Polyvalent Snake Antivenom Research Articles

Clinical, hematobiochemical, and pathological findings and therapeutic management of viperine snake envenomation in zebu cattle.

The present investigation was carried out to study the epidemiology, clinical signs, bleeding profile, kidney function, and pathology and to evaluate the therapeutic protocol for viperine snake envenomation in zebu cattle over a period of 14years. A total of 98 cases of viperine bite were reported with the highest incidence during monsoon months in grazing male zebu cattle. Ascending swelling over the affected limb with lameness or asymmetrical swelling over the face with dyspnea was a consistent clinical finding. Increased bleeding tendency was invariably observed in ailing cattle with major bleeding from the site of the bite. Hematobiochemistry showed neutrophilic leukocytosis, thrombocytopenia, prolonged capillary blood clotting time, and elevation of BUN and creatinine. The characteristic gross pathological lesions observed were widespread petechial to ecchymotic hemorrhages in the lungs, liver, heart, spleen, abomasal mucosa, and intramuscular or subcutaneously at the site of bite. Histopathological examination revealed presence of necrohemorrhagic changes within the liver, heart, kidneys, skeletal muscles, and subcutaneously or intradermally at the site of bite. Diagnosis of viperine snakebite was made based on circumstantial evidence of bite, progressive swelling, and bleeding at the site of bite. The severity was assessed based on prolongation of capillary blood clotting time, thrombocytopenia, and kidney dysfunction. Therapeutic protocol comprising polyvalent anti-snake venom along with supportive therapy for 5-9days showed encouraging results with 88.30% survival rate. In conclusion, the precise diagnosis of viperine snake envenomation in cattle can be made from history and typical clinical signs while severity and treatment can be monitored based on bleeding profile.

A comparative study in the outcome between the two fixed doses of polyvalent anti snake venom, 10 vials versus 20 vials, with mechanical ventilation in children with severe neurotoxic snake envenomation

Background: Every year about 50,000, people die of snake bites in India. Anti-snake venom and mechanical ventilation is mainstay of treatment in cases with severe neurotoxic envenomation. ASV is costly and scarce resource. There is lack of universal consensus towards the optimal dose of ASV in management protocol for children with severe neurotoxic snake envenomation. Objective was to compare the difference in outcome between two fixed doses of ASV, 10vials versus 20 vials, in children with severe neurotoxic snake envenomationMethods: This comparative observational study was carried out for a period of 3 years in Department of Pediatrics of SVS Medical College, Mahabubnagar, Telangana, India. Children with history of snake bite and clinical evidence of neuroparalysis were included. In addition to the mechanical ventilation and other supportive measures, every alternate patient was administered with 10vials (low dose) and 20 vials (high dose) of ASV over 1 hour. Outcome was compared between the two groups.Results: Of the 62 patients, 32 were in each group. The median time to extubation was 41 hours and 39.5 hours and mean duration of the hospital stay was 4.6 days and 4.5 days among the low dose and high dose groups, respectively. There were three deaths, one from low dose group and two from high dose group.Conclusions: There was no significant difference in outcome between the 10 vials vs 20 vials of ASV in addition to mechanical ventilation in treatment of children with severe neurotoxic snake envenomation. So, 10 vials of ASV can be utilized to reduce the cost of treatment.

Isolation and pharmacological characterization of α-Elapitoxin-Na1a, a novel short-chain postsynaptic neurotoxin from the venom of the Chinese Cobra (Naja atra)

