of skeletal muscle responses to ischemia are unclear.

Pandemic driven innovation: A pilot evaluation of an alternative respiratory pathogen collection device

Background

Methods

Results

Conclusion

Hyperbaric oxygen therapy does not alleviate tourniquet-induced acute ischemia-reperfusion injury in mouse skeletal muscles

During tourniquet application, blood flow is restricted to a limb to stop excessive limb hemorrhage in a trauma setting and to create a bloodless operating field in the surgical setting. During tourniquet-related ischemia, aerobic respiration stops, and ATP is depleted, and during subsequent reperfusion, there is an increase in reactive oxygen species (ROS) production and other endogenous substances, which leads to acute ischemia-reperfusion (IR) injuries, including tissue necrosis and skeletal muscle contractile dysfunction. Hyperbaric oxygen (HBO) therapy can increase the arterial oxygen tension in the tissues of patients with general hypoxia/anoxia, including carbon monoxide poisoning, circulatory arrest, and cerebral and myocardial ischemia. Here, we studied the protective effects of HBO pretreatment with 100% oxygen at 2.5 ATA against tourniquet/IR injury in mice. After one hour of HBO therapy with 100% oxygen at 2.5 ATA was administered to C57/BL6 mice, a rubber band was placed at the hip joint of the unilateral hindlimb to induce 3 h of ischemia and then released for 48 h of reperfusion. We analyzed gastrocnemius muscle morphology and contractile function and measured the levels of ATP and ROS accumulation in the muscles. HBO pretreatment did not improve tourniquet/IR-injured gastrocnemius muscle morphology and muscle contraction. Tourniquet/IR mice with HBO pretreatment showed no increase in ATP levels in IR tissues, but they did have a decreased amount of ROS accumulation in the muscles, compared to IR mice with no HBO pretreatment. These data suggest that one hour of HBO pretreatment with 100% oxygen at 2.5 ATA increases the antioxidant response to lower ROS accumulation but does not increase ATP levels in IR muscles and improve tourniquet/IR-injured muscle morphology and contractile function.

Therapeutic effects of masitinib on abnormal mechanoreception in a mouse model of tourniquet-induced extremity ischemia-reperfusion

Tourniquets are widely used to stop extremity hemorrhage, but their use and subsequent release can result in nerve damage and degeneration, leading to neurological deficits. Increasing evidence has suggested a pivotal role of inflammation in nerve damage and abnormal mechanoreception. In this study, we investigated the therapeutic effects of masitinib (Mas), an anti-neuroinflammatory drug, on the mechanoreception of sensory neurons in a mouse model of tourniquet-induced hind paw ischemia-reperfusion (tourniquet/IR). C57BL/6 mice were subjected to 3 h of ischemia by placing a rubber band at the ankle joint and evaluated for subsequent reperfusion injury on day 1, 3, 7, 14, and 28 based on the experiments. Treatment with Mas (28 mg/kg/day, i.p.) began on the day of IR induction and lasted for 1, 3, 7, 14, or 28 days. Tourniquet/IR caused sensory nerve denervation in the skin of paw pads and abolished the hind paw mechanoreception to mechanical stimulation during the first 3 days of reperfusion. Sensory nerves gradually reinnervated in the skin of paw pads and allodynia began to appear on day 7. The maximum reaction occurred on day 14 and was maintained throughout the study period. Treatment with Mas mitigated nerve damage and improved hind paw mechanoreception to mechanical stimulation by decreasing the production of reactive oxygen species (ROS) during the early stages of tourniquet/IR. Mas also alleviated allodynia and decreased inflammatory cytokines (IL-1β and TNFα) in the skin of paw pads from days 7-28. Our data suggest that treatment with Mas significantly ameliorated paw numbness and allodynia in mouse hind paw tourniquet/IR.

A comparison of acute mouse hindlimb injuries between tourniquet- and femoral artery ligation-induced ischemia-reperfusion

The tourniquet or femoral artery ligation is widely used to stop extremity hemorrhage or create a bloodless operating field in the combat scenario and civilian setting. However, these procedures with subsequent reperfusion also induce ischemia-reperfusion (IR) injuries. To fully evaluate animal models of limb IR injuries, we compared tourniquet- and femoral artery ligation-induced IR injuries in the hindlimb of mice. In C57/BL6 mice, 3 h of unilateral hindlimb ischemia was induced by placement of a rubber band at the hip joint or a surgical ligation of the femoral artery. The tourniquet or femoral artery ligation was then released, allowing for 24 h of reperfusion. Compared to the femoral artery ligation/IR, the tourniquet/IR induced more severe skeletal muscle damage, including muscle necrosis and interruption of muscle fibers. There was no gastrocnemius muscle contraction in tourniquet/IR, while femoral artery ligation/IR markedly weakened gastrocnemius muscle contraction. Motor nerve terminals disappeared, and endplate potentials (EPPs) were undetectable in tourniquet/IR, whereas femoral artery ligation/IR only induced mild impairment of motor nerve terminals and decreased the amplitude of EPPs. Additionally, western blot data showed that proinflammatory cytokine levels (IL-1β and TNF-α) were higher in the tourniquet/IR than that in femoral artery ligation/IR. Moreover, tourniquet/IR caused significant tissue edema and dilation of lymphatic vessels in the hindlimb, compared to femoral artery ligation/IR. The above data demonstrated that tourniquet/IR-induced acute hindlimb injuries are more severe than those induced by femoral artery ligation/IR. This suggests that future investigators should determine which hindlimb IR model (tourniquet/IR or femoral artery ligation/IR) is optimal depending on the purpose of their study.

