1) CASE SERIES/BOTHROPS JARARACUSSU: In a series of 29 cases of proven Bothrops jararacussu envenomations, shock and intractable severe hypotension (i.e., blood pressure undetectable in one case) were the main clinical features in 2 fatal exposures. An adult and child died despite large doses of antivenom and aggressive supportive care. Although bites by this species are relatively infrequent, it is suggested that larger snakes (i.e., longer than 50 cm) are more venomous (Milani et al, 1997).

1) Following a Crotalus durissus terrificus evenomation, a 24-year-old man developed shock which was likely secondary to profuse bleeding that occurred at both the fang marks and venipuncture sites during the first 12 hours (Ekenback et al, 1985).

1) Episodes of hypotension, bradycardia, and other clinical symptoms commonly associated with shock have been reported within 15 minutes of being bitten by a bushmaster. In regions of Colombia, bushmaster bites have produced hypotension along with sweating and nausea (Jorge et al, 1997).

1) CASE REPORT: A 74-year-old man was bitten by a B lanceolatus (Fer-de-lance pit viper) and did not seek help immediately. Two days later, he was found comatose and transported to the hospital with normal vital signs, laboratory studies and a normal angio-MRI. A myocardial infarction was diagnosed based on ECG changes and an elevated serum troponin-1c levels. He was treated in the cardiac care unit with no signs of neurologic improvement. Six days after the bite, the patient developed atrial fibrillation and left ventricular failure and rupture of the papillary muscles of the mitral valve; the patient did not respond to resuscitation efforts. Autopsy revealed diffuse thrombotic microangiopathy, with intimal-medial dissection by thrombi, of the small arteries and arterioles of the heart, mesentery, brain, kidneys and lungs (Malbranque et al, 2008).

1) South American rattlesnake (Crotalus spp) envenomation can result in acute respiratory failure secondary to neurotoxic or myotoxic activity of the venom. This can result in ventilatory disorders and impaired respiratory muscle function (Meier & White, 1995).

1) Severe coagulopathy in a 60-year-old man bitten by a Bothrops asper resulted in spontaneous bleeding that included hemoptysis (Kornalik & Vorlova, 1990).

1) CASE SERIES: In a series of 309 patients bitten by Bothrops species, 8 patients (2.6%) with a mean age of 51.9 years developed a cerebrovascular event (ie, hemorrhagic stroke {n=7}, or ischemic stroke {n=1}). Of the 8 patients, 6 presented 8 hours or more after being bitten. All had evidence of decreased neurologic function on admission (coma or lethargy). Each also had pain and swelling around the bite site, and four had signs of systemic bleeding. CT indicated intracranial hemorrhage in the cerebral hemispheres (n=5), cerebellum (n=1), and the subarachnoid space (n=1). Five of the eight patients died and the remaining 3 developed permanent sequelae (Mosquera et al, 2003).

1) Three patients died within 4 days of envenomation by Bothrops lanceolatus species. Death was due to massive cerebral infarctions. Thrombotic complications have been reported occasionally following B lanceolatus envenomation (Thomas et al, 1996).
2) CASE REPORT: A 74-year-old man was bitten by a B lanceolatus (Fer-de-lance pit viper) and did not seek help immediately. Two days later, he was found comatose and transported to the hospital with normal vital signs, laboratory studies and a normal angio-MRI and tetraplegia. A myocardial infarction was diagnosed based on ECG changes and an elevated serum troponin-1c levels. He was treated in the cardiac care unit with no signs of neurologic improvement. Six days after the bite, the patient died. Upon autopsy, myocardial and cerebral infarcts were observed and may have been associated with the presence of diffuse thrombotic microangiopathy involving the arteries and arterioles of the brain and heart, as well as other organs (Malbranque et al, 2008).

1) CROTALUS DURISSUS TERRIFICUS: A man developed persistent neurological symptoms (over a month), after c. d. terrificus envenomation. Symptoms gradually improved following rehabilitative therapy. However, the patient remained weak and incontinent of urine at night. Six months after exposure, the patient reported feeling well, but an electromyogram showed evidence of reinnervation of the motor units, and the action potential of the sensory nerves were still considered low (Ekenback et al, 1985a).

