Development of antibody-detection ELISA based on beta-bungarotoxin for evaluation of the neutralization potency of equine plasma against Bungarus multicinctus in Taiwan.

Animal testing has been the primary approach to assess the neutralization potency of antivenom for decades. However, the necessity to sacrifice large numbers of experimental animals during this process has recently raised substantial welfare concerns. Furthermore, the laborious and expensive nature of animal testing highlights the critical need to develop alternative in vitro assays. Here, we developed an antibody-detection enzyme-linked immunosorbent assay (ELISA) technique as an alternative approach to evaluate the neutralization potency of hyperimmunized equine plasma against B. multicinctus, a medically important venomous snake in Taiwan. Firstly, five major protein components of B. multicinctus venom, specifically, α-BTX, ß-BTX, γ-BTX, MTX, and NTL, were isolated. To rank their relative medical significance, a toxicity score system was utilized. Among the proteins tested, ß-BTX presenting the highest score was regarded as the major toxic component. Subsequently, antibody-detection ELISA was established based on the five major proteins and used to evaluate 55 hyperimmunized equine plasma samples with known neutralization potency. ELISA based on ß-BTX, the most lethal protein according to the toxicity score, exhibited the best sensitivity (75.6 %) and specificity (100 %) in discriminating between high-potency and low-potency plasma, supporting the hypothesis that highly toxic proteins offer better discriminatory power for potency evaluation. Additionally, a phospholipase A2 (PLA2) competition process was implemented to eliminate the antibodies targeting toxicologically irrelevant domains. This optimization greatly enhanced the performance of our assay, resulting in sensitivity of 97.6 % and specificity of 92.9 %. The newly developed antibody-detection ELISA presents a promising alternative to in vivo assays to determine the neutralization potency of antisera against B. multicinctus during the process of antivenom production.

Detection of cytotoxins by sandwich-ELISA for discrimination of cobra envenomation and indication of necrotic severity.

Snake envenoming is both a healthcare and socioeconomic problem for developing countries and underserved communities. In Taiwan, clinical management of Naja atra envenomation is a major challenge, since cobra venom-induced symptoms are usually confused with hemorrhagic snakebites and current antivenom treatments do not effectively prevent venom-induced necrosis for which early surgical debridement should be administered. Identification and validation of biomarkers of cobra envenomation is critical for progress in setting a realistic goal for snakebite management in Taiwan. Previously, cytotoxin (CTX) was determined as one of potential biomarker candidates; however, its ability to discriminate cobra envenoming remains to be verified, especially in clinical practice. In this study, we selected a monoclonal single-chain variable fragment (scFv) and a polyclonal antibody to develop a sandwich enzyme-linked immunosorbent assay (ELISA) for CTX detection, which successfully recognized CTX from N. atra venom over that from other snake species. Using this specific assay, the CTX concentration in envenoming mice was shown to remain consistent in about 150 ng/mL during the 2-hour post-injection period. The measured concentration was highly correlated with the size of local necrosis in mouse dorsal skin, which the correlation coefficient is about 0.988. Furthermore, our ELISA method displayed 100 % of specificity and sensitivity in discriminating cobra envenoming among snakebite victims through CTX detection and the level of CTX in victim plasma was ranged from 5.8 to 253.9 ng/mL. Additionally, patients developed tissue necrosis at plasma CTX concentrations higher than 150 ng/mL. Thus, CTX not only serves as a verified biomarker for discrimination of cobra envenoming but also a potential indicator of severity of local necrosis. In this context, detection of CTX may facilitate reliable identification of envenoming species and improve snakebite management in Taiwan.

Taiwan cobra envenoming: serum venom concentration before and after specific treatment and relationship with debridement of necrotic wound tissue.