Accuracy and Acceptance of a Self-Collection Model for Respiratory Tract Infection Diagnostics: A Concise Clinical Literature Review

Background

Nurses are the primary clinicians who collect specimens for respiratory tract infection testing. The specimen collection procedure is time and resource-consuming, but more importantly, it places nurses at risk for potential infection. The practice of allowing patients to self-collect their diagnostic specimens may provide an alternative testing model for the current COVID-19 outbreaks. The objective of this paper was to evaluate the accuracy and patient perception of self-collected specimens for respiratory tract infection diagnostics.

Methods

A concise clinical review of the recently published literature was conducted.

Results

A total of 11 articles were included the review synthesis. The concept of self-collected specimens has a high patient acceptance rate of 83-99%. Self-collected nasal-swab specimens demonstrated strong diagnostic fidelity for respiratory tract infections with a sensitivity between 80-100%, this is higher than the 76% sensitivity observed with self-collected throat specimens. In a comparative study evaluating a professionally collected to a self-collected specimen for COVID-19 testing, a high degree of agreement (k = 0.89) was observed between the two methods.

Conclusion

As we continue to explore for testing models to combat the COVID-19 pandemic, self-collected specimens is a practical alternative to nurse specimen collection.

Long-Term Assessment of the Effects of COVID-19 and Isolation Care on Survivor Disability and Anxiety

We conducted an assessment of disability, anxiety, and other life impacts of COVID-19 and isolation care in a unique cohort of individuals. These included both community admissions to a university hospital as well as some of the earliest international aeromedical evacuees. Among an initial 16 COVID-19 survivors that were interviewed 6-12 months following their admission into isolation care, perception of their isolation care experience was related to their reporting of long-term consequences. However, anxiety and disability assessed with standard scores had no relationship with each other. Both capture of the isolation care experience and caution relying on single scoring systems for assessing long-term consequences in survivors are important considerations for on-going and future COVID-19 and other pandemic survivor research.

Implementation of a COVID-19 cohort area resulted in no surface or air contamination in surrounding areas in one academic emergency department

Introduction

As a result of the COVID-19 pandemic and highly contagious nature of SARS-CoV-2, emergency departments (EDs) have been forced to implement new measures and protocols to minimize the spread of the disease within their departments. The primary objective of this study was to determine if the implementation of a designated COVID-19 cohort area (hot zone) within a busy ED mitigated the dissemination of SARS-CoV-2 throughout the rest of the department.

Methods

In an ED of a tertiary academic medical center, with 64,000 annual visits, an eight room pod was designated for known COVID-19 or individuals with high suspicion for infection. There was a single entry and exit for donning and doffing personal protective equipment (PPE). Health care workers (HCW) changed gowns and gloves between patients, but maintained their N-95 mask and face shield, cleaning the shield with a germicidal wipe between patients. Staffing assignments designated nurses and technicians to remain in this area for 4 h, where physicians regularly moved between the hot zone and rest of the ED. Fifteen surface samples and four air samples were taken to evaluate SARS-CoV-2 contamination levels and the effectiveness of infection control practices. Samples were collected outside of patient rooms in 3 primary ED patient care areas, the reception area, the primary nurses station, inside the cohort area, and the PPE donning and doffing areas immediately adjacent. Samples were recovered and analyzed for the presence of the E gene of SARS-CoV-2 using RT-PCR.

Results

SARS-CoV-2 was not detected on any surface samples, including in and around the cohort area. All air samples outside the COVID-19 hot zone were negative for SARS-CoV-2, but air samples within the cohort area had a low level of viral contamination.

Conclusion

A designated COVID-19 cohort area resulted in no air or surface contamination outside of the hot zone, and only minimal air, but no surface contamination, within the hot zone.

Macrophage depletion in stellate ganglia alleviates cardiac sympathetic overactivation and ventricular arrhythmogenesis by attenuating neuroinflammation in heart failure

Cardiac sympathetic overactivation is involved in arrhythmogenesis in patients with chronic heart failure (CHF). Inflammatory infiltration in the stellate ganglion (SG) is a critical factor for cardiac sympathoexcitation in patients with ventricular arrhythmias. This study aims to investigate if macrophage depletion in SGs decreases cardiac sympathetic overactivation and ventricular arrhythmogenesis in CHF. Surgical ligation of the coronary artery was used for induction of CHF. Clodronate liposomes were microinjected into bilateral SGs of CHF rats for macrophage depletion. Using cytokine array, immunofluorescence staining, and Western blot analysis, we found that macrophage expansion and expression of TNFα and IL-1β in SGs were markedly increased in CHF rats. Flow cytometry data confirmed that the percentage of macrophages in SGs was higher in CHF rats than that in sham rats. Clodronate liposomes significantly reduced CHF-elevated proinflammatory cytokine levels and macrophage expansion in SGs. Clodronate liposomes also reduced CHF-increased N-type Ca2+ currents and excitability of cardiac sympathetic postganglionic neurons and inhibited CHF-enhanced cardiac sympathetic nerve activity. ECG data from 24-h, continuous telemetry recording in conscious rats demonstrated that clodronate liposomes not only restored CHF-induced heterogeneity of ventricular electrical activities, but also decreased the incidence and duration of ventricular tachycardia/fibrillation in CHF. Macrophage depletion with clodronate liposomes attenuated CHF-induced cardiac sympathetic overactivation and ventricular arrhythmias through reduction of macrophage expansion and neuroinflammation in SGs.

