Local anesthetic systemic toxicity in the pediatric patient.

Lidocaine and prilocaine are local anesthetics, a class of medications which are frequently used in clinical medicine to minimize pain in a variety of procedures. They are commonly found in over-the-counter products such as topical anesthetic creams advertised to relieve localized muscle and joint pain. While safe and well-tolerated when used appropriately, an overdose of these anesthetics increases the risk for local anesthetic systemic toxicity (LAST), which in severe cases can present with seizures, cardiac dysrhythmias, and ultimately cardiovascular collapse. The reduced muscle mass of pediatric patients puts them at an increased risk of LAST due to the depot effect of the systemically absorbed anesthetic. Methemoglobinemia may also be associated with local anesthetic toxicity. Our case involves a previously healthy 15-month-old female who presented to one of our networks' emergency departments in status epilepticus following an accidental ingestion of a tube of 2.5% lidocaine/2.5% prilocaine cream. Her seizure activity was initially resistant to intraosseous benzodiazepine administration, but ultimately resolved following administration of lipid emulsion and sodium bicarbonate. Additionally, the patient had refractory hypoxia on the monitor which resolved shortly after administration of methylene blue. After stabilization, the patient was transferred to the Pediatric ICU and ultimately made a complete recovery. LAST is a life-threatening presentation which requires early recognition by clinicians, as well as an understanding of the appropriate treatment modalities. We review the assessment and management of LAST, with special focus on the pediatric patient.

Imaging Molecular Adhesion in Cell Rolling by Adhesion Footprint Assay.

Rolling adhesion, facilitated by selectin-mediated interactions, is a highly dynamic, passive motility in recruiting leukocytes to the site of inflammation. This phenomenon occurs in postcapillary venules, where blood flow pushes leukocytes in a rolling motion on the endothelial cells. Stable rolling requires a delicate balance between adhesion bond formation and their mechanically-driven dissociation, allowing the cell to remain attached to the surface while rolling in the direction of flow. Unlike other adhesion processes occurring in relatively static environments, rolling adhesion is highly dynamic as the rolling cells travel over thousands of microns at tens of microns per second. Consequently, conventional mechanobiology methods such as traction force microscopy are unsuitable for measuring the individual adhesion events and the associated molecular forces due to the short timescale and high sensitivity required. Here, we describe our latest implementation of the adhesion footprint assay to image the P-selectin: PSGL-1 interactions in rolling adhesion at the molecular level. This method utilizes irreversible DNA-based tension gauge tethers to produce a permanent history of molecular adhesion events in the form of fluorescence tracks. These tracks can be imaged in two ways: (1) stitching together thousands of diffraction-limited images to produce a large field of view, enabling the extraction of adhesion footprint of each rolling cell over thousands of microns in length, (2) performing DNA-PAINT to reconstruct super-resolution images of the fluorescence tracks within a small field of view. In this study, the adhesion footprint assay was used to study HL-60 cells rolling at different shear stresses. In doing so, we were able to image the spatial distribution of the P-selectin: PSGL-1 interaction and gain insight into their molecular forces through fluorescence intensity. Thus, this method provides the groundwork for the quantitative investigation of the various cell-surface interactions involved in rolling adhesion at the molecular level.

Failure Rates During Reuse of Disposable N95 Masks in Clinical Practice in the Emergency Department.