The Chinese Cobra (Naja atra) is an elapid snake of major medical importance in southern China. Although previous studies have shown that postsynaptic neurotoxins account for 11–23% of N. atra venom, envenomed patients do not display marked signs of neurotoxicity. We have previously shown that the lack of clinical neurotoxicity following snake envenoming by some species with ‘neurotoxic’ venoms may be related to the high prevalence of short-chain postsynaptic neurotoxins in these venoms. In this study, we describe the isolation and characterization of α-Elapitoxin-Na1a (α-EPTX-Na1a; 6949 Da), a short-chain postsynaptic neurotoxin, which accounts for approximately 9% of N. atra crude venom. α-EPTX-Na1a (30–300 nM) produced concentration-dependent inhibition of indirect-twitches, with a t90 value of 17 ± 2 min at 300 nM, and abolished contractile responses to exogenous acetylcholine and carbachol, in the chick biventer cervicis nerve-muscle preparation. The prior addition of either Chinese N. atra monovalent antivenom (0.3 U/ml) or Australian polyvalent snake antivenom (2.4 U/ml), prevented the in vitro neurotoxic effects of α-EPTX-Na1a (30 nM). Addition of each of these antivenoms at the t90 time point partially reversed the in vitro neurotoxicity caused by α-EPTX-Na1a (30 nM). The inhibition of indirect twitches by α-EPTX-Na1a (30 nM) was not reversed by repeatedly washing the tissue. α-EPTX-Na1a displayed pseudo-irreversible antagonism of concentration-response curves to carbachol with a pA2 value of 8.21. De novo protein sequencing of α-EPTX-Na1a revealed a typical short-chain postsynaptic neurotoxin profile of 62 amino acids which shared >98% amino acid sequence similarity with short-chain postsynaptic neurotoxins from other Naja species. When compared to short-chain neurotoxins isolated from cobras in China, α-EPTX-Na1a contained novel residues K47Q (i.e. lysine to glutamine), N48T (i.e. asparagine to threonine) and G49A (i.e. glycine to alanine). In conclusion, α-EPTX-Na1a is a potent, pseudo-irreversible, short-chain neurotoxin. The high prevalence of α-EPTX-Na1a in Chinese N. atra venom is likely to explain the mild neurotoxicity experienced by envenomed patients.

Plants used for the treatment of snakebite among Hausa-Fulani Tribes in Tsiga District, Bakori Local Government Area Katsina State Nigeria

Traditional snakebite Healers farmers and Fulani cattle rearers in some villages in Tsiga District, Bakori local government Area Katsina State, were interviewed through the use of structured questionnaires for the various ways they manage snakebite in their livestock and among the people of their community they provided information on plants and parts used, mode of preparation and administration, habit, source and availability of medicinal plants. Field excursions were conducted along forest trails taking traditional healers as guides and voucher specimens of cited medicinal plants were collected. Result obtained showed that at least 83% of the respondents rely on the use of plants in managing snakebite on people or their livestock. Plants belonging to 12 different families were encountered. The common venomous snakes found in the study area include Black necked spiting Cobra (Naja nigricollis), puff adder (Bitis arietans), and saw scaled viper (Echis carinatus) polyvalent anti-snake venom is the only known therapeutic agent available throughout the world major drawback of serum therapy is its prohibitive cost and chance that victims may avail untimely medical care because of remote locations when bitten. The present article presents plants used for the treatment of snakebite randomness or the use of a variety of species in different families appear to be a feature of traditional snakebite treatments. Plants encountered can provide an alternative to the use of conventional antivenom.

Trimeresurus Malabaricus Bites: Need of Species-specific Management for Snakebites.

Dear Editor, Apart from the “big four” species of venomous snakes, the pit vipers (hump nosed, Malabar, bamboo) and banded kraits are the other types seen in Kerala. Malabar pit viper (Trimeresurus malabaricus) is an elusive species, seen in the forests of the Western Ghats. We have come across the case of a 54-year-old healthy female after a snakebite. On examination, she had a bite mark on the right parietal region of the scalp, with swelling and tenderness in the surrounding area extending to the neck. She also had multiple tender lymph nodes in the right jugulodigastric and posterior auricular groups [Figure 1a]. She had no features of neurotoxicity. Her 20-min whole blood clotting test (WBCT) was prolonged. The snake was later identified and confirmed to be a Malabar pit viper [Figure 1b]. 20-min WBCT and coagulation profiles repeated periodically for the next 48 hr were normal. Even though characteristics of pit viper bites have been previously profiled,[12] the incidence of Malabar pit viper bites is less. Envenomation following Malabar pit viper bites results in significant local reaction and hematotoxicity, along with milder forms of renal impairment. The Polyvalent anti-snake venom (ASV) used in India does not contain antibodies against pit viper venom and since cross neutralization with venoms of other species of snakes has not been proven,[3] its use is considered futile the treatment. With snakebites other than the “big four” snakes covered by the polyvalent ASV on the rise, the need for newer techniques for identification of snakes and development of species and region-specific antivenom is the need of the hour.Figure 1: (a) Enlarged right jugulodigastric lymph node with swelling seen on the right neck. (b) Photograph of the offending snake Malabar pit viper (Trimeresurus malabaricus) on the tree branchDeclaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

