Dosage comparison of snake anti-venomon coagulopathy (original) (raw)
Related papers
Background : Viperine snake bites cause hemotoxicity in the form of coagulation dysfunction. Optimal dose requirement of anti-snake venom (ASV) and duration of therapy in such situation have not yet been fully explored. Our aim in this study was to compare two low-dose continuous infusion regimes with the standard high dose intermittent bolus regime in treating systemic envenomation and preventing its recurrence. Methods : A prospective interventional study was conducted on 90 adult patients with snake bite with hemotoxicity. Patents were allocated into three treatment regimes, each regime being tried on 30 patients. Regimen I (standard high dose regimen) consisted of conventional, intermittent bolus dosage of 100 ml of ASV as a loading dose followed by 50 ml every six hours till whole blood coagulation time (CT) became normal. Regimen II consisted of 30 ml of ASV as a loading dose followed by 30 ml continuous infusion every six hours till two CTs at an interval of six hours were normal and a further dose of 30ml over 24 hours. Regimen III was similar to Regimen II in all aspects except that loading dose was 70 ml (instead of 30 ml). Results : In patients with mild envenomation, even though the average requirement of ASV was only marginally lower in Regimen II (128.6 ml) as compared to in Regimen I (137.5 ml), one patient on Regimen I had relapse of coagulation dysfunction. In patients with moderate envenomation, average requirement of ASV was 221.3 ml and 179 ml in Regimens II and III respectively, which was much less than in Regimen I (343.8 ml) (p values 0.05 and 0.01 respectively). Further, no patient receiving Regimen III had relapse of coagulation dysfunction. In severe envenomation, average dose of ASV required was almost similar in Regimens II and III, i.e., 213.7 ml and 233.7 ml respectively, as compared to 433.3 ml required in Regimen I (p values 0.02 and 0.001 respectively). However, time lapse for CT normalization was only 18 hours in Regimen III as compared to 23.6 hours and 24 hours in Regimens I and II respectively. Conclusion : Regimens consisting of continuous intravenous infusion of ASV i.e., Regimen II in mild envenomation and Regimen III in moderate and severe envenomation are likely to make significant saving of ASV and reduction of recurrence of coagulation dysfunction. ©
Bratislava Medical Journal, 2019
OBJECTIVE: Viperidae snakes are responsible for 95 % of the bites caused by exotic-bred snakes in our country. Their envenoming may be associated with a severe acute coagulation disorder-venom-induced consumption coagulopathy (VICC). Thus, its early prediction is vital for an adequate therapy including antivenom delivery. MATERIAL AND METHODS: Laboratory coagulation tests of 14 patients suffering from VICC were processed and statistically analyzed to evaluate the importance of individual parameters in the time after the bite. RESULTS: The pathological values of D-dimer (D-dim) and fi brinogen (FBG) were found to be the fi rst indicators of VICC development, with a median time of 4.55 hours since the bite, while median values for prothrombin time and international normalized ratio (PT/INR), activated partial thromboplastin time (APTT), and thrombin time (TT) were 5.9 h, 8.15 h, and 5.5 h, respectively. In the fi rst samples, the values of D-dim were found to be pathologically increased in all 14 patients, while pathological levels of FBG were seen only in 11 cases. PT/ INR and APTT were prolonged in 8 and 6 cases, respectively. CONCLUSION: An increase in D-dim values was found to be the fi rst parameter signaling developing VICC in all analyzed cases (Tab. 2, Ref. 12).
PLOS Neglected Tropical Diseases, 2023
Introduction Envenoming by Echis spp. (carpet or saw-scaled vipers) causes haemorrhage and coagulopathy and represents a significant proportion of snakebites in the savannah regions of West Africa. Early diagnosis of envenoming is crucial in the management of these patients and there is limited evidence on the utility of the 20-minute whole blood clotting test (20WBCT) in diagnosing venom-induced consumptive coagulopathy (VICC) following envenoming by Echis ocellatus. Methods A prospective observational cohort study was conducted at the Kaltungo General Hospital in Northeastern Nigeria from September 2019 to September 2021. Standardised 20WBCTs were conducted by trained hospital staff and citrated plasma samples were collected at numerous timepoints. Prothrombin time (PT) and international normalised ratio (INR) were determined using a semi-automated analyser and INR values were calculated using international sensitivity indices (ISI). The sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), and likelihood ratios of the 20WBCT compared to an INR � 1.4 were calculated, alongside 95% confidence intervals.
