Mordedura de Phalotris lemniscatus (Duméril, Bibron & Duméril, 1854) (Squamata, Dipsadidae) en Uruguay / Phalotris lemniscatus (Duméril, Bibron & Duméril, 1854) (Squamata, Dipsadidae) bites in Uruguay

Phalotris lemniscatus es la única especie representante del género Phalotris en Uruguay. Esta especie tiene una amplia distribución que incluye Uruguay, Rio Grande do Sul en Brasil y el norte de Argentina que se extiende a las áreas fronterizas con Bolivia y Paraguay. Aunque este ofidio no es agresivo, se registraron dos accidentes en Uruguay en los que se observó acción local y sistémica del veneno. Los mismos ocurrieron en las manos después de manipulación excesiva y prolongada de los ejemplares. Localmente presentaron edema leve, pero en términos sistémicos el veneno de Phalotris causó alteraciones en la coagulación. Los pacientes se recuperaron totalmente después de 3 días. Serán necesarios más estudios para establecer una terapia adecuada para los envenenamientos graves provocados por esta especie.

Phalotris lemniscatus is the only species representative of Phalotris genus in Uruguay. This species has a wide distribution that includes Uruguay, Rio Grande do Sul in Brazil and northern Argentina extending to the areas bordering Bolivia and Paraguay. Although this snake is not aggressive, there were two snakebite accidents in Uruguay. They occurred on the hands after excessive and prolonged handling of the specimens. Locally they showed mild edema, but in systemically Phalotris venom caused alterations in blood coagulation. The patients recovered completely after 3 days. More studies will be required to establish an adequate therapy for Phalotris severe envenomations.

Severe systemic effects of Merrem's hump-nosed viper bite.

OBJECTIVE: To report unpredictable severe systemic effects of hump-nosed viper envenomation. SETTING: Medical unit, General hospital, Anuradhapura. METHODS: The clinical outcome of seven patients bitten by Merrem's hump-nosed viper were monitored until recovery or death. Limited autopsies were performed on the latter. Offending snakes were positively identified by medical officers and in one instance by a herpetologist. CONCLUSION: Merrem's hump-nosed viper bites, caused an array of potentially fatal systemic manifestations. One patient developed neurological effects, severe Raynaud's syndrome leading to ascending gangrene of distal limbs and adult repiratory distress syndrome (ARDS), in addition to the known complications of severe renal cortical necrosis and haemostatic dysfunction. Two patients who developed acute renal failure and prolonged coagulopathy recovered completely. The combination of extensive renal cortical necrosis, disseminated intravascular coagulation, and ARDS proved fatal in three.

Acute changes in serum cortisol levels following Russel's viper bites in Myanmar.

Forty-eight Russell's viper bite patients (40 males, 8 females), age ranging from 16-76 years were studied. Out of 48 patients, 14 were found to have a prolonged whole blood clotting time test (WBCT) (i.e. incoagulable blood) (Group 1); 23 had a normal WBCT (i.e. clotted blood) (Group II); and 11 patients had a normal WBCT on admission which changed to non-clotting during the clinical course (Group III). Four patients from group I developed hypotension and 2 expired. The serum cortisol concentration (mean +/- SEM) on admission among groups I and II were 639 +/- 45.6 and 424 +/- 33.2 nmol/l respectively. The blood cortisol level in 35 subjects (controls) were 370.7 +/- 17.7 nmol/l (mean +/- SEM). There was a significant rise of blood cortisol in patients with incoagulable blood when compared to controls at the time of admission to the hospital (p < 0.05); but there was no significant difference among those patients with clotted blood. A much higher mean serum cortisol level was observed in 4 patients with hypotension as compared to 10 patients without shock. These patients with hypotension according to our study shown to have a favorable response to steroid therapy and eventually recovered. Whether higher doses of steroid in addition to antiserum confer extra benefit in suppressing nonspecific venom effects on the pituitary and/or adrenal is not known.

Bothrops alternatus envenoming in young dogs

Bothrops alternatus venom was intramuscularly inoculated (3mg/kg) into 12 dogs, 30 to 65 days old. Spontaneou bleeding commenced twenty minutes later. Blood samples obtained 3 and 20 minutes after venom inoculation presented spontaneuous clotting formation. Plasmatic fibrinogen decreased within 3 minutes. Partial thromboplastin time (PTT) and one-stage prothrombin time (PT) were found. Plasma did not coagulate 40 minutes after inoculation. Platelet counts did not vary but their function was altered. Histopathology pointed out severe muscular necrosis and massive hemorrhage in the inoculation area. Regional ganglia showed intense hemorrhage. The 45 and 65-day-old animals showed alveolar thickening of the septum and generalized congestion, but the 30-day-old animals showed thrombosis of small arteries and arterioles. Renal lesions were different with the age. Cortical tubular necrosis was present in puppies, and intense cortical tubular hydropic degeneration was present in adult dogs. Thymus hemorrhage and necrosis were present.