1) Nausea and vomiting are relatively common following moderate to severe pit viper envenomations (Meier & White, 1995).

1) CASE REPORT: A 28-year-old man was bitten on the finger by a L. m. muta (a male, approximately 182 cm long) and developed nausea, vomiting and profuse watery diarrhea within 1 hour of envenomation, along with localized pain and swelling of the digit. Despite antivenom (L. muta venom), antiemetic therapies, and IV hydration, the patient continued to have bilious vomiting, abdominal colic, and repeated episodes of watery diarrhea up to 8 hours after the bite. Symptoms gradually resolved 24 hours after exposure (Jorge et al, 1997).

1) Hematemesis has been reported following envenomations by Bothrops, Lachesis muta and Crotalus durissus terrificus species (Kornalik & Vorlova, 1990; Ekenback et al, 1985).

1) Hematemesis and melena occurred in a young adult man following a Crotalus durissus terrificus envenomation (Ekenback et al, 1985).

1) LACHESIS (BUSHMASTER): A 28-year-old man, envenomated by a bushmaster pit viper, developed hemorrhagic manifestations characterized by hypofibrinogenemia without thrombocytopenia. Coagulation studies were notable for prolonged prothrombin time (PT) with a normal activated partial thromboplastin time (aPTT). The authors suggested, that consumption of factor VII by circulating venom produced the clinical and laboratory effects observed (Torres et al, 1995).

1) The presence of a low platelet count upon admission has been associated with severe systemic bleeding in patients envenomated by Bothrops jararaca species. The early use of antivenom is recommended (Santoro et al, 2008).

1) CASE REPORT: A woman died within 45 minutes of pulmonary hemorrhage following a Bothrops jararacussu envenomation. At autopsy, evidence of hemorrhage and disseminated intravascular coagulation were present. As compared with other Bothrops species, B. jararacussu (found in the jungles/forests of Brazil) venom has a higher lethal potency. The authors speculated that the rapid onset of symptoms and death may have been due to IV inoculation as noted by a bite mark near the great saphenous vein (Benvenuti et al, 2003).
2) CASE SERIES: In a retrospective study of 792 snakebites by Bothropoides jararaca presenting to the Vital Brazil Hospital of Paulo Brazil, blood clotting time was abnormal in 457 (59%) patients with 40.8% (n=316) cases reported as incoagulable (Nicoleti et al, 2010).

1) In a case series of Bothrops lanceolatus envenomations, of the 11 patients with thromboses, 5 had no coagulation abnormalities, 3 developed disseminated intravascular coagulopathy, and 3 had thrombocytopenia. Laboratory parameters indicated an increase in fibrinogen levels and aPTT in most patients (Thomas et al, 1996).

1) Pit viper envenomations can commonly result in rapid localized swelling. Following severe envenomations, edema may progress along with ecchymosis and local tissue injury. Bothrops and Lachesis species can lead to massive swelling that can include the entire limb (Jorge et al, 1997; Meier & White, 1995). Although not commonly reported, compartment syndrome can develop following envenomation (Franca et al, 2003; Meier & White, 1995).

1) CASE REPORT: A 28-year-old man bitten on the index finger developed almost immediate swelling and pain, which gradually progressed over several hours to include swelling of the entire limb within 6 hours. Despite antivenom therapy (within 2 hours of the bite) and supportive care, the limb and shoulder area remained swollen for 24 hours after the bite. Swelling remained for five days, along with blistering of the hand, but the patient retained full range of motion and no residual necrosis was reported (Jorge et al, 1997).

1) In a prospective and transverse study of snakebites by Bothrops and Bothropoides (these include: Bothropoides erythromelas, Bothrops leucurus and Bothropoides neuwiedi) in the State of Paraiba, edema (n=357; 87.1), pain (n=393; 95.9%) and ecchymosis (n=109; 25.9%) were the most common local effects observed. Overall most cases resulted in mild (64.6%) envenomation (Oliveira et al, 2010).