An Experimental Study On Anti venom Activity Of Visha Bilwadi Gutika In Cobra Venom Injected Wistar Albino Rats

Visha Bilwadi Gutika is an herbal formulation mentioned in Kriya Kaumadhi used in snake bite cases in Kerala. In this study, an attempt has been made to explore the therapeutic value and mode of action in Wistar Albino Rats injected with cobra venom. The lyophilised snake venom of cobra was dissolved in saline and administered to rats. The lyophilised polyvalent anti snake venom was used as reference standard drug. The test drug Visha Bilwadi Gutika was evaluated for its efficacy to neutralise the cobra venom by assessing the lethality, haematological, biochemical and histological changes. The venom used in this study was found to have LD50 of 1098μg/kg using OECD 425 protocol. Analysis of the result shows good protection by Visha Bilwadi Gutika against low intensity envenomation. Moderate protection was observed against high dose venom injection in acute conditions. Haematological examination shows significant decrease in RBC, platelets, ALP and cholesterol in comparison to normal control group.

Can the methanolic extract of Andrographis paniculata be used as a supplement to anti-snake venom to normalize hemostatic parameters: A thromboelastographic study

Ethnopharmacological relevance of Andrographis paniculataThe whole plant (including leaves and roots) is used in traditional Ayurveda and Siddha medicine to treat various clinical conditions such as fever, respiratory tract infections, colic pain, liver disorders, diabetes, hypertension, and inflammation. It is also used as an antidote for snake-bite, poisonous bites of insects and recommended as a dietary supplement to boost immunity. Aim of the studyIn-vitro thromboelastographic evaluation of the efficacy of methanolic extract of Andrographis paniculata (MAP) and polyvalent anti-snake venom (ASV) in neutralizing the Naja naja (N.N) venom-induced changes in hemostatic parameters. Materials and methodsThromboelastographic evaluation of hemostatic parameters was initiated by adding 3μg N.N venom to citrated whole blood from healthy volunteers. The effect of different concentrations of ASV and MAP in neutralizing the toxicity of N.N venom were studied in two groups. In group 1 experiments, citrated whole blood (340μl) was mixed with N.N venom (3μg), immediately followed by successive addition of ASV (5μl, 8μl and 15μl) or MAP (15μg, 30μg, 60μg and 120 μg) or combination of ASV and MAP (3μl ASV+30μg MAP and 3μl ASV+60μg MAP). In group 2 experiments, N.N venom was incubated with whole blood for 90 minutes at 37°C, followed by successive addition of ASV (5μl, 10μl, and 15μl) or MAP (30μg and 60μg) or combination of ASV and MAP (5μl ASV+30μg MAP and 5μl ASV+60μg MAP). ResultIn Group 1 experiments, N.N venom caused significant (p<0.05) increase in R-time, K-time, LY30% and a decrease in angle and MA. Optimum effect on hemostatic parameters was observed at a concentration of 8μl ASV, where all the deleterious effects of the venom were completely reversed. Similarly, the addition of MAP to the assay system could reproduce results as ASV, in reversing the deleterious effects of the venom. This occurred in a concentration-dependent manner, from 15μg-60μg, with the optimum results at 60μg. When ASV concentration was reduced to 3μl and supplemented with MAP (30μg or 60μg), the positive supplementary effect of MAP was demonstrated.In Group 2 experiments, N.N venom caused significant (p<0.05) changes in all TEG parameters, with most deleterious changes observed in MA and LY30% compared to Group 1 experiments. ASV when added in increasing concentrations (5-15μl), had beneficial effects only on K-time, angle, and MA. When added together with ASV, MAP (30μg or 60μg) could significantly (p<0.05) supplement the effect of ASV (5μl) in improving R-time, K-time, and angle. ConclusionThis in-vitro study demonstrates the effectiveness of MAP as a supplement to ASV in combating the deleterious effects of N.N venom on hemostasis. However, further in-vivo experiments in animal models are required to substantiate these effects.

