CRITICAL ARRIVAL: ASSESSMENT ON ARRIVAL
– Vasculotoxic patients presenting with bleeding from multiple orifices with hypotension, reduced urine output, obtunted mentation (drowsy, confused), cold extremities need urgent attention and ICU care for volume replacement, pressor support, dialysis and infusion of blood and blood products (See following sections).
– Neuroparalytic patients presenting with respiratory paralysis, tachypnoea or bradypnoea or paradoxical respiration (only moving abdomen), obtunded mentation, and peripheral skeletal muscle paralysis need urgent ventilator management with endotracheal intubation, ventilation bag or ventilator assistance.
– Other patients can be evaluated to decide severity of their illness.
Patient assessment: Non critical arrival and Critical patients after stabilization
– Determine the time elapsed since the snakebite and as to what the victim was doing at the time of the bite, history of sleeping on floor bed in previous night.
– Determine if any traditional medicines have been used.
– Obtain a brief medical history (e.g., date of last tetanus immunization, use of any medication, presence of any systemic disease, and history of allergy)
– If the victim has brought the snake, identification of the species should be carried out carefully, since crotalids can envenomate even when dead. This is why bringing the killed snake into the emergency department should be discouraged.
– Careful assessment of the site of the bite and signs of local envenomation and examination of the patient should be carried out and recorded (Annexure 1). Monitor the patient closely and repeat all above, every 1-2 hourly.
– Check for and monitor the following: Pulse rate, respiratory rate, blood pressure and 20 minutes Whole Blood clotting test (20 WBCT) every hour for first 3 hours and every 4 hours for remaining 24 hours.
– Check distal pulses and monitor if there is presence of gross swelling. The presence of a pulse does not rule out compartment syndrome. Pain on passive movement, pallor, pulseless limb, hypoaesthesia over the sensory nerve passing through the compartment are suggestive of compartment syndrome.
Measure compartment pressure directly if there is concern that a compartment syndrome is developing. The diagnosis is established if the compartment pressure, measured directly by inserting a 16 G IV cannula and connecting it with manometer, is raised above 40 cm water/saline. Direct measurement is necessary before resorting to fasciotomy since compartment syndrome is rare in snakebite victims and fasciotomy done without correction of hemostatic abnormality may cause the patient to bleed to death