Abstract Introduction Severe methemoglobinemia is a rare but potentially fatal cause of hypoxia and shock. While traditionally linked to inadvertent or iatrogenic drug or chemical exposure, intentional ingestion of sodium nitrite—readily obtainable for online purchase—has emerged as a novel method of self-harm. Rapid recognition and treatment are essential to prevent death. Case Presentation A 27-year-old previously healthy woman was found unresponsive at home with a white powder and a cup of water nearby. Emergency medical services noted profound cyanosis and an oxygen saturation of 75% despite 100% oxygen. On arrival, her Glasgow Coma Scale was 5, and she was hypotensive with a lactic acidosis (4.4) requiring immediate intubation and vasopressor support. Arterial blood appeared chocolate-brown with a high PaO2 (574), prompting co-oximetry which revealed a methemoglobin level of 88% (normal 2%). Intravenous methylene blue was administered emergently with rapid improvement in oxygenation and hemodynamics. Subsequent investigation confirmed intentional ingestion of sodium nitrite purchased online. The patient was quickly weaned off vasopressors and then extubated on hospital day 3 with intact cognition although significant weakness that recovered with an inpatient rehabilitation stay. Discussion This case illustrates a rapidly fatal but reversible toxidrome that may initially masquerade as refractory hypoxia or septic shock. Sodium nitrite is easily purchased online, often marketed on easily accessible chat forums as a “peaceful suicide” substance, contributing to a rise in intentional poisonings. Clinicians must maintain a high index of suspicion when faced with unexplained cyanosis, low oxygen saturation unresponsive to supplemental oxygen, and a normal PaO2. Immediate recognition and methylene blue administration are lifesaving. Conclusion As intentional sodium nitrite ingestion becomes more prevalent, awareness among frontline and critical care providers is imperative. Early identification of methemoglobinemia and prompt antidotal therapy can transform an otherwise fatal presentation into a survivable event. This abstract is funded by: None
Hildenbrand et al. (Fri,) studied this question.