Retention of En Route Cricothyroidotomy Skills in Novice Providers Following a Simulation-Based Mastery Learning Curriculum.

INTRODUCTION: Surgical cricothyroidotomy (SC) is a vital skill that combat first responders must master as airway obstruction is the third most preventable cause of death on the battlefield. Degradation of skills over time is a known problem, and there is inadequate knowledge regarding the rate of SC skill retention. Our prior study showed that simulation-based mastery learning was effective in training 89 novices how to reliably perform an en route SC to mastery performance standards. This study aims to assess the durability of this skill by bringing participants back in 3 separate cohorts at 6, 12, or 24 months following the initial training to perform SC in the same test environment. MATERIALS AND METHODS: This was a randomized prospective trial. Random cohorts of equal subjects who previously underwent SC simulation-based mastery learning training were selected to return at 6, 12, and 24 months to retest in the same en route medical evacuation (MEDEVAC) helicopter scenario. A total of 22, 14, and 10 subjects returned at 6, 12, and 24 months, respectively, due to Coronavirus-19 impacts and travel limitations. Participants in the 24-month cohort received a refresher training prior to retesting. All attempts were recorded and blindly graded using the same 10 item standardized SC checklist used in initial training. Our previous work found that mastery criteria for performing a SC were ≤40 seconds and completion of 9/10 items on the checklist. Outcome measures in this study were time to complete the procedure and percent of subjects who completed at least 9/10 items on the SC checklist. RESULTS: There was an increase in time required to complete the procedure compared to initial training in all three retesting cohorts (initial: median 27.50, interquartile range 25.38-31.07 seconds; 6 months: median 36.33, interquartile range 31.59-55.22 seconds; 12 months: median 49.50, interquartile range 41.75-60.75 seconds; 24 months: median 38.79, interquartile range 30.20-53.08 seconds; P < .0001, P < .0001, P = .0039). There was a decline in median value checklist scores compared to initial training in the 6- and 12-month retesting cohorts (initial: median 10.00/10, interquartile range 9.50-10.00; 6 months: median 8.00/10, interquartile range 6.75-9.00; 12 months: median 8.00/10, interquartile range 6.75-9.25; P < .0001, P < .001). There was no difference in median checklist scores between the initial and 24-month retesting scenario (initial: median 10.00/10, interquartile range 9.50-10.00; 24 months: 10.00/10, interquartile range 9.00-10.00; P= .125). There was a decrease in retention of skills as only 31.82% of subjects at 6 months and 14.29% at 12 months met the defined passing criteria of time to completion of ≤40 seconds and checklist score of ≥9/10. A brief refresher course several months prior to the 24-month cohort retesting greatly increased the retention of SC procedural skills, with 60% of subjects meeting the time and checklist criteria. CONCLUSIONS: This study showed that the skill required to perform a SC after initial mastery training does decay significantly. A brief refresher course can help increase retention of skills. Based on our findings SC skills should be refreshed at a minimum of every 6 months to assure optimal proficiency.

Development of a Simulation Surgical Cricothyroidotomy Curriculum for Novice Providers: A Learning Curve Study.

