Consensus Standard for Evidence Integration into EMS Education and High-Stakes Testing.

BACKGROUND: Incorporating emerging knowledge into Emergency Medical Service (EMS) competency assessments is critical to reflect current evidence-based out-of-hospital care. However, a standardized approach is needed to incorporate new evidence into EMS competency assessments because of the rapid pace of knowledge generation. OBJECTIVE: The objective was to develop a framework to evaluate and integrate new source material into EMS competency assessments. METHODS: The National Registry of Emergency Medical Technicians (National Registry) and the Prehospital Guidelines Consortium (PGC) convened a panel of experts. A Delphi method, consisting of virtual meetings and electronic surveys, was used to develop a Table of Evidence matrix that defines sources of EMS evidence. In Round One, participants listed all potential sources of evidence available to inform EMS education. In Round Two, participants categorized these sources into: (a) levels of evidence quality; and (b) type of source material. In Round Three, the panel revised a proposed Table of Evidence. Finally, in Round Four, participants provided recommendations on how each source should be incorporated into competency assessments depending on type and quality. Descriptive statistics were calculated with qualitative analyses conducted by two independent reviewers and a third arbitrator. RESULTS: In Round One, 24 sources of evidence were identified. In Round Two, these were classified into high- (n = 4), medium- (n = 15), and low-quality (n = 5) of evidence, followed by categorization by purpose into providing recommendations (n = 10), primary research (n = 7), and educational content (n = 7). In Round Three, the Table of Evidence was revised based on participant feedback. In Round Four, the panel developed a tiered system of evidence integration from immediate incorporation of high-quality sources to more stringent requirements for lower-quality sources. CONCLUSION: The Table of Evidence provides a framework for the rapid and standardized incorporation of new source material into EMS competency assessments. Future goals are to evaluate the application of the Table of Evidence framework in initial and continued competency assessments.

Rate of Endothelial Cell Loss and Graft Survival in Descemet Membrane Endothelial Keratoplasty in Eyes Requiring a Rebubble.

PURPOSE: We aimed to compare the rate of 6-month endothelial cell loss (ECL) and 6-month graft survival in eyes that did not require a postoperative rebubble with eyes that did require a postoperative rebubble after Descemet membrane endothelial keratoplasty (DMEK) surgery. METHODS: A consecutive series of DMEK surgeries performed from September 2013 to March 2020 was retrospectively analyzed. Eyes that did not require a rebubble for graft detachment were compared with eyes with 1 rebubble and eyes with 2 or more rebubbles for 6-month ECL and graft survival. A subanalysis of the rebubble rate for different indications for transplantation was also performed. RESULTS: One thousand two hundred ninety-eight eyes were included in this study. The 6-month ECL for eyes with no rebubbles, 1 rebubble, and ≥2 rebubbles was 29.3% ± 16.2% (n = 793), 36.4% ± 18.6% (n = 97, P = 0.001), and 50.1% ± 19.6% (n = 28, P < 0.001), respectively. The 6-month graft survival rate for eyes with no rebubbles, 1 rebubble, and ≥2 rebubbles was 99.5%, 97.8% ( P = 0.035), and 81.8% ( P < 0.001), respectively. When compared to the rebubble rate for DMEK for Fuchs dystrophy (156/1165 eyes = 13.4%), the rebubble rates were statistically higher for DMEK for failed penetrating keratoplasty (28.5%, P = 0.021) and pseudophakic bullous keratopathy (28.0%, P = 0.036). CONCLUSIONS: Eyes undergoing any rebubble procedure in the postoperative period after DMEK have an increased risk of endothelial cell loss and graft failure at 6 months postoperative. DMEK in eyes for failed penetrating keratoplasty and failed DMEK had the highest rebubble rate, with the former reaching statistical significance.

Deriving National Continued Competency Priorities for Emergency Medical Services Clinicians.

