The Efficacy of Antivenin Latrodectus (Black Widow) Equine Immune F(abʹ)2 Versus Placebo in the Treatment of Latrodectism: A Randomized, Double-Blind, Placebo-Controlled, Clinical Trial

Snake Antivenoms-Toward Better Understanding of the Administration Route

Envenomations induced by animal bites and stings constitute a significant public health burden. Even though a standardized protocol does not exist, parenterally administered polyclonal antivenoms remain the mainstay in snakebite therapy. There is a prevailing opinion that their application by the i.m. route has poor efficacy and that i.v. administration should preferentially be chosen in order to achieve better accomplishment of the antivenom therapeutic activity. Recently, it has been demonstrated that neutralization not only in the systemic circulation but also in the lymphatic system might be of great importance for the clinical outcome since it represents another relevant body compartment through which the absorption of the venom components occurs. In this review, the present-day and summarized knowledge of the laboratory and clinical findings on the i.v. and i.m. routes of antivenom administration is provided, with a special emphasis on the contribution of the lymphatic system to the process of venom elimination. Until now, antivenom-mediated neutralization has not yet been discussed in the context of the synergistic action of both blood and lymph. A current viewpoint might help to improve the comprehension of the venom/antivenom pharmacokinetics and the optimal approach for drug application. There is a great need for additional dependable, practical, well-designed studies, as well as more practice-related experience reports. As a result, opportunities for resolving long-standing disputes over choosing one therapeutic principle over another might be created, improving the safety and effectiveness of snakebite management.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Redback spider bites in children in South Australia: A 10-year review of antivenom effectiveness

OBJECTIVE

To describe the South Australian paediatric redback spider bite experience and to examine the hypothesis that redback antivenom (RBAV) treatment in children is clinically effective.

METHODS

Retrospective chart review of all children under 18 years of age presenting to the EDs of the three major paediatric or mixed hospitals in Adelaide, South Australia, with a discharge diagnosis of redback spider envenomation between 1 January 2010 and 31 March 2020. The main outcome measures include: patient and bite demographics; presenting symptoms and signs; treatment provided; clinical effects at 2 h post RBAV administration on pain, diaphoresis, blood pressure, heart rate and systemic features; overall clinical impression of RBAV effectiveness and resolution of symptoms prior to discharge.

RESULTS

There were 256 patient encounters involving 235 patients. Latrodectism was described in one-third (34%) of the cases. Sixty-one patients received RBAV and in 57 (93%) patients the RBAV had good clinical effect. Two hours post RBAV administration, pain resolved in 71%, hypertension resolved in 62%, diaphoresis resolved in 43% and tachycardia resolved in 82%. There were no cases of urticaria or anaphylaxis and one case of serum sickness.

CONCLUSIONS

This retrospective review of redback spider envenomation in South Australian children over a 10-year period has demonstrated clinical effectiveness of RBAV in paediatric patients across all age groups, observed in both clinician perceived results and measurable outcomes. RBAV remains an effective treatment for redback envenomation in children.

Practical Review of the Management of Animal Bites

Animal bites are common worldwide. Due to the plethora of animals, there are diverse pathogens with specific associated risks and treatment algorithms. It is crucial to understand these to develop and execute appropriate management plans. This practical review was designed to amalgamate the most common bites worldwide and synthesize data to help guide treatment plans.

METHODS

A PubMed literature search was performed focusing on the major animal bites. High-level studies were preferred and analyzed but lower-level studies were also used if high-level studies did not exist.

RESULTS

The tables presented in this article cover the pertinent information regarding the incidence, common presentation, initial treatment, and potential complications associated with bites from dogs, cats, horses, rodents, snakes, marine life, and spiders. Many of the pathogens associated with the bites are treatable with various and somewhat common antimicrobials, though some are less easy to access. Basic irrigation, debridement, and wound culture are common to almost every animal and should be the first step in treatment.

CONCLUSIONS

Based on the current studies, the most important factor in treating animal bites is timely presentation to a medical facility and/or physician. It is critical that the offending animal be accurately identified to help guide medical and surgical algorithms, including specific antimicrobial treatment guided by the most commonly presenting pathogens specific to certain animals.

Silently Suffering: A Pediatric Black Widow Spider Envenomation

BACKGROUND

Black widow spiders are distributed worldwide and, although rarely fatal, account for significant morbidity. Diagnosis can be challenging, and children are at risk of increased morbidity due to their small size.

CASE REPORT

We present a case of a 3-year-old boy who was brought to our emergency department because of sudden ear pain followed by labored breathing, abdominal pain, refusal or inability to speak, and grunting respirations. A black widow spider bite was suspected based on additional history obtained, and the spider was found in his helmet, confirming the diagnosis. The patient had progressive respiratory distress and somnolence and was intubated and transferred to a local pediatric intensive care unit. Antivenom was not initially available and eventually declined by the family. The child received supportive care and recovered after several days. Why Should an Emergency Physician Be Aware of This? This case illustrates the potentially deadly effects a black widow envenomation could cause in a child, and that bite location can affect the constellation of symptoms. It is a reminder that toxins, including that of the black widow spider, should be on the differential for acute abdominal pain, especially with autonomic features.

Latrodectus geometricus (Aranea: Theridiidae) envenoming: Rapid resolution of symptoms following F(ab')2 antivenom therapy

The Brown Widow spider (Latrodectus geometricus) is an invasive species whose geographic range has been expanding worldwide. It is a relative species of the Black Widow and Red-backed spiders of the genus Latrodectus. Despite its broad geographic distribution cases of Brown Widow envenomation have rarely been documented. The venom of L. geometricus is similar to the venom of L. mactans with the primary venom component being alpha-latrotoxin, and consequent envenoming by L. geometricus to humans has resulted in symptoms similar to those reported for other Latrodectus spp. Specific FDA approved Latrodectus antivenom (IgG) available in North America has been effectively used in treating venom-induced symptoms following L. mactans envenoming. The patient reported here involved a confirmed L. geometricus envenoming who was efficaciously treated with an alternately available F(ab')₂ antivenom from Mexico.

Patient-reported Outcome Measures in Emergency Care Research: A Primer for Researchers, Peer Reviewers, and Readers

Patient-reported outcomes (PROs) are of increasing importance in clinical research because they capture patients' experience with well-being, illness, and their interactions with health care. Because PROs tend to focus on specific symptoms (e.g., pain, anxiety) or general assessments of patient functioning and quality of life that offer unique advantages compared to traditional clinical outcomes (e.g., mortality, emergency department revisits), emergency care researchers may benefit from incorporation of PRO measures into their research design as a primary or secondary outcome. Patients may also benefit from the ability of PROs to inform clinical practice and facilitate patient decision making, as PROs are obtained directly from the lived experience of other patients with similar conditions or health status. This review article introduces and defines key terminology relating to PROs, discusses reasons for utilizing PROs in clinical research, outlines basic psychometric and practical assessments that can be used to select a specific PRO measure, and highlights examples of commonly utilized PRO measures in emergency care research.