Antivenom Use Research Articles

Epidemiology and characteristics of coral snake bites reported to the National Poison Data System (2006‒2022).

North American coral snake envenomations can result in life-threatening neurotoxicity. Their bites are relatively rare, making large studies difficult. Using the National Poison Data System (NPDS), we sought to investigate the epidemiological trends and clinical outcomes associated with North American coral snake bites over a 17-year period. NPDS cases involving coral snakes from January 1, 2006, to December 31, 2022, were analyzed. Data collected included patient age, date, geographic location, clinical effects, treatments administered, and medical outcomes including incidence of "dry bites" (non-envenomation) and death. During the 17-year period, a total of 1374 cases were reported and analyzed. Cases included adults (≥20 years), accounting for 80% (n=1107), and pediatric patients (≤19 years), accounting for 20% (n=267) of total cases. Out of 50 US states and District of Columbia, 20 states reported cases. Florida and Texas accounted for 90.5% of all bites (n=1243) with April being the month with the most reported cases (n=184). The most bites (n=96) were reported in 2008 and the fewest (n=69) in 2016. Male patients predominated for both pediatric (75.7%, n=202) and adult cases (75.3%, n=834). Moderate to major clinical outcomes were documented in approximately 30% of total cases; with no reported deaths. Moderate effect is defined as the patient exhibited symptoms as a result of the exposure that were more pronounced, more prolonged, or more of a systemic nature than minor symptoms. Major effect was defined as the patient exhibited symptoms as a result of the exposure that were life threatening or resulted in significant residual disability or disfigurement. The three most reported clinical effects were wound/sting, dermal irritation/pain, and edema. Antivenom was administered in 21% (n=286) of total cases and 37% (n=511) of patients were admitted to a critical care unit. Dry bites occurred in 7% (n=100) of total cases. Coral snake bites were rare, but consistently reported. While bites were associated with significant morbidity in adult and pediatric patients, there were no deaths reported. Antivenom use declined over the study period but was not associated with an increase in morbidity. An increased incidence of intubations was seen in association with decreased antivenom use.

Efficacy and safety of two Antivenoms in the treatment of eastern copperhead (Agkistrodon contortrix) envenomations in Southeast Texas.

There are two Food and Drug Administration-approved antivenoms for the treatment of North American pitviper envenomations: Crotalidae polyvalent immune fab (ovine) (CroFab, henceforth FabAV) and Crotalidae immune F(ab')2 (equine) (Anavip, henceforth Fab2AV). This study compared the effectiveness and safety of the two products in eastern copperhead envenomations. We retrospectively reviewed eastern copperhead bites on which our toxicology service consulted between January 1, 2021 and November 1, 2023. Collected data included patient demographics, bite location, clinical features, antivenom use, response to treatment, and adverse reactions to antivenom. There were 134 patients with confirmed copperhead envenomations. We administered antivenom to 89 patients, of which 36 (40%) were female. The median age was 42 years old (range: 2-89 years). Fifty-nine patients received Fab2AV and 30 were treated with FabAV. Initial control was achieved in 30 (100%) patients treated with FabAV. In the Fab2AV group, 53 (89.8%) achieved control; six patients with acute adverse reactions declined further treatment despite persistent symptoms. The median FabAV dose required for initial control was six vials (range: 4-6). A median dose of 10 vials (range: 10-30) was used in the Fab2AV group. Repeat doses of Fab2AV were required in 15 (25.4%) cases. There were no acute adverse reactions to FabAV. Acute adverse reactions were seen in seven (11.9%) of patients treated with Fab2AV. Fewer patients treated with FabAV required repeat antivenom dosing to attain initial control following eastern copperhead envenomation. A higher percentage of patients treated with Fab2AV developed acute adverse reactions.

Experıences Of Emergency Physıcıans On Scorpıon Stıngs

INTRODUCTION and PURPOSE: This study aims to evaluate the level of knowledge and approaches of emergency physicians about scorpion stings. MATERIALS and METHODS: In the study, aquestionnaire including 16 questions was administered to emergency physicians about their titles, length of service in the emergency department, geographical region and institutional information, experiences with scorpion stings, treatment approaches, and hospitalization information of the patients. RESULTS: A total of 282 physicians participated in the study. In emergency medicine physicians (EMPs), regularly checking the availability of scorpion antivenom (p=0.01), taking precautions for complications before antivenom administration (p=0.03), and preferring intravenous (IV) route for scorpion antivenom administration were found to be significantly higher compared to other title groups. Needing consultation before scorpion antivenom (p=0.01) and recommending antibiotic prophylaxis to sting patients (p=0.02) were significantly lower in EMPs compared to other title groups. 31.7% (n=26) of general practitioners administered antivenom "half to the wound edge/half intramuscularly", which is significantly higher compared to other groups (p=0.01). Hospitalization problems in sting cases were most frequently experienced in university hospitals (p= 0.01). DISCUSSION and CONCLUSION: Our study indicated errors in managing scorpion sting patients and antivenom use. The necessity of reorganization of vocational and undergraduate training should be evaluated.