Inhibition of N-type calcium channels in cardiac sympathetic neurons attenuates ventricular arrhythmogenesis in heart failure

AIMS

Cardiac sympathetic overactivation is an important trigger of ventricular arrhythmias in patients with chronic heart failure (CHF). Our previous study demonstrated that N-type calcium (Cav2.2) currents in cardiac sympathetic post-ganglionic (CSP) neurons were increased in CHF. This study investigated the contribution of Cav2.2 channels in cardiac sympathetic overactivation and ventricular arrhythmogenesis in CHF.

METHODS AND RESULTS

Rat CHF was induced by surgical ligation of the left coronary artery. Lentiviral Cav2.2-α shRNA or scrambled shRNA was transfected in vivo into stellate ganglia (SG) in CHF rats. Final experiments were performed at 14 weeks after coronary artery ligation. Real-time polymerase chain reaction and western blot data showed that in vivo transfection of Cav2.2-α shRNA reduced the expression of Cav2.2-α mRNA and protein in the SG in CHF rats. Cav2.2-α shRNA also reduced Cav2.2 currents and cell excitability of CSP neurons and attenuated cardiac sympathetic nerve activities (CSNA) in CHF rats. The power spectral analysis of heart rate variability (HRV) further revealed that transfection of Cav2.2-α shRNA in the SG normalized CHF-caused cardiac sympathetic overactivation in conscious rats. Twenty-four-hour continuous telemetry electrocardiogram recording revealed that this Cav2.2-α shRNA not only decreased incidence and duration of ventricular tachycardia/ventricular fibrillation but also improved CHF-induced heterogeneity of ventricular electrical activity in conscious CHF rats. Cav2.2-α shRNA also decreased susceptibility to ventricular arrhythmias in anaesthetized CHF rats. However, Cav2.2-α shRNA failed to improve CHF-induced cardiac contractile dysfunction. Scrambled shRNA did not affect Cav2.2 currents and cell excitability of CSP neurons, CSNA, HRV, and ventricular arrhythmogenesis in CHF rats.

CONCLUSIONS

Overactivation of Cav2.2 channels in CSP neurons contributes to cardiac sympathetic hyperactivation and ventricular arrhythmogenesis in CHF. This suggests that discovering purely selective and potent small-molecule Cav2.2 channel blockers could be a potential therapeutic strategy to decrease fatal ventricular arrhythmias in CHF.

Dexamethasone Improves Wound Healing by Decreased Inflammation and Increased Vasculogenesis in Mouse Skin Frostbite Model

INTRODUCTION

Frostbite is thought to result from initial vasoconstriction, ischemia, intracellular ice crystal formation, and inflammation caused by reperfusion injury. Corticosteroids have demonstrated beneficial anti-inflammatory effects in the treatment of other ischemia/reperfusion clinical conditions. The objective of this study was to determine the effect of dexamethasone (dex) on wound healing, inflammatory response, and vasculogenesis in a mouse skin frostbite model.

METHODS

Treatment and control groups of C57/BL6 mice were subjected to frostbite using a previously described model. Treatment with intraperitoneal dex (1 mg·kg^-1·d^-1) began on the day of frostbite induction and lasted for 7 d. Over 4 wk, we compared wound diameter; morphology by visual inspection, hematoxylin-eosin staining, and Masson's trichrome staining; density of inflammatory cytokines IL-1β and TNFα using Western blot analysis; and formation of microvasculature using immunofluorescence staining. Data were analyzed using 1-way or 1-way repeated-measures analysis of variance.

RESULTS

After frostbite injury, morphological images demonstrated epidermal necrosis and loss in the frostbitten skin as well as infiltration of inflammation-related leukocytes. Increased production of inflammatory cytokines and disappearance of the microvasculature also occurred in the frostbitten skin. In comparison to the control group, treatment with dex promoted wound healing as demonstrated by decreased wound diameter; decreased levels of inflammatory cytokines, and accelerated formation of mature microvasculature.

CONCLUSIONS

In this animal model, dex improved wound healing in frostbitten skin and demonstrated both anti-inflammatory effects and stimulation of vasculogenesis. This study suggests that the use of potent anti-inflammatory agents may be an effective strategy for mitigating frostbite injury.

Advanced Preparation Makes Research in Emergencies and Isolation Care Possible: The Case of Novel Coronavirus Disease (COVID-19)

The optimal time to initiate research on emergencies is before they occur. However, timely initiation of high-quality research may launch during an emergency under the right conditions. These include an appropriate context, clarity in scientific aims, preexisting resources, strong operational and research structures that are facile, and good governance. Here, Nebraskan rapid research efforts early during the 2020 coronavirus disease pandemic, while participating in the first use of U.S. federal quarantine in 50 years, are described from these aspects, as the global experience with this severe emerging infection grew apace. The experience has lessons in purpose, structure, function, and performance of research in any emergency, when facing any threat.

Crossover Assessment of Intraoral and Cuffed Ventilation by Emergency Responders

OBJECTIVES

A cuffed bag valve mask (BVM) is the most common device used by emergency medical responders to ventilate patients. The BVM can be difficult for users to seal around the patient's mouth and nose. An intraoral mask (IOM) with snorkel-like design may facilitate quicker and better ventilation particularly under austere conditions.

METHODS

Both a BVM and IOM were utilized by 27 trained emergency medical technicians and paramedics to ventilate a lightly embalmed cadaver. Ventilation efficacy, workload, and usability were assessed for both devices across four study conditions.

RESULTS

The IOM was superior to the BVM in delivered tidal volume ratio (measure of leak, p < 0.03) and minute ventilation (p < 0.0001). Workload, ergonomic and usability assessments indicated that the IOM facilitated gripping through the reduced hand interface size (p < 0.01), decreased user effort (p < 0.001), and reduced upper limb workload (p = 0.0088).