1) In a retrospective study of 792 snakebites by Bothropoides jararaca presenting to the Vital Brazil Hospital of Paulo Brazil, most cases (80%) showed no or mild envenomation. Most cases presented with pain (n=651; 82.2%) edema (n=646; 81.6%), and ecchymosis (n=388; 49%) (Nicoleti et al, 2010).

1) CASE REPORT: A 43-year-old man was bitten by a Bothriopsis taeniata (the snake was identified at the hospital) above the ankle and was admitted about 2.5 hours later with swelling to just below the knee with minimal bleeding. The patient was alert and oriented and laboratory studies showed a slightly elevated creatine kinase and lactate dehydrogenase, but otherwise normal. The patient was treated with anti-Bothrops antivenom and leg swelling resolved within 2 days and the patient was discharged with no sequelae. Bothriopsis tatenia is a rare pit viper found in Brazil (Torrez et al, 2009).

1) Pit viper envenomations can produce local infection, due to the buccal flora of a snake. Bothrops species in South America have been commonly associated with infection. The most frequent pathogens isolated are gram negative aerobes, Staphylococcus aureus, and anaerobic microorganisms. In Brazil, the rate of infection varies by both species and geographic region (Meier & White, 1995).

1) In a case series of 56 children who were envenomated by Bothrops spp and treated with antivenom, one of the main clinical complications observed was local infection in 15.1% (including cellulitis, 9.6%, and abscesses, 5.5%) of cases. Severe envenomations were associated with a higher frequency of local infection (Bucaretchi et al, 2001). In another case series, local abscesses were reported in 5 patients (n=29) following B. jararacucu envenomation and 6 developed local necrosis (one case resulted in amputation) (Milani et al, 1997).

1) Soft tissue infections have been observed in 11% to 30% of envenomations by Bothrops asper. Cellulitis is usually prominent. Other effects can include impetigo, abscess and fascitis. Infection is more likely to occur following a moderate to severe envenomation and is more likely in patients that develop severe edema, hemorrhage, myotoxicity and necrosis (Otero-Patino, 2009).

1) Infection with gram-negative organisms and clostridial gas gangrene have been reported following Lachesis muta bites (Jorge et al, 1997).

1) Compartment syndrome has been observed in 3% of patients envenomated by B asper. In some cases, severe swelling can lead to compartment syndrome especially bites on an extremity (eg, finger, foot) (Otero-Patino, 2009).

1) CASE REPORT: A 39-year-old man was bitten by a B jararaca (species identified in the emergency department) on the leg and developed intense local pain and swelling. Within 6 hours of envenomation, the patient received 8 vials of bothropic antivenom for moderate to severe envenomation. Approximately, 8 hours after envenomation, elevated anterior compartment pressures (60 mm Hg) were observed, but improved with antivenom therapy. However, at 20 hours post bite, serum CK levels (3452 Units/L and 6729 Units/L at 40 hours post bite ) were elevated with ongoing pain in the leg. A fasciotomy was performed at 57 hours due to increased anterior intracompartmental pressure (66 mm Hg). His hospital course was further complicated by infection and permanent fibular palsy with foot drop (Bucaretchi et al, 2010).

1) Bleeding at the puncture site is relatively common following pit viper (eg, Crotalus, Bothrops, Lachesis muta) envenomations (Meier & White, 1995)

1) Rhabdomyolysis and alterations in serum creatine kinase are possible with Crotalus envenomations. In South America, if rhabdomyolysis is present, myotoxicity is also possible (Meier & White, 1995).

1) Severe elevations in CPK and significant rhabdomyolysis occurred with Crotalus durissus terrificus envenomation in an adult and child, despite antivenom therapy. At autopsy, rhabdomyolysis was evident in both cases (Azevedo-Marques et al, 1985).

