Objective: Although anaphylaxis can result in poor outcomes, studies on the factors influencing the biphasic reaction of anaphylaxis have been limited. In this study, we evaluated the clinical information of patients at high risk for the biphasic reaction of anaphylaxis. Methods: This retrospective observational study was conducted in the emergency department (ED) of a single tertiary center. We enrolled patients diagnosed with and treated for anaphylaxis from January 2014 to December 2020. We gathered the electronic medical data of the patients who satisfied the diagnostic criteria for anaphylaxis and were treated with epinephrine. The enrolled patients were divided into those showing either a uniphasic reaction or a biphasic reaction depending on the need for multidose epinephrine. Results: The cohort included 255 patients of anaphylaxis (48.6%, male). Of these patients, 59 (23%) showed a biphasic reaction. Patients displaying a biphasic reaction had a longer median time from their ED visit to the administration of the first dose of epinephrine compared to those showing a uniphasic reaction-8 (4-13) vs. 7 (3-12) minutes. Patients showing a biphasic reaction were statistically associated with a longer time from their visit to the ED to epinephrine administration (odds ratio [OR], 1.073; 95% confidence interval [CI], 1.011-1.140; P=0.021), lower mean arterial pressure (OR, 0.971; 95% CI, 0.951-0.991; P=0.006), lower pulse rate (OR, 0.973; 95% CI, 0.954-0.991; P=0.004), and a lower rate of food allergen (OR, 0.406; 95% CI, 0.169-0.976; P=0.044). Conclusion The delayed administration of epinephrine upon ED arrival was associated with biphasic reactions in addition to lower mean arterial pressure and pulse rate, and exposure to non-food allergen. This study presents evidence supporting the prompt use of epinephrine in patients with anaphylaxis. However, further prospective studies in this regard would be needed.

Purpose: This study investigated the characteristics and treatment outcomes of patients who visited the emergency department due to intoxication and analyzed the impact of the coronavirus disease 2019 (COVID-19) pandemic on their visits. Methods: A retrospective study was conducted using data from the National Emergency Department Information System (NEDIS) on patients who visited the emergency department due to intoxication between January 2014 and December 2020. In total, 277,791 patients were included in the study, and their demographic and clinical data were analyzed. A model was created from 2014 to 2019 and applied to 2020 (i.e., during the COVID-19 pandemic) to conduct a time series analysis distinguishing between unexpected accidents and suicide/self-harm among patients who visited the emergency department. Results: The most common reason for visiting the emergency department was unintentional accidents (48.5%), followed by self-harm/suicide attempts (43.8%). Unexpected accident patients and self-harm/suicide patients showed statistically significant differences in terms of sex, age group, hospitalization rate, and mortality rate. The time series analysis showed a decrease in patients with unexpected accidents during the COVID-19 pandemic, but no change in patients with suicide/self-harm. Conclusion Depending on the intentionality of the intoxication, significant differences were found in the age group, the substance of intoxication, and the mortality rate. Therefore, future analyses of patients with intoxication should be stratified according to intentionality. In addition, the time series analysis of intentional self-harm/suicide did not show a decrease in 2010 in the number of patients, whereas a decrease was found for unintentional accidents.

Objective: Early prediction of the multiple organ dysfunction syndrome (MODS) and providing early innovative treatment may improve outcomes in patients with severe trauma. Lactate and serum albumin levels, which are widely used markers predicting the severity of critically ill patients, tend to diverge during clinical deterioration. This study aimed to evaluate the clinical utility of the lactate/albumin ratio (LAR) as a predictive factor for MODS and 30-day mortality in patients with severe trauma. Methods: This retrospective, observational cohort study was performed with patients prospectively integrated into a critical pathway for trauma. We analyzed severe trauma patients (Injury Severity Score≥16) admitted to the emergency department (ED), between January 1, 2011, and May 31, 2017. The outcomes were the development of MODS and 30-day mortality. Results: In total, 348 patients were enrolled, of which 18 (5.2%) died within 96 hours of ED admission, and the remaining 330 patients (94.8%) were evaluated for the development of MODS. An increase in the LAR at admission (odds ratio, 1.618; P=0.028) was an independent predictor of MODS development. The area under the receiver operating characteristic curve (0.755) and Harrell's C-index (0.783) showed that LAR could predict MODS and 30-day mortality. Conclusion Initial LAR is an independent predictor of MODS development in patients with severe trauma. Our study results suggest that an elevated LAR can be a useful prognostic marker in patients with severe trauma.