Toxicon : official journal of the International Society on Toxinology, 2005
Snakebite affects around 2.5 million humans annually, with greater than 100,000 deaths. Coagulopathy is a significant cause of both morbidity and mortality in these patients, either directly, or indirectly. This paper reviews clinical aspects of snakebite coagulopathy, including types of coagulopathy (procoagulant, fibrinogen clotting, fibrinolytic, platelet-active, anticoagulant, thrombotic, haemorrhagic), diagnosis and treatment. Examples of clinical laboratory findings in selected types of snakebite coagulopathy are presented. Where available, antivenom is the most effective treatment, while standard treatments for other forms of coagulopathy, such as factor replacement therapy and heparin, are either ineffective or dangerous in snakebite coagulopathy, except in specific situations.
Saw-scaled vipers (genus Echis) are one of the leading causes of snakebite morbidity and mortality in parts of Sub-Saharan Africa, the Middle East, and vast regions of Asia, constituting a public health burden exceeding that of almost any other snake genus globally. Venom-induced consumption coagulopathy, owing to the action of potent procoagulant toxins, is one of the most relevant clinical manifestations of envenomings by Echis spp. Clinical experience and prior studies examining a limited range of venoms and restricted antivenoms have demonstrated for some antivenoms an extreme lack of antivenom cross-reactivity between different species of this genus, sometimes resulting in catastrophic treatment failure. This study undertook the most comprehensive testing of Echis venom effects upon the coagulation of human plasma, and also the broadest examination of antivenom potency and cross-reactivity, to-date. 10 Echis species/populations and four antivenoms (two African, two Asian) were studied. The results indicate that the venoms are, in general, potently procoagulant but that the relative dependence on calcium or phospholipid cofactors is highly variable. Additionally, three out of the four antivenoms tested demonstrated only a very narrow taxonomic range of effectiveness in preventing coagulopathy, with only the SAIMR antivenom displaying significant levels of cross-reactivity. These results were in conflict with previous studies using prolonged preincubation of antivenom with venom to suggest effective crossreactivity levels for the ICP Echi-Tab antivenom. These findings both inform upon potential clinical effects of envenomation in humans and highlight the extreme limitations of available treatment. It is hoped that this will spur efforts into the development of antivenoms with more comprehensive coverage for bites not only from wild snakes but also from specimens widely kept in zoological collections.
Toxicology letters, 2017
Saw-scaled vipers (genus Echis) are one of the leading causes of snakebite morbidity and mortality in parts of Sub-Saharan Africa, the Middle East, and vast regions of Asia, constituting a public health burden exceeding that of almost any other snake genus globally. Venom-induced consumption coagulopathy, owing to the action of potent procoagulant toxins, is one of the most relevant clinical manifestations of envenomings by Echis spp. Clinical experience and prior studies examining a limited range of venoms and eected antivenoms have demonstrated for some antivenoms an extreme lack of antivenom cross-reactivity between different species of this genus, sometimes resulting in catastrophic treatment failure. This study undertook the most comprehensive testing of Echis venom effects upon the coagulation of human plasma, and also the broadest examination of antivenom potency and cross-reactivity, to-date. 10 Echis species/populations and four antivenoms (two African, two Asian) were stud...