Comparing the Use of Crotaline-Polyvalent Immune Fab (Ovine) Versus Observation in Children.

In the United States, studies are inconclusive regarding the indications for polyvalent antivenom administration for crotaline envenomation. We compared polyvalent antivenom administration versus observation used at 2 separate institutions. We hypothesized that deferring antivenom leads to increased hospital length of stay and surgical interventions. Retrospective chart review of children who presented to Le Bonheur Children's Hospital (LBCH) in Memphis, Tennessee, and Monroe Carell Jr Children's Hospital at Vanderbilt (MCJCHV) in Nashville, Tennessee, from 2009 to 2021. Patient demographics, treatment utilization, bite location, and outcomes from both sites were statistically examined. A total of 183 patients met the inclusion criteria (123 at LBCH, 60 at MCJCHV). At LBCH, mean age was 9.2 years, 54% were male, and 79% of known snakes identified as copperheads. At MCJCHV, mean age was 8.9 years, 65% were male, and 88% of known snakes identified as copperheads. The most commonly envenomated areas for both sites were the foot (42%), hand (27%), and ankle (26%). Patients at LBCH were managed with antivenom only 25% of the time, whereas 75% were observed; 82% of MCJCHV patients were managed with antivenom (P < 0.001). There were no significant differences in length of stay (mean, 1.5 days at LBCH and 1.8 days at MCJCHV; P = 0.136) or surgical intervention (3.3% of LBCH encounters, 5.0% of MCJCHV encounters; P = 0.685). Secondary outcomes aside from coagulopathy and admission location (intensive care unit vs floor) were also not significant. The use of antivenom did not impact hospital length of stay or surgical interventions. Our results should be interpreted cautiously as our study reflects regional experiences with snake species in the Southeast United States and not North America as a whole. Other institutional differences in management and smaller n at MCJCHV may have contributed to different outcomes. Further study is needed to determine intermediate and long-term effects of deferring antivenom use.

Fasciotomy following North American pit viper envenomation in Texas 2004–2021

Introduction North American pit viper envenomation occurs over 4,000 times annually in the United States, with polyvalent Fab antivenom being the primary treatment. Fasciotomy is occasionally performed due to concerns about compartment syndrome. We utilized our direct access to Texas Poison Center Network data to create a new snakebite abstraction form and database on relevant available information between 2004 and 2021 and to identify, describe, and estimate the incidence of fasciotomy following pit viper envenomation in Texas. Methods We searched the Texas Poison Center Network database for cases during 2004–2021 using keywords such as fasciotomy, surgery, compartment pressure, and compartment syndrome. Descriptive statistics summarized the data. Results Of 16,911 reported envenomations, 0.69 percent involved fasciotomies (n = 117). Most common bite sites were digits/hands and lower extremities. Patients who underwent fasciotomy were typically male, aged 20–59, and 10 years younger than the total snakebite population. Only 6 percent of reported compartment syndrome cases had a compartment pressure measurement. Antivenom was administered in 101 (86.3 percent) cases, 92 (91.1 percent) of which received only Fab antivenom product. Patients with bites from rattlesnakes (47.9 percent) were associated with most fasciotomies Discussion Our findings suggest a potential increase in snakebite exposures, accompanied by a decrease in fasciotomies. Overall, copperheads constituted the majority of snakebites, but most fasciotomies were from rattlesnake envenomations (47.9 percent). In this cohort, compartment syndrome diagnosis and decisions regarding fasciotomy were primarily based on clinical evaluation/surgeon expertise without compartment pressure measurements. Despite the efficacy of antivenom, only 86.3 percent of patients in our study received antivenom. Conclusions Fasciotomy after North American pit viper envenomation in Texas is uncommon (0.69 percent) and has decreased over time, possibly due to increased antivenom use or surgeon comfort with nonsurgical management.