Investigaçao dos casos de acidentes ofídicos na populaçao pantaneira,no Passo do Lontra,MS agosto/1993 a julho /1994 / Investigation about snake bite cases in population of pantanal sul-mato-grossense,in Passo do Lontra-MS August/1993 to July/1994

A regiao Centro-Oeste apresenta os maiores índices de acidentes ofídicos no Brasil.Entretanto,pouco se sabe a esse respeito na regiao do Pantanal sul-mato-grossense.Esse estudo visou obter dados sobre esse assuntoutilizando-se de um inquerito epidemiologico.Os autores estudaram a frequência dos acidentes ofídicos nessa localidade,observando a prática de metodos de prevençao e tratamento para esse tipo de agravo.

Evaluation of platelet number and function and fibrinogen level in patients bitten by snakes of the Bothrops genus

Platelet function and plasma fibrinogen levels were evaluated in 14 patients,1O males and 4 females, aged 13-59 years bitten by Bothrops genus snakes. There was a statistical difference (p< 0.05) among plasma fibrinogen levels evaluated 24 and 48 hours after envenomation. There was a tendency towards normalization after 48 hours of treatment. The low platelet number was clear in 24-48 hour evaluations with a tendency towards normalization after 48 hours of treatment (p< 0.05). When platelet function was stimulated by collagen and epinephrine, it appeared to be within normal values. On the other hand, when it was stimulated by adenosine diphosphate (ADP), platelet function was hypoaggregated by a single micromol concentration until 48 hours after treatment. At a 3 micromol concentration, there were alterations only before specific treatment (p < 0.05). Fibrinogen levels and fibrin degradation product (FDP) levels appeared to be altered in 83.33 per cent of patients evaluated. The authors suggest that platelet hypoaggregation is related to decreased fibrinogen and increased FDP levels.

Effects of antithrombin III and antivenom on procoagulant activity of Russell's viper venom in a whole blood model.

The procoagulant activities of Russell's viper venom were assessed in an in vitro whole blood model. Sequential samplings showed that the generation of fibrinopeptide A (FPA), a marker of thrombin activity, and platelet factor 4 (PF4), a marker of platelet activity, exhibited bi-phasic kinetics with an initial slow phase followed by a rapid phase of secretion. In the presence of Russell's viper venom, the generation of both FPA and PF4 was accelerated with the bi-phasic kinetics of PF4 being maintained while that of FPA completely disappeared. Administration of either antivenom (1,600 ng) or 10 IU antithrombin III (AT-III) had no antagonistic effect against the venom but combination of both resulted in a significant prolongation of both FPA and PF4 release (p < 0.05). High dose AT-III (20 IU) resulted in normalization of both FPA and PF4 kinetics and serial levels of both parameters were lower than those treated with the combined regimen, although these were not statistically significant. Unlike the untreated venom activated whole blood, there was no clot formation following treatment with either the combined regimen or high dose AT-III. The results of this study suggested that the effect of Russell's viper venom on the clotting cascade is more potent and direct than that on platelet activity. There were complementary effects between antivenom and AT-III is controlling of both FPA and PF4 release induced by the venom. Furthermore, in this in vitro experiment, AT-III alone when administered in a sufficient dose, abolished the procoagulant effects of Russell's viper venom.

Heparin therapy in Russell's viper bite victims with disseminated intravascular coagulation: a controlled trial.

A controlled clinical trial of low dose heparin was carried out in confirmed cases of Russell's viper bite. Twenty patients with systemic envenoming were included in the study. They were randomized to receive low dose heparin in an initial dose of 50 units/kg body weight intravenously immediately after antivenom followed by a continuous infusion of 10 unit 3 kg/hour in isotonic saline for 24 hours, or antivenom alone. Response to treatment was assessed clinically as well as by serial measurements of coagulation factors and biochemical values. No significant difference was observed in the outcome among two groups, the recovery rate from the clotting defect being similar in both. The mean serum creatinine values of the two groups were also not statistically different. The results indicated that there is no beneficial effect of adding heparin to the standard treatment by antivenom.