OBJECTIVE: Continued competency is poorly defined in emergency medical services (EMS), with no established method for verifying continued competency at a national level. The objective of this project was to refine understanding of continued competency for EMS clinicians in the U.S. and establish priorities for developing competency assessments. METHODS: A panel of EMS managers, educators, medical directors, and experts in competency assessment, simulation, and certification used a modified Delphi technique to address two questions: "What is the content for continued competency in EMS that should be assessed or verified?" (content) and "How should continued competency of EMS clinicians be demonstrated?" (process). The Delphi process was conducted through electronic conferencing and survey software over a 6-month period. In round one, panelists responded to open-ended prompts and their contributions were analyzed and categorized into themes by independent reviewers. In round two, the panel rated theme importance using five-point Likert-type scales. In round three, the panel ranked their top 10 themes, and in round four, the panel selected the most important themes for each of the two questions through consensus-building discussions. Descriptive statistics and thematic analyses were performed with Excel and STATA 16. RESULTS: Fourteen invited experts participated in all Delphi activities. The panel contributed 70 content and 35 process items from the original prompts. Following thematic analysis, these contributions were reduced to 21 and 14 unique themes, respectively. The final top five prioritized themes for content important for continued competency included (1) airway, respiration, and ventilation, (2) patient assessment, (3) pharmacology, (4) pediatrics, and (5) management of time critical disease progressions. The final top five prioritized themes for the processes for continued competency assessment included (1) assessments of evidence-based practice, (2) performance-based assessments, (3) combined knowledge and skill assessments, (4) performance improvement over time, and (5) frequent, short knowledge assessments. CONCLUSION: This modified Delphi process identified priorities for content and assessment, laying the groundwork for EMS continued competency at a national level. These findings can be leveraged by national task forces to develop transparent and consistent guidelines for systems that verify continued competency related to certification, licensure, and local credentialing.

Examination of a Modified Graft Preparation Technique to Induce Double-Scroll Formation and Promote the Use of Younger Descemet Membrane Endothelial Keratoplasty Donor Tissue.

PURPOSE: The purpose of this study was to determine whether controlled balanced salt solution (BSS) bursts during graft preparation can safely promote formation of a double-scrolled Descemet membrane endothelial keratoplasty (DMEK) graft in younger donor tissue. METHODS: DMEK grafts prepared from young donor tissue (average age, 55 years; range, 39-66 years) were floated in BSS to spontaneously form scrolls (N = 10 pairs). Controlled BSS bursts were used to promote double-scroll (DS) formation in 1 member of each pair. Grafts were stained, preloaded, and shipped before cell viability analysis. After appropriate training, a less experienced technician performed this technique on 10 additional corneas. Outcomes measured for both technicians include the success rate for obtaining a DS, scroll conformation after shipping, and endothelial cell loss (ECL). RESULTS: There was no difference in ECL between grafts subjected to additional manipulation compared with unmanipulated mate grafts (observer 1: 15.2% ± 3.3% vs. 15.2% ± 4.4%, P = 0.99; observer 2: 16.3% ± 2.9% vs. 15.9% ± 4.5%, P = 0.8). A technician experienced with this technique had a 90% success rate, whereas a less experienced technician had a 70% success rate. The mean ECL of the 10 grafts manipulated by the less experienced technician was not significantly different from results obtained from the experienced technician (observer 1: 18.5% ± 6.0% vs. 15.2% ± 3.3%, P = 0.15; observer 2: 18.1% ± 5.6% vs. 16.3% ± 2.9%, P = 0.34). Scrolls maintained their conformation during shipping events. CONCLUSIONS: Double-scroll graft formation using controlled BSS bursts is a reliable technique that can be performed without causing additional damage to DMEK grafts. This technique may make graft unscrolling easier and can promote the use of younger donor tissue for DMEK.

Guidance for Cardiopulmonary Resuscitation of Children With Suspected or Confirmed COVID-19.

This article aims to provide guidance to health care workers for the provision of basic and advanced life support to children and neonates with suspected or confirmed coronavirus disease 2019 (COVID-19). It aligns with the 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular care while providing strategies for reducing risk of transmission of severe acute respiratory syndrome coronavirus 2 to health care providers. Patients with suspected or confirmed COVID-19 and cardiac arrest should receive chest compressions and defibrillation, when indicated, as soon as possible. Because of the importance of ventilation during pediatric and neonatal resuscitation, oxygenation and ventilation should be prioritized. All CPR events should therefore be considered aerosol-generating procedures. Thus, personal protective equipment (PPE) appropriate for aerosol-generating procedures (including N95 respirators or an equivalent) should be donned before resuscitation, and high-efficiency particulate air filters should be used. Any personnel without appropriate PPE should be immediately excused by providers wearing appropriate PPE. Neonatal resuscitation guidance is unchanged from standard algorithms, except for specific attention to infection prevention and control. In summary, health care personnel should continue to reduce the risk of severe acute respiratory syndrome coronavirus 2 transmission through vaccination and use of appropriate PPE during pediatric resuscitations. Health care organizations should ensure the availability and appropriate use of PPE. Because delays or withheld CPR increases the risk to patients for poor clinical outcomes, children and neonates with suspected or confirmed COVID-19 should receive prompt, high-quality CPR in accordance with evidence-based guidelines.