INTRODUCTION: Airway obstruction is the third most common cause of preventable death on the battlefield, accounting for 1%-2% of total combat fatalities. No previous surgical cricothyroidotomy (SC) studies have analyzed the learning curve required to obtain proficiency despite being studied in numerous other surgical technique training experiments. The aims of this study were to establish expert SC performance criteria, develop a novel standardized SC curriculum, and determine the necessary number of practice iterations required by a novice to reach this pre-determined performance goal. MATERIALS AND METHODS: A standardized checklist and SC performance standards were established based on the performance of 12 board certified Military Health System surgeons with prior experience on performing a SC using a simulated trauma mannequin. Expert-level criteria were defined as a SC time to completion of 40 s or less and checklist score of at least 9/10, including all critical steps. Study subjects included 89 novice providers (54 active-duty first- and second-year medical students and 35 Navy corpsmen). Subjects received instruction on performing a SC using the principles of mastery learning and performed a final test of SC proficiency on a trauma mannequin within a realistic simulated MEDEVAC helicopter. The total number of subject practice attempts, checklist scores, and time to completion were measured and/or blindly scored. Learning curve and exponential plateau equations were used to characterize their improvement in mean time to SC completion and checklist scores. RESULTS: Mean pre-test knowledge scores for the entire group were 11.8 ± 3.1 out of 24 points. Total mean practice learning plateaued at checklist scores of 9.9/10 after 7 iterations and at a mean completion time of 30.4 s after 10 iterations. During the final test performance in the helicopter, 67.4% of subjects achieved expert-level performance on the first attempt. All subjects achieved expert-level performance by the end of two additional attempts. While a significantly larger proportion of medical students (79.9%) successfully completed the helicopter test on the first attempt compared to corpsmen (54.3%), there were no statistically significant differences in mean SC completion times and checklist scores between both groups (P > 0.05). Medical students performed a SC only 1.3 s faster and scored only 0.16 points higher than corpsmen. The effect size for differences were small to negligible (Cohen's d range 0.18-0.33 for SC completion time; Cohen's d range 0.45-0.46 for checklist scores). CONCLUSION: This study successfully defined SC checklist scores and completion times based on the performance of experienced surgeons on a simulator. Using these criteria and the principles of mastery learning, novices with little knowledge and experience in SC were successfully trained to the level of experienced providers. All subjects met performance targets after training and overall performance plateaued after approximately seven iterations. Over two-thirds of subjects achieved the performance target on the first testing attempt in a simulated helicopter environment. Performance was comparable between medical student and corpsmen subgroups. Further research will assess the durability of maintaining SC skills and the timing for introducing refresher courses after initial skill acquisition.

A Rare but Morbid Occurrence: Development of Glioblastoma Multiforme During Tumor Necrosis Factor Inhibitor Therapy.

The use of biologic therapies continues to become more prevalent in the treatment of inflammatory bowel disease, particularly for more severe disease. Although generally safe and effective, specific biologic classes such as tumor necrosis factor inhibitor (anti-TNF) medications are known to increase the risk of certain cancers. Glioblastoma multiforme (GBM) is an aggressive brain tumor which tends to arise sporadically but may be associated with anti-TNF therapies. Here, we present a case of a 69-year-old male with Crohn's disease who developed GBM while on adalimumab therapy. This case report highlights the potential rare association between GBM and anti-TNF therapy and further discusses the difficulty of managing active Crohn's disease with concomitant GBM, specifically the difficulty encountered in managing a disease flare.

ACUTE POSTERIOR MULTIFOCAL PLACOID PIGMENT EPITHELIOPATHY AFTER IMMUNIZATION WITH MULTIPLE VACCINES.

PURPOSE: To report a case of acute posterior multifocal placoid pigment epitheliopathy occurring in temporal association with multiple immunizations in a previously healthy 25-year-old woman. METHODS: Acute posterior multifocal placoid pigment epitheliopathy was diagnosed based on ophthalmological findings of bilateral placoid subretinal lesions complicated by a serous retinal detachment in the left eye. RESULTS: Through HLA typing, the patient was found to possess the HLA-B*40 and HLA-DB1*15 alleles. She was treated with topical prednisolone acetate 1% and monitored for several months. The serous retinal detachment resolved, and visual acuity returned to normal. CONCLUSION: This case report adds to the body of knowledge regarding possible atypical interplay between vaccines and specific T-cell receptors of the host immune system and adds Polio and Tetanus to the growing list of vaccines potentially triggering acute posterior multifocal placoid pigment epitheliopathy. Increased awareness of the presentation of acute posterior multifocal placoid pigment epitheliopathy and that it may arise after immunization may also improve evaluation of acute changes in visual acuity.

Alternaria alternata Accelerates Loss of Alveolar Macrophages and Promotes Lethal Influenza A Infection.

Chronic inhalation of fungi and fungal components has been linked to the development of respiratory disorders, although their role with respect to the pathogenesis of acute respiratory virus infection remains unclear. Here, we evaluate inflammatory pathology induced by repetitive administration of a filtrate of the ubiquitous fungus, Alternaria alternata, and its impact on susceptibility to infection with influenza A. We showed previously that A. alternata at the nasal mucosae resulted in increased susceptibility to an otherwise sublethal inoculum of influenza A in wild-type mice. Here we demonstrate that A. alternata-induced potentiation of influenza A infection was not dependent on fungal serine protease or ribonuclease activity. Repetitive challenge with A. alternata prior to virus infection resulted proinflammatory cytokines, neutrophil recruitment, and loss of alveolar macrophages to a degree that substantially exceeded that observed in response to influenza A infection alone. Concomitant administration of immunomodulatory Lactobacillus plantarum, a strategy shown previously to limit virus-induced inflammation in the airways, blocked the exaggerated lethal response. These observations promote an improved understanding of severe influenza infection with potential clinical relevance for individuals subjected to continuous exposure to molds and fungi.

