Feasibility of Out-of-Hospital Cardiac Arrest Ultrasound by EMS Physicians.

INTRODUCTION: Point-of-care ultrasound (POCUS) has been suggested as a useful tool to predict survival and guide interventions in out-of-hospital cardiac arrest (OHCA). While POCUS has been deployed in prehospital settings, a minimal amount of data exists on prehospital use, particularly by personnel with limited ultrasound experience. We aimed to characterize the feasibility and barriers to prehospital POCUS during OHCA by emergency medicine services (EMS) physicians in training. METHODS: We deployed the SonoSite iViz portable ultrasound device for use by EMS physicians for OHCA in an urban EMS system. All physicians received POCUS education as part of their graduate medical training and were provided an instructional video on use of the SonoSite iViz device. POCUS use was limited to identifying cardiac motion during pulse checks, without interrupting resuscitation, and the results could be used to supplement management at the physicians' discretion. Data were recorded prospectively by saving images on the device and through a custom electronic form within the patient care report. The primary measure was the frequency of use of POCUS during OHCA. Secondarily, we characterized agreement by expert (ultrasound fellowship trained) faculty (using a kappa statistic) and identified reported barriers to the use of prehospital POCUS. RESULTS: From November 2016 to March 2017, 348 physician field responses were reviewed, including 127 cases of OHCA. There were 106 patients remaining in arrest on physician arrival, with 56 (52.8%) cases of POCUS use. Still or video images were recorded in 48 cases; video in 34 cases. From video images, agreement in identifying cardiac motion between the EMS physician and expert reviewer occurred in 91% of cases (K = 0.82). Reasons cited for not using POCUS included return of circulation soon before or after arrival, prioritizing clinical interventions, not having the ultrasound device, mechanical failure, and cessation of resuscitation per advanced directives. CONCLUSION: Use of POCUS by EMS physicians to detect cardiac activity in OHCA is feasible and correlates with expert interpretation. Several avoidable barriers were identified and should be considered in the future implementation of prehospital POCUS. Larger studies are needed to determine what role POCUS may play in prehospital cardiac arrest management.

Drinking to near death--acute water intoxication leading to neurogenic stunned myocardium.

Neurogenic stunned myocardium is a rare disease entity that has been typically described as a consequence of subarachnoid hemorrhage and, less commonly, seizures. Here we describe a case of a healthy young woman who drank excessive free water causing acute hyponatremia complicated by cerebral edema and seizure, leading to cardiogenic shock from neurogenic stunned myocardium. Two days later, she had complete return of her normal cardiac function.

Novel use of ultrasound in the ED: ultrasound-guided hematoma block of a proximal humeral fracture.

Proximal humeral fractures are a common injury after falls, particularly in the elderly population. An ultrasound-guided hematoma block is a novel technique for analgesia in cases when standard intravenous analgesia is not efficacious. We present a case in which ultrasound-guided hematoma block was the ideal method for adjunctive pain control in a patient with a comminuted humeral head fracture.

A taste of periodic fever syndromes.

Periodic fevers are acquired or inherited disorders of innate immunity, which were first described in the 1940s. The patients are typically young at onset and have regularly recurring fevers for a few days to a few weeks with systemic inflammatory symptoms that are interrupted by symptom-free periods. There is a variety of clinical manifestations including gastrointestinal complaints, myalgias, arthralgias, and rash. A differential diagnosis in these patients may include recurrent infections, other inflammatory disorders, and neoplastic disease. This clinical review focuses on a sample of autoinflammatory disorders including familial Mediterranean fever, tumor necrosis factor receptor 1-associated periodic syndrome, hyperimmunoglobulinemia D syndrome, the cryopyrin-associated periodic syndrome, and periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome. We review the basics, pertinent clinical and laboratory features, and management of each entity.

When Is "Pseudo-Ludwig's Angina" Associated With Coagulopathy Also a "Pseudo" Hemorrhage?