Modified procedure for Loading "Flat" DMEK Grafts Into an Injector.

PURPOSE: The aim of this study was to determine whether loading a Descemet membrane endothelial keratoplasty (DMEK) graft using a drop-in procedure results in more endothelial cell loss (ECL) than the standard suction procedure. METHODS: Pairs of donor corneas with equivalent preprocessing endothelium were prepared using the standard protocol of our eye bank. One member of each pair was loaded into an injector using the standard suction protocol. The mate graft was loaded using a drop-in protocol, in which the edge of the graft was gently grasped with a forceps, lifted to the edge of the injector, and dropped inside. Grafts were evaluated for ECL and examined for grab marks or other loading-associated damage. RESULTS: There was no difference in mean ECL of grafts prepared for DMEK using the standard protocol (20.6% ± 4.5%) compared with that of mate grafts prepared using the drop-in loading protocol (19.5% ± 4.8%, P = 0.59). There was no consistent pattern of damage in the drop-in-loaded grafts, as grab marks or other tissue damage associated with the drop-in loading protocol were not consistently identified by a trained corneal surgeon. CONCLUSIONS: ECL was not significantly different in grafts prepared using a drop-in loading procedure compared with grafts prepared using the standard suction protocol. The drop-in loading protocol may be particularly useful to surgeons who load their own grafts and eye bank processing technicians who encounter a "flat" DMEK graft that does not scroll or a loosely scrolled DMEK graft.

Younger Donor Tissue in Descemet Membrane Endothelial Keratoplasty Surgery: Clinical Outcomes.

PURPOSE: To determine whether using younger donor tissue for Descemet membrane endothelial keratoplasty (DMEK) surgery influences clinical outcomes. METHODS: Scroll tightness, unscrolling time, rebubble rate, and preoperative and 3- and 6-month postoperative endothelial cell density (ECD) and endothelial cell loss (ECL) were compared for 661 DMEK grafts prepared from younger (aged younger than 50 yrs, n = 81) and older donors (aged 50 yrs or older, n = 580) with Student t test, χ2 test, or Mann-Whitney U test. RESULTS: There was no difference in overall unscrolling time (younger donors: 3.1 ± 3.1 min, older donor: 2.9 ± 2.7 min, P = 0.503). Experienced faculty surgeons, compared with fellows, had a significantly lower unscrolling times for both younger donors (2.4 ± 2.3 vs. 4.6 ± 3.9 min, P = 0.002) and older donors (2.5 ± 2.1 vs. 3.7 ± 3.3 min, P <0.001). Rebubble rates were not statistically different between younger (12.3%) and older donors (15.0%, P = 0.527). Three-month ECD was higher in grafts from younger compared with that in those from older donors (2138 ± 442 vs. 1974 ± 470 cells/mm2, P = 0.024). Six-month ECD was similar for younger (1972 ± 509 cells/mm2) and older donors (1947 ± 460 cells/mm2, P = 0.585). There was no difference in 3- or 6-month ECL comparing younger (3-mo: 24.3% ± 13.4%; 6-mo: 31.1% ± 15.2%) with older donors (3-mo: 25.9% ± 15.5%, P = 0.489; 6-mo: 27.8% ± 15.1%, P = 0.231). CONCLUSIONS: DMEK grafts prepared from younger donors exhibited similar unscrolling times, rebubble rates, and 3- and 6-month ECL compared with older donors. Experienced surgeons might begin to accept DMEK grafts from younger donors with confidence.

The Role of Donor Rim Fungal Cultures.

