Evolution of coagulation abnormalities following Russell's viper bite in Burma

Abstract

The evolution of coagulation abnormalities was studied in Russell's viper bite victims who, on admission to hospital, showed no clinical signs of systemic envenoming. Based on the laboratory results and subsequent clinical course, three groups were distinguished. The first group, consisting of five cases, showed no activation of coagulation at any stage. The second group, consisting of six cases, developed mild to moderate abnormalities in some tests, particularly in the aPTT and factor V assay, which corrected to normal without treatment. The third group, consisting of nine patients, developed haemostatic abnormalities as early as 1-2 h after the bite, which progressed to severe defibrination 4-8 h later at which time antivenom was given. Comparison of the haemostatic abnormalities in the three groups suggested that serial monitoring of the serum FDP concentration may be of value in predicting the likelihood of systemic envenoming and progression to complete defibrination.

Detection of Venom after Antivenom Is Not Associated with Persistent Coagulopathy in a Prospective Cohort of Russell's Viper (Daboia russelii) Envenomings

“…Russell's viper venom contains factor X and factor V activators which result in the activation of the clotting pathway manifesting as venom induced consumption coagulopathy (VICC) [18] , [19] . VICC in Russell's viper envenoming is characterised by a prolonged prothrombin time (PT) or international normalised ratio (INR), decreased levels of fibrinogen, decreased levels of factor V, decreased levels of factor X, and elevated d-Dimer concentrations [6] , [20] – [22] . Once antivenom is administered there is a resolution of VICC with normalising of the clotting function times and replenishing of the clotting factors including a gradual increase in fibrinogen levels.…”

Venom Concentrations and Clotting Factor Levels in a Prospective Cohort of Russell’s Viper Bites with Coagulopathy

“…An earlier study by Than et al found a similar association between venom concentrations and the severity of the coagulopathy. [ 15 ] There was an association between venom concentrations and factor V and Factor X, consistent with the Factor V activator and Factor X activator toxins in the venom.…”

“…[ 14 – 17 ] Two studies also reported serial measurements of factor V and factor X, with initial low levels that recovered over 24 hours consistent with our study. [ 15 , 16 ]…”

“…The presence of very higher factor VII, VIII and IX levels (392%, 313% and 463% respectively; Fig 2 ) prior to antivenom is an unexpected finding, although earlier studies have reported high values in a small number of patients. [ 15 , 16 ] A possible explanation for this finding is that the presence of Russell’s viper venom (RVV) factor X activator toxin in the sample results in falsely high factor levels. The in vitro activity of the toxin would appear similar to the activity of factor VII, VIII and IX.…”

Bedside Coagulation Tests in Diagnosing Venom-Induced Consumption Coagulopathy in Snakebite

“…The search found numerous clinical studies from a range of different settings that have used a WBCT, including from Australia [ 30 ], India [ 31 ], Sri Lanka [ 32 ], Thailand [ 33 , 34 ], Myanmar [ 35 , 36 , 37 , 38 ], Nigeria [ 25 ], Brazil [ 39 ] and Papua New Guinea [ 40 , 41 ]. Further, the WBCT has been used to detect VICC caused by taxonomically diverse snakes, including true vipers such as Russell’s viper ( Daboia russelii ) [ 12 , 31 , 34 , 35 , 36 , 37 , 38 , 42 , 43 , 44 , 45 ], saw-scaled viper ( Echis carinatus ) [ 32 ], pit-vipers such as Bothrops jararaca [ 39 , 46 ], South-Asian hump nosed pit vipers ( Hypnale hypnale , Hypnale zara , Hypnale nepa ) [ 14 , 28 , 47 ], Malayan pit viper ( Calloselasma rhodostoma ) [ 48 ] and green pit vipers ( Trimeresurus albolabris and Trimeresurus macrops ) [ 49 , 50 ], as well as Australasian elapids such as Western brown snake ( Pseudonaja nuchalis ) [ 30 ], mulga snake ( Pseudechis autralis ) [ 30 ], Papuan taipan ( Oxyuranus scutellatus canni ) [ 40 , 41 ], Papuan black snake ( Pseudechis papuanus ) [ 51 ], some colubrids such as Philodryas olfersii [ 52 ] and Philodryas patagoniensis , and lamprophiids such as Mock viper ( Tomodon dorsatus ) […”