Purpose: Given the morphological characteristics of schistocytes, thrombotic microangiopathy (TMA) score can be beneficial as it can be automatically and accurately measured. This study aimed to investigate whether serial TMA scores until 48 h post admission are associated with clinical outcomes in patients undergoing targeted temperature management (TTM) after out-of-hospital cardiac arrest (OHCA). Materials and Methods: We retrospectively evaluated a cohort of 185 patients using a prospective registry. We analyzed TMA scores at admission and after 12, 24, and 48 hours. The primary outcome measures were poor neurological outcome at discharge and 30-day mortality. Results: Increased TMA scores at all measured time points were independent predictors of poor neurological outcomes and 30-day mortality, with TMA score at time-12 showing the strongest correlation [odds ratio (OR), 3.008; 95% confidence interval (CI), 1.707–5.300; p<0.001 and hazard ratio (HR), 1.517; 95% CI, 1.196–1.925; p<0.001]. Specifically, a TMA score ≥2 at time-12 was closely associated with an increased predictability of poor neurological outcomes (OR, 6.302; 95% CI, 2.841–13.976; p<0.001) and 30-day mortality (HR, 2.656; 95% CI, 1.675–4.211; p<0.001). Conclusion Increased TMA scores predicted neurological outcomes and 30-day mortality in patients undergoing TTM after OHCA. In addition to the benefit of being serially measured using an automated hematology analyzer, TMA score may be a helpful tool for rapid risk stratification and identification of the need for intensive care in patients with return of spontaneous circulation after OHCA.

Purpose: A pilot project using epinephrine at the scene under medical control is currently underway in Korea. This study aimed to determine whether prehospital epinephrine administration is associated with improved survival and neurological outcomes in out-of-hospital cardiac arrest (OHCA) patients who received epinephrine during cardiopulmonary resuscitation (CPR) in the emergency department. Materials and Methods: This retrospective observational study used a nationwide multicenter OHCA registry. Patients were classified into two groups according to whether they received epinephrine at the scene or not. The associations between prehospital epinephrine use and outcomes were assessed using propensity score (PS)-matched analysis. Multivariable logistic regression analysis was performed using PS matching. The same analysis was repeated for the subgroup of patients with non-shockable rhythm. Results: PS matching was performed for 1084 patients in each group. Survival to discharge was significantly decreased in the patients who received prehospital epinephrine [odds ratio (OR) 0.415, 95% confidence interval (CI) 0.250–0.670, p<0.001]. However, no statistical significance was observed for good neurological outcome (OR 0.548, 95% CI 0.258–1.123, p=0.105). For the patient subgroup with non-shockable rhythm, prehospital epinephrine was also associated with lower survival to discharge (OR 0.514, 95% CI 0.306–0.844, p=0.010), but not with neurological outcome (OR 0.709, 95% CI 0.323–1.529, p=0.382). Conclusion Prehospital epinephrine administration was associated with decreased survival rates in OHCA patients but not statistically associated with neurological outcome in this PS-matched analysis. Further research is required to investigate the reason for the detrimental effect of epinephrine administered at the scene.

