Methemoglobinemia after ingestion of ammonium nitrate can lead to significant morbidity and mortality in affected patients. Ammonium nitrate is a primary ingredient in synthetic "cold packs," which are used in healthcare as a substitute for bags of ice. Acute or chronic ingestion can have serious consequences to patient health including isosmotic diuresis, metabolic acidosis, circulatory collapse and gastritis. Methemoglobinemia is a result of nitrite toxicity. This toxicity can be compounded by patient comorbidities, which may further complicate treatment. Rapid and accurate diagnosis is essential in the treatment of Methemoglobinemia following ammonium nitrate ingestion.We present the case of a 76 year-old woman who was admitted for small bowel obstruction (SBO) and unintentionally ingested the contents of a cold pack. The patient subsequently became tachycardic, hypotensive, and unresponsive requiring urgent resuscitation and management in the ICU setting. Methemoglobin levels were elevated. The patient was treated with methylene blue (MB) and made a full recovery.

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