Quantitative analysis of apparent diffusion coefficients to predict neurological prognosis in cardiac arrest survivors: an observational derivation and internal-external validation study.

BACKGROUND: This study aimed to validate apparent diffusion coefficient (ADC) values and thresholds to predict poor neurological outcomes in out-of-hospital cardiac arrest (OHCA) survivors by quantitatively analysing the ADC values via brain magnetic resonance imaging (MRI). METHODS: This observational study used prospectively collected data from two tertiary academic hospitals. The derivation cohort comprised 70% of the patients randomly selected from one hospital, whereas the internal validation cohort comprised the remaining 30%. The external validation cohort used the data from another hospital, and the MRI data were restricted to scans conducted at 3 T within 72-96 h after an OHCA experience. We analysed the percentage of brain volume below a specific ADC value at 50-step intervals ranging from 200 to 1200 × 10-6 mm2/s, identifying thresholds that differentiate between good and poor outcomes. Poor neurological outcomes were defined as cerebral performance categories 3-5, 6 months after experiencing an OHCA. RESULTS: A total of 448 brain MRI scans were evaluated, including a derivation cohort (n = 224) and internal/external validation cohorts (n = 96/128, respectively). The proportion of brain volume with ADC values below 450, 500, 550, 600, and 650 × 10-6 mm2/s demonstrated good to excellent performance in predicting poor neurological outcomes in the derivation group (area under the curve [AUC] 0.89-0.91), and there were no statistically significant differences in performances among the derivation, internal validation, and external validation groups (all P > 0.5). Among these, the proportion of brain volume with an ADC below 600 × 10-6 mm2/s predicted a poor outcome with a 0% false-positive rate (FPR) and 76% (95% confidence interval [CI] 68-83) sensitivity at a threshold of > 13.2% in the derivation cohort. In both the internal and external validation cohorts, when using the same threshold, a specificity of 100% corresponded to sensitivities of 71% (95% CI 58-81) and 78% (95% CI 66-87), respectively. CONCLUSIONS: In this validation study, by consistently restricting the MRI types and timing during quantitative analysis of ADC values in brain MRI, we observed high reproducibility and sensitivity at a 0% FPR. Prospective multicentre studies are necessary to validate these findings.

Association of ultra-early diffusion-weighted magnetic resonance imaging with neurological outcomes after out-of-hospital cardiac arrest.

BACKGROUND: This study aimed to investigate the association between ultra-early (within 6 h after return of spontaneous circulation [ROSC]) brain diffusion-weighted magnetic resonance imaging (DW-MRI) and neurological outcomes in comatose survivors after out-of-hospital cardiac arrest. METHODS: We conducted a registry-based observational study from May 2018 to February 2022 at a Chungnam national university hospital in Daejeon, Korea. Presence of high-signal intensity (HSI) (PHSI) was defined as a HSI on DW-MRI with corresponding hypoattenuation on the apparent diffusion coefficient map irrespective of volume after hypoxic ischemic brain injury; absence of HSI was defined as AHSI. The primary outcome was the dichotomized cerebral performance category (CPC) at 6 months, defined as good (CPC 1-2) or poor (CPC 3-5). RESULTS: Of the 110 patients (30 women [27.3%]; median (interquartile range [IQR]) age, 58 [38-69] years), 48 (43.6%) had a good neurological outcome, time from ROSC to MRI scan was 2.8 h (IQR 2.0-4.0 h), and the PHSI on DW-MRI was observed in 46 (41.8%) patients. No patients in the PHSI group had a good neurological outcome compared with 48 (75%) patients in the AHSI group. In the AHSI group, cerebrospinal fluid (CSF) neuron-specific enolase (NSE) levels were significantly lower in the group with good neurological outcome compared to the group with poor neurological outcome (20.1 [14.4-30.7] ng/mL vs. 84.3 [32.4-167.0] ng/mL, P < 0.001). The area under the curve for PHSI on DW-MRI was 0.87 (95% confidence interval [CI] 0.80-0.93), and the specificity and sensitivity for predicting a poor neurological outcome were 100% (95% CI 91.2%-100%) and 74.2% (95% CI 62.0-83.5%), respectively. A higher sensitivity was observed when CSF NSE levels were combined (88.7% [95% CI 77.1-95.1%]; 100% specificity). CONCLUSIONS: In this cohort study, PHSI findings on ultra-early DW-MRI were associated with poor neurological outcomes 6 months following the cardiac arrest. The combined CSF NSE levels showed higher sensitivity at 100% specificity than on DW-MRI alone. Prospective multicenter studies are required to confirm these results.