Objective: Aneurysmal subarachnoid hemorrhage (SAH) is a common emergency condition, resulting in high morbidity and mortality. The delta neutrophil index (DNI), which reflects the fraction of circulating immature granulocytes, is significantly associated with systemic inflammation after infection or sterile injury. Aneurysmal SAH also leads to systemic inflammation after a brain injury. This study aimed to evaluate the relationship between the DNI and poor neurologic outcomes in patients with aneurysmal SAH. Methods: We retrospectively identified patients (>18 years old) with aneurysmal SAH consecutively admitted to the emergency department (ED) between January 1, 2011, and November 30, 2018. The diagnosis of aneurysmal SAH was confirmed using clinical and radiological findings. DNI was determined at 0, 24, 48, and 72 hours after ED admission. The primary result was a poor neurologic outcome using the modified Rankin scale. Results: A total of 352 patients with aneurysmal SAH were included in this study. A multivariable logistic regression model revealed that a high value of DNI at 24 hours after ED admission was a strong independent predictor of poor neurologic outcome upon discharge (odds ratio [OR], 1.471; 95% confidence interval [CI], 1.081-2.001; P=0.014). Among patients with aneurysmal SAH, DNI >1.0% at 24 hours was significantly associated with poor neurologic outcomes upon discharge (OR, 5.037; 95% CI, 3.153-8.044; P<0.001). Conclusion DNI can be determined easily and rapidly after ED admission without any additional cost or time burden. A high DNI value at 24 hours after ED admission is significantly associated with a poor neurologic outcome upon discharge among patients with aneurysmal SAH.

Objective: This study aimed to investigate the risk factors of post-contrast acute kidney injury (PAKI) and the usefulness of the Mehran score for predicting PAKI in patients who underwent contrast-enhanced abdominopelvic computed tomography (CE-APCT) in the emergency department (ED). Methods: This was a retrospective observational study. Patients who underwent CE-APCT and had a follow-up creatinine test within 72 hours in the period January to June, 2017, were enrolled for the study. PAKI is defined as a 25% or higher increase in the level of serum creatinine (sCr) within 72 hours after receiving contrast, or an increase in the level of sCr by 0.5 mg/dL. The odds ratio (OR) of risk factors and incidence of PAKI after CE-APCT were analyzed according to the Mehran risk group, and compared to expected incidence. Univariate and multivariate logistic regression analyses were performed for each risk factor. Results: A total of 1,718 patients were enrolled in the study. Of these, 203 patients (11.8%) developed PAKI, and 2 patients (0.1%) required dialysis. Hypotension (systolic blood pressure <80 mmHg) was determined to be statistically significant (P=0.029; OR, 3.181) among the considered risk factors of PAKI. In the group having abnormal estimatedglomerular filtration rate (<90 mL/min/1.73 m2), the age and rate of the underlying disease (congestive heart failure, hypertension) was found to be higher in the PAKI group. The receiver operating curve of Mehran score (area under the curve: 0.521 in model A, 0.520 in model B) was statistically not significant in the univariate analysis. A higher Mehran score was associated with a higher proportion of patients who underwent prophylactic treatment. Conclusion There are no definite useful risk factors, including the Mehran score, for predicting PAKI in patients who underwent contrast-enhanced computed tomography in the ED.

Objective: Aneurysmal subarachnoid hemorrhage (SAH) is a common emergency condition, resulting in high morbidity and mortality. The delta neutrophil index (DNI), which reflects the fraction of circulating immature granulocytes, is significantly associated with systemic inflammation after infection or sterile injury. Aneurysmal SAH also leads to systemic inflammation after a brain injury. This study aimed to evaluate the relationship between the DNI and poor neurologic outcomes in patients with aneurysmal SAH. Methods: We retrospectively identified patients (>18 years old) with aneurysmal SAH consecutively admitted to the emergency department (ED) between January 1, 2011, and November 30, 2018. The diagnosis of aneurysmal SAH was confirmed using clinical and radiological findings. DNI was determined at 0, 24, 48, and 72 hours after ED admission. The primary result was a poor neurologic outcome using the modified Rankin scale. Results: A total of 352 patients with aneurysmal SAH were included in this study. A multivariable logistic regression model revealed that a high value of DNI at 24 hours after ED admission was a strong independent predictor of poor neurologic outcome upon discharge (odds ratio [OR], 1.471; 95% confidence interval [CI], 1.081-2.001; P=0.014). Among patients with aneurysmal SAH, DNI >1.0% at 24 hours was significantly associated with poor neurologic outcomes upon discharge (OR, 5.037; 95% CI, 3.153-8.044; P<0.001). Conclusion DNI can be determined easily and rapidly after ED admission without any additional cost or time burden. A high DNI value at 24 hours after ED admission is significantly associated with a poor neurologic outcome upon discharge among patients with aneurysmal SAH.