Background: Bivalent freeze-dried neurotoxic (FN) antivenom has been the primary treatment since the 1980s for Taiwan cobra (Naja atra) envenomation in Taiwan. However, envenomation-related wound necrosis is a significant problem after cobra snakebites. In the present study, we analyzed the changes in serum venom concentration before and after antivenom administration to discover their clinical implications and the surgical treatment options for wound necrosis. Methods: The patients were divided into limb swelling and wound necrosis groups. The clinical outcome was that swelling started to subside 12 hours after antivenom treatment in the first group. Serum venom concentrations before and after using antivenoms were measured to assess the antivenom's ability to neutralize the circulating cobra venom. The venom levels in wound wet dressing gauzes, blister fluids, and debrided tissues were also investigated to determine their clinical significance. We also observed the evolutional changes of wound necrosis and chose a better wound debridement timing. Results: We prospectively enrolled 15 Taiwan cobra snakebite patients. Males accounted for most of this study population (n = 11, 73%). The wound necrosis group received more antivenom doses than the limb swelling group (4; IQR:2-6 vs 1; IQR:1-2, p = 0.05), and less records of serum venom concentrations changed before/after antivenom use (p = 0.0079). The necrotic wound site may release venom into circulation and cause more severe envenomation symptoms. Antivenom can efficiently diminish limb swelling in cobra bite patients. However, antivenom cannot reduce wound necrosis. Patients with early debridement of wound necrosis had a better limb outcome, while late or without debridement may have long-term hospital stay and distal limb morbidity. Conclusions: Antivenom can efficiently eliminate the circulating cobra venom in limb swelling patients without wound necrosis. Early debridement of the bite site wound and wet dressing management are suggestions for preventing extended tissue necrosis and hospital stay.

Wound Infection of Snakebite from Venomous Protobothrops mucrosquamatus, Viridovipera stejnegeri and Naja atra in Taiwan: Validation of BITE and Cobra BITE Scoring Systems and their Bacteriological Differences in Wound Cultures.

Patients bitten by Protobothrops mucrosquamatus, Viridovipera stejnegeri, and Naja atra develop different degrees of wound infection. This study validated BITE and Cobra BITE scoring systems that we established previously. Bacteriological studies of patients with wound infection were conducted. The operating characteristic curves and area under the curve (AUC) and wound infection rates were compared between the derivation set (our previous study patient population) and the validation set (new patient cohorts enrolled between June 2017 and May 2021). No significant differences in the AUC for both the BITE (0.84 vs. 0.78, p = 0.27) and Cobra BITE (0.88 vs. 0.75, p = 0.21) scoring systems were observed between the derivation and validation sets. Morganella morganii and Enterococcus faecalis were the two most commonly detected bacteria in the microbiological study. More bacterial species were cultured from N. atra-infected wounds. Antibiotics such as amoxicillin with clavulanic acid, oxacillin, and ampicillin may not be suitable for treating patients with P. mucrosquamatus, V. stejnegeri, and N. atra bites in Taiwan. Carbapenem, third-generation cephalosporins, and fluoroquinolone may be superior alternatives.

Clinical characteristics of new psychoactive substances: A multicenter study.

BACKGROUND: New psychoactive substances (NPS) are synthetic alternatives to illicit drug abuse that are not under international control but may pose a public health threat. Moreover, the symptoms and signs of NPS users may be quite variable. This study aimed to figure out the clinical characteristics of NPS users presented to the emergency department (ED). METHODS: A total of 1385 cases were tested via urine toxicity screening from March 25, 2019, to January 28, 2020, in six medical centers, and ten hospitals, in Taiwan. A total of 123 non-NPS cases and 77 NPS-use cases were enrolled in this study. We compared the patient data-vital signs, presentation, co-morbidities, behaviors, symptoms, electrocardiograms, laboratory data, length of stays-and outcomes of NPS users and non-NPS drug users. RESULTS: NPS users were 5.7 years younger than the non-NPS drug users (37 vs. 42.7 years, p = 0.022). Presently, NPS users had a 2.6-fold (27.2%) higher rate of suicide and a 2.9-fold (11.7%) greater possibility of violence than non-NPS drug users. Moreover, in NPS users, eye-opening was affected at a scale of 3.1 versus 3.4 (p = 0.048) in non-NPS drug users in the evaluation of consciousness and they experienced a 4.3-fold greater feeling of palpitation (p = 0.024) and had 8.1-fold higher chance of presenting facial flush (p = 0.032) than non-NPS drug users. CONCLUSION: NPS users are relatively younger, are more likely to experience facial flush and palpitation and engage in more self-harm, violence, and suicide than non-NPS drug users. Physicians need to pay attention to people who have altered, bizarre mental statuses with the clinical characteristics described above.