The Effect of Neutrophil/Lymphocyte Ratio and Mean Platelet Volume on the use of Antivenom in Snake Bites and Scorpion Stings

Objective: We evaluated the distribution, use of antivenom, treatments applied during the follow-ups, and effects on the use of NLR and MPV antivenom in cases of snake bites and scorpion stings followed in the paediatric intensive care unit (PICU) and the effects of these cases on the length of stay in the intensive care unit and hospital. &#x0D; Materials and Methods: Demographic characteristics of the patients followed in the PICU and the severity of their clinical findings at admission, antivenom use after snake and scorpion bites were retrospectively examined from the clinical course in the hospital automation system and archived file records.&#x0D; Results: Of 38 patients who were followed up in the PICU for snake and scorpion bites, half were followed up for snake bites and half for scorpion bites. Antivenom treatment was applied according to the clinical stage. There was a positive correlation between antivenom-administered patients and NLR (p

Pediatric Rattlesnake Envenomations Treated With Crotalidae Equine Immune F(Ab') 2 Antivenom : A 3-Year Retrospective Observational Analysis.

Rattlesnake envenomations are uncommon, and the majority occur in adults. Although Crotalidae equine immune F(ab') 2 antivenom (F(ab') 2 AV; trade name ANAVIP) was introduced in 2018, no pediatric specific studies of F(ab') 2 AV have been reported to date. The objective of this study was to evaluate the clinical performance and adverse effects of F(ab') 2 AV in children. A single-center, retrospective chart review was performed on patients with rattlesnake envenomation presenting to a children's hospital between October 2018 and August 2022. Inclusion criteria were age younger than 18 years and F(ab') 2 AV use. Exclusion criteria were other antivenom use at any time and presentation beyond 24 hours postenvenomation.Demographic characteristics, hemoglobin, platelet count, fibrinogen, international normalized ratio, number of F(ab') 2 AV vials used, infusion-related complications, and clinical outcomes were collected. Twenty-six patients, 19 males and 7 females, with a mean age of 7.7 years (0.67 to 16 years) met inclusion criteria. Fourteen (54%) were treated with only the initial 10 vial F(ab') 2 AV doses. Twelve patients were given additional doses with a median additional vials of 10 (4-34 vials; interquartile range, 8.75-12 vials). The median total vials given for all patients was 10 (10-44 vials; interquartile range, 10-20 vials).Two patients developed acute infusion reactions. Both were treated by slowing the infusion rate and with medications (diphenhydramine, corticosteroids). No delayed reactions were noted. No patients required blood products or surgical interventions.After discharge, no complications, recurrent symptoms, return visits, or readmissions were reported. Follow-up by chart review or phone was obtained for 18 patients, and no postdischarge complications were noted. Seven patients had postdischarge hematologic laboratory evaluations and all were normal. Although limited by small sample size and postdischarge follow-up, F(ab') 2 AV was well tolerated in our series of pediatric patients, consistent with prior studies of all age groups.

Suspected snakebite in a tertiary referral centre in Western Sydney: a 10-year case series

ABSTRACT We aimed to determine the epidemiology and clinical management of patients presenting to an Australian tertiary emergency department (ED) with a suspected snake bite. Nepean Hospital covers a geographical area known to harbour venomous elapid snake species. A Retrospective chart review of all patients presenting to Nepean ED from 2011 to 2020 was performed. We searched the electronic medical records (eMR) for triage presentations including search terms of “snakebite”, “bite” “envenomation”, or “bite-snake” and a discharge or independent diagnosis of “snakebite” or “envenomation”. Our review identified 110 patients presenting with snakebite, of whom nine had signs or symptoms indicating envenomation. The most common envenomation syndrome was venom-induced consumption coagulopathy (VICC) and the most commonly suspected culprit snake was the Eastern Brown Snake. Our data broadly agreed with national data on epidemiology and demographics. We noted a satisfactory rate of compliance with local snake bite protocols with evidence of early diagnosis and antivenom administration. We had no cases of anaphylaxis and one case of serum sickness. Our study of a tertiary hospital experience in the management of snake bite demonstrated an appropriate adherence to national guidelines and early clinician recognition of envenomation syndromes. It also demonstrated appropriate antivenom use without obvious time delay.

