Critical Care, SRM Medical College Hospital & Research Center, Kattankulathur Kanchipuram, Tamil Nadu 603203
SRM is a tertiary hospital surrounded by 110 villages with a rural agrarian community. Cobra and Saw Scaled Viper bites are common. The latter causes haemotoxicity, including procoagulant activity, and ASV is titrated against haematological responses. We relate our experiences on prognostic value of haematological investigations.
All snakebite victims were admitted to the ICU equipped with ventilators, pulse-oximeters, etc., and an intensivist team trained in BLS/ACLS skills. First aid, severity assessment, and ASV administration with baseline ECG, CXR, and haematological and blood biochemistry were done, including LFT, RFT, BT, CT, APTT, PT, D-dimer, FDP and total fibrinogen. Assessments of patient's vitals were monitored 1/2-hourly; clotting time measured 6–hourly, and subsequent ASV doses administered as required. Repeat D-dimer, FDP and fibrinogen were tested even after clotting time had returned to normal, and ASV stopped. Patients were observed for 48 hours after cessation of ASV therapy, and discharged.
Alterations in fibrinogen, FDP and D-dimer occurred in all the viperine bites but normalized late, long after CT had normalized. ASV was not resumed based on altered FDP/D-dimer. Patient was discharged once clinically and haematologically stabilized (including FDP/D-dimer & fibrinogen).
Saw scaled viper venom has procoagulants, disintegrins and haemorrhagins. Procoagulants are mainly factor V/X/IX-activating, prothrombin activating and fibrinogen clotting. Fibrin cross-linking occurs outside the protected environment of platelet plug. In massive envenomation, thrombi formation may cause coronary or cerebral events. Fibrinolysis occurs close on the heels of thrombi formation, causing reduction in total fibrinogen. Hence heparin is considered taboo. ASV was titrated against clotting time alone as a gold standard. ASV need not be wasted based on FDP/D-dimer and fibrinogen.