The Clinical Usefulness of Taiwan Bivalent Freeze-Dried Hemorrhagic Antivenom in Protobothrops mucrosquamatus- and Viridovipera stejnegeri-Envenomed Patients.

Snakebites from Protobothrops mucrosquamatus (Taiwan habus) and Viridovipera stejnegeri (green bamboo vipers) account for the most venomous snakebites in Taiwan. The bivalent freeze-dried hemorrhagic (FH) antivenom is employed to treat these two snakebite patients without a strict clinical trial. We evaluated the clinical usefulness of Taiwan bivalent freeze-dried hemorrhagic (FH) antivenom in Taiwan habu- and green bamboo viper-envenomed patients. We checked ELISA- based serum venom antigen levels before and after FH antivenom to evaluate FH's ability to neutralize patients' serum snake venom and its usefulness in reducing limb swelling after snakebites. Patients who had higher serum venom antigen levels had more severe limb swelling. Of the 33 enrolled patients, most of their snake venom antigen levels were undetected after the appliance of antivenom. Most enrolled patients (25/33) had their limb swelling subside within 12 h after antivenom treatment. The failure to reduce limb swelling was probably due to an inadequate antivenom dose applied in more severely envenomated patients. Our data indicate the feasibility of the FH antivenom in effectively eliminating venom and resolving the affected limb swelling caused by Taiwan habu and green bamboo viper bites.

Clinical Presentations and Predictors of In-Hospital Mortality in Illicit Drug Users in the New Psychoactive Substances (NPS) Endemic Era in Taiwan.

Predictors of mortality in illicit drug users involving Novel Psychoactive Substances (NPS) and multiple substances have not been elucidated. We aimed to define predictors of mortality in the NPS endemic era's illicit drug users to strengthen patient care in emergency treatment. This was a retrospective study. LC-MS/MS-confirmed positive illicit drug users who visited the emergency departments (ED) of six medical systems were enrolled. Demographic information, physical examinations, and laboratory data were abstracted for mortality analysis. There were 16 fatalities in 355 enrolled patients. The most frequently used illicit drugs were amphetamines, followed by opioids, cathinones, and ketamine. The most frequently detected cathinones among the 16 synthetic cathinones were eutylone, followed by mephedrone. The combined use of cathinones and ketamine was most commonly observed in our results. Univariate analysis revealed that the mortality patients were older, with deep coma, faster heart rate and respiratory rate, lower blood pressures and O2 room air saturation, more seizures, abnormal breath sounds, and had urine incontinence compared to the survivor patients. The mortality patients also had acute kidney injury, higher potassium, blood sugar, liver function test, and lactate level. The results of multiple logistic regression demonstrated that SBP < 90 mmHg, dyspnea, blood sugar > 140 mg/dl, and HCO3 < 20.6 mmHg were independent predictors of in-hospital mortality. Regardless of the pattern of the use of illicit drugs, the predictors allow for risk stratification and determining the optimal treatment.

Risk factors associated with peri-intubation cardiac arrest in the emergency department.