Sublingual hematoma secondary to short-acting anticoagulants such as warfarin has been labeled "pseudo-Ludwig's angina" to distinguish it from the classic syndrome of localized infection and swelling involving the upper airway. Sublingual hematoma with airway compromise secondary to brodifacoum, a common long-acting anticoagulant rodenticide, has only been reported in the veterinary literature. We report a case of massive tongue swelling and impending airway compromise in the context of an intentional long-acting anticoagulant ingestion leading to coagulopathy. The swelling was initially presumed to be due either to infection or hemorrhage, but this was not supported by computed tomography scan imaging. Instead, the patient's clinical course was consistent with corticosteroid-responsive angioedema, temporally associated with the ingested brodifacoum.

Selective alterations in postsynaptic markers of chandelier cell inputs to cortical pyramidal neurons in subjects with schizophrenia.

Markers of GABA neurotransmission between chandelier neurons and their synaptic targets, the axon initial segment (AIS) of pyramidal neurons, are altered in the dorsolateral prefrontal cortex (dlPFC) of subjects with schizophrenia. For example, immunoreactivity for the GABA membrane transporter (GAT1) is decreased in presynaptic chandelier neuron axon terminals, whereas immunoreactivity for the GABA(A) receptor alpha2 subunit is increased in postsynaptic AIS. To understand the nature and functional significance of these alterations, we determined the density, laminar distribution, and length of AIS immunoreactive (IR) for ankryin-G and betaIV spectrin, two proteins involved in the regulation of synapse structure and ion channel clustering at AIS, in dlPFC area 46 from 14 matched triads of subjects with schizophrenia or major depressive disorder (MDD) and normal comparison participants. The density of ankyrin-G-IR AIS in the superficial, but not in the deep, cortical layers was significantly decreased by 15-19% in the subjects with schizophrenia relative to the other participant groups. In contrast, no group differences were present in the density of betaIV spectrin-IR AIS. The length of labeled AIS did not differ across participant groups for either ankyrin-G or betaIV spectrin. The density of ankyrin-G-IR AIS was not altered in the dlPFC of macaque monkeys chronically exposed to antipsychotic medications. Given the important role of ankyrin-G in the recruitment and stabilization of sodium channels and other integral membrane proteins to AIS, our findings suggest that these processes are selectively altered in superficial layer pyramidal neurons in subjects with schizophrenia.

Postnatal development of synaptic structure proteins in pyramidal neuron axon initial segments in monkey prefrontal cortex.

In the primate prefrontal cortex (PFC), the functional maturation of the synaptic connections of certain classes of gamma-aminobutyric acid (GABA) neurons is very complex. For example, the levels of both pre- and postsynaptic proteins that regulate GABA neurotransmission from the chandelier class of cortical interneurons to the axon initial segment (AIS) of pyramidal neurons undergo marked changes during both the perinatal period and adolescence in the monkey PFC. In order to understand the potential molecular mechanisms associated with these developmental refinements, we quantified the relative densities, laminar distributions, and lengths of pyramidal neuron AIS immunoreactive for ankyrin-G, betaIV spectrin, or gephyrin, three proteins involved in regulating synapse structure and receptor localization, in the PFC of rhesus monkeys ranging in age from birth through adulthood. Ankyrin-G- and betaIV spectrin-labeled AIS declined in density and length during the first 6 postnatal months, but then remained stable through adolescence and into adulthood. In contrast, the density of gephyrin-labeled AIS was stable until approximately 15 months of age and then markedly declined during adolescence. Thus, molecular determinants of the structural features that define GABA inputs to pyramidal neuron AIS in monkey PFC undergo distinct developmental trajectories with different types of changes occurring during the perinatal period and adolescence. In concert with previous data, these findings reveal a two-phase developmental process of GABAergic synaptic stability and GABA neurotransmission at chandelier cell inputs to pyramidal neurons that likely contributes to the protracted maturation of behaviors mediated by primate PFC circuitry.