ABSTRACT: Culturing all donor rims for fungus makes no sense. Only 1% of all cultures will be positive, and of those positive cultures, only 6% will also have a clinical infection. Prophylactically treating all positive cultures means 94% of patients will be treated unnecessarily. Fungal cultures do not reliably direct specific medication choice, and fungal infections of the interface in endothelial keratoplasty and deep anterior lamellar keratoplasty are nearly impervious to medical therapy. Suspected fungal infections of the deep stromal interface should be treated expeditiously with penetrating keratoplasty before peripheral spread or endophthalmitis occur.

Descemet Stripping Automated Endothelial Keratoplasty: The influence of preoperative endothelial cell density and triple procedures on grafts at 5 years postoperative.

The purpose is to determine if the preoperative central endothelial cell density (ECD) in triple (phacoemulsification plus intraocular lens implantation plus DSAEK) and non-triple Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) procedures have a relationship with the 5-year postoperative ECD or percent Endothelial Cell Loss (ECL).Out of 986 consecutive DSAEK surgeries for Fuchs dystrophy, 241 eyes had 5-year ECD measurements available. Endothelial cell densities were then evaluated against preoperative ECDs to obtain measures of ECL. Triple and non-triple procedures were isolated and compared independently.One hundred eighty two eyes had undergone a triple procedure and 59 had not. The mean ECD at 5 years was 1560 ±â€Š648 cells/mm for triples and 1483 ±â€Š621 cells/mm for non-triples (P = .42). Endothelial Cell loss was 44.4% ±â€Š21.7% and 44.4% ±â€Š22.0%, respectively for eyes that underwent a triple or non-triple (P = .99). There was a moderate, but significant correlation between preoperative ECD and the ECD at 5 years after DSAEK for both triples (r = 0.39, P < .001), and non-triples (r = 0.32, P = .01), respectively.In Descemets stripping automated endothelial keratoplasty grafts, higher preoperative donor ECD was correlated with higher ECD at 5 years postoperatively but was unaffected by a concurrent cataract surgery in the triple procedure.

Donor DMEK Tissue Characteristics: Association With Rebubble Rate and 6-Month Endothelial Cell Loss.

PURPOSE: To determine whether specific donor characteristics influence postoperative rebubble rate and 6-month endothelial cell loss (ECL) in Descemet membrane endothelial keratoplasty (DMEK). METHODS: A retrospective analysis of a consecutive series of 857 DMEK surgeries using eye bank-prepared donor tissue was performed between September 2013 and April 2018. DMEK graft characteristics including donor age, preoperative endothelial cell density (ECD), preservation time, death-to-preservation time, and donor diabetes status were analyzed for correlation with rebubble rate and 6-month postoperative ECL. Subgroup analyses of donor age, preoperative ECD, preservation time, death-to-preservation time, preparation-to-surgery time, and diabetes severity were also performed. Statistically significant relationships between donor characteristics and rebubble rate or 6-month postoperative ECL were determined using Pearson correlation, one-way analysis of variance, t test, and χ analysis. RESULTS: The overall rate of rebubble after 857 surgeries performed by 7 surgeons during the study period was 12.6%. There was no significant relationship between postoperative rebubble rate and donor age, preoperative ECD, preservation time, death-to-preservation time, preparation-to-surgery time, or donor diabetes status. The subgroup analysis of these characteristics also yielded no significant relationship with rebubble rate. There was also no significant relationship between 6-month postoperative ECL and analyzed donor factors. CONCLUSIONS: Donor characteristics such as higher donor age, lower preoperative ECD (<2500), longer preservation time, and donor diabetes did not increase the rebubble rate or the 6-month ECL after DMEK. These results indicate that common surgeon preferences for donor tissues that are younger, fresher, with higher cell count, and without diabetes do not translate into superior postsurgical outcomes.

The Last 200 Surgeon-Loaded Descemet Membrane Endothelial Keratoplasty Tissue Versus the First 200 Preloaded Descemet Membrane Endothelial Keratoplasty Tissue.