Quantitative analysis of early apparent diffusion coefficient values from MRIs for predicting neurological prognosis in survivors of out-of-hospital cardiac arrest: an observational study.

BACKGROUND: This study aimed to quantitatively analyse ultra-early brain diffusion-weighted magnetic resonance imaging (DW-MRI) findings to determine the apparent diffusion coefficient (ADC) threshold associated with neurological outcomes in comatose survivors of out-of-hospital cardiac arrest (OHCA). METHODS: This retrospective study included adult survivors of comatose OHCA who underwent DW-MRI imaging scans using a 3-T MRI scanner within 6 h of the return of spontaneous circulation (ROSC). We investigated the association between neurological outcomes and ADC values obtained through voxel-based analysis on DW-MRI. Additionally, we constructed multivariable logistic regression models with pupillary light reflex (PLR), serum neuron-specific enolase (NSE), and ADC values as independent variables to predict poor neurological outcomes. The primary outcome was poor neurological outcome 6 months after ROSC, determined by the Cerebral Performance Category 3-5. RESULTS: Overall, 131 patients (26% female) were analysed, of whom 74 (57%) showed poor neurological outcomes. The group with a poor neurological outcome had lower mean whole brain ADC values (739.1 vs. 787.1 × 10-6 mm/s) and higher percentages of voxels with ADC below threshold in all ranges (250-1150) (all P < 0.001). The mean whole brain ADC values (area under the receiver operating characteristic curve [AUC] 0.83) and the percentage of voxels with ADC below 600 (AUC 0.81) had the highest sensitivity of 51% (95% confidence interval [CI] 39.4-63.1; cut-off value ≤ 739.2 × 10-6 mm2/s and > 17.2%, respectively) when the false positive rate (FPR) was 0%. In the multivariable model, which also included PLR, NSE, and mean whole brain ADC values, poor neurological outcome was predicted with the highest accuracy (AUC 0.91; 51% sensitivity). This model showed more accurate prediction and sensitivity at an FPR of 0% than did the combination of PLR and NSE (AUC 0.86; 30% sensitivity; P = 0.03). CONCLUSIONS: In this cohort study, early voxel-based quantitative ADC analysis after ROSC was associated with poor neurological outcomes 6 months after cardiac arrest. The mean whole brain ADC value demonstrated the highest sensitivity when the FPR was 0%, and including it in the multivariable model improved the prediction of poor neurological outcomes.

Early ECMO initiation in the emergency department for refractory hypoxemic respiratory failure caused by NaDCC intoxication.

We describe a case of acute respiratory failure caused by inhalation of gas formed from a reaction of intentional dissolution of sodium dichloroisocyanurate (NaDCC) tablets in water. A patient had refractory respiratory failure despite the use of conventional therapy, including lung-protective mechanical ventilation. Early veno-venous extracorporeal membrane oxygenation (VV-ECMO) support was initiated in the emergency department (ED). The patient was weaned from ECMO on hospital day 6 and discharged from the ICU on hospital day 27. Cases of severe inhalation injury with acute respiratory failure refractory to conventional treatments and mechanical ventilator support may benefit from VV-ECMO. Literature on early initiation of ED-VV-ECMO in NaDCC-induced refractory respiratory failure is rare. This case may be used as a guide in the management of subsequent cases as it shows that early initiation of ED-VV-ECMO was beneficial to the patient.

Efficacy of cardiopulmonary resuscitation performance while wearing a powered air-purifying respirator.