CONCLUSIONS

In the assessed model, the IOM represented a better choice for airway management than the standard cuffed BVM. An emergency medical device that is intuitive, efficacious and less demanding has the potential to reduce responder stress and improve resuscitation efforts, especially during austere rescue and patient transport.

Substrates and potential therapeutics of ventricular arrhythmias in heart failure

Heart failure (HF) is a clinical syndrome characterized by ventricular contractile dysfunction. About 50% of death in patients with HF are due to fetal ventricular arrhythmias including ventricular tachycardia and ventricular fibrillation. Understanding ventricular arrhythmic substrates and discovering effective antiarrhythmic interventions are extremely important for improving the prognosis of patients with HF and reducing its mortality. In this review, we discussed ventricular arrhythmic substrates and current clinical therapeutics for ventricular arrhythmias in HF. Base on the fact that classic antiarrhythmic drugs have the limited efficacy, side effects, and proarrhythmic potentials, we also updated some therapeutic strategies for the development of potential new antiarrhythmic interventions for patients with HF.

Dexamethasone Protects Against Tourniquet-Induced Acute Ischemia-Reperfusion Injury in Mouse Hindlimb

Extremity injuries with hemorrhage have been a significant cause of death in civilian medicine and on the battlefield. The use of a tourniquet as an intervention is necessary for treatment to an injured limb; however, the tourniquet and subsequent release results in serious acute ischemia-reperfusion (IR) injury in the skeletal muscle and neuromuscular junction (NMJ). Much evidence demonstrates that inflammation is an important factor to cause acute IR injury. To find effective therapeutic interventions for tourniquet-induced acute IR injuries, our current study investigated effect of dexamethasone, an anti-inflammatory drug, on tourniquet-induced acute IR injury in mouse hindlimb. In C57/BL6 mice, a tourniquet was placed on unilateral hindlimb (left hindlimb) at the hip joint for 3 h, and then released for 24 h to induce IR. Three hours of tourniquet and 24 h of release (24-h IR) caused gastrocnemius muscle injuries including rupture of the muscle sarcolemma and necrosis (42.8 ± 2.3% for infarct size of the gastrocnemius muscle). In the NMJ, motor nerve terminals disappeared, and endplate potentials were undetectable in 24-h IR mice. There was no gastrocnemius muscle contraction in 24-h IR mice. Western blot data showed that inflammatory cytokines (TNFα and IL-1β) were increased in the gastrocnemius muscle after 24-h IR. Treatment with dexamethasone at the beginning of reperfusion (1 mg/kg, i.p.) significantly inhibited expression of TNFα and IL-1β, reduced rupture of the muscle sarcolemma and infarct size (24.8 ± 2.0%), and improved direct muscle stimulation-induced gastrocnemius muscle contraction in 24-h IR mice. However, this anti-inflammatory drug did not improve NMJ morphology and function, and sciatic nerve-stimulated skeletal muscle contraction in 24-h IR mice. The data suggest that one-time treatment with dexamethasone at the beginning of reperfusion only reduced structural and functional impairments of the skeletal muscle but not the NMJ through inhibiting inflammatory cytokines.

Transition of Care from the Emergency Department to the Outpatient Setting: A Mixed-Methods Analysis

Introduction

The goal of this study was to characterize current practices in the transition of care between the emergency department and primary care setting, with an emphasis on the use of the electronic medical record (EMR).

Methods

Using literature review and modified Delphi technique, we created and tested a pilot survey to evaluate for face and content validity. The final survey was then administered face-to-face at eight different clinical sites across the country. A total of 52 emergency physicians (EP) and 49 primary care physicians (PCP) were surveyed and analyzed. We performed quantitative analysis using chi-square test. Two independent coders performed a qualitative analysis, classifying answers by pre-defined themes (inter-rater reliability > 80%). Participants' answers could cross several pre-defined themes within a given question.

Results

EPs were more likely to prefer telephone communication compared with PCPs (30/52 [57.7%] vs. 3/49 [6.1%] P < 0.0001), whereas PCPs were more likely to prefer using the EMR for discharge communication compared with EPs (33/49 [67.4%] vs. 13/52 [25%] p < 0.0001). EPs were more likely to report not needing to communicate with a PCP when a patient had a benign condition (23/52 [44.2%] vs. 2/49 [4.1%] p < 0.0001), but were more likely to communicate if the patient required urgent follow-up prior to discharge from the ED (33/52 [63.5%] vs. 20/49 [40.8%] p = 0.029). When discussing barriers to effective communication, 51/98 (52%) stated communication logistics, followed by 49/98 (50%) who reported setting/environmental constraints and 32/98 (32%) who stated EMR access was a significant barrier.

Conclusion

Significant differences exist between EPs and PCPs in the transition of care process. EPs preferred telephone contact synchronous to the encounter whereas PCPs preferred using the EMR asynchronous to the encounter. Providers believe EP-to-PCP contact is important for improving patient care, but report varied expectations and multiple barriers to effective communication. This study highlights the need to optimize technology for an effective transition of care from the ED to the outpatient setting.

Reduced N-Type Ca2+ Channels in Atrioventricular Ganglion Neurons Are Involved in Ventricular Arrhythmogenesis

Background

Attenuated cardiac vagal activity is associated with ventricular arrhythmogenesis and related mortality in patients with chronic heart failure. Our recent study has shown that expression of N‐type Ca²⁺ channel α‐subunits (Ca_v2.2‐α) and N‐type Ca²⁺ currents are reduced in intracardiac ganglion neurons from rats with chronic heart failure. Rat intracardiac ganglia are divided into the atrioventricular ganglion (AVG) and sinoatrial ganglion. Ventricular myocardium receives projection of neuronal terminals only from the AVG. In this study we tested whether a decrease in N‐type Ca²⁺ channels in AVG neurons contributes to ventricular arrhythmogenesis.

