A 23-month-old, 8-kg boy with known glucose-6-phosphate dehydrogenase (G6PD) deficiency presented with a coin lodged in the upper esophagus and required urgent rigid esophagoscopy under general anesthesia. Anesthetic management was planned to avoid drugs with oxidative potential and to minimize physiologic stressors that could contribute to hemolysis or methemoglobinemia. General anesthesia was performed using agents considered safe in patients with G6PD deficiency, with intraoperative management focused on maintaining normoxia using the lowest possible inspired oxygen concentration needed to maintain oxygen saturation above 95%, normothermia, and hemodynamic stability. The foreign body was removed without complications, and there were no clinical signs of hemolysis or methemoglobinemia during hospitalization. Postoperative monitoring included serial hemoglobin assessment and clinical surveillance for jaundice and dark urine for more than 24 hours, with no evidence of delayed hemolysis. A follow-up phone call at 72 hours confirmed that there were no symptoms. This case highlights a practical perioperative approach to emergent pediatric anesthesia in a patient with G6PD deficiency, emphasizing careful drug selection and proactive prevention and monitoring of oxidative triggers.

Garlic (Allium sativum) contains organosulfur compounds capable of inducing oxidative damage to erythrocytes in dogs, leading to hemolytic anemia and methemoglobinemia. Although Allium toxicosis is relatively common, fatal cases with detailed histopathological characterization are rarely reported. This case report describes a fatal episode of garlic toxicosis in a 3-year-old female mixed-breed dog. At necropsy, gastric contents included food material and raw garlic cloves (16 g). Gross findings included pulmonary hyperemia and thoracic hemorrhagic effusion. Histopathological examination revealed multifocal myocardial hemorrhages, diffuse pulmonary capillary congestion, hepatic sinusoidal dilation with hemorrhagic areas, splenic hemorrhage, and renal glomerular capillary dilation. These lesions were consistent with systemic hypoxic and vascular injury secondary to oxidative erythrocyte damage. The lower quantity of garlic recovered compared with reported toxic doses suggests possible individual susceptibility or incomplete recovery of ingested material. This case highlights the diagnostic value of histopathology in suspected Allium fatal toxicosis and contributes to increasing the limited literature describing these outcomes in dogs.

An outbreak of acute mortality affecting 13% of a herd of 450 beef cattle is described in the province of Salta, Argentina. The incident occurred after the introduction of the herd into a paddock that had previously been used for cattle confinement. Approximately 8 h after being introduced into the paddock, the affected animals developed hyperacute clinical signs, including weakness, ataxia, tachycardia and brown mucous membranes, followed by death within minutes. The autopsy findings included poorly coagulated dark chocolate-brown blood and generalized congestion, consistent with methemoglobinemia. The paddock vegetation was almost entirely composed of Tithonia tubaeformis. Diphenylamine tests on rumen contents, aqueous humor and plant material were positive for nitrates. This is the first report of T. tubaeformis as a cause of nitrate/nitrite poisoning.

Idiopathic angioedema is a potentially life-threatening cause of acute airway compromise, with reported mortality rates up to 30% when airway intervention is delayed. Methemoglobinemia, a dyshemoglobinemia that reduces hemoglobin's oxygen-carrying capacity, can be acquired from drugs such as dapsone and occurs in approximately 0.4-1% of exposed patients. The coexistence of these two entities is exceptionally rare, posing diagnostic and management challenges in the emergency setting.

Excessive nitrite in food poses a serious threat to public health. This compound not only induces methemoglobinemia by interfering with oxygen transport in the blood but also serves as a precursor to carcinogenic N-nitrosamines, posing long-term cancer risks. Thus, the development of rapid and highly sensitive methods for nitrite detection is crucial for ensuring food safety. Laccase mimics, which have been widely used for the degradation and detection of phenolic compounds, have recently emerged as promising tools for sensing various food contaminants. However, their application for nitrite detection has not been reported to date.

Neonatal cyanosis is commonplace, usually from respiratory or cardiac causes. Consideration of alternative or combined aetiologies was required when a 3-hour-old term male neonate with central cyanosis, low oxygen saturation (SpO2), and persistent pulmonary hypertension of the newborn (PPHN) confirmed on echocardiography, failed to respond to PPHN interventions. The high oxygen saturation gap and methemoglobin (MetHb) level of 16.2% shifted the working diagnosis to methemoglobinaemia. Possible triggering drugs were stopped and methylene blue was given without effect, prompting testing for haemoglobin variants. Though the SpO2 remained in the mid-80s, MetHb levels decreased, pulmonary pressures normalised by day of life (DOL) 4, and he was discharged home on DOL 22. Diagnostic testing confirmed the haemoglobin F-M-Fort Ripley mutation (HBG2: c.277C>T), a variant that affects fetal haemoglobin only and is therefore self-limited. In this case, the concurrent presentation of PPHN and congenital methaemoglobinaemia created significant diagnostic and therapeutic challenges.

BACKGROUND Methemoglobinemia is an uncommon hemoglobinopathy caused by oxidation of heme iron from its ferrous (Fe[2+]) state to the ferric (Fe[3+]) state, resulting in functional anemia that does not improve with supplemental oxygen. "Poppers" is a slang term for recreational drugs marketed as nail polish removers or room deodorizers, often sold under brand names such as "Jungle Juice," which may cause methemoglobinemia due to their nitrite content. CASE REPORT A 67-year-old White woman accidentally ingested "Jungle Juice" nail polish remover containing isobutyl nitrite, resulting in severe methemoglobinemia. Clinical hallmarks included cyanosis, chocolate-colored blood, refractory hypoxemia unresponsive to supplemental oxygen, and a partial pressure of oxygen (PaO2)-saturation gap. CONCLUSIONS Methemoglobinemia is a potentially life-threatening hemoglobinopathy that causes functional anemia unresponsive to supplemental oxygen. "Poppers" can induce methemoglobinemia. Despite legislative efforts to regulate these products and prevent misuse, manufacturers continue to exploit regulatory loopholes by producing chemical analogs exempt from current drug laws. Additionally, there has been an emerging trend of sodium nitrite ingestion to induce methemoglobinemia in suicide attempts over recent years, driven by its accessibility and increasing online dissemination. Given the rise in "popper" use and sodium nitrite ingestion, emergency physicians should be aware of these trends and the associated products to facilitate early recognition and prompt treatment of this rare condition.