(A) Non poisonous sting
Signs and symptoms
Severe excruciating, burning pain at sting site, radiating along adjacent dermatomes. No other systemic involvement.
- Infiltration of local anesthetic agent without adrenaline, gives temporary relief from pain.
- Dehyroemetine hydrochloride injected at the sting site gives prolonged relief.
- Oral non steroidal antiinflamatory drug (NSAID) with antacid.
- Anxiolytic: Diazepam.
- Myocardial failure and pulmonary edema: Propped up position, oxygen, intravenous aminophylline, repeat dose of prazosin and in massive life threatening pulmonary edema where time is great enemy, immediate pulmonary congestion reduced by sublingual iso–sorbide dinitrate or NTG and then sodium nitroprusside drip but such situation is rarely arises if prazosin administered earlier.
- Anxiolytic: Diazepam.
- Immunization for tetanus.
- Dopamine, Adrenaline.
(B) Poisonous sting (Bite)
Signs and Symptoms
- Vomiting once or twice, profuse sweating from all over body, sweats literally flows over body, sweating persisted for 7 to 17 hours after sting.
Hypersalivation persisted 5 to 10 hours. These symptoms resulting in hypovolemia (Dehydration).
- Victim is agitated, confused, anxious had propped up eyes and puffy face.
- Severe priapism in male persisted 5 to 24 hours.
- Hypertension, blood pressure raise up to 240/160 mm Hg. due to autonomic stimulation.
- Hypotension, 60 to 70 mm of Hg due to hypovolemia and vesodilation caused by Acetyl chorine action.
- Bradycardia (heart rate 42–58) or tachycardia (110–210).
- Cardiac arrhythmias – Ventricular premature contraction bigiminy, trigiminy, couplets and rarely no sustained ventricular tachycardia is transient and often self limiting, do not require any active intervention unless there is hemodynemic disturbances.
- Transient systolic parasternal lift and grade 2/6 systolic murmur.
- Shivering due to sweating.
- Ice cool extremities and skin looks frost bitten, victims complaint of parasthesias (needle, pins and ants all over body) due to severe vaso–constriction caused by catecholamine induced alpha stimulation.
- Fasciculations and tendon reflexes are exaggerated.
- Abdominal pain.
- Pain at the sting site is mild or initially due to vasoconstriction.
- Pulmonary edema with haemoptysis.
- Peripheral circulatory failure, tachrcardia and convulsions.
- Reassurance to victim and relatives (this is essential in kokan area particularly thane, raigad and ratnagiri where from 30 to 40 % mortality due to acute pulmonary edema as a result of scorpion sting reported in the past. People are more afraid of scorpion than snake bite).
- Vigorous oral rehydration therapy to replace loss of fluid due to sweating vomiting and hypersalivation.
Prazosin 250 microgram to child and 500 microgram to adult administered as early as possible, 2nd dose repeated within 4 hours according to response if temperature of skin, extremities, pulse volume, blood pressure (reduction in raised blood pressure and improvement if hypotension on admission), subjective feeling and reduction in paraesthesias. Later on repeated six hourly till extremities became dry warm usually took 10 to 24 hour. During this therapy victim must experience severe excruciating burning pain at sting site which was mild or absent initially confirming improved tissue perfusion caused by alpha blockade property of prazosin. Once prazosin is administered blood pressure, pulse rate should be manually monitored every 30 minute for hours, then every hour for next six hour and every 4 hourly till extremities became warm.
First dose phenomenon
Rarely severe hypertension due to profound vasodilaton can occur after initial dose usually within 30 to 90 minute after first dose. To avoid this initial dose administered is very low, victims are not allowed to sit or stand and vigorous replacement of hypovolemia by ORS.
Slow calcium channel blocker because of negative inotropic action can precipitate pulmonary edema and should not be used in impending myocardial failure with hypertension. It has no additional benefit over prazosin in severe hypertension due to scorpion sting.
While discharging the patient
- Extremities are dry and warm (Compare with relatives).
- Had severe pain at sting site which was absent or mild on admission.
- Good volume pulse with pulse pressure 20–30 mm of Hg and rate less than 90 per minute.
- Sleep without sedation.
- Passed normal urine output without diuretics.