Methods and Results

Lentiviral Ca_v2.2‐α shRNA (2 μL, 2×10⁷ pfu/mL) or scrambled shRNA was in vivo transfected into rat AVG neurons. Nontransfected sham rats served as controls. Using real‐time single‐cell polymerase chain reaction and reverse‐phase protein array, we found that in vivo transfection of Ca_v2.2‐α shRNA decreased expression of Ca_v2.2‐α mRNA and protein in rat AVG neurons. Whole‐cell patch‐clamp data showed that Ca_v2.2‐α shRNA reduced N‐type Ca²⁺ currents and cell excitability in AVG neurons. The data from telemetry electrocardiographic recording demonstrated that 83% (5 out of 6) of conscious rats with Ca_v2.2‐α shRNA transfection had premature ventricular contractions (P<0.05 versus 0% of nontransfected sham rats or scrambled shRNA‐transfected rats). Additionally, an index of susceptibility to ventricular arrhythmias, inducibility of ventricular arrhythmias evoked by programmed electrical stimulation, was higher in rats with Ca_v2.2‐α shRNA transfection compared with nontransfected sham rats and scrambled shRNA‐transfected rats.

Conclusions

A decrease in N‐type Ca²⁺ channels in AVG neurons attenuates vagal control of ventricular myocardium, thereby initiating ventricular arrhythmias.

Correlation of Ventricular Arrhythmogenesis with Neuronal Remodeling of Cardiac Postganglionic Parasympathetic Neurons in the Late Stage of Heart Failure after Myocardial Infarction

Introduction: Ventricular arrhythmia is a major cause of sudden cardiac death in patients with chronic heart failure (CHF). Our recent study demonstrates that N-type Ca²⁺ currents in intracardiac ganglionic neurons are reduced in the late stage of CHF rats. Rat intracardiac ganglia are divided into the atrioventricular ganglion (AVG) and sinoatrial ganglion. Only AVG nerve terminals innervate the ventricular myocardium. In this study, we tested the correlation of electrical remodeling in AVG neurons with ventricular arrhythmogenesis in CHF rats. Methods and Results: CHF was induced in male Sprague-Dawley rats by surgical ligation of the left coronary artery. The data from 24-h continuous radiotelemetry ECG recording in conscious rats showed that ventricular tachycardia/fibrillation (VT/VF) occurred in 3 and 14-week CHF rats but not 8-week CHF rats. Additionally, as an index for vagal control of ventricular function, changes of left ventricular systolic pressure (LVSP) and the maximum rate of left ventricular pressure rise (LV dP/dt_max) in response to vagal efferent nerve stimulation were blunted in 14-week CHF rats but not 3 or 8-week CHF rats. Results from whole-cell patch clamp recording demonstrated that N-type Ca²⁺ currents in AVG neurons began to decrease in 8-week CHF rats, and that there was also a significant decrease in 14-week CHF rats. Correlation analysis revealed that N-type Ca²⁺ currents in AVG neurons negatively correlated with the cumulative duration of VT/VF in 14-week CHF rats, whereas there was no correlation between N-type Ca²⁺ currents in AVG neurons and the cumulative duration of VT/VF in 3-week CHF. Conclusion: Malignant ventricular arrhythmias mainly occur in the early and late stages of CHF. Electrical remodeling of AVG neurons highly correlates with the occurrence of ventricular arrhythmias in the late stage of CHF.

Morphological Regeneration and Functional Recovery of Neuromuscular Junctions after Tourniquet-Induced Injuries in Mouse Hindlimb

Tourniquet application and its subsequent release cause serious injuries to the skeletal muscle, nerve, and neuromuscular junction (NMJ) due to mechanical compression and ischemia-reperfusion (IR). Monitoring structural and functional repair of the NMJ, nerve, and skeletal muscle after tourniquet-induced injuries is beneficial in exploring potential cellular and molecular mechanisms responsible for tourniquet-induced injuries, and for establishing effective therapeutic interventions. Here, we observed long-term morphological and functional changes of the NMJ in a murine model of tourniquet-induced hindlimb injuries. Unilateral hindlimbs of C57/BL6 mice were subjected to 3 h of tourniquet by placing an orthodontic rubber band, followed by varied periods of tourniquet release (1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks). NMJ morphology in the gastrocnemius muscle was imaged, and the endplate potential (EPP) was recorded to evaluate NMJ function. In NMJs, nicotinic acetylcholine receptor (nAChR) clusters normally displayed an intact, pretzel-like shape, and all nAChR clusters were innervated (100%) by motor nerve terminals. During 3 h of tourniquet application and varied periods of tourniquet release, NMJs in the gastrocnemius muscle were characterized by morphological and functional changes. At 1 day and 3 days of tourniquet release, nAChR clusters retained normal, pretzel-like shapes, whereas motor nerve terminals were completely destroyed and no EPPs recorded. From 1 to 6 weeks of tourniquet release, motor nerve terminals gradually regenerated, even reaching that seen in sham mice, whereas nAChR clusters were gradually fragmented with prolongation of tourniquet release. Additionally, the amplitude of EPPs gradually increased with prolongation of tourniquet release. However, even at 6 weeks after tourniquet release, the amplitude of EPPs did not restore to the level seen in sham mice (13.9 ± 1.1 mV, p < 0.05 vs. sham mice, 29.8 ± 1.0 mV). The data suggest that tourniquet application and subsequent release impair the structure and function of NMJs. Morphological change in motor nerve terminals is faster than in nAChR clusters in NMJs. Slow restoration of fragmented nAChR clusters possibly dampens neuromuscular transmission during the long phase following tourniquet release.