BACKGROUND: The use of personal protective equipment for respiratory infection control during cardiopulmonary resuscitation (CPR) is a physical burden to healthcare providers. The duration for which CPR quality according to recommended guidelines can be maintained under these circumstances is important. We investigated whether a 2-min shift was appropriate for chest compression and determined the duration for which chest compression was maintained in accordance with the recommended guidelines while wearing personal protective equipment. METHODS: This prospective crossover simulation study was performed at a single center from September 2020 to October 2020. Five indicators of CPR quality were measured during the first and second sessions of the study period. All participants wore a Level D powered air-purifying respirator (PAPR), and the experiment was conducted using a Resusci Anne manikin, which can measure the quality of chest compressions. Each participant conducted two sessions. In Session 1, the sequence of 2 min of chest compressions, followed by a 2-min rest, was repeated twice; in Session 2, the sequence of 1-min chest compressions followed by a 1-min rest was repeated four times. RESULTS: All 34 participants completed the study. The sufficiently deep compression rate was 65.9 ± 31.1% in the 1-min shift group and 61.5 ± 30.5% in the 2-min shift group. The mean compression depth was 52.8 ± 4.3 mm in the 1-min shift group and 51.0 ± 6.1 mm in the 2-min shift group. These two parameters were significantly different between the two groups. There was no significant difference in the other values related to CPR quality. CONCLUSIONS: Our findings indicated that 1 min of chest compressions with a 1-min rest maintained a better quality of CPR while wearing a PAPR.

Lactate dehydrogenase to albumin ratio as a prognostic factor in lower respiratory tract infection patients.

PURPOSE: To verify the role of lactate dehydrogenase to albumin (LDH/ALB) ratio as an independent prognostic factor for mortality due to the lower respiratory tract infection (LRTI) in the emergency department (ED). METHODS: We reviewed the electronic medical records of patients who were admitted to the ED for the management of LRTI between January 2018 and December 2020. Initial vital signs, laboratory data, and patient severity scores in the ED were collected. The LDH/ALB ratio was compared to other albumin-based ratios (blood urea nitrogen to albumin ratio, C-reactive protein to albumin ratio, and lactate to albumin ratio) and severity scales (pneumonia severity index, modified early warning score, CURB-65 scores), which are being used as prognostic factors for in-hospital mortality. Multivariable logistic regression was performed to identify independent risk factors. RESULTS: The LDH/ALB ratio was higher in the non-survivor group than in the survivor group (median [interquartile range]: 217.6 [160.3;312.0] vs. 126.4 [100.3;165.1], p < 0.001). In the comparison of the area under the receiver operating characteristic curve (AUC) for predicting in-hospital mortality, the AUC of the LDH/ALB ratio (0.808, 95% confidence interval: 0.757-0.842, p < 0.001) was wider than other albumin-based ratios and severity scales, except the blood urea nitrogen to albumin ratio. In the multivariable logistic regression analysis, the LDH/ALB ratio independently affected in-hospital mortality. CONCLUSION: The LDH/ALB ratio may serve as an independent prognostic factor for in-hospital mortality in patients with LRTI.

Utility of the blood urea nitrogen to serum albumin ratio as a prognostic factor of mortality in aspiration pneumonia patients.

PURPOSE: This study aimed to determine whether the blood urea nitrogen to serum albumin (B/A) ratio is a useful prognostic factor of mortality in patients with aspiration pneumonia. METHODS: The study included patients with aspiration pneumonia who had been admitted to our hospital via the emergency department (ED) between January 1, 2014 and December 31, 2018. The 28-day mortality after the ED visits was the primary end point of this study. The data of the survivors and non-survivors were compared. RESULTS: A final diagnosis of aspiration pneumonia was made for 443 patients during the study period. Significant differences were observed in age, respiratory rate, albumin levels, total protein levels, blood urea nitrogen levels, C-reactive protein levels, glucose, and Charlson comorbidity index scores between the survivor and non-survivor groups. Moreover, the B/A ratio was significantly higher in the non-survivor group than that in the survivor group. The area under the curve for the B/A ratio was 0.70 [95% confidence interval (CI) 0.65-0.74], 0.71 for the PSI (95% CI 0.67-0.76), 0.64 for CURB-65 (95% CI 0.60-0.69), and 0.65 for albumin (95% CI 0.60-0.70) on the receiver operating characteristic curve for predicting mortality within 28 days of the ED visit. Multivariable logistic regression analysis revealed that the B/A ratio (>7, OR 3.40, 95% CI 1.87-6.21, P < 0.001) was associated with mortality within 28 days of the ED visit. CONCLUSION: The B/A ratio is a simple and potentially useful prognostic factor of mortality in aspiration pneumonia patients.