Incidence of serum sickness following Indian polyvalent antivenom therapy in a cohort of snake-envenomed patients in rural Sri Lanka

Introduction Serum sickness is a poorly reported delayed adverse reaction following snake antivenom therapy. We aimed to assess the frequency of serum sickness associated with administering Indian polyvalent antivenom in Sri Lanka. Methods We recruited patients from the Anuradhapura snakebite cohort who were admitted to a rural tertiary care hospital in Sri Lanka over one year period. Patients were interviewed over the phone 21 to 28 days post-envenoming to collect data on clinical effects: fever/chills, arthralgia/myalgia, rash, malaise, headache, abdominal pain, and nausea/vomiting. The presence of three or more symptoms between the 5th to 20th days after snake envenoming was defined as serum sickness. Results We were able to contact 98/122 (80%) patients who received antivenom and 423/588 (72%) who did not receive antivenom during the study period. The treated patients received a median dose of 20 vials (interquartile range: 20–30) of Indian polyvalent antivenom and of them, 92 (92%) received premedication. However, 67/98 (68%) developed acute adverse reactions to antivenom, including 19/98 (19%) developing anaphylaxis. Only 4/98 (4%) who received antivenom met the criteria for serum sickness, compared to none who did not receive antivenom therapy. All patients who developed serum sickness were envenomed by Russell’s vipers, were premedicated, and received VINS Bioproducts antivenom. Three of them were treated with hydrocortisone in the acute stage, as premedication or as a treatment for acute adverse reactions of antivenom. Although all four patients sought medical advice for their symptoms, only one was clinically suspected to be serum sickness and treated, while the others were treated for infections. Conclusions We confirmed that Indian polyvalent antivenom use in Sri Lanka is associated with high rates of acute adverse reactions. In contrast to studies of other antivenoms only a small proportion of patients developed serum sickness.

Evaluation of Clinical Profile and Complications Associated with Snake Bite among Such Patients at a Tertiary Care Hospital

Background: Snakebite occurs in Pakistan ofently mostly an occupational infection like farmers, plantation workers, fishers, and even among wildlife park rangers and military personnel. Monsoons are essential to farming, and most farmers are from lower-income backgrounds. Snake bite morbidity and fatality rates are species- and time-specific. The sufferers are often from lower socioeconomic classes, despite the absence of evidence to support their usage in the treatment of snake bite poisoning. Snake bites may be fatal if not treated quickly, thus having accurate data on the frequency and severity of these incidents is crucial for both diagnosis and policymaking. So, the study focuses on the evaluation of clinical profile and complications associated with snake bite among such patients at a tertiary care hospital. Objective: The objective of this study is to identify potential contributors to snake bite occurrences and also to determine the mortality and morbidity rates associated with snakebites and how they vary by snake species, venom type, bite location, and anti-venom use. Study Design: Observational Retrospective Study. Settings: This study is conducted in the department of Forensic Medicine and Toxicology, Sheikh Zayed Medical College, Rahim Yar Khan Pakistan. Duration: One year from Jan 2022 to Dec 2022. Methods: Both sexes from any age group and only suspected of snake bite were included. The poison illness other than snake bite were excluded from the study. Tertiary care facilities located in Pakistan included 150 snake bite cases were studied retrospectively between (study period). Using hospital records, researchers were able to learn specifics about snakebite-related mortality and morbidity, such as the species of snake if known, the method of envenomation, the victim's age, sex, residence, occupation, bite site, bite location, clinical manifestations of snakebite, initial treatment, and antivenom use. The admission and death registry were used to compile the historical record of data. Results: There were 96 male and 57 female enrolled in the study. The afternoon had the highest rate of bites (47% during the day), followed by the morning (28%), for a total of 78.5% during the day and 26.5% during the night. Seventy-five percent of the victims were alert when they were taken to the hospital, and most stayed there for between three and ten days as part of their surveillance, improvement, and recovery. The ages have been divided into different groups and we found that majority were from between 30 to 40 years. Pain, swelling, bleeding, tingling, numbness, and a blackened discoloration of the skin were all seen locally in 92 percent of the cases. Conclusion: Surveillance of envenomation’s is crucial for defining standards, arranging therapeutic supplies, and teaching medical personnel on Snakebite treatment since under-reporting of Snake bite occurrences has led to variances in observed rates of it. In addition, it has been noted that snake bites continue to be a significant occupational (farming) danger for people of working age, particularly men, in rural areas.

Approach to the diagnosis and management of snakebite envenomation in South Africa in humans.