Objective: This study aimed to investigate the risk factors of post-contrast acute kidney injury (PAKI) and the usefulness of the Mehran score for predicting PAKI in patients who underwent contrast-enhanced abdominopelvic computed tomography (CE-APCT) in the emergency department (ED). Methods: This was a retrospective observational study. Patients who underwent CE-APCT and had a follow-up creatinine test within 72 hours in the period January to June, 2017, were enrolled for the study. PAKI is defined as a 25% or higher increase in the level of serum creatinine (sCr) within 72 hours after receiving contrast, or an increase in the level of sCr by 0.5 mg/dL. The odds ratio (OR) of risk factors and incidence of PAKI after CE-APCT were analyzed according to the Mehran risk group, and compared to expected incidence. Univariate and multivariate logistic regression analyses were performed for each risk factor. Results: A total of 1,718 patients were enrolled in the study. Of these, 203 patients (11.8%) developed PAKI, and 2 patients (0.1%) required dialysis. Hypotension (systolic blood pressure <80 mmHg) was determined to be statistically significant (P=0.029; OR, 3.181) among the considered risk factors of PAKI. In the group having abnormal estimatedglomerular filtration rate (<90 mL/min/1.73 m2), the age and rate of the underlying disease (congestive heart failure, hypertension) was found to be higher in the PAKI group. The receiver operating curve of Mehran score (area under the curve: 0.521 in model A, 0.520 in model B) was statistically not significant in the univariate analysis. A higher Mehran score was associated with a higher proportion of patients who underwent prophylactic treatment. Conclusion There are no definite useful risk factors, including the Mehran score, for predicting PAKI in patients who underwent contrast-enhanced computed tomography in the ED.

Purpose: The purpose of this study was to investigate the cause of acute fatal poisoning and the time of death by analyzing the National Emergency Department Information System (NEDIS) of South Korea. Methods: The NEDIS data from 2014 to 2018 excluding non-medical visits were used for this study. The patients with acute poisoning were extracted using diagnostic codes. The toxic substances were classified into pharmaceuticals, pesticides, gases, artificial poisonous substances, and natural toxic substances. Patients were classified according to the time of death, place of death, and region. In each case, the most causative substances of poisoning were identified. Results: There were 380,531 patients including poisoning-related diagnoses, of which 4,148 (1.1%) died, and the WHO age-standardized mortality rate was 4.8 per 100,000. Analysis of 2,702 death patients whose primary diagnosis was acute poisoning, the most common cause of poisoning death was pesticides (62%), followed by therapeutic drugs, gas, and artificial toxic substances. Herbicides were the most common pesticides at 64.5%. The proportion of mortality by time, hyperacute (<6 h) 27.9%, acute (6-24 h) 32.6%, subacute (1-7 d) 29.7%, and delayed period (>7 d) were 9.8%. Conclusion This study suggests that the most common cause of poisoning death was pesticides, and 60% of deaths occurred within 24 hours. The 71% of mortality from pesticides occurred within 6-24 hours, but mortality from gas was mostly within 6 hours. According to the geographic region, the primary cause of poisoning death was varied to pesticides or pharmaceuticals.