Clinical relationship between blood concentration and clinical symptoms in aconitine intoxication.

BACKGROUND: Aconitine is well-known for its potential analgesic, anti-inflammatory, and circulation promoting effects and has been widely used as a folk medicine in South Korea. Owing to its extremely toxic nature and relatively low safety margin, intoxication is sometimes fatal. The toxic compound mainly affects the central nervous system, heart, and muscle, resulting in cardiovascular complications. PURPOSE: To determine the exact relationship between blood concentration of aconitine and clinical manifestation. BASIC PROCEDURES: The National Forensic Service (NFS) was commissioned to assist in a quantitative analysis of highly toxic aconitine and corresponding blood concentrations by analyzing the body fluids of three patients who were suspected of aconitine poisoning. MAIN FINDINGS: Aconitine blood values tested by the NFS showed that patients with a blood concentration below a certain level developed symptoms slowly and showed a high severity of clinical manifestation. There was no correlation between blood concentration and symptoms or ECG results. CONCLUSIONS: In case of suspected aconitine poisoning, an emergency care department should be visited, even with symptomatic improvement, and the patient should be monitored for at least 24 h, depending on the level of recovery and changes in ECG results.

Cerebrospinal Fluid Lactate Levels, Brain Lactate Metabolism and Neurologic Outcome in Patients with Out-of-Hospital Cardiac Arrest.

BACKGROUND/OBJECTIVE: Cerebrospinal fluid (CSF) and serum lactate levels were assessed to predict poor neurologic outcome 3 months after return of spontaneous circulation (ROSC). We compared arterio-CSF differences in the lactate (ACDL) levels between two neurologic outcome groups. METHODS: This retrospective observational study involved out-of-hospital cardiac arrest (OHCA) survivors who had undergone target temperature management. CSF and serum samples were obtained immediately (lactate0), and at 24 (lactate24), 48 (lactate48), and 72 (lactate72) h after ROSC, and ACDL was calculated at each time point. The primary outcome was poor 3-month neurologic outcome (cerebral performance categories 3-5). RESULTS: Of 45 patients, 27 (60.0%) showed poor neurologic outcome. At each time point, CSF lactate levels were significantly higher in the poor neurologic outcome group than in the good neurologic outcome group (6.97 vs. 3.37, 4.20 vs. 2.10, 3.50 vs. 2.00, and 2.79 vs. 2.06, respectively; all P < 0.05). CSF lactate's prognostic performance was higher than serum lactate at each time point, and lactate24 showed the highest AUC values (0.89, 95% confidence interval, 0.75-0.97). Over time, ACDL decreased from - 1.30 (- 2.70-0.77) to - 1.70 (- 3.2 to - 0.57) in the poor neurologic outcome group and increased from - 1.22 (- 2.42-0.32) to - 0.64 (- 2.31-0.15) in the good neurologic outcome group. CONCLUSIONS: At each time point, CSF lactate showed better prognostic performance than serum lactate. CSF lactate24 showed the highest prognostic performance for 3-month poor neurologic outcome. Over time, ACDL decreased in the poor neurologic outcome group and increased in the good neurologic outcome group.

The Association Between Neurological Prognosis and the Degree of Blood-Brain Barrier Disruption in Cardiac Arrest Survivors Who Underwent Target Temperature Management.