1) SOUTH AMERICA: Following pit viper envenoming (eg, in particular Crotalus durissus), systemic myotoxicity can develop. Initial symptoms usually include muscle pain which can be severe, along with myoglobinuria (red or dark urine) and evidence of rhabdomyolysis (increased serum creatine kinase {especially CK(3) and CK(2)}). Myoglobinuric acute renal failure is the most common cause of death in Crotalus envenomations (Meier & White, 1995a).
2) CENTRAL AMERICA: Localized myonecrosis frequently develops after pit viper envenomation, and if extensive can result in significant pain. In most cases, myonecrosis is a result of myotoxins having a phospholipase A(2) structure, which can produce muscle cell damage by disrupting the integrity of skeletal muscle cells. However, evidence of systemic myotoxicity usually does not develop (Meier & White, 1995a).

1) Acute renal failure is relatively common following Bothrops spp and some Crotalus spp (ie, C. durissus durissus, C. durissus terrificus) envenomations. Its presence is likely multifactorial, and has been associated with the development of myoglobinuria (most common cause), rhabdomyolysis or prolonged hypotension (Otero-Patino, 2009; Pinho et al, 2008; Milani et al, 1997; Amaral et al, 1980; Azevedo-Marques et al, 1985; Caiaffa et al, 1994; Avila et al, 1980; Hardy, 1994; Rosado-Lopez & Laviada-Arrigunaga , 1977).

1) In Central America, the development of renal failure is secondary to several factors: tubular necrosis secondary to ischemia, direct effect of venom on the kidneys, and inadequate tissue perfusion secondary to hypovolemia. Although localized myonecrosis can occur, rhabdomyolysis or myoglobinuria (even in severe cases) have not been reported in this region (Meier & White, 1995).

1) CROTALUS and BOTHROPS SPECIES: In South America, myoglobinuric acute renal failure is the most common cause of death in Crotalus envenomations. The myotoxic effects (myoglobin liberation and excretion in the urine) and possible nephrotoxic effects of the venom likely contribute to the clinical effects observed. The development of acute renal failure is dependent on the severity of the envenomation and timing of antivenom therapy. Within the first 48 hours, acute tubular necrosis with oliguria or anuria can develop (Meier & White, 1995).
2) CHARACTERISTICS:
3) PREDICTIVE FINDINGS: In a study of 87 victims of South American rattlesnake (Crotalus durissus terrificus, C. d. collilineatus and others) envenomation, myalgia and neurotoxic facies were predictive of renal failure in patients older than 40 years (Silveira & Nishioka, 1992).

1) CASE SERIES/BOTHROPS JARARACUSSU: In a series of 29 cases of Bothrops jararacussu envenomations, metabolic acidosis developed in two patients that died from envenomation. In the first case, a 3-year-old girl developed intractable metabolic acidosis (pH 6.65, bicarbonate 3.5 mmol/L), along with shock, respiratory failure and coma. Despite antivenom and aggressive care, the child died within 19 hours of envenomation (Milani et al, 1997).

a) If blood is still liquid and runs out it is indicative of a venom-induced coagulopathy.
b) Inaccurate results may occur if the vessel had been cleaned previously with detergent. Incoagulable blood is more frequently associated with viper envenomations.

1) A blinded methodological study was conducted to determine the potential effectiveness of various plastic containers as compared to glass in performing the whole blood clotting time (WBCT) (for 20 minutes) in envenomed patients. An initial pilot study demonstrated that WBCT without venom was significantly different between glass and various plastic containers (ie, polypropylene, polyethylene and polycarbonate). Polypropylene and plain polyethylene were considered unsuitable for further testing because of their prolonged clotting times of greater than 60 minutes in the presence of venom. The findings further suggested that various venom concentrations (0 ng/mL to 100,000 ng/ml were initially tested) could significantly alter the clotting time. No clotting was observed in either the glass or polycarbonate tube for venom concentrations above 100 ng/mL. Samples of 0 ng/mL and 10 ng/mL were used in the study because they clotted in 20 minutes. Polycarbonate (mean time of 29.5 minutes in the presence of venom) was considered a suitable alternative to glass if the threshold for clot identification was increased to 35 minutes. However, the authors concluded that differentiating between various plastic materials may be difficult and polycarbonate tubes may not be readily available in all healthcare facilities; therefore, the authors recommended the continued use of glass tubes (Stone et al, 2006).