Acidente crotálico na infância: aspectos clínicos, laboratoriais, epidemiológicos e abordagem terapêutica / Crotalid bites in children: clinical, laboratory, epidemiologic aspects and treatment approach

Foram atendidas no Hospital das Clínicas da Faculdade de Medicina de Ribeiräo Preto/USP, durante os anos de 1980 a 1989, 21 crianças vítimas de acidente crotálico, 16 das quais apresentaram sinais clínicos de envenenamento grave à admissäo e 5, de envenenamento moderado. Quatro pacientes (20 por cento desenvolveram necrose tubular aguda, dois dos quais necessitaram métodos dialíticos. Um paciente (5 por cento) foi a óbito no 13§ dia do acidente, após intercorrências graves, como hemorragia digestiva e insuficiência respiratória aguda. Säo apresentadas as características clínicas, laboratoriais e epidemiológicas do acidente crotálico nesses pacientes, enfatizando os conhecimentos atuais sobre a fisiopatologia do envenenamento por Crotalus durissus terrificus. Ao mesmo tempo, pretendeu-se contribuir para a correta abordagem terapêutica, no que diz respeito ao emprego adequado do soro antiveneno e à prevençäo da necrose tubular aguda, a mais séria e grave complicaçäo do acidente crotálico

Alteraçäo do tempo de coagulaçäo sanguínea em pacientes picados por serpente Bothrops jararaca adulta e filhote / Changes of the blood coagulation time in patients bitten by young and adult Bothrops jararaca snakes

Trezentos e quarenta e oito casos de acidentes por Bothrops jararaca adulta (grupo A) atendidos no Hospital Vital Brasil, no período de 1975 a 1984, foram comparados com 623 casos de acidentes pela mesma serpente pórem filhote, atendidos no mesmo local e período (grupo B). Näo houve diferença estatisticamente significante entre os dois grupos no que se refere a faixa etária dos pacientes ou ao tempo decorrido entre o acidente e o atendimento. O grupo B, entretanto, apresentou incoagulabilidade sangüínea mais frequentemente do que o grupo A. Conclui-se qie os filhoes de Bothrops jararaca säo mais capazes do que as adultas de causar incoagulabilidade sangüínea em suas vítimas humanas

Las serpientes del genero bothrops en la amazonia colombiana: aspectos biomedicos (epidemiologia, clinica y biologia del ofidismo) / Snakes of bothrops genus in colombian amazonia: biomedical aspects (epidemiology, clinics and snakes biology)

Durante el periodo 1982- 1987 se estudiaron y trataron 279 casos humanos de mordeduras por diferentes especies de serpientes de los generos Bothrops, Micrucus (corales) y por colubridos de los grupos opistoglifodontes. Estas ultimas corresponden a los ofidios que poseen un par de dientes inyectores del veneno, situado a cada lado de la maxila y hacia el extremo posterior de esta. Mediante el examen clinico y de laboratorio se comprobo en 265 casos (94%) que la mordedura fue causada por una especie del genero Bothrops; tres accidentes fueron provocados por micrurus (1.7%) cinco casos por colubridos opistoglofodontes (1.8%) y seis mordeduras determinadas por colubridos del grupo aglifodontes (serpientes no venenosas). Los ofidios que causaron los accidentes fueron identificados mediante el examen directo de la serpiente agresora en 30% de los casos y en el 70% restante se reconocio la especie responsable correlacionando los hallazgos semiologicos clinicos y de laboratorio con las caracteristicas morfologicas del ofidio suministradas por los pacientes. Los resultados obtenidos mediante la investigacion realizada muestran en 94% de los pacientes los signos y sintomas de un accidente bothropico. Estas conclusiones coinciden con las observaciones medicas publicadas para otras regiones de Colombia y en otros paises de Sur America. Dentro del genero bothrops la especie B. atrox causo el 95% de los accidentes humanos registrados en el periodo de estudio. Consideramos, por los resultados senalados, que el B. atrox en la Amazonia colombiana es la especie mas importante...

Clinical features of viper bites in 72 Thai children.

A study of snake bites in 72 children admitted to Department of Paediatrics Chulalongkorn Hospital, during January 1972 to December 1977, was investigated in depth. In 29 cases, snakes were definitely identified as green pit viper. Nature of the bite was demonstrated. Their two main clinical manifestations were local swelling and bleeding diathesis. The former was graded I to IV in increasing severity. The latter consisted of ecchymosis, haematoma, haematemesis, haematuria, bleeding gums, epistaxis and bloody stool. Each of these two clinical signs seemed to be caused by a different component of the venom as they did not always manifest in association. Swelling, though not a specific sign, was however generally the sign that heralded the envenomization. 88.1% and 94.5% of systemic bleeding episodes occurred respectively within 24 and 48 hours after the bite. Only 6 episodes, 5.5%, occurred beyond 48 hours.

Bleeding manifestations in snake bite.

Bleeding following bites by the Malayan Pit Viper can either be local or systemic. Bleeding at the site of the bite is due to the local action of the venom as a vasculotoxin. Systemic bleeding occurs with severe poisoning and appears to be mainly dependent on platelet deficiency and the co-existing defibrination syndrome appears to play a minor role in the initiation of bleeding. Thus in the clinical situation non-clotting blood with no overt bleeding can continue up to weeks when specific antivenene is not given. Assessment of the severity of poisoning can easily be made at the bedside. Specific viper antivenene rapidly corrects the spontaneous bleeding and clotting defect of severe systemic poisoning but has no effect on local poisoning.