BACKGROUND: This study aimed to compare day-specific associations of blood-brain barrier (BBB) disruption with neurological outcome in survivors of out-of-hospital cardiac arrest (OHCA) treated with target temperature management (TTM) and lumbar drainage. METHODS: This retrospective single-center study included 68 survivors of OHCA who underwent TTM between April 2018 and December 2019. The albumin quotient (QA) was calculated as QA = albumincerebrospinal fluid/albuminserum immediately (day 1) and 24 (day 2), 48 (day 3), and 72 h (day 4) after the return of spontaneous circulation. The degree of BBB disruption was weighted using the following scoring system: QA value of 0.007 or less (normal), QA value greater than 0.007-0.01 (mild), QA value greater than 0.01-0.02 (moderate), and QA value greater than 0.02 (severe). Points were assigned as follows: 0 (normal), 1 (mild), 4 (moderate), and 9 (severe). Neurological outcome was determined at 6 months after the return of spontaneous circulation, as well as cerebral performance category (CPC), dichotomized as good (CPC score 1-2) and poor (CPC score 3-5) outcome. RESULTS: We enrolled 68 patients (48 men, 71%); 37 (54%) patients had a poor neurological outcome. The distributions of poor versus good outcomes at 6 months in patients with moderate and severe BBB disruption were 19 of 22 (80%) vs. 18 of 46 (50%) on day 1, 31 of 37 (79%) vs. 6 of 31 (32%) on day 2, 32 of 37 (81%) vs. 5 of 31 (30%) on day 3, and 32 of 39 (85%) vs. 5 of 29 (30%) on day 4 (P < 0.001), respectively. Using receiver operating characteristic analyses, optimal cutoff values (sensitivity, specificity) of QA levels for the prediction of neurological outcome were as follows: day 1, greater than 0.009 (56.8%, 87.1%); day 2, greater than 0.012 (81.1%, 87.1%); day 3, greater than 0.013 (83.8%, 87.1%); day 4, greater than 0.013 (86.5%, 87.1%); the sum of all time points, greater than 0.039 (89.5%, 79.4%); and scoring system, greater than 9 (91.9%, 87.1%). CONCLUSIONS: In this proof of concept study, QA was associated with poor neurological outcome in survivors of OHCA treated with TTM with no contraindication to lumbar drainage. A large multicenter prospective study is needed to validate the utility of BBB disruption as a prognosticator of neurological outcome.

Analysis of Factors Affecting Emergency Physicians' Attitudes toward Deceased Organ & Tissue Donation.

BACKGROUND: This study aimed to investigate differences in knowledge, and attitudes toward deceased organ and tissue donation of emergency physicians. Additionally, we analyzed factors affecting the attitudes toward deceased organ and tissue donation. METHODS: We conducted a survey of specialists and residents registered with the Korean Society of Emergency Medicine in December 2020. The respondents' sex, age, position, personal registration for organ donation, experience of soliciting organ donation, participation in related education, knowledge, and attitude about brain death organ donation, and attitude toward stopping life-sustaining treatments were investigated. According to the characteristics of the respondents (specialists or residents, experience and education on organ and tissue donation), their knowledge and attitude toward deceased organ donation were compared. Stepwise hierarchical multiple regression analysis was used to investigate the factors affecting the attitudes toward deceased organ and tissue donation. RESULTS: Of the total 428 respondents, there were 292 emergency medicine specialists and 136 medical residents. Specialists and those who registered or wished to donate organs had higher knowledge and attitude scores regarding deceased organ and tissue donation. Those who had experience recommending organ and tissue donation more than 6 times had higher knowledge scores on deceased organ and tissue donation and higher overall scores in attitude. Those who received education from the Korean Organ Donation Agency had higher knowledge scores. Specialists, and those who wished to donate or had registered as organ donors and had a higher life-sustaining treatment attitude score and knowledge about deceased organ and tissue donation, had more positive attitudes toward deceased organ and tissue donation. CONCLUSION: For more potential deceased organ and tissue donors to be referred for donation, there should be continuous education for emergency physicians on brain-dead organ and tissue donation-related knowledge and procedures. In addition, institutional or systematic improvements that can lead to organ donation when deciding on the withdrawal of life-sustaining treatment should be considered.

Measuring global impairment of cerebral perfusion using dynamic susceptibility contrast perfusion-weighted imaging in out-of-hospital cardiac arrest survivors: A prospective preliminary study.