INTRODUCTION: The coronavirus 2019 pandemic caused a shortage of disposable N95 respirators, prompting healthcare entities to extend the use of these masks beyond their intended single-use manufacturer recommendation with a paucity of supporting research. METHODS: We performed a prospective cohort study of ED healthcare workers (HCW) ("subjects") required to use respirators at an academic, Level I trauma center. Subjects had been previously fit tested and assigned an appropriately sized N95 mask per hospital protocol. Per study protocol, subjects were fit tested periodically throughout their shifts and on multiple shifts over the eight-week study period. Data points collected included the age of the mask, subjective assessment of mask seal quality, and fit test results. We analyzed the data using Fisher's exact test, and calculated odds ratios (OR) to determine the failure rate of disposable N95 masks following reuse. RESULTS: A total of 130 HCWs underwent fit testing and 127 were included for analysis. Mask failure rate climbed after day 2 of use, with 33.3% of masks failing at day 3, 42.9% at day 4, and 50% at ≥ day 5. Categorizing the masks into those being used for two or fewer days vs those in use for three or more, failure was more common on day 3 of use or older compared to those in the first two days of use (41.8% vs 8.3%, P < 0.0001) with an OR of failure with an older mask of 7.9 (confidence interval [CI], 2.8-22.3). The healthcare workers' assessment of poor seal was 33.3% sensitive (CI, 18.6-51.9) and 95.7% specific (CI, 88.8-98.6) for fit test failure. CONCLUSION: Disposable N95 masks have significant failure rates following reuse in clinical practice. Healthcare personnel also performed poorly in assessing the integrity of the seal of their disposable respirators.

The pragmatic use of industrial elastomeric facemasks in health care practice during the COVID-19 pandemic.

INTRODUCTION: The COVID-19 pandemic has forced health care workers to explore alternative personal protective equipment (PPE) strategies due to traditional product shortages in the setting of increased global demand. Some physicians have chosen to use elastomeric face masks (EFMs), traditionally used in non-healthcare industries. METHODS: We performed a prospective cohort study of Emergency Medicine (EM) physicians working at a Level 1 Trauma Center who chose to use self-supplied EFMs for PPE. All subjects used commercial EFMs with disposable filters (N95, P95, or P100). All subjects chose their mask size independently with no input from employee health regarding appropriate fit. Per study protocol, subjects were fit tested periodically during clinical shifts over the course of the 6-week study period. All investigators performing fit testing underwent OSHA qualitative fit testing training. Data collected included mask/filters age, subjective assessment of mask seal quality, and fit test results. The data were analyzed using descriptive statistics. RESULTS: 105 fit tests were performed on physicians wearing EFMs over the course of 49 shifts. Physicians felt their fit was adequate for all tests performed. There were no fit test failures in any subjects. CONCLUSIONS: EFMs have an extremely low failure rate. Physicians are able to assess the adequacy of fit and accurately choose EFM size.

The efficacy of continuous use disposable N95 masks in clinical practice in the emergency department.

During the SARS-CoV-2 pandemic, many emergency departments (EDs) initiated continuous use of N95 disposable respirators (N95s) rather than discarding them after each use to conserve respirators. This study investigates the efficacy of wearing disposable N95s continuously during clinical work. METHODS: This is a prospective cohort study of ED staff required to wear N95s continuously throughout their shifts. Subjects were doctors, nurses, and technicians who were previously fitted for their assigned N95 by employee health. Subjects were fit tested periodically throughout their shifts. Investigators filled out a questionnaire for each subject noting the hours of continuous N95 wear. Data were analyzed using descriptive statistics. RESULTS: One hundred thirteen N95s were evaluated, with 23 failures at first testing. These were not retested. Twenty-seven N95s passed at the start of a shift and did not have repeat testing during the course of the shift. These were excluded from further analysis. Seventeen N95s passed testing after several hours of continuous wear, but only had a single fit test done partway or at the end of a shift. These were assumed to have passed if tested at shift start, and were assigned as "passes" for continuous use. Forty-six N95s had an initial pass and were evaluated for continuous use, of which 6 subsequently failed later in the shift, giving a fail rate with continuous use of 9.5%. CONCLUSION: Continuous use of disposable N95s throughout an ED shift is reasonable during a PPE shortage if wearers are assured of fit at the start of their shift.

A Case of Cocaine-Induced Uvular Edema.

A 26-year-old male presented to the emergency department with a chief complaint of globus sensation and sore throat in the setting of recent cocaine use. On physical examination, he was found to have isolated uvular edema and erythema. After excluding other potential inciting mechanisms of Quincke's disease, he was treated with anti-inflammatory medication and was observed for any development of airway compromise prior to discharge.