BACKGROUND: Peri-intubation cardiac arrest is an uncommon, serious complication following endotracheal intubation in the emergency department. Although several risk factors have been previously identified, this study aimed to comprehensively identify risk factors associated with peri-intubation cardiac arrest. METHODS: This retrospective, nested case-control study conducted from January 1, 2016 to December 31, 2020 analyzed variables including demographic characteristics, triage, and pre-intubation vital signs, medications, and laboratory data. Univariate analysis and multivariable logistic regression models were used to compare clinical factors between the patients with peri-intubation cardiac arrest and patients without cardiac arrest. RESULTS: Of the 6983 patients intubated during the study period, 5130 patients met the inclusion criteria; 92 (1.8%) patients met the criteria for peri-intubation cardiac arrest and 276 were age- and sex-matched to the control group. Before intubation, systolic blood pressure and diastolic blood pressure were lower (104 vs. 136.5 mmHg, p < 0.01; 59.5 vs. 78 mmHg, p < 0.01 respectively) and the shock index was higher in the patients with peri-intubation cardiac arrest than the control group (0.97 vs. 0.83, p < 0.0001). Cardiogenic pulmonary edema as an indication for intubation (adjusted odds ratio [aOR]: 5.921, 95% confidence interval [CI]: 1.044-33.57, p = 0.04), systolic blood pressure < 90 mmHg before intubation (aOR: 5.217, 95% CI: 1.484-18.34, p = 0.01), and elevated lactate levels (aOR: 1.012, 95% CI: 1.002-1.022, p = 0.01) were independent risk factors of peri-intubation cardiac arrest. CONCLUSIONS: Patients with hypotension before intubation have a higher risk of peri-intubation cardiac arrest in the emergency department. Future studies are needed to evaluate the influence of resuscitation before intubation and establish airway management strategies to avoid serious complications.

Management and Prognosis of Snake Envenomation Among Pediatric Patients: A National Database Study.

Background: Snakebites constitute a common medical emergency in tropical and subtropical regions. Pediatric snake envenomation is a special category that has not been well studied. This study investigated the management and prognostic factors of snake envenomation in children using a Taiwanese national database. Methods: This observational study used the National Health Insurance database of all pediatric snake envenomation patients treated from 2005 to 2009. Patients' demographic data, antivenom types and doses, medical and surgical interventions, and prognostic variables were collected. Comparisons were made according to the envenomation types, age groups, and whether the patients were hospitalized using univariate and multivariate methods. Results: A total of 106 patients' data were collected. Of the patients, 73 (68.9%) were male, 62 (58.5%) were under the age of 12, 69 (65.1%) received intravenous (IV) antibiotic treatment, 38 (35.9%) were hospitalized, 5 (4.72%) required surgical intervention, and none died. Compared with non-hospitalized patients, the patients who required hospitalization were more likely to have suffered hemorrhagic envenomation ( p = 0.035), receive IV antibiotic treatment ( p = 0.0078), and require surgical intervention ( p = 0.005). In the multivariate analysis, hemorrhagic envenomation was an independent predictor for hospitalization (odds ratio: 3.47, 95% confidence interval: 1.18-10.21) after adjusting for other covariates. No significant differences were observed between age groups in total antivenom usage ( p = 0.2880), IV antibiotic usage ( p = 0.3190), hospitalization ( p = 0.3988), and surgical intervention ( p = 0.1874). Conclusions: In this Taiwanese population-based national database study, antivenom treatment of pediatric snakebite patients resulted in zero mortality and a low surgical intervention rate. Patients with hemorrhagic envenomation were associated with a higher probability of hospitalization.

Comparison of clinical characteristics between meth/amphetamine and synthetic cathinone users presented to the emergency department.

BACKGROUND: Synthetic cathinones (SC) are popular new psychoactive substances that produce sympathomimetic toxicity. Meth/amphetamine and SC have similar chemical structures and pharmacological effects. We aimed to compare the clinical characteristics between meth/amphetamine and SC users presenting to the emergency department (ED). METHODS: This retrospective observational cohort study included patients who presented to six EDs from May 2017 to April 2021 with symptoms that related to recreational drug use and whose urine toxicology tests were positive only for meth/amphetamine or SC through liquid chromatography-tandem mass spectrometry. RESULTS: There were 379 patients who tested positive only for meth/amphetamine (MA group), and 87 patients tested positive only for SC (SC groups). Patients in the MA group were older than those in the SC group (median (IQR); MA: 37.0 (30-43.7), SC: 25.0 (21.0-32.7), p < 0.001). There were no significant between-group differences in the sex distribution and initial chief complaints. Compared with the MA group, the SC group had more cases of tachycardia (≥ 135/min; MA: 29 (8.2%), SC:16 (19.0%), p = 0.0031) and hyperthermia (≥ 38 °C; MA: 31 (8.2%), SC:18 (20.7%), p = 0.001). Besides, the SC group had significantly higher levels of creatinine kinase (CK, IU/L; MA: 263 (115-601), SC: 497 (206-9216), p = 0.008) as well as a higher risk of rhabdomyolysis (CK > 1000; MA:32 (8.4%), SC: 16 (18.4%), p = 0.006) and severe rhabdomyolysis (CK > 10,000; MA:10 (2.6%), SC:10 (11.5%), p = 001). Multivariable logistic regression analyses indicated SC group in comparison with the MA group (adjusted odds ratio: 2.732, 95% confidence interval: 1. 250-5.972, p = 0.012) was an association with the risk of rhabdomyolysis. CONCLUSION: Our findings demonstrate that tachycardia, hyperthermia, and rhabdomyolysis were more common among cathinone users than among meth/amphetamine users presented to EDs.

