Deadly shades of green: A cautionary tale of an organic biopesticide poisoning

Introduction

Methemoglobinemia is a potentially life-threatening condition characterized by the reduced oxygen-carrying capacity of hemoglobin. With the increasing popularity of natural and herbal biopesticides, there is a growing risk of exposure to substances that can induce this dyshemoglobinemia. This case report highlights the importance of recognizing and promptly treating methemoglobinemia in the context of biopesticide exposure, a concern relevant to various healthcare professionals.

Case description

A 70-year-old male presented to the emergency department (ED) in an unresponsive state following suspected ingestion of an unknown quantity of an organic biopesticide labeled "Bull Fight". Initial management included fluid resuscitation, endotracheal intubation and mechanical ventilation. The patient developed significant hypoxia and hypotension. Abnormal blood color and a saturation gap raised suspicion of methemoglobinemia, which was confirmed by co-oximetry (68.7 % MetHb). Treatment with methylene blue was initiated, leading to initial improvement. However, the patient experienced rebound methemoglobinemia, requiring additional doses of methylene blue. Despite treatment, the patient ultimately succumbed to pneumonia.

Discussion

This case underscores the potential dangers of organic biopesticides and the importance of considering methemoglobinemia in patients with unexplained cyanosis, saturation gap, and abnormal blood color. The increasing use of natural and herbal products in agriculture may expose individuals to undisclosed ingredients capable of inducing methemoglobinemia. Healthcare professionals across various specialities, including emergency medicine, critical care, toxicology, and primary care, must remain vigilant and maintain a high index of suspicion for this condition, especially in cases of biopesticide exposure.

Conclusion

Awareness of methemoglobinemia and its association with biopesticide exposure is crucial for all healthcare providers who may encounter such cases. Prompt recognition and treatment can be lifesaving. As natural biopesticide use increases, clinicians should be prepared to diagnose and manage methemoglobinemia effectively. Careful monitoring is crucial to detect and prevent rebound methemoglobinemia. Ongoing education and preparedness are essential to address risks associated with emerging agricultural practices and products.