Current Treatment for Venom-Induced Consumption Coagulopathy Resulting from Snakebite
PLoS Neglected Tropical Diseases, 2014
Venomous snakebite is considered the single most important cause of human injury from venomous animals worldwide. Coagulopathy is one of the commonest important systemic clinical syndromes and can be complicated by serious and life-threatening haemorrhage. Venom-induced consumption coagulopathy (VICC) is the commonest coagulopathy resulting from snakebite and occurs in envenoming by Viperid snakes, certain elapids, including Australian elapids, and a few Colubrid (rear fang) snakes. Procoagulant toxins activate the clotting pathway, causing a broad range of factor deficiencies depending on the particular procoagulant toxin in the snake venom. Diagnosis and monitoring of coagulopathy is problematic, particularly in resource-poor countries where further research is required to develop more reliable, cheap clotting tests. MEDLINE and EMBASE up to September 2013 were searched to identify clinical studies of snake envenoming with VICC. The UniPort database was searched for coagulant snake toxins. Despite preclinical studies demonstrating antivenom binding toxins (efficacy), there was less evidence to support clinical effectiveness of antivenom for VICC. There were no placebo-controlled trials of antivenom for VICC. There were 25 randomised comparative trials of antivenom for VICC, which compared two different antivenoms (ten studies), three different antivenoms (four), two or three different doses or repeat doses of antivenom (five), heparin treatment and antivenom (five), and intravenous immunoglobulin treatment and antivenom (one). There were 13 studies that compared two groups in which there was no randomisation, including studies with historical controls. There have been numerous observational studies of antivenom in VICC but with no comparison group. Most of the controlled trials were small, did not use the same method for assessing coagulopathy, varied the dose of antivenom, and did not provide complete details of the study design (primary outcomes, randomisation, and allocation concealment). Non-randomised trials including comparison groups without antivenom showed that antivenom was effective for some snakes (e.g., Echis), but not others (e.g., Australasian elapids). Antivenom is the major treatment for VICC, but there is currently little high-quality evidence to support effectiveness. Antivenom is not risk free, and adverse reactions can be quite common and potentially severe. Studies of heparin did not demonstrate it improved outcomes in VICC. Fresh frozen plasma appeared to speed the recovery of coagulopathy and should be considered in bleeding patients. Citation: Maduwage K, Isbister GK (2014) Current Treatment for Venom-Induced Consumption Coagulopathy Resulting from Snakebite. PLoS Negl Trop Dis 8(10): e3220.
PLoS neglected tropical diseases, 2015
Russell's viper envenoming is a major problem in South Asia and causes venom induced consumption coagulopathy. This study aimed to investigate the kinetics and dynamics of venom and clotting function in Russell's viper envenoming. In a prospective cohort of 146 patients with Russell's viper envenoming, we measured venom concentrations, international normalised ratio [INR], prothrombin time (PT), activated partial thromboplastin time (aPTT), coagulation factors I, II, V, VII, VIII, IX and X, and von Willebrand factor antigen. The median age was 39y (16-82y) and 111 were male. The median peak INR was 6.8 (interquartile range[IQR]:3.7 to >13), associated with low fibrinogen [median,<0.01g/L;IQR:<0.01-0.9g/L), low factor V levels [median,<5%;IQR:<5-4%], low factor VIII levels [median,40%;IQR:12-79%] and low factor X levels [median,48%;IQR:29-67%]. There were smaller reductions in factors II, IX and VII over time. All factors recovered over 48h post-antivenom. ...
Clinical implications of coagulotoxic variations in Mamushi (Viperidae: Gloydius) snake venoms
Comparative Biochemistry and Physiology, Part C, 2019
Snake bite is currently one of the most neglected tropical diseases affecting much of the developing world. Asian pit vipers are responsible for a considerable amount of envenomations annually and bites can cause a multitude of clinical complications resulting from coagulopathic and neuropathic effects. While intense research has been undertaken for some species of Asian pit viper, functional coagulopathic effects have been neglected for others. We investigated their effects upon the human clotting cascade using venoms of four species of Gloydius and Ovophis okinavensis, a species closely to Gloydius. All species of included within this investigation displayed varying fibrinogenolytic effects, resulting in a net anticoagulant outcome. Gloydius saxatilis and Gloydius ussuriensis displayed the most variable effects from differing localities, sampled from Russia and Korea. As this Gloydius investigation includes some geographical variation, notable results indicate key variations of these species that point to possible limitations in antivenom cross-reactivities, which may have implications for the clinical care of victims envenomed by these snakes.