Gender differences in clinical characteristics of emergency department patients involving illicit drugs use with analytical confirmation.

BACKGROUND: To compare gender differences in socio-demographics, clinical manifestations, and laboratory test results of individuals who visited emergency departments (EDs) involving drug use. METHODS: We retrospectively collected the data from 10 hospitals in Taiwan on drug-related ED visits from May 2017 to December 2020. We then examined the gender differences in their socio-demographics, clinical manifestations, urine toxicological results, and other laboratory tests results using chi-square or multivariable logistic regression. RESULTS: Among individuals with drug-related ED visits, there were 546 (73.7%) men and 195 (26.3%) women. The most commonly used drugs were meth/amphetamine, followed by synthetic cathinones, and ketamine and its analogs. Compared to men, women were younger (32.03 ± 10.86 vs. 36.51 ± 10.84 years, p < 0.001) and more likely to use new psychoactive substances (NPS) (p = 0.011). Men were more likely to have human immunodeficiency virus infection (p < 0.001), whereas women were more likely to report psychiatric comorbidities (p = 0.003). Women were less likely to have aggressive behaviors (odds ratio (OR): 0.59, 95% CI: 0.39-0.88). After adjusting for socio-demographics and drug types, women were still less likely to have aggressive behaviors than men (adjusted OR: 0.59, 95% CI: 0.38-0.93). The likelihood of rhabdomyolysis and intensive care unit admission was higher in men (p < 0.001). CONCLUSION: We found considerable gender differences in clinical characteristics among ED-visiting drug users, which could offer valuable information for the future development of more tailored gender-specific drug prevention and treatment strategies.

The Clinical Presentations of Nitrous Oxide Users in an Emergency Department.

Today, the concomitant abuse of nitrous oxide (N2O) and illicit drugs is evident and problematic. However, there are few reports regarding the clinical manifestations of N2O users when they present to the emergency department (ED). The purpose of this study was to describe the clinical presentations, the associated illicit substances used in combination, and the outcomes in N2O users visiting the ED. This was a retrospective observational cohort study. All N2O adult users admitted to the ED at Linkou Chang Gung Memorial Hospital between 2012 and 2020 were included. Demographic variables, clinical symptoms, and examination results were collected from medical records. Univariate comparisons were conducted between pure N2O users and combined illicit drug users. A total of 40 patients were included, 24 of which were pure N2O users. Limb weakness and numbness accounted for the majority of chief complaints. Neurologic symptoms were the most common clinical manifestations (90%). A more severe ED triage level, faster heart rate, greater agitation, and cardiovascular symptoms were significantly noted in combined illicit drug users. In ED, limb numbness/weakness should arouse physicians' awareness of patients using N2O. Combined use of N2O and illicit drugs can cause great harm to health.

Emergency department visits due to new psychoactive substances and other illicit drugs in Taiwan: preliminary results of the Taiwan Emergency Department Drug Abuse Surveillance (TEDAS) project.