Evolution of the Model of the Clinical Practice of Emergency Medicine: 1979 to Present

The Model of the Clinical Practice of Emergency Medicine (the EM Model) is a three-dimensional representation of the clinical practice of emergency medicine. It is a product of successful collaboration involving the American Board of Emergency Medicine (ABEM), the American College of Emergency Physicians (ACEP), the Society for Academic Emergency Medicine (SAEM), the Emergency Medicine Residents' Association (EMRA), the Council of Emergency Medicine Residency Directors (CORD), the Residency Review Committee for Emergency Medicine (RRC-EM), and the American Academy of Emergency Medicine (AAEM). In 2017, the most recent update and revision of the EM Model will be published. This document will represent the culmination of nearly 40 years of evolution, from a simple listing of presenting patient complaints, clinical symptoms, and disease states into a three-dimensional representation of the clinical practice of emergency medicine. These dimensions include conditions and components, physician tasks, and patient acuity. In addition, over the years, two other documents have been developed, the Knowledge, Skills, and Abilities (KSAs) and the Emergency Medicine Milestones. Both serve as related and complementary educational and assessment tools. This article will review the development of the EM Model from its inception in 1979 to today.

Process Development for the Care of the Person Under Investigation for Ebola Virus Disease: a Collaboration of Biocontainment Unit and Emergency Medicine Personnel

Patients presenting with epidemiological risk factors for Ebola virus disease (EVD) and symptoms consistent with the disease require screening with a molecular assay. If the initial test is negative, but the patient has been symptomatic for less than 3 days, a follow-up test is required to reliably exclude the disease. During this time, persons under investigation (PUI) for EVD may have illnesses other than EVD that require further evaluation and management and well-defined processes are essential to the delivery of consistent, high-quality care for these patients while preserving the safety of healthcare providers.

Bitten by a Dragon

Komodo dragons (Varanus komodoensis) are large lizards known to take down prey even larger than themselves. They rarely attack humans. A 38-year-old woman was bitten by a Komodo dragon on her hand while cleaning its enclosure. She was transiently hypotensive. The wounds were extensively cleaned, and she was started on prophylactic antibiotics. Her wounds healed without any infectious sequelae. Komodo dragon bites are historically thought to be highly infectious and venomous. Based on a literature review, neither of these are likely true. As in any bite, initial stabilization followed by wound management are the main components to therapy.

A description of teaching methods using an on-site instructor versus a distant site instructor to train laryngoscopy to medical students in Hanoi, Vietnam, from Omaha, Nebraska, by video communication

This study demonstrated a method to train medical students at Hanoi Medical School in airway management from Omaha, Nebraska, using tele-mentoring techniques. Correct placement of the endotracheal tube was documented by tele-broncoscopy following intubation. This technology may increase medical training capabilities in remote or developing areas of the world. Medical care delivery could be performed using this technology by tele-mentoring a lesser trained medical provider at a distant site enabling them to accomplish complex medical tasks.

Interunit handoffs from emergency department to inpatient care: A cross-sectional survey of physicians at a university medical center

BACKGROUND

Emergency department (ED) to inpatient physician handoffs are subject to complex challenges. We assessed physicians' perceptions of the ED admission handoff process and identified potential barriers to safe patient care.

METHODS

We conducted a cross-sectional survey at a 627-bed tertiary care academic medical center. Eligible participants included all resident, fellow, and faculty physicians directly involved in admission handoffs from emergency medicine (EM) and 5 medical admitting services. The survey addressed communication quality, clinical information, interpersonal perceptions, assignment of responsibilities, organizational factors, and patient safety. Participants reported their responses via a 5-point Likert scale and an open-ended description of handoff-related adverse events.

RESULTS

Response rates were 63% for admitting (94/150) and 86% for EM physicians (32/37). Compared to EM respondents, admitting physicians reported that vital clinical information was communicated less frequently for all 8 content areas (P < 0.001). Ninety-four percent of EM physicians felt defensive at least "sometimes." Twenty-nine percent of all respondents reported handoff-related adverse events, most frequently related to ineffective communication. Sequential handoffs were common for both EM and admitting services, with 78% of physicians reporting they negatively impacted patient care.

CONCLUSION

Physicians reported that patient safety was often at risk during the ED admission handoff process. Admitting and EM physicians had divergent perceptions regarding handoff communication, and sequential handoffs were common. Further research is needed to better understand this complex process and to investigate strategies for improvement.

Emergency Department Processes for the Evaluation and Management of Persons Under Investigation for Ebola Virus Disease

INTRODUCTION

Due to the recent Ebola virus outbreak in West Africa, patients with epidemiologic risk for Ebola virus disease and symptoms consistent with Ebola virus disease are presenting to emergency departments (EDs) and clinics in the United States. These individuals, identified as a person under investigation for Ebola virus disease, are initially screened using a molecular assay for Ebola virus. If this initial test is negative and the person under investigation has been symptomatic for < 3 days, a repeat test is required after 3 days of symptoms to verify the negative result. In the time interval before the second test result is available, manifestations of the underlying disease process for the person under investigation, whether due to Ebola virus disease or some other etiology, may require further investigation to direct appropriate therapy.