On the Potential of Phytochemical Remedy for Envenomation and the Consequent Endocrinopathy, with a Note on Conservation – A Case Study of Venom Informatics

Envenomation is a serious neglected health issue at the global level that affects millions of people every year. It is highly prevalent among farmers and rural natives and is mainly due to the bite from snakes, spiders, frogs, dogs, wasps, bees, ants, etc. Many plants with antidote potential grow around our backyard without proper recognition and, unfortunately, several of them are under threat of extinction due to human interference and other environmental factors. The sustainable utilization of those antidote herbs can benefit as a life saver to the needy patients. The herbs can also be farmed and used commercially for the pharmaceutical application and incorporated with biotechnology and bioinformatics with a vision of synthesizing antidote drugs with less or no side effects. The objective of the present work is to create awareness among the public for the wise use of wild and local herbs, and their sustainable utilization with a computational case study on laboratory experiments done in two traditional plant based antidotes, selected from literature. The investigation is focused on Daboia russelii venom neutralization via in silico approach which can significantly reduce the time, expense, labour and samples taken. Our approach will add to the conventional non-specific polyvalent anti-snake venom (ASV) with more specific plant-based antidotes.

Snake envenomation: is the 20 min whole blood clotting test (WBCT20) the optimum test for management?

The 20 min whole blood clotting test (WBCT20) is a simple bedside test recommended by World Health Organization (WHO) to assess hemotoxic envenomation and guide administration of polyvalent anti-snake venom (ASV). However, reliability and validity of this test has not been well documented in literature. Sixty consecutive patients with history of snake bite were prospectively evaluated at a teaching hospital in India over 2 years. Envenomation was established by clinical and laboratory criteria. WBCT20 was done at 0, 4 and 12 h using standardized protocol. Prothrombin time (PT) with international normalized ratio (INR) was estimated at similar intervals to detect venom-induced consumption coagulopathy. Sensitivity, specificity and likelihood ratios (LR) were determined for WBCT20 using envenomation criteria as gold standard. WBCT20 was compared with PT/INR at cutoff values of ≥1.4 and ≥1.2. Two observers performed test-retest correlation to determine inter-observer variability of WBCT20. . WBCT20 is a highly sensitive test with excellent reliability for detecting envenomation. However, the false positive rate in this study was 24%. Asymptomatic snake bite patients with a positive WBCT20 but no corresponding clinical signs of envenomation should be tested using PT/INR before receiving ASV to prevent unnecessary waste of anti-venom.

A polyvalent coral snake antivenom with broad neutralization capacity.

Coral snakes of the genus Micrurus have a high diversity and wide distribution in the Americas. Despite envenomings by these animals being uncommon, accidents are often severe and may result in death. Producing an antivenom to treat these envenomings has been challenging since coral snakes are difficult to catch, produce small amounts of venom, and the antivenoms produced have shown limited cross neutralization. Here we present data of cross neutralization among monovalent antivenoms raised against M. dumerilii, M. isozonus, M. mipartitus and M. surinamensis and the development of a new polyvalent coral snake antivenom, resulting from the mix of monovalent antivenoms. Our results, show that this coral snake antivenom has high neutralizing potency and wide taxonomic coverage, constituting a possible alternative for a long sought Pan-American coral snake antivenom.