INTRODUCTION: The use of new psychoactive substances (NPSs) has markedly increased worldwide; thus, it is important to monitor NPS-related effects. The Taiwan Emergency Department Drug Abuse Surveillance (TEDAS) project aims to assess the patterns of recreational drug use in patients presenting to emergency departments (EDs) across the country. Here, we report the preliminary results of this project. METHODS: This observational study included the collection and analysis of urine samples and assessment of the clinical presentation of patients from 79 EDs across Taiwan. Clinical features were recorded through a questionnaire filled by attending doctors or nurses who collected urine samples for clinical diagnosis. Urine samples were analyzed for 110 drugs and metabolites using electrospray ionization liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: Between February and November 2019, a total of 2649 patients were enrolled for urine drug analysis. A total of 675 cases older than 12 years (males, n = 480) had NPS or other illicit drugs detected in their urine samples. Overall, 1271 counts of drugs, among which 717 (56.4%) were NPS. At least one NPS was detected in 340 patients (50.4%), and 292 cases were positive for multiple drugs. The most frequently detected drug was methamphetamine/amphetamine, followed by synthetic cathinones, ketamine and its two analogs, and opioids. The most common drug combination was cathinones plus ketamine and/or its analogs (n = 56). Younger patients (OR = 3.3, p≤.0001) and women (OR = 1.5, p = .01) were more likely to have NPS detected in their urine samples. NPS-positive cases frequently experienced chest pain (OR = 2.6, p = .03), tachycardia (OR = 2.6, p = .0002), and suicide attempt/non-suicidal self-harm (OR = 1.8, p = .004), whereas depressed consciousness (OR = 0.5, p = .001) was less frequent among NPS-positive cases than among other illicit drug-positive cases. CONCLUSIONS: The TEDAS project provides a nationwide epidemiological profile of recreational drug use in Taiwan. More than half of the recreational drugs were NPSs, which were comprehensively detected using LC-MS/MS.

The acute paraquat poisoning mortality (APPM) score to predict the risk of death in paraquat-poisoned patients.

CONTEXT: Mortality prediction in paraquat poisoning is a major issue since most prediction rules are inapplicable if the exact ingestion time cannot be determined and/or the serum paraquat concentration is not readily available, as in most countries. Therefore, we aimed to develop and validate a new prediction rule not requiring these two parameters. METHODS: We designed a 10-year observational cohort study including all consecutive paraquat-poisoned patients managed in two Taiwanese hospitals. We built one cohort to define and one cohort to validate this prediction rule. Parameters independently related to mortality determined using a multivariate analysis were used to formulate the Acute Paraquat Poisoning Mortality (APPM) score. RESULTS: Overall, 321 paraquat-poisoned patients were included, 156 in the derivation and 165 in the validation cohort. Mortality rates in the derivation and validation cohorts were 73% and 81%, respectively (p = 0.20). The three parameters chosen of 28-day mortality at presentation were urine paraquat level >10 ppm (using a colorimetric sodium dithionite-based test; odds ratio (OR), 12.70; 95% confidence interval (CI), 2.64-61.24), white blood cells >13.0 G/L (OR, 5.50; CI, 1.41-21.48) and blood glucose >140 mg/dL [7.8 mmol/L] (OR, 7.45; CI, 1.70-32.86). In the derivation cohort, the area under the ROC curve (AUC-ROC) of the APPM score did not significantly differ from AUC-ROCs of serum paraquat (0.95, p = 0.25) and the Severity Index of Paraquat Poisoning (0.95, p = 0.33). AUC-ROCs of the APPM score in the derivation and validation cohorts were 0.91 and 0.94, respectively. CONCLUSION: We built and validated a reliable score to predict 28-day mortality in paraquat-poisoned patients at presentation, independently from the ingestion time and serum paraquat measurement.

A novel flowchart to predict mortality and analyse effectiveness of routinely used pharmacological regimens in paraquat poisoning.

Paraquat is responsible for an extremely high case-fatality rate poisoning. Mortality prediction remains a major issue since evidence to support benefits of routinely used treatments is lacking. We aimed to develop an easy-to-use prediction flowchart not requiring the ingestion time, for which accuracy is frequently questionable, and to evaluate the effectiveness of routinely used pharmacological therapies on mortality. We designed a two-centre cohort study including consecutive paraquat-poisoned adults with confirmed diagnosis based on serum/urine paraquat measurement. We built a flowchart using a multivariate analysis of death predictors and analysed the outcome according to the administered therapies. Overall, 256 patients were enrolled. Mortality rate was 75%. Independent death predictors on admission were serum creatinine (odds ratio [OR], 5.07; 95% confidence interval [CI], 1.97-13.05) and serum paraquat concentration (OR, 2.26; CI, 1.66-3.09). The area-under-the flowchart curve was 0.91. Overall sensitivity and specificity were 81.5% and 94.8%, respectively. More survivors than non-survivors of severe poisoning received methylprednisolone (P = 0.04). While not significantly differing in severity, methylprednisolone-treated patients had better survival (P = 0.04). To conclude, we defined an efficient flowchart to predict mortality in paraquat poisoning at presentation, even if ingestion time is undetermined. Methylprednisolone seems effective to improve the outcome, especially in the most severe cases.