PURPOSE: The purpose of this study was to compare the clinical outcomes from using eye bank-prepared, endothelium-out preloaded Descemet membrane endothelial keratoplasty (DMEK) tissue with those obtained with endothelium-out surgeon-loaded DMEK tissue using the same surgical technique at 1 site. METHODS: This study retrospectively reviewed 400 consecutive cases of DMEK from March 2016 to April 2018. The last 200 cases using surgeon-loaded tissue were compared with the first 200 cases using preloaded tissue. Statistical analysis was performed using the Wilcoxon signed-rank test, binomial logistic regression, Kruskal-Wallis 1-way analysis of variance, Student t test, or Pearson χ tests. RESULTS: Comparing surgeon-loaded versus preloaded DMEK tissue, respectively, no statistical difference was found in the mean 6-month postoperative values for endothelial cell loss (32.9% ± 18.5% vs. 29.9% ± 16.4%, P = 0.31), best corrected visual acuity (20/26 vs. 20/25, P = 0.54), or change in central corneal thickness (-14.4% ± 8.9% vs. -15.6% ± 11.7%, P = 0.43). The mean 1-year endothelial cell loss was also not significantly different (37.6% ± 17.2% vs. 33.2% ± 14.8%, P = 0.07). Overall, the rebubble rate for surgeon-loaded tissue was 17.5% and 12.5% for preloaded tissue, a statistically nonsignificant difference. Operative outcomes for mean tissue scroll tightness (1-4) and tissue unscroll time (minutes) for surgeon-loaded and preloaded tissue were similar between groups (2.4 vs. 2.2, P = 0.12 and 3.5 vs. 3.3 minutes, P = 0.50). CONCLUSIONS: Tissue that is trephinated, stained, and loaded into an injector by the eye bank and then shipped to the surgeon had no difference in clinical outcomes compared with tissue where the surgeon performs these steps. The safety and speed of using preloaded tissue should be considered by DMEK surgeons.

Intraoperative fibrin formation during Descemet membrane endothelial keratoplasty.

PURPOSE: To describe Descemet membrane endothelial keratoplasty (DMEK) cases complicated by spontaneous intraoperative fibrin formation. METHODS: DMEK surgeries performed at two centers using a standardized technique were reviewed retrospectively for the occurrence of intraoperative fibrin formation. Cases were assessed for recipient medical history, donor age, best spectacle-corrected visual acuity (BSCVA), intraoperative unscrolling time, 6-month endothelial cell loss (ECL), and the course of the mate donor cornea. RESULTS: In this review of 868 cases of standardized DMEK surgery with surgical peripheral iridotomy, 32 eyes of 29 patients (3.7%) were complicated by the formation of intraoperative fibrin formation, including 3 patients that developed fibrin in both eyes. Three of the 32 grafts failed (9.4%). None of the mate corneas transplanted (n = 27) developed complications related to fibrin. The donor age ranged from 51 to 75 years and recipient age ranged from 49 to 82 years (median, 66 years). Unscrolling time ranged from 1 to 105 min (median, 15 min). Nine eyes required one rebubble procedure. No eyes had vision-limiting comorbidities, and the 6-month BSCVA was ≥20/40 in all eyes. Six-month ECL ranged from 19% to 73% (median, 44%). CONCLUSIONS: We conclude that fibrin formation during DMEK surgery is an uncommon but important complication that can make graft manipulation more difficult, and may have deleterious effects on endothelial cell density and graft survival.

Efficacy and Safety of Various Amphotericin B Concentrations on Candida albicans in Cold Storage Conditions.

PURPOSE: To determine the concentration of amphotericin B that would be both effective against Candida albicans contamination and safe for corneal endothelial cells (CECs) in cold storage conditions. METHODS: Triplicate media cultures were inoculated with 10 colony-forming units (CFUs)/mL of C. albicans (American Type Culture Collection 10231), supplemented with amphotericin B (0-20 µg/mL), stored in cold conditions (2°C-8°C) for 72 hours, and analyzed quantitatively for CFUs. C. albicans concentration in each sample was determined initially and after 6, 24, 48, and 72 hours of storage. CEC mitochondrial function (oxygen consumption rate), apoptosis, and necrosis were examined in donor corneas after 7 days of amphotericin B exposure and compared with untreated controls. CEC viability was also examined by calcein-AM staining and Fiji segmentation after 72 hours or 2 weeks of amphotericin B exposure to mimic potential eye bank practices. RESULTS: Amphotericin B concentrations of 1.25, 2.5, and 5.0 µg/mL resulted in 0.47, 1.11, and 1.21 log10 CFU reduction after only 6 hours of cold storage and continued to decrease to 3.50, 3.86, and 4.49 log10 reductions after 72 hours, respectively. By contrast, amphotericin B 0.255 µg/mL showed only 1.01 log10 CFU reduction after 72 hours of incubation. CEC mitochondrial function and viability did not differ in donor corneas exposed to amphotericin B ≤2.59 µg/mL compared with the controls. CONCLUSIONS: Optimal efficacy of amphotericin B against C. albicans is achieved in cold storage conditions at concentrations ≥1.25 µg/mL, and 2.5 µg/mL reduces Candida contamination by >90% after 6 hours of cold storage without sacrificing CEC health.