MATERIALS AND METHODS

ED administrators, physicians, and nurses proposed processes to provide care that is consistent with other ED patients. Biocontainment unit administrators, industrial hygienists, laboratory directors, physicians, and other medical personnel examined the ED processes and offered biocontainment unit personal protective equipment and process strategies designed to ensure safety for providers and patients.

CONCLUSION

ED processes for the safe and timely evaluation and management of the person under investigation for Ebola virus disease are presented with the ultimate goals of protecting providers and ensuring a consistent level of care while confirmatory testing is pending.

Assessment of a Brief Handoff Skills Workshop for Incoming Interns: Do past Handoff Experiences Impact Training Outcomes?

BACKGROUND

Patient care handoffs are a core professional activity that incoming interns are expected to perform without direct supervision upon starting residency, yet training in medical schools is inconsistent.

OBJECTIVE

To implement a brief handoff communication workshop for incoming interns and determine whether learner-level determinants were associated with differences in training outcomes.

METHODS

We conducted a one-hour interactive handoff skills workshop for all incoming interns at a Midwestern academic medical center. We performed paired pre/post-intervention assessments of participants' attitudes and ability to perform representative handoff skills. The results were analyzed in aggregate and based upon participants' prior handoff experiences using Wilcoxon signed-rank test.

RESULTS

Ninety-nine of 108 interns (91.7%) completed both pre- and post-surveys. There was significant improvement in all 10 attitude-based questions (P ≤ 0.014 for all) and on the skills assessment (1.07 vs 2.16 on 0-4 point scale, SD 1.25, P ≤ 0.001). Results remained significant regardless of prior training, number of handoffs observed, number of handoffs performed, medical school, or residency discipline.

CONCLUSION

A brief interactive workshop for incoming interns can improve participants' confidence and performance of basic handoff skills, regardless of previous training or experience.

Milk-alkali-induced pancreatitis in a chronically hypocalcemic patient with DiGeorge syndrome

BACKGROUND

Pancreatitis is a common diagnosis in the emergency department (ED), and milk-alkali syndrome (MAS) is an uncommon etiology for pancreatitis. MAS is caused by increased calcium and alkali ingestion, causing hypercalcemia accompanied by metabolic alkalosis and renal failure. Once considered rare, MAS is an increasingly common cause of hypercalcemia. Awareness of the resurgence of this syndrome is important for emergency physicians when recalling the causes of renal failure and pancreatitis. We present a case of pancreatitis and acute renal failure (ARF) in a chronically hypocalcemic DiGeorge syndrome patient, resulting from hypercalcemia secondary to excessive ingestion of calcium carbonate tablets.

CASE REPORT

A patient with DiGeorge syndrome and chronic abdominal pain due to gastroesophageal reflux disease (GERD) presented to our ED for severe abdominal pain. He reported nausea and vomiting, as well as epigastric pain that seemed worse than his typical pain. Laboratory evaluation revealed pancreatitis and ARF, although the patient had no prior history of these conditions. Upon further questioning, his mother divulged that the patient had been taking large quantities of calcium carbonate tablets for his worsening GERD symptoms. The patient was admitted to the intensive care unit where his pancreatitis and ARF eventually resolved as his calcium levels returned to his baseline. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: MAS is a relatively uncommon diagnosis, but can lead to serious sequelae such as pancreatitis and ARF. Questioning the patient about calcium ingestion is an important facet to the diagnosis and work-up of pancreatitis and ARF. Recognition of this etiology can improve patient outcomes and prevent recurrences.

Comparison of Airtraq optical laryngoscope and Storz video laryngoscope in a cadaver model

BACKGROUND

Airway management in the emergency department is a critical intervention that requires both standard techniques and rescue techniques to ensure a high rate of success. Recently, video laryngoscope (VL) systems have become increasingly common in many large urban EDs, but these systems may exceed the budgets of smaller rural EDs and EMS services and the Airtraq optical laryngoscope (OL) may provide an effective, low-cost alternative. We hypothesized that laryngeal view and time to endothracheal tube placement for OL and VL intubations would not be significantly different.

METHODS

This was a prospective, crossover trial.

SETTING

University-based emergency medicine residency program procedure laboratory utilizing lightly embalmed cadavers.

SUBJECTS

PGY1-3 emergency medicine residents. The study subjects performed timed endotracheal intubations alternately using the OL and VL. The subjects then rated the Cormack-Lehane laryngeal view for each device.

STATISTICAL ANALYSIS

Mean time to intubation and the mean laryngeal view score were calculated with 95% confidence intervals and statistical significance was determined by Student's t test.

RESULTS

Fourteen subjects completed the study. The average laryngeal view achieved with the OL vs. the VL was not significantly different, with Cormack-Lehane grade of 1.14 vs. 1.07, respectively. Time to endotracheal intubation, however, was significantly different (P<0.001) with the average time to intubation for the OL 25.49 seconds (95% CI: 17.95-33.03) and the VL 13.41 seconds (10.27-16.55).

CONCLUSION

The Airtraq OL and the Storz VL yielded similar laryngeal views in the lightly embalmed cadaver model. Time to endotracheal tube placement, however, was less for the VL.