Influential Factors of Local Tissue Necrosis after Taiwan Cobra Bites: A Secondary Analysis of the Clinical Significance of Venom Detection in Patients of Cobra Snakebites.

Local tissue swelling, inflammation, and wound necrosis are observed in Taiwan cobra bites. Knowledge of the factors influencing local tissue necrosis after cobra bites might improve the cobra bite treatment strategy. Therefore, we aimed to explore the factors influencing local tissue necrosis after cobra bites. This was a retrospective observational cohort study. All patients clinical presentations including serum venom levels for determining the influential factors in this study were obtained from Hung et al.'s previous study. Clinical features, such as bite information, initial swelling, patient presentation time, serum venom levels, and antivenom, use were extracted. The measurement outcome was the development of wound necrosis. The factors influencing wound necrosis were investigated using univariate and logistic regression analyses. The influential factors of local tissue necrosis and their areas under the curve were: initial limb swelling, 0.88; presentation time × serum level, 0.80; initial necrosis, 0.75; patient presentation time, 0.70. Serum venom level alone cannot be used as a predictive factor. The development of tissue necrosis might be associated with the venom factor, time factor, and their interaction. These influential factors can be used in future studies to evaluate antivenom efficacy.

Hemodynamic and electromechanical effects of paraquat in rat heart.

Paraquat (PQ) is a highly lethal herbicide. Ingestion of large quantities of PQ usually results in cardiovascular collapse and eventual mortality. Recent pieces of evidence indicate possible involvement of oxidative stress- and inflammation-related factors in PQ-induced cardiac toxicity. However, little information exists on the relationship between hemodynamic and cardiac electromechanical effects involved in acute PQ poisoning. The present study investigated the effects of acute PQ exposure on hemodynamics and electrocardiogram (ECG) in vivo, left ventricular (LV) pressure in isolated hearts, as well as contractile and intracellular Ca2+ properties and ionic currents in ventricular myocytes in a rat model. In anesthetized rats, intravenous PQ administration (100 or 180 mg/kg) induced dose-dependent decreases in heart rate, blood pressure, and cardiac contractility (LV +dP/dtmax). Furthermore, PQ administration prolonged the PR, QRS, QT, and rate-corrected QT (QTc) intervals. In Langendorff-perfused isolated hearts, PQ (33 or 60 µM) decreased LV pressure and contractility (LV +dP/dtmax). PQ (10-60 µM) reduced the amplitudes of Ca2+ transients and fractional cell shortening in a concentration-dependent manner in isolated ventricular myocytes. Moreover, whole-cell patch-clamp experiments demonstrated that PQ decreased the current amplitude and availability of the transient outward K+ channel (Ito) and altered its gating kinetics. These results suggest that PQ-induced cardiotoxicity results mainly from diminished Ca2+ transients and inhibited K+ channels in cardiomyocytes, which lead to LV contractile force suppression and QTc interval prolongation. These findings should provide novel cues to understand PQ-induced cardiac suppression and electrical disturbances and may aid in the development of new treatment modalities.

Wound Infections from Taiwan Cobra (Naja atra) Bites: Determining Bacteriology, Antibiotic Susceptibility, and the Use of Antibiotics-A Cobra BITE Study.

