Clinical effects of red‐bellied black snake ( Pseudechis porphyriacus ) envenoming and correlation with venom concentrations: Australian Snakebite Project (ASP‐11)

Abstract

Objective: To describe the clinical features and laboratory findings in patients with definite red‐bellied black snake (RBBS; Pseudechis porphyriacus) bites, including correlation with results of venom assays. Design, patients and setting: Prospective cohort study of patients with definite RBBS bites, recruited to the Australian Snakebite Project from January 2002 to June 2010. Main outcome measures: Clinical and laboratory features of envenoming; peak venom concentrations and antivenom treatment. Results: There were 81 definite RBBS bites; systemic envenoming occurred in 57 patients (70%) and local envenoming alone occurred in one patient. Systemic envenoming was characterised by local envenoming in 55 patients (96%), systemic symptoms in 54 patients (95%), anticoagulant coagulopathy with a raised activated partial thromboplastin time (aPTT) in 35 patients (61%) and myotoxicity in seven patients (12%). One patient required non‐invasive ventilation for severe myotoxicity that resulted in muscle weakness. Three patients developed local ulceration. There were no deaths. Twenty‐two envenomed patients (39%) received tiger snake or black snake antivenom, and administration within 6 hours of the bite was associated with normalisation of the aPTT. Eight patients (36%) had immediate hypersensitivity reactions to antivenom, including one case of anaphylaxis. The median peak venom concentration in 37 systemically envenomed patients with serum available was 19 ng/mL (interquartile range, 12–50 ng/mL; range, 3–360 ng/mL), which did not correlate with clinical severity. In 17 patients who received antivenom and had venom concentration measured, no venom was detected in serum after the first antivenom dose, including nine who were given one vial of tiger snake antivenom. Conclusion: RBBS envenoming caused local effects, systemic symptoms, anticoagulant coagulopathy and, uncommonly, myotoxicity. One vial of tiger snake or black snake antivenom appears to be sufficient to remove venom and neutralise reversible effects, but hypersensitivity reactions occurred in over a third of patients.

Death Adder Envenoming Causes Neurotoxicity Not Reversed by Antivenom - Australian Snakebite Project (ASP-16)

“…It also explains, in part, the reason for the predominance of upper limb bites, when compared to other studies of Australian snakes [37]. The study supports the fact that death adder bites from snakes in the wild are rare.…”

“…An anticoagulant type coagulopathy was seen in two patients, an effect that has not been described in Australian death adder bites before. This is similar to the coagulopathy seen in Australian black snake bites with an elevation of the aPTT [37] and although a useful marker of envenoming is unlikely to be clinically significant. Normal fibrinogen levels confirm that it is not a consumption coagulopathy.…”

Diagnosis of snake envenomation using a simple phospholipase A2 assay

“…In addition, cases of black snake ( Pseudechis porphyriacus ) were included from the Australian snakebite project19. The design of the Australian snakebite project has previously been described in detail and approval has been obtained from the Hunter New England Area Health Human Research Ethics Committee and nineteen other Human Research and Ethics Committees covering all institutions involved around Australia1920. Informed consent was obtained from all patients and the experiments were undertaken in accordance with the National Health and Medical Research Council guidelines.…”

“…Serum samples were tested with venom specific enzyme immunoassay (EIA) for Russell's viper venom and hump-nosed pit viper venom for Sri Lankan cases, and black snake venom for Australian cases, to confirm envenomation319. Clotting studies on citrate samples and clinical data were used to confirm systemic envenoming32122.…”

Bites by the Monocled Cobra, Naja kaouthia, in Chittagong Division, Bangladesh: Epidemiology, Clinical Features of Envenoming and Management of 70 Identified Cases

“…However, a study of bites by the Australian red-bellied black snake, Pseudechis porphyriacus , demonstrated no correlation between peak venom antigen concentration and clinical severity of envenoming 34. We identified several patients bitten by N. kaouthia with minimal signs of either local or systemic envenoming.…”