Patent Blue V as an Alternative Stain for DMEK Grafts: Safety, Stain Retention, and Feasibility.

PURPOSE: To determine whether Patent Blue V (PB) can be used as an alternative dye for staining Descemet membrane endothelial keratoplasty (DMEK) grafts. METHODS: DMEK grafts from donor corneas were stained with 2.5% PB for 4 minutes (n = 2), 2.5% PB for 10 minutes (n = 2), or 0.06% trypan blue (TB) for 4 minutes (n = 1). The stain intensity of the grafts was compared initially and at different time points over a 15-minute period of balanced salt solution wash using a grading scale based on a serial dilution series of PB. Three additional grafts were stained with 2.5% PB for 10 minutes and used in mock surgeries to assess stain retention after injection and manipulation in a donor eye model for 25 minutes. To assess the safety of PB, DMEK grafts were prepared from 10 pairs of corneas where one cornea was stained with 0.06% TB for 4 minutes and the mate cornea was stained with 2.5% PB for 10 minutes. The grafts were preloaded and stored for 5 days in Optisol-GS at 2°C to 8°C, and endothelial cell loss was quantified using Calcein-AM staining and FIJI segmentation by 2 masked readers. RESULTS: PB stain intensities were lighter than TB-stained grafts. Grafts stained with 2.5% PB for 10 minutes retained sufficient color for the 25-minute duration of mock surgery. The average endothelial cell loss for PB versus TB grafts was 21.6% ± 5.3% versus 20.2% ± 5.4% (P = 0.202) as determined by reader 1 and 23.6% ± 4.8% versus 21.2% ± 5.8% (P = 0.092) as determined by reader 2. CONCLUSIONS: PB is a viable alternative dye in DMEK grafts for applications where TB may not be available or approved for use.

Endothelial keratoplasty: The relationship between recipient anterior chamber depth and endothelial cell loss.

PURPOSE: To determine the relationship between anterior chamber depth (ACD) and percent endothelial cell loss (ECL) after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK). METHOD: In 78 eyes receiving triple procedure (DSAEK combined with cataract extraction and posterior chamber intraocular lens (PCIOL) implantation), ACD was measured preoperatively with an intraocular lens (IOL) Master and ECL was calculated with specular microscopy at 6 months, 1, 2, 3, and 4 years postoperatively. ACD and ECL from all 78 eyes were compared using correlation analysis and students t test. Eyes were then separated into 2 groups based on ACD, group 1 with ACD < 3mm and group 2 with ACD ≥ 3mm. Students t test was then performed to compare group 1 and group 2 ECL at 6 months, 1, 2, 3, and 4 years postoperative. RESULTS: Mean ACD for all 78 eyes was 2.93 ±â€Š0.43 mm. Mean ECL was 32.7%, 27.6%, 29.6%, 32.5%, and 37.2% at 6 months, 1, 2, 3, and 4 years. No significant correlation between ACD and ECL was observed at any time point for the combined analysis of 78 eyes (P > .05). At 2 and 4 years postoperative, mean ECL was 32.6% ±â€Š16.1% and 43.0% ±â€Š23.2% in eyes with ACD < 3mm and 25.3% ±â€Š13.0% and 29.6% ±â€Š18.2% in eyes with ACD ≥ 3 mm (P = .041 at 2 years and .008 at 4 years). CONCLUSION: ACD and ECL were not directly correlated; however, there may be a threshold ACD in which shallower anterior chambers preoperatively result in greater donor ECL over time.