Severe methemoglobinemia due to insecticide poisoning
A 26-year-old lady with no premorbid illnesses allegedly consumed about 20 ml of an insecticide called ‘Kick’ (composition: Biological extracts-2%, Stabilizers-8%, and Fillers and others-90%) with suicidal intent. She was found unresponsive and was taken to a local hospital where she was intubated and mechanically ventilated. She was referred to our hospital after 24 hours of ingestion for further management. At presentation, she was cyanotic with a heart rate of 160/min and blood pressure of 110/70 mm Hg. Saturation measured by pulse oxymetry was 80% on 100% oxygen and her blood was noted to be dark brown in color []. This raised the suspicion of methemoglobinemia and was confirmed by serum MetHb levels of 91% on co-oximetry. Glucose 6 phosphate dehydrogenase (G6PD) level was normal. She was administered 2 mg/kg of methylene blue and a repeat Arterial Blood Gas (ABG) at 1 hour showed a reduction in MetHb level to 27%. Another bolus dose was administered following which the MetHb level decreased further to 13.6%. In view of possible rebound increase in MetHb levels, methylene blue infusion was started at 10 mg/hr for 24 hours and gradually tapered off over the next 24 hours. On the 3rd day, she developed hemolysis and methylene blue had to be discontinued following which hemolysis resolved. Three pints of packed red cells were transfused to maintain the hemoglobin level above 9 gm%. MetHb levels slowly decreased and reached levels of <2% only after 6 days. High dose injection Vitamin C and Riboflavin was also administered. Her sensorium improved with the above measures and she was slowly weaned off the ventilator after 9 days. She had complete neurological recovery at discharge from the ward.