BACKGROUND AND PURPOSE: This study aimed to assess the global impairment and prognostic performance of cerebral perfusions (CP) measured by dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) in out-of-hospital cardiac arrest (OHCA) patients after sustained restoration of spontaneous circulation (ROSC). MATERIALS AND METHODS: This is a single-centre, prospective observational study. OHCA patients performed DSC-PWI within 8 h after ROSC were enrolled. We quantified the CP parameters, such as cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), time to peak (TTP), and time to maximum of the residue function (Tmax) either by normalization or arterial input function (AIF). The primary and secondary outcomes were survival to discharge and comparison of prognostic performance between CP parameters and serum neuron-specific enolase (NSE) using area under the receiver operating characteristic (AUROC) and sensitivity values. RESULTS: Thirty-one patients were included in this study. CBV and TTP quantified by normalization, and MTT and Tmax quantified by AIF showed significantly higher CP values in the non-survival group (p = 0.02, 0.03, 0.02, and <0.01, respectively). Their AUROCs and 100% specific sensitivities were 0.74/25.0%, 0.60/33.3%, 0.75/56.3%, and 0.79/43.8%, respectively. MTT quantified by AIF showed sensitivity in predicting mortality at an early stage of PCA care, comparable with NSE. CONCLUSION: Hyperaemia and delayed CP were generally observed in OHCA patients regardless of outcomes. MTT and Tmax quantified by AIF have prognostic performance in predicting mortality, comparable with NSE. Further prospective multicentre studies are required to confirm our results.

A novel predictive tool for prognosis in elderly patients with urinary tract infection: Modified PRACTICE.

PURPOSE: We evaluated whether combining the serum albumin level and the Prediction Rule for Admission policy in Complicated urinary Tract InfeCtion LEiden (PRACTICE) class could be a prognostic predictor in elderly patients with urinary tract infection (UTI). METHODS: We retrospectively included adult patients (age ≥ 65 years) with UTI who were hospitalized in the emergency department (ED) between January 1, 2014 and December 31, 2018. We graded the serum albumin level and classified the PRACTICE score; the modified PRACTICE was defined as the sum of the albumin level grade and the PRACTICE class. We comparatively assessed the predictive value for in-hospital mortality and admission to the intensive care unit (ICU) in survivor and non-survivor groups. RESULTS: In total, the study analysis included 1159 patients, and in-hospital mortality was 3.4% (n = 39). The modified PRACTICE score (4.0 [1.4] vs 6.1 [1.2], p < 0.001) was significantly increased in the non-survivor group. The area under the curve value of factors associated with in-hospital mortality were the Modified Early Warning Score (MEWS) 0.57 (95% CI 0.54-0.60), albumin 0.83 (95% CI 0.81-0.85), PRACTICE 0.71 (95% CI 0.69-0.74), and the modified PRACTICE 0.86 (95% CI 0.84-0.88). Factors associated with ICU admission were MEWS 0.65 (95% CI 0.62-0.68), albumin 0.66 (95% CI 0.64-0.69), PRACTICE 0.66 (95% CI 0.63-0.68), and the modified PRACTICE 0.72 (95% CI 0.69-0.74). CONCLUSION: The modified PRACTICE score can be a useful prognostic predictor in elderly patients with UTI.

Interleukin-6 as a Potential Predictor of Neurologic Outcomes in Cardiac Arrest Survivors Who Underwent Target Temperature Management.

BACKGROUND: Serum interleukin-6 (IL-6) is a cytokine released in response to an inflammatory stimulus or tissue injury. IL-6 levels are known to increase in patients with brain injury. OBJECTIVE: We investigated the neurologic outcomes associated with serum IL-6 levels in out-of-hospital cardiac arrest (OHCA) survivors who underwent target temperature management (TTM). METHODS: This was a prospective single-center observational study from October 2018 to November 2019 in a cohort of 45 patients. Serum inflammatory markers (IL-6, C-reactive protein, white blood cells) were determined in samples obtained immediately and at 24, 48, and 72 h after the return of spontaneous circulation (ROSC). Poor neurologic outcome, defined as Cerebral Performance Category 3-5 at 3 months after cardiac arrest, was the primary outcome. RESULTS: Among 45 patients enrolled in this study, 25 (55.6%) patients showed a poor neurologic outcome. IL-6 levels were significantly higher in the poor neurologic outcome group immediately (IL-60) after ROSC. The area under the curve (AUC) value of IL-60 was the highest among those of serum IL-6, CRP, and WBC at each time point. The IL-6 levels for predicting poor neurologic outcome had a sensitivity of 75.0%, with 80% specificity at IL-60. The AUC of IL-60 was 0.810 (95% confidence interval 0.664-0.913), with a cutoff value of 346.7 pg mL-1. CONCLUSIONS: Serum IL-6 level immediately after ROSC was a highly specific and sensitive marker for the 3-month poor neurologic outcome, and may be a useful early predictive marker of neurologic outcome in OHCA survivors treated with TTM.