Impact of eosinophil-peroxidase (EPX) deficiency on eosinophil structure and function in mouse airways.

Eosinophil peroxidase (EPX) is a major constituent of the large cytoplasmic granules of both human and mouse eosinophilic leukocytes. Human EPX deficiency is a rare, autosomal-recessive disorder limited to the eosinophil lineage. Our intent was to explore the impact of EPX gene deletion on eosinophil content, structure, and function. In response to repetitive intranasal challenge with a filtrate of the allergen, Alternaria alternata, we found significantly fewer eosinophils peripherally and in the respiratory tracts of EPX-/- mice compared to wild-type controls; furthermore, both the major population (Gr1-/lo ) and the smaller population of Gr1hi eosinophils from EPX-/- mice displayed lower median fluorescence intensities (MFIs) for Siglec F. Quantitative evaluation of transmission electron micrographs of lung eosinophils confirmed the relative reduction in granule outer matrix volume in cells from the EPX-/- mice, a finding analogous to that observed in human EPX deficiency. Despite the reduced size of the granule matrix, the cytokine content of eosinophils isolated from allergen-challenged EPX-/- and wild-type mice were largely comparable to one another, although the EPX-/- eosinophils contained reduced concentrations of IL-3. Other distinguishing features of lung eosinophils from allergen-challenged EPX-/- mice included a reduced fraction of surface TLR4+ cells and reduced MFI for NOD1. Interestingly, the EPX gene deletion had no impact on eosinophil-mediated clearance of gram-negative Haemophilus influenzae from the airways. As such, although no clinical findings have been associated with human EPX deficiency, our findings suggest that further evaluation for alterations in eosinophil structure and function may be warranted.

A flow-cytometric method to evaluate eosinophil-mediated uptake of probiotic Lactobacillus reuteri.

Eosinophils are resident leukocytes of gut mucosa. Here we present a combined flow cytometric-antibiotic protection assay to identify mouse eosinophils capable of bacterial uptake, specifically, Gram-positive Lactobacillus reuteri, in studies performed ex vivo. The assay may be adapted for use in vivo.

SiglecF+Gr1hi eosinophils are a distinct subpopulation within the lungs of allergen-challenged mice.

Although eosinophils as a group are readily identified by their unique morphology and staining properties, flow cytometry provides an important means for identification of subgroups based on differential expression of distinct surface Ags. Here, we characterize an eosinophil subpopulation defined by high levels of expression of the neutrophil Ag Gr1 (CD45+CD11c-SiglecF+Gr1hi). SiglecF+Gr1hi eosinophils, distinct from the canonical SiglecF+Gr1- eosinophil population, were detected in allergen-challenged wild-type and granule protein-deficient (EPX-/- and MBP-1-/-) mice, but not in the eosinophil-deficient ΔdblGATA strain. In contrast to Gr1+ neutrophils, which express both cross-reacting Ags Ly6C and Ly6G, SiglecF+Gr1hi eosinophils from allergen-challenged lung tissue are uniquely Ly6G+ Although indistinguishable from the more-numerous SiglecF+Gr1- eosinophils under light microscopy, FACS-isolated populations revealed prominent differences in cytokine contents. The lymphocyte-targeting cytokines CXCL13 and IL-27 were identified only in the SiglecF+Gr1hi eosinophil population (at 3.9 and 4.8 pg/106 cells, respectively), as was the prominent proinflammatory mediator IL-13 (72 pg/106 cells). Interestingly, bone marrow-derived (SiglecF+), cultured eosinophils include a more substantial Gr1+ subpopulation (∼50%); Gr1+ bmEos includes primarily a single Ly6C+ and a smaller, double-positive (Ly6C+Ly6G+) population. Taken together, our findings characterize a distinct SiglecF+Gr1hi eosinophil subset in lungs of allergen-challenged, wild-type and granule protein-deficient mice. SiglecF+Gr1hi eosinophils from wild-type mice maintain a distinct subset of cytokines, including those active on B and T lymphocytes. These cytokines may facilitate eosinophil-mediated immunomodulatory responses in the allergen-challenged lung as well as in other distinct microenvironments.