Snake bite management is largely driven by expert opinion and consensus, however there are a few large retrospective studies and RCT's that have improved the quality of medical guidance currently available. South African snakes are different in the venomous potential and it behooves the hospital provider and the average medical practitioner to know the current best practice concepts concerning assessment, treatment and antivenom use. The recent SASS meeting in July 2022 provided an update and national consensus from which this Hospital Care document is derived.

Risk of stroke following antivenom use after venomous snakebite: correspondence.

Journal Article Accepted manuscript Risk of stroke following antivenom use after venomous snakebite: correspondence Get access C -C Chen, C -C Chen Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung, TaiwanDepartment of Occupational Medicine, Chung Shan Medical University Hospital, Taichung, TaiwanSchool of Medicine, Chung Shan Medical University, Taichung, Taiwan Search for other works by this author on: Oxford Academic PubMed Google Scholar P -J Yang, P -J Yang Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung, TaiwanSchool of Medicine, Chung Shan Medical University, Taichung, Taiwan Search for other works by this author on: Oxford Academic PubMed Google Scholar P -H Wang, P -H Wang School of Medicine, Chung Shan Medical University, Taichung, TaiwanInstitute of Medicine, Chung Shan Medical University, Taichung, Taiwan Search for other works by this author on: Oxford Academic PubMed Google Scholar S -C Chen S -C Chen Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung, TaiwanDepartment of Occupational Medicine, Chung Shan Medical University Hospital, Taichung, TaiwanSchool of Medicine, Chung Shan Medical University, Taichung, TaiwanInstitute of Medicine, Chung Shan Medical University, Taichung, Taiwan Address correspondence to Prof. S.-C. Chen; No. 110, Sec. 1, Jianguo N. Rd., Taichung 402306, Taiwan (R.O.C.); e-mail: sccy399@gmail.com Search for other works by this author on: Oxford Academic PubMed Google Scholar QJM: An International Journal of Medicine, hcad075, https://doi.org/10.1093/qjmed/hcad075 Published: 26 April 2023 Article history Received: 22 April 2023 Published: 26 April 2023

Evolution in the choice of therapies used to treat latrodectism: Redback spider antivenom or standard analgesic medications. Nothing to rave about.

Redback spider (RBS) antivenom (RBSAV) use appears to have decreased since the results of the RAVE-2 antivenom efficacy study were released. The aims of this study were to assess change in RBSAV use over time and compare responses to treatment for antivenom and other analgesics. Retrospective audit of RBS bite referrals to a toxicology unit, from January 2010 to January 2022. Data included demographics, pain severity, treatment (analgesia or RBSAV), response to treatment, re-presentation rate, adverse events, change in antivenom use over time. Of 270 presentations, 157 with moderate or severe pain were included (RBSAV n= 51, analgesia n= 106). Median age was 39 years, n= 81 (51%) female. Those receiving antivenom were more likely to report severe pain n= 46/51 (84%) versus n= 68/106 (58%) (P= 0.006). Eighty-three percent of antivenom doses were administered between 2010 and 2013. Analgesia-only group received various combinations of paracetamol, NSAIDs, and opioids. In those receiving RBSAV, 17/48 (35%), 26/48 (54%), 5/48 (10%) reported a partial, complete or no reduction in pain, respectively, versus 30/77 (39%), 43/77 (58%) and 4/77 (5%), for analgesia-only group. Post-treatment pain was not recorded in three RBSAV and 28 analgesia-only patients. Pain reduction was no different for intravenous and intramuscular antivenom. Re-presentation for ongoing pain was more common in the analgesia-only group, 16/106 (15%) versus 1/51 (2%) for antivenom (P= 0.013). Antivenom use fell over the study period. There was no difference in pain relief between RBSAV and analgesia-only groups. RBSAV, regardless of route of administration, was no better than standard analgesics in pain reduction in the present study.