Serial measurement of glyphosate blood concentration in a glyphosate potassium herbicide-intoxicated patient: A case report.

INTRODUCTION: This report describes changes in blood and urine concentrations of glyphosate potassium over time and their correlations with clinical symptoms in a patient with acute glyphosate potassium poisoning. CASE REPORT: A 67-year-old man visited the emergency center after ingesting 250 mL of a glyphosate potassium-based herbicide 5 h before. He was alert but presented with nausea, vomiting, and bradyarrhythmia with atrial fibrillation (tall T waves). Laboratory findings revealed a serum potassium level of 6.52 mEq/L. After treatment with an injection of calcium gluconate, insulin with glucose, bicarbonate, and an enema with polystyrene sulfonate, the patient's serum potassium level normalized and the bradyarrhythmia converted to a normal sinus rhythm. During admission, the blood and urine concentration of glyphosate and urine aminomethylphosphonic acid (AMPA, a glyphosate metabolite) was measured at regular time intervals. The patient's glyphosate blood concentration on admission was 11.48 mg/L, and it had decreased rapidly by 16 h and maintained about 1mgl/L by 70 h after admission. Urine glyphosate and AMPA levels had also decreased rapidly by 6 h after admission. DISCUSSION: Glyphosate potassium poisoning causes hyperkalemia. Blood concentrations of glyphosate were decreased rapidly by 16 h after admission, and urine concentrations were also decreased by 6 h after admission.

Reversible Acute Blindness in Suspected Metformin-Associated Lactic Acidosis.

BACKGROUND: Metformin is commonly used for the treatment of type 2 diabetes mellitus. Renal insufficiency is one of the contraindications for its use. Inadvertent prescription in patients with renal insufficiency may lead to metformin-associated lactic acidosis (MALA), which is associated with a high risk of mortality. Consequently, the early recognition and management of MALA is essential. CASE REPORT: We present the case of a 68-year-old man who had reversible blindness resulting from severe lactic acidosis. On presentation, he was alert, oriented, and had no complaints except mild abdominal discomfort and blindness. He denied any history of trauma or drug abuse. The results of the laboratory studies showed severe metabolic acidosis with a high anion gap and increased levels of serum creatinine. There were no predisposing ocular or neurologic lesions that could have induced the blindness. Although the blood levels of methanol, ethanol, and metformin were not estimated, correction of acidosis and hemodialysis led to a complete recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Rarely, transient blindness may occur in patients with fatal severe metabolic acidosis. Evaluation for the presence of metabolic acidosis and a detailed medical history are essential in the management of acute blindness in such patients.

The learning curve in diagnosing acute appendicitis with emergency sonography among novice emergency medicine residents.

PURPOSE: Ultrasonography (US) has good accuracy for diagnosing appendicitis when it is performed by emergency physicians. This study aimed to determine the amount of experience that is required to achieve competency in this field. METHODS: Three novice emergency medicine residents completed a 1-day training course regarding the US diagnosis of appendicitis. Then, they performed appendix US in the emergency department on patients complaining of right lower quadrant pain. All included patients also underwent computed tomography or US performed by a board-certified radiologist, to confirm the emergency US diagnosis. The agreement between the diagnoses of novices and experts was evaluated. RESULTS: A total of 266 patients were included, and the overall Cohen's kappa coefficient was 0.77 (95% confidence interval [CI]: 0.69-0.84). The kappa value of first 20 cases was 0.49 (95% CI: 0.27-0.71). It increased rapidly during evaluation of the first 20 cases. After the first 20 cases, the kappa coefficient was 0.84 (95% CI: 0.77-0.92). The sensitivity and specificity values for the first 20 cases were 64.3% (95% CI: 77.6%-90.7%) and 84.4% (95% CI: 85.4%-95.4%), respectively. After the first 20 cases, the sensitivity and specificity values increased to 90.9% (95% CI: 83.4%-95.8%) and 93.5% (95% CI: 87.0%-97.3%), respectively. CONCLUSIONS: A minimum of 20 cases are needed to achieve competency in emergency US diagnosis of acute appendicitis.

