Currently, no effective therapy and potential target have been elucidated for preventing myocardial ischemia and reperfusion injury (I/R). We hypothesized that the administration of recombinant klotho (rKL) protein could attenuate the sterile inflammation in peri-infarct regions by inhibiting the extracellular release of high mobility group box-1 (HMGB1). This hypothesis was examined using a rat coronary artery ligation model. Rats were divided into sham, sham+ rKL, I/R, and I/R+ rKL groups (n = 5/group). Administration of rKL protein reduced infarct volume and attenuated extracellular release of HMGB1 from peri-infarct tissue after myocardial I/R injury. The administration of rKL protein inhibited the expression of pro-inflammatory cytokines in the peri-infarct regions and significantly attenuated apoptosis and production of intracellular reactive oxygen species by myocardial I/R injury. Klotho treatment significantly reduced the increase in the levels of circulating HMGB1 in blood at 4 h after myocardial ischemia. rKL regulated the levels of inflammation-related proteins. This is the first study to suggest that exogenous administration of rKL exerts myocardial protection effects after I/R injury and provides new mechanistic insights into rKL that can provide the theoretical basis for clinical application of new adjunctive modality for critical care of acute myocardial infarction.

BACKGROUND AND PURPOSE: The use of invasive cerebral angiography with CTA for active treatment of patients with suspected ischemic strokes has been increasing recently. This study aimed to identify the incidence of postcontrast acute kidney injury using baseline renal function when CTA and cerebral angiography were performed sequentially. MATERIALS AND METHODS: This retrospective observational study evaluated adults (18 years of age or older) with ischemic stroke who underwent CTA and cerebral angiography sequentially between 2010 and 2018. The incidence of postcontrast acute kidney injury was determined using the baseline estimated glomerular filtration rate. The value of the baseline estimated glomerular filtration rate at which the occurrence of postcontrast acute kidney injury increased was also determined. RESULTS: Postcontrast acute kidney injury occurred in 57/601 (9.5%) patients. Those with a baseline estimated glomerular filtration rate of <30 mL/min/1.73 m² showed a higher incidence of acute kidney injury. Age, chronic kidney disease, medication (nonsteroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, β blockers, statins, and insulin) use following contrast media exposure, and serum albumin affected the incidence of postcontrast acute kidney injury. The incidence of postcontrast acute kidney injury increased when the baseline estimated glomerular filtration rate was <43 mL/min/1.73 m². CONCLUSIONS: Patients with low baseline renal function had the highest incidence of postcontrast acute kidney injury after CTA and cerebral angiography, but no fatal adverse effects were documented. Thus, patients suspected of having a stroke should be actively managed with respect to neurovascular function.

Red blood cell transfusion is frequently prescribed in the emergency department for patients with gastrointestinal bleeding (GIB), but the association of time to transfusion with patient outcome has not been thoroughly evaluated. A retrospective cohort study analyzed adult patient data with GIB who visited the emergency department of single university-affiliated hospital between January 2016 and April 2022. The associations of time to transfusion and patient outcomes, 30-day and in-hospital mortality, were assessed. Among a total of 2,284 patients, 1,395 (61.1%) received red blood cell transfusion within 4 h of emergency department admission. Analysis of the time to transfusion showed the association between late transfusion (transfusion after 4 h) and the risk of 30-day mortality (adjusted hazard ratio, 1.65, 95% CI 1.17-2.32, p = .004) and in-hospital mortality (adjusted odds ratio 1.71, 95% CI 1.24-2.35, p < .001). Subgroup analysis revealed that the association between time to transfusion and 30-day mortality was found only in those with upper GIB, nonvariceal bleeding and a low haemoglobin level (<7.5 g/dL). Early transfusion was associated with higher 30-day transfusion demand, while no associations with length of stay and adverse transfusion reaction were noted. In this study, a longer time to red blood cell transfusion was associated with an increased risk of 30-day and in-hospital mortality of patients with GIB, especially in those with upper GIB, nonvariceal bleeding and a low haemoglobin level. In the emergency department, prompt red blood cell transfusion decisions for patients with GIB may improve patient outcomes.