OUTCOMES OF TREATMENT OF SNAKE AND SCORPION ENVENOMATION IN BIRDS OF PREY, WITH AND WITHOUT ANTIVENOM

Birds of prey are vulnerable to envenomation from animals in their natural environment, including scorpions and pit vipers. Severity of clinical effects varies depending on envenomating species, dose of venom injected, and anatomic site of venom inoculation. Fatality from envenomation has been reported, but use of antivenom in birds of prey is rare. Of 18 identified cases involving envenomation in birds of prey, five received antivenom and survived, seven recovered spontaneously or with supportive care only, and six without antivenom treatment died: four bitten by rattlesnakes of genus Crotalus, one by a cottonmouth (water moccasin, Agkistrodon piscivorus), and one by a coral snake (Micrurus fulvius). Illustrative cases include (1) a California condor (Gymnogyps californianus) fatally envenomated by a rattlesnake of genus Crotalus; (2) a red-tailed hawk (Buteo jamaicensis) bitten by a western diamondback rattlesnake (Crotalus atrox) and successfully treated with IV equine whole-immunoglobulin antivenom despite an apparent acute infusion reaction; (3) a northern crested caracara (Caracara cheriway) with neurotoxicity following envenomation by a bark scorpion (Centruroides sculpturatus), successfully treated with IV equine F(ab')2 antivenom; and (4) a barn owl (Tyto alba) presumed stung by a bark scorpion, with diagnosis proved by specific enzyme-linked immunosorbent assay (ELISA), successfully treated with intramuscular equine F(ab')2 antivenom. Supportive care for envenomation includes oxygen supplementation, maintenance of airway, analgesics, and fluid therapy. Antivenom may be useful, and its use should be considered for symptomatic envenomation. Additional considerations in the context of antivenom use include dose, route of administration, volume, readiness of antihistamines and epinephrine for treatment of possible adverse events, and consultation with a medical toxinologist.

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

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. 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. 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. 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.

Developing a computational pharmacokinetic model of systemic snakebite envenomation and antivenom treatment

Snakebite envenomation is responsible for over 100,000 deaths and 400,000 cases of disability annually, most of which are preventable through access to safe and effective antivenoms. Snake venom toxins span a wide molecular weight range, influencing their absorption, distribution, and elimination within the body. In recent years, a range of scaffolds have been applied to antivenom development. These scaffolds similarly span a wide molecular weight range and subsequently display diverse pharmacokinetic behaviours. Computational simulations represent a powerful tool to explore the interplay between these varied antivenom scaffolds and venoms, to assess whether a pharmacokinetically optimal antivenom exists. The purpose of this study was to establish a computational model of systemic snakebite envenomation and treatment, for the quantitative assessment and comparison of conventional and next-generation antivenoms. A two-compartment mathematical model of envenomation and treatment was defined and the system was parameterised using existing data from rabbits. Elimination and biodistribution parameters were regressed against molecular weight to predict the dynamics of IgG, F(ab’)2, Fab, scFv, and nanobody antivenoms, spanning a size range of 15–150 kDa. As a case study, intramuscular envenomation by Naja sumatrana (equatorial spitting cobra) and its treatment using Fab, F(ab’)2, and IgG antivenoms was simulated. Variable venom dose tests were applied to visualise effective antivenom dose levels. Comparisons to existing antivenoms and experimental rescue studies highlight the large dose reductions that could result from recombinant antivenom use. This study represents the first comparative in silico model of snakebite envenomation and treatment.

BITES study: A qualitative analysis among emergency medicine physicians on snake envenomation management practices.

IntroductionAntivenom is currently considered standard treatment across the full spectrum of severity for snake envenomation in the United States. Although safe and effective antivenoms exist, their use in clinical practice is not universal.ObjectiveThis study explored physicians’ perceptions of antivenom use and experience with snake envenomation treatment in order to identify factors that influence treatment decisions and willingness to administer.MethodsWe conducted a qualitative study including in-depth interviews via online video conferencing with physicians practicing in emergency departments across the United States. Participants were selected based on purposive sampling methods. Data analysis followed inductive strategies, conducted by two researchers. The codebook and findings were discussed within the research team.FindingsSixteen in-depth interviews with physicians from nine states across the US were conducted. The participants’ specialties include emergency medicine (EM), pediatric EM, and toxicology. The experience of treating snakebites ranged from only didactic education to having treated over 100 cases. Emergent themes for this manuscript from the interview data included perceptions of antivenom, willingness to administer antivenom and influencing factors to antivenom usage. Overall, cost-related concerns were a major barrier to antivenom administration, especially in cases where the indications and effectiveness did not clearly outweigh the potential financial burden on the patient in non-life- or limb-threatening cases. The potential to decrease recovery time and long-term functional impairments was not commonly reported by participants as an indication for antivenom. In addition, level of exposure and perceived competence, based on prior education and clinical experience, further impacted the decision to treat. Resources such as Poison Center Call lines were well received and commonly used to guide the treatment plan. The need for better clinical guidelines and updated treatment algorithms with clinical and measurable indicators was stated to help the decision-making process, especially among those with low exposure to snake envenomation patients.ConclusionsA major barrier to physician use of antivenom is a concern about cost, cost transparency and cost–benefit for the patients. Those concerns, in addition to the varying degrees of awareness of potential long-term benefits, further influence inconsistent clinical treatment practices.