A clinical dilemma in an unconscious patient

Snake bite is a major life-threatening emergency seen more commonly in rural tropical countries. In general, about 70% of the bites are nonpoisonous, 15% are dry bites, and only 15% cause envenomation. Venom is the saliva of snake ejected during biting, from the poison apparatus (the modified parotid glands). It can be neurotoxic, vasculotoxic, or myotoxic in its action. The polyvalent antisnake venom is effective against most common poisonous snakes. Prompt diagnosis and timely administration of the polyvalent antisnake venom can reduce mortality and morbidity to a great extent. We present a case which was brought to the emergency department of without any previous forthcoming history of snakebite, with symptom such as abdominal pain, chest pain, vomiting, and respiratory distress followed by loss of consciousness. The patient was timely resuscitated and with prompt use of polyvalent ASV and neostigmine the patient recovered without any neurological symptoms within a week.

Assessment of quality, safety, and pre-clinical toxicity of an equine polyvalent anti-snake venom (Pan Africa): Determination of immunological cross-reactivity of antivenom against venom samples of Elapidae and Viperidae snakes of Africa

Snakebite causes a large amount of morbidities and mortalities in Africa. The safety, efficacy, and homogeneity of anti-snake venoms are crucial for snakebite treatments to be effective with minimal adverse effects. We assessed the homogeneity of preparations of three different batches of Combipack snake venom antiserums (Pan Africa) [CSVAPA] by quantitatively analysing F(ab’)2, IgG, and other contaminating proteins of plasma. LC-MS/MS analysis showed that approximately 92.4% of the proteins from the CSVAPA samples was IgG/F(ab’)2 and the percent composition of contaminating proteins in CSVAPA varied from 0.07 to 4.6%. Batch 1 of the CSVAPA also contained a minor amount of undigested IgG and F(ab’)2 aggregates. CSVAPA contained more than 60% venom-specific antibodies, showed moderate complement activation, no IgE contamination, safe level of endotoxin, and also showed pre-clinical safety. The immuno cross-reactivity of CSVAPA against 14 Viperidae and Elapidae snake venoms of Africa was tested by ELISA and immunoblotting, and the neutralization of major enzymatic venom activities, demonstrating that high molecular weight (>50 kDa) venom proteins are better recognized/neutralized compared to relatively low molecular weight (<20 kDa) venom proteins. CSVAPA at a dose of 3–12 times higher than the clinical dose did not cause deaths or adverse reaction of treated rabbits. The results suggest the satisfactory quality, safety, and efficacy of CSVAPA.

Management of snakebite victims using low dose antisnake venom in a tertiary hospital in Southern Nigeria: A 5-year Retrospective study

Objective : Antisnake venom (ASV) is a specific antidote for the management of snake bite envenomations. This study profiled the treatment and outcome of adult snake bite victims managed using low dose antisnake venom. Methods: This was a 5-year retrospective study that involved all adult patients who presented in University of Benin Teaching Hospital, Benin City, Nigeria, with a history of snake bite. Information obtained were demographic characteristics, clinical features, and administered treatment per established. All patients with a diagnosis of snake bite envenomation were administered ASV. Results : Sixty patients were seen during the study period, 35(58.3%) males, 25(41.7%) females with a mean age was 34.7±13.3. The mean time from bite to presentation was 14.67±14.05 hours with range of 1- 48 hours. Twenty patients (33.3%) had snake bite envenomations, of these eleven (57.9%) were managed and discharged after administration of 30 to 40 mls of polyvalent ASV. The mean dose of PASV used was 3.9 ± 2.0 vials. The most encountered clinical indication for ASV administration was progressive painful swelling. No death was recorded throughout this period studied. Conclusion : Adoption of the low dose regimen in the management of snake bite envenomations may be as effective as the traditional high dose regimen. Key words: Snake bite, envenomation, polyvalent antisnake venom, Nigeria.

Multidrug-resistant infection following snakebite envenoming: A case report

Snake Bite Envenoming (SBE) is a major under-appreciated medical and public health problem causing significant mortality and morbidity, particularly among rural dwellers throughout the tropics. Occasionally, snakebite may lead to important complications such as amputation, blindness resulting from spitting cobra (Naja nigricollis) induced venom ophthalmia, foetal loss, wound infection, tetanus and scarring with potential for malignant transformation. Here, we report a case of a 13 year old student bitten by a snake whose bite site became infected with multidrug resistant Methicillin Resistant Staphylococcus aureus (MRSA). He was bitten on the neck, in the night while sleeping on his bed. The bite site suppurated, the skin underwent necrosis and began to discharge thick brownish pus necessitating surgical exploration to drain deep-seated abscesses. The patient survived the acute phase after receiving intravenous polyvalent anti-snake venom (EchiTab-Plus(R)) and intravenous Levofloxacin in addition to wound care. The case stresses the need for comprehensive care of victims of snakebite. This care should be multidisciplinary, and health care workers should be educated on snakebite wound care and management.