Wound necrosis and secondary infection are common complications after Naja atra bites. Clinical tools to evaluate the infection risk after Taiwan cobra bites are lacking. In this Cobra BITE study, we investigated the prevalence of wound infection, bacteriology, and corresponding antibiotic usage in patients presenting with Taiwan cobra snakebites. Patients with wound infection lacking tissue necrosis were included in developing Cobra BITE score utilizing univariate and multiple logistic regression, as patients with wound necrosis require antibiotics for infection treatment. 8,295,497 emergency department visits occurred in the span of this study, with 195 of those patients being diagnosed as having cobra bites. Of these patients, 23 had wound necrosis, and 30 had wound infection, resulting in a wound infection rate of 27.2% (53/195). Enterococcus faecalis and Morganella morganii were the main bacteria identified in the culture report regardless of whether patients' wounds had necrosis. As per our Cobra BITE score, the three factors predicting secondary wound infection after cobra bites are hospital admission, a white blood cell count (in 103/µL) × by neu-trophil-lymphocyte ratio value of ≥114.23, and the use of antivenin medication. The area under the receiver operating characteristic curve for the Cobra BITE score system was 0.88; ideal sensitivity and specificity were 0.89 and 0.76. This scoring system enables the assessment of wound infections after N. atra bites, and it could be modified and improved in the future for other Naja spp. bites.

Rapid and Efficient Enrichment of Snake Venoms from Human Plasma Using a Strong Cation Exchange Tip Column to Improve Snakebite Diagnosis.

Snake envenomation is a serious public health issue in many tropical and subtropical countries. Accurate diagnosis and immediate antivenom treatment are critical for effective management. However, the venom concentration in the victims' plasma is usually low, representing one of the bottlenecks in developing clinically applicable assays for venom detection and snakebite diagnosis. In this study, we attempted to develop a simple method for rapid enrichment of venom proteins from human plasma to facilitate detection. Our experiments showed that several major protein components of both Naja atra (N. atra) and Bungarus multicinctus (B. multicinctus) venoms have higher isoelectric point (pI) values relative to high-abundance human plasma proteins and could be separated via strong cation exchange-high-performance liquid chromatography (SCX-HPLC). Based on this principle, we developed an SCX tip column-based protocol for rapid enrichment of N. atra and B. multicinctus venom proteins from human plasma. Application of liquid chromatography-tandem mass spectrometry (LC-MS/MS) led to the identification of cytotoxin and beta-bungarotoxin as the major proteins enriched by the SCX tip column in each venom sample. The entire process of venom enrichment could be completed within 10-15 min. Combination of this method with our previously developed lateral flow strip assays (rapid test) significantly enhanced the sensitivity of the rapid test, mainly via depletion of the plasma protein background, as well as increase in venom protein concentration. Notably, the SCX tip column-based enrichment method has the potential to efficiently enrich other Elapidae snake venoms containing proteins with higher pI values, thereby facilitating venom detection with other assays. This simple and rapid sample preparation method should aid in improving the clinical utility of diagnostic assays for snakebite.

Does Hemoperfusion Increase Survival in Acute Paraquat Poisoning? A Retrospective Multicenter Study.

The efficacy of hemoperfusion (HP) in patients with acute paraquat poisoning (PQ) remains controversial. We conducted a multi-center retrospective study to include acute PQ-poisoned patients admitted to two tertiary medical centers between 2005 and 2015. We used the Severity Index of Paraquat Poisoning (SIPP) to stratify the severity of PQ-poisoned patients. The indication to start HP was a positive result for the semiquantitative urine PQ test and presentation to the hospital was within 24 h. Early HP was defined as the first session of HP performed within five hours of PQ ingestion. A total of 213 patients (100 HP group, 113 non-HP group) were eligible for the study. The overall 60-day mortality of poisoned patients was 75.6% (161/213). Multivariate Cox regression analysis showed no statistically significant difference in 60-day survival between HP and non-HP groups (95% confidence interval (CI): 0.84-1.63, p = 0.363). Further subgroup analysis in the HP group showed early HP (95%CI: 0.54-1.69, p = 0.880), and multiple secessions of HP (95%CI: 0.56-1.07, p = 0.124) were not significantly related to better survival. Among acute PQ-poisoned patients, this study found that HP was not associated with increased 60-day survival. Furthermore, neither early HP nor multiple secessions of HP were associated with survival.