Predictors of FabAV use in copperhead envenomation

Context Crotaline snake envenomation is a serious medical condition affecting thousands of Americans each year. Variation in the treatment of Crotaline snakebites exists among physicians in the United States. Management of copperhead snakebites is controversial with some experts advocating minimal intervention, rarely necessitating antivenom use and, even more rarely, surgical intervention. This study assessed the use of Crotaline Polyvalent Immune Fab antivenom (Ovine) (FabAV) and explored factors influencing the decision to prescribe antivenom for copperhead envenomation in patients in Northeastern Oklahoma. Methods A retrospective cohort study examining electronic medical records of patients with copperhead snakebites from July 1, 2014 to August 31, 2019. Data collected included: patient demographics, transfer information, snake species, bite site, progression of local tissue effects, additional clinical and lab results, patient comorbidities, and treatment strategy. Associations between patient variables and treatment were evaluated using the chi-square test of independence, median test, and logistic regression analysis. Associations were statistically significant if p < 0.05. Discussion Of the 130 patients bitten by a copperhead, a majority (75%) received FabAV. Symptoms of copperhead envenomation were mostly limited to the progression of tissue damage. Predictors of treatment with FabAV included progression of venom effects across major joints, younger age, comorbidities, and upper extremity bites. Conclusions Patients who have multiple comorbidities, upper extremity bites and progression of venom effects across major joints are more likely to be treated with FabAV. The high usage of FabAV at the study site underscores the need for continued work to optimize the use of antivenom for copperhead envenomations.

No Change in the Use of Antivenom in Copperhead Snakebites in Ohio.

Historically, copperhead snake (Agkistrodon contortrix) envenomations were not treated with antivenom owing to related adverse events and little benefit. However, recent studies have shown improved outcomes with antivenom use. We hypothesized that the frequency of antivenom use for copperhead envenomation in Ohio has increased as benefits of administration became more widely known. All copperhead snakebites reported to the Ohio poison control centers from 2006 through 2016 were compiled. Antivenom use, bite severity, and disposition were abstracted. A nonparametric test for trend was used to evaluate changes over time for the number of patients treated with antivenom and patient disposition. Logistic regression was used to assess the odds of admission vs discharge with antivenom administration, bite severity, age, and sex as independent variables. Ninety-eight patients reported copperhead snakebites to the poison control centers. The test of trend showed no change in the proportion of patients treated with antivenom by year (P=0.42). There was no difference in the proportion of patients discharged home (P=0.38) per year. Logistic regression showed antivenom use was associated with an odds ratio for admission of 46.7 (95% CI: 7.3-296.4). The frequency of antivenom use for copperhead bites did not significantly increase between 2006 and 2016. Administration of antivenom was associated with a large increase in the odds of admission to the hospital, even when controlling for bite severity. Further education regarding the benefits and safety of antivenom may increase its use for copperhead snakebites, but may lead to an increase in hospital admissions.

The Snake Study: Survey of National Attitudes and Knowledge in Envenomation.

Despite recent reviews of best practice for the treatment of Australian venomous bites and stings, there is controversy about some aspects of care, particularly the use of antivenom. Our aim was to understand current attitudes and practice in the management of suspected snake envenoming. A single-stage, cross-sectional survey of Australian emergency care physicians who had treated snake envenomation in the previous 36 months was conducted. Hospital pharmacists were also invited to complete a survey about antivenom availability, usage, and wastage in Australian hospitals. The survey was available between 5 March and 16 June 2019. A total of 121 snake envenoming cases were reported, and more than a third (44.6%) of patients were not treated with antivenom. For those treated with antivenom (n = 67), 29 patients (43%) received more than one ampoule. Nearly a quarter of respondents (21%) identified that antivenom availability was, or could be, a barrier to manage snake envenoming, while cost was identified as the least important factor. Adverse reactions following antivenom use were described in 11.9% of cases (n = 8). The majority of patients with suspected envenoming did not receive antivenom. We noted variation in dosage, sources of information, beliefs, and approaches to the care of the envenomed patient.