Task analysis method for procedural training curriculum development

A central venous catheter (CVC) is an important medical tool used in critical care and emergent situations. Integral to proper care in many circumstances, insertion of a CVC introduces the risk of central line-associated blood stream infections and mechanical adverse events; proper training is important for safe CVC insertion. Cognitive task analysis (CTA) methods have been successfully implemented in the medical field to improve the training of postgraduate medical trainees, but can be very time-consuming to complete and require a significant time commitment from many subject matter experts (SMEs). Many medical procedures such as CVC insertion are linear processes with well-documented procedural steps. These linear procedures may not require a traditional CTA to gather the information necessary to create a training curriculum. Accordingly, a novel, streamlined CTA method designed primarily to collect cognitive cues for linear procedures was developed to be used by medical professionals with minimal CTA training. This new CTA methodology required fewer trained personnel, fewer interview sessions, and less time commitment from SMEs than a traditional CTA. Based on this study, a streamlined CTA methodology can be used to efficiently gather cognitive information on linear medical procedures for the creation of resident training curricula and procedural skills assessments.

Ergonomics of novices and experts during simulated endotracheal intubation

Endotracheal Intubation (ETI) is an airway procedure commonly used to secure the airway for a variety of medical conditions. Proficiency in ETI procedures requires significant clinical experience and insufficient data currently exists describing the physical ergonomics of successful direct laryngoscopy. The research objectives of this study were to examine how ETI time, error and practitioner biomechanics varied among clinical experience levels and hospital bed heights. The participant population included novice and expert personnel, differentiated by their exposure to ETI procedures. Participants used a standard laryngoscope and blade to perform ETI trials on an airway manikin trainer at predesigned hospital bed heights. Participants were evaluated based on ETI time and accuracy, as well as wrist postures and muscle utilization. Hospital bed height did not affect task completion time, error rates or muscle utilization. Expert participants exhibited less ulnar deviation and forearm supination during task trials, as well as a higher utilization of the bicep brachii and anterior deltoid muscles. Expert grasped instrumentation differently, requiring less wrist manipulation required to achieve ideal instrument positions. By encouraging ergonomic best-practices in hand and arm postures during ETI training, the opportunity exists to improve patient safety and reduce the learning curve associated with ETI procedures.

Using the intubating laryngeal tube in a manikin - user evaluation of a new airway device

This work describes the use of a new intubation device, the intubating laryngeal tube (iLTA) as developed by Boedeker. Emergency Department residents and staff from the University of Nebraska Medical Center performed intubations using the Laerdal Difficult Airway Trainer Manikin(TM). The participants' perceived value of the intubating laryngeal tube as well as its efficacy in intubation performance were measured and found to be highly favorable.

Endotracheal intubation with a traditional videolaryngoscope blade versus an integrated suction blade in a hemorrhagic airway cadaver model

Lightly embalmed hemorrhagic cadaver models and the Storz CMAC videolaryngoscope fitted with either an integrated suction blade vs. a traditional blade were used to determine efficacy of the instruments in hemorrhagic airway intubation. Significant differences were found between the devices in intubation success rates of the viscosity saliva and frothy blood models, as well as a significant difference in intubation times in the frothy blood model. Feedback provided by the study participants indicated preference for the integrated video suction blade in hemorrhagic airway intubation.

Rural clinical experiences for emergency medicine residents: a curriculum template

Rural emergency departments (EDs) in the United States are less likely to be staffed with emergency medicine (EM) residency-trained and American Board of Emergency Medicine (ABEM)-certified physicians than urban EDs. Rural EM clinical experiences during residency training have been suggested as a strategy to encourage future rural practice, but past Accreditation Council for Graduate Medical Education (ACGME) Residency Review Committee for Emergency Medicine program requirements and a lack of familiarity with rural rotations in the EM graduate medical education (GME) community have limited their availability. To provide a template for the development and implementation of a rural EM clinical experience, Kern's six-step approach was followed.

Emergency medicine rural rotations: a program director's guide

The Institute of Medicine's 2006 report titled "Hospital-Based Emergency Care: At the Breaking Point" called national attention to the lack of specialty-trained emergency care practitioners, particularly in rural America. One suggested strategy for narrowing the gap between the prevalence of residency-trained, board-certified emergency physicians practicing in rural and urban emergency departments is the development of rural clinical experiences for emergency medicine residents during the course of their training. This article addresses promotion of a rural emergency medicine rotation to hospital leadership and resident recruits, examines funding sources, discusses medical liability and disability insurance options, provides suggestions for meeting faculty and planned educational activity residency review committee requirements, and offers guidance about site selection to direct emergency medicine academic leaders considering or planning a new rural emergency medicine rotation.

Workload Comparison of Intraoral Mask to Standard Mask Ventilation Using a Cadaver Model

Background: The bag-valve mask (BVM) is critical to providing positive pressure ventilation for patients who are not breathing or who are breathing inadequately. This simple hand-held device enables healthcare professionals to quickly provide mechanical ventilation in emergent and non-emergent situations. However, the difficulty of achieving and maintaining an adequate seal between the BVM and face reduces ventilation volume and the success rate of resuscitation efforts. A novel IntraOral Mask (IOM) was developed by NuMask to eliminate these difficulties by creating a seal inside the mouth using a snorkel-like mouthpiece. There have been no published reports comparing the human factors and ergonomics of these masks. Therefore, the aim of this study was to compare the perceived workload of the standard BVM and the NuMask IOM. Method: Twenty-five emergency medicine students performed mechanical ventilation on a cadaver model using both masks. Workload was assessed using the NASA-TLX after ventilating with each mask. Results: Overall workload and effort were rated significantly less for the IOM (p < 0.05). In general, the IOM had lower median ratings for physical demand, mental demand and frustration compared to the BVM. Conclusion: Overall, the IOM appears to facilitate gripping through its novel snorkel-like design and reduced hand interface size by decreasing the perceived effort and workload of the healthcare responder. However, further clinical and ergonomic investigations are needed to ascertain whether the IOM improves mechanical ventilation performance and therefore resuscitation success rates.