Objective This study aimed to introduce a novel negative pressure aerosol box (Carrycure Isolator) and to test its efficiency and limitations, with the hope of suggesting improvements and further directions.Methods A novel aerosol box (Carrycure Isolator) was invented. A single-center, randomized, crossover simulation study of 28 emergency medicine physicians was designed. Three trials of each participant using an intubation manikin were conducted, including intubation without the aerosol box (trial A), intubation with the aerosol box (trial B), and intubation with the aerosol box after familiarization (trial C). The primary endpoint was the time to intubation. The secondary endpoints were first-attempt success, number of attempts, percentage of glottic opening score, and Cormack-Lehane view. Collected data were statistically analyzed for their significance.Results The median times to intubation of trials A, B, and C were 30.5 (interquartile range [IQR], 28.0–40.0 seconds), 59.0 (IQR, 50.0–75.5 seconds), and 34.0 seconds (IQR, 30.5–47.0 seconds), respectively. Post hoc analysis showed that the time to intubation in trial B was significantly longer than that in trial A (P<0.05), while that the time to intubation in trial C was significantly shorter than that in trial B (P<0.05). Results concerning secondary endpoints showed similar patterns. Participants reported performing intubation with Carrycure Isolator to be relatively difficult, necessitating significant arm movement and view restrictions while increasing their time to intubation.Conclusion Physicians took a longer time to intubate a manikin using the Carrycure Isolator, a novel negative pressure aerosol box. However, the time was improved after a period of familiarization.

Objective The efficacy of previously developed respiratory barrier enclosures to limit healthcare workers’ exposure to aerosols from COVID-19 patients remains unclear; in addition, the design of these devices is unsuitable for transportation or other emergency procedures. Therefore, we developed a novel negative pressure respiratory isolator to improve protection from patient-generated aerosols and evaluated its protective effect in conversion to systemic isolator. Methods This in vitro study simulated droplets by nebulizing 1% glycerol + 99% ethanol solution. We performed cardiopulmonary resuscitation (CPR) and converted a respiratory barrier enclosure into a systemic isolator with a respiratory barrier as well as a respiratory barrier with negative pressure generator (NPG), which were compared with control and room air. During the procedure, particles were counted for 30 seconds and the count was repeated 10 times. Results During CPR, the total number of particles in the respiratory barrier with NPG (280,529; interquartile range [IQR], 205,263–359,195; P=0.970) was similar to that in the control (308,789; IQR, 175,056–473,276). Using NPG with a respiratory barrier reduced the number of particles to 27,524 (IQR, 26,703– 28,905; P=0.001). Particle number during conversion of the respiratory barrier into a systemic isolator was also lower than in the control (25,845; IQR, 19,391– 29,772; P=0.001). Conclusion The novel isolator was converted to a systemic isolator without air leakage. The aerosol-blocking effect of the isolator was quantified using a particle counter during CPR. Further studies comparing the barrier effect of isolators within various pressure differentials are warranted.

Objective Emergency department (ED) triage systems are used to classify the severity and urgency of emergency patients, and Korean medical institutions use the Korean Triage and Acuity Scale (KTAS). During the COVID-19 pandemic, appropriate treatment for emergency patients was delayed due to various circumstances, such as overcrowding of EDs, lack of medical workforce resources, and increased workload on medical staff. The purpose of this study was to evaluate the accuracy of the KTAS in predicting the urgency of emergency patients during the COVID-19 pandemic. Methods This study retrospectively reviewed patients who were treated in the ED during the pandemic period from January 2020 to June 2021. Patients were divided into COVID-19–screening negative (SN) and COVID-19–screening positive (SP) groups. We compared the predictability of the KTAS for urgent patients between the two groups. Results From a total of 107,480 patients, 62,776 patients (58.4%) were included in the SN group and 44,704 (41.6%) were included in the SP group. The odds ratios for severity variables at each KTAS level revealed a more evident discriminatory power of the KTAS for severity variables in the SN group (P<0.001). The predictability of the KTAS for severity variables was higher in the SN group than in the SP group (area under the curve, P<0.001). Conclusion During the pandemic, the KTAS had low accuracy in predicting patients in critical condition in the ED. Therefore, in future pandemic periods, supplementation of the current ED triage system should be considered in order to accurately classify the severity of patients.