Neurotoxicity following snakebite and the challenges of management in an urban area—a case report

Snakebites disproportionately affect the lower socioeconomic segments of the society, people with poorly constructed houses, and those with limited access to education and health care. Cases of snakebite are rare in urban areas. Therefore, health centers located in urban areas are sometimes unprepared for managing cases of snakebite. Potent snake antivenoms are not available, and most healthcare workers lack basic training needed for the management of snakebite. Here, we report a case of 28-year-old cleric who was rushed to the accident and emergency unit of an urban tertiary hospital on account of snakebite injury involving the left forearm. At presentation, there was history of persistent vomiting and hypersalivation. However, there was no history of bleeding from the site of bite, hematemesis, hematuria, or bleeding from any orifice. He later became confused with altered level of consciousness, developed bilateral ptosis, and broken neck sign. The patient survived after receiving intravenous polyvalent snake antivenom (EchiTab-plus; Instituto Clodomiro Picado, Costa Rica), which was incidentally purchased for laboratory experiment and not for patient care. The case highlights the challenges frequently encountered in the management of snakebite victims, especially in nonendemic areas; it also stresses the need for urban health centers to stock snake antivenom in their pharmacy and train healthcare workers in the management and care of snakebite victims.

False positive immunoassay for acetyl choline receptor antibody (AChR Ab) in patients exposed to polyvalent antisnake venom

Acute flaccid paralysis is a neuromuscular emergency characterized by rapidly worsening weakness that evolves quickly to cause diaphragmatic failure. The challenge for the treating physician is to stabilize the patient, generate the differential diagnosis and determine the management; all in quick time. Neurotoxic snake bites have inadequate signs of inflammation and are easily missed. Myasthenic crisis, on the other hand, could be the first sign of myasthenia gravis in up to 20% of patients. Both present with acute respiratory failure and inadequate history. Two of our patients presented with similar clinical picture, and received polyvalent anti-snake venom obtained from hyperimmunised horses (Equus caballus). Both tested positive for anti-acetyl choline receptor antibody. After recovery, both patients narrated a history suggestive of neurotoxic envenomation. We later discovered that patients, who are exposed to polyvalent anti-snake venom (Equus caballus) prior to radioimmunoassay, demonstrate high titers of Anti-AChR Ab in their serum erroneously.

Prognosis of Hepatic Amyloidosis Status and Insufficiency in Snake Antivenom Producing Horses

Hyperimmunization of horses with specific antigens to harvest antisera is associated with high incidence of liver amyloidosis. The histopathologic examination is the gold standard method for diagnosis of the hepatic amyloidosis. The aim of the present study was to determine whether the clinical manifestations and serum values of appropriate chemical constituents due to liver injury, provide the prognostic criteria for liver amyloidosis and insufficiency. it was endeavored to determine the usage duration and survival in the horses, applied for polyvalent snake antivenom products. Thirty-seven Iranian, mixed breed male horses used for snake antivenom production were recruited in this study. All of the clinical characteristics of liver disease were assessed and the appropriate serum biochemical parameters were screened between two hyperimmunization stages. The results revealed that weakness, progressive weight-loss and chronic diarrhea were the warning signs for end of the period of using a horse in snake antivenom production. However, moderate to severe colic, often, was the sign of imminent death due to acute hepatic swelling and rupture. However, Serum biochemical findings were not suitable and useful for the assessment of outcome compared with the clinical manifestations. In this study, the authors have attempted to introduce the clinical and serum biochemical findings that are useful for prediction of the liver amyloidosis and insufficiency and, to determine the usage duration and survival in these horses. Consequently, a preliminary scoring guideline for assessing the issue was suggested.