Life-threatening hemothorax due to azygos vein rupture after chest compression during cardiopulmonary resuscitation.

Hemothorax is not an uncommon cardiopulmonary resuscitation(CPR)­related complication. But hemothorax related to azygos vein injury (AVI) is a rare condition following blunt chest trauma, with no report of CPR-related AVI in the literature. We present a case of azygosve in rupture in a middle-aged woman after repeated chest compression during 1 hour of CPR. She eventually presented with massive hemothorax due to azygos vein rupture diagnosed by computed tomography (CT). When faced with a patient with massive hemothorax after chest compression, azygos vein rupture should be considered as a complication.

Usefulness of the compression-adjusted ventilation for adequate ventilation rate during cardiopulmonary resuscitation.

BACKGROUND: To perform high-quality cardiopulmonary resuscitation (CPR), high-quality chest compression and ventilation support should be performed. However, many providers still have not maintained an adequate ventilation rate but hyperventilated during CPR. Thus, this study was conducted to verify that the compression-adjusted ventilation (CAV) would be a more accurate ventilation method compared with the conventional ventilation (CV). METHODS: Volunteer medical students and emergency medical services personnel were recruited. They were randomly divided into either the CV group or the CAV group. In the CV group, participants performed ventilation with estimation of the rate of 8 to 10 per minute (1 ventilation/6-8 seconds). In the CAV group, the ventilation rate was adjusted in line with the compression rate (compression:ventilation, 12:1). In each group, 2-rescuer adult CPR was performed on a manikin, which was intubated with an endotracheal tube, during a period of 8 minutes. The compression rate and the ventilation rate were recorded during CPR. RESULTS: Data on 56 medical students and 41 emergency medical services personnel were analyzed. No significant difference was observed in compression rate (P =.817); however, median (interquartile range) ventilation rate differed significantly between the CV and CAV groups (8.79 [2.19] per minute vs 9.25 [1.07] per minute, P = .016). In addition, compared with the CV group, adequacy of ventilation rate was better in the CAV group (47.9% vs 85.7%, P < .001). CONCLUSION: In comparison with the CV, the CAV is a more accurate method for maintenance of an adequate ventilation rate.

Blood-brain barrier permeability for the first 24 hours in hypoxic-ischemic brain injury following cardiac arrest.

BACKGROUND: This study aimed to explore the changes in blood-brain barrier (BBB) permeability and intracranial pressure (ICP) for the first 24 h after the return of spontaneous circulation (ROSC) and their association with injury severity of cardiac arrest. METHODS: This prospective study analysed the BBB permeability assessed using the albumin quotient (Qa) and ICP every 2 h for the first 24 h after ROSC. The injury severity of cardiac arrest was assessed using Pittsburgh Cardiac Arrest Category (PCAC) scores. The primary outcome was the time course of changes in the BBB permeability and ICP for the first 24 h after ROSC and their association with injury severity (PCAC scores of 1-4). RESULTS: Qa and ICP were measured 274 and 197 times, respectively, in 32 enrolled patients. Overall, the BBB permeability increased progressively over time after ROSC, and then it increased significantly at 18 h after ROSC compared with the baseline. In contrast, the ICP revealed non-significant changes for the first 24 h after ROSC. The Qa in the PCAC 2 group was < 0.01, indicating normal or mild BBB disruption at all time points, whereas the PCAC 3 and 4 groups showed a significant increase in BBB permeability at 14 and 22 h, and 12 and 14 h after ROSC, respectively. CONCLUSION: BBB permeability increased progressively over time for the first 24 h after ROSC despite post-resuscitation care, whereas ICP did not change over time. BBB permeability has an individual pattern when stratified by injury severity.