A CASE OF NEUROTOXIC SNAKE BITE IN A METROPOLITAN CITY (NEW DELHI): PAIN ABDOMEN WITH ANAPHYLAXIS AS A PRESENTATION

Snake bites present as life threatening emergencies and are seen more commonly in rural tropical countries. Snake bites have neurotoxic, hemotoxic, myotoxic or mixed presentation. We present a case of neurotoxic snake bite in an urban setting of New Delhi, a metropolitan city, where snake bites aren’t common. The patient presented as an acute emergency in casualty, without any previous forthcoming history of snake bite, with a history of pain abdomen, vomiting and signs of anaphylaxis. Rapidly progressive neurological deficit started with ptosis followed by stridor, dyspnoea, respiratory arrest and shock. The patient was given standard management of anaphylaxis and snakebite (polyvalent anti-snake venom and neostigmine) based on WHO guidelines of snake bite. Patient recovered without any neurological deficit within a week. Although snakebites are rare in urban setting, they are reported. Neurotoxic snakebites can occur in sleep by kraits and can present as catastrophic life threatening emergency in early morning hours, as in our case.

Use of anti-snake venom and clinical outcomes in snake envenomation: a prospective observational study

Background: The only effective measure to prevent or reverse most of the manifestations of venomous snake-bite is timely administration of antisnake venom (ASV) with or without adjunctive treatment as necessary in each case. But recently several concerns have been raised with regard to use of polyvalent ASV. Hence the present study was conducted to assess use of ASV, early adverse reactions to ASV, adjunctive treatment and clinical outcomes in snake-bite patients, which would help to identify areas of problem and provide basis for planning strategies to increase rational use of drugs.Methods: It was a prospective observational study approved by Institutional Ethics Committee. All indoor patients with systemic manifestations of snake envenomation were included in the study. All participants gave written informed consent. Data was obtained prospectively using a structured case record form. Descriptive statistics was used to express the results.Results: Among 52 patients, snake-bite predominantly affected males (59.62%) than females (40.38%). The most common site of snake-bite was lower limb (65.38%). The main indication for ASV administration was vasculotoxic snake-bite (59.62%). Mean dose of ASV use was 18.21±15.51 vials. Mortality was seen in one patient. Majority of patients (28/52, 53.85%) received ASV in the range of 1-10 vials for the management of snake-bite.Conclusions: The use and dose of ASV was appropriate in vasculotoxic snake-bite while few neurotoxic snake-bite patients needed higher than recommended dose.

Clinical profile & complications of neurotoxic snake bite & comparison of two regimens of polyvalent anti-snake venom in its treatment.

Background & objectives:The optimal anti-snake venom (ASV) dose required to treat neurotoxic snake envenomation is not known. Low-dose ASV (national protocol: maximum dose 200 ml) may be as efficacious as the conventional regimen (100 ml six hourly till all symptoms disappear), but a direct comparison of the regimens is not available. The aim of this study was to test the efficacy of low-dose ASV regimen against the conventional high-dose regimen.Methods:The clinical profile of 51 patients with neurotoxic snake envenomation was studied. Patients were treated with either the national protocol or the conventional protocol for ASV administration. The time to complete recovery of symptoms, duration of mechanical ventilation and total dose of ASV were compared.Results:More patients were females (28 vs. 23) bitten in the early morning hours (2400-0600 h). Thirty nine of 51 (76.4%) patients required mechanical ventilation. In terms of progression of neuroparalysis, time to complete resolution of ptosis and occurrence of VAP and ASV reactions, there was no difference. Duration of mechanical ventilation was less with the national protocol (24 vs. 43.5 h). Significantly less amount of ASV was used with the national protocol (224 vs. 982 ml) per patient. There were no mortality or permanent neurological sequelae with either regimen.Interpretation & conclusions:In this preliminary study, it was found that the national ASV protocol was as effective as the conventional regimen for neurotoxic snake bites. However, the findings need to be tested in a larger randomized controlled trial for definitive conclusions.