The Dose Makes the Poison: A Case Report of Acquired Methemoglobinemia

Abstract

Background: Methemoglobinemia (MET) should be suspected in cases where cyanosis is not associated with signs and symptoms of lung and/or heart disease, or in a cyanotic child exhibiting discrepancies in the partial pressure of oxygen in the arterial blood, the blood oxygen saturation, and the clinical assessment. Case presentation: A 10-month-old girl was taken to the Pediatric Emergency Department for the acute, sudden development of significant peroral cyanosis associated with gray pigmentation of the skin. The problem was evidenced approximately one hour after she ingested a homemade puree of mixed vegetables, mainly composed of potatoes and chards that had been prepared three days before and had been kept in the refrigerator since then. Physical examination revealed that the child was very pale, conscious, and without respiratory distress. Oxygen saturation of hemoglobin in the arterial blood (SpO2) was 94%. Respiratory, cardiovascular, and abdominal evaluations did not reveal any signs of disease. A venous blood sample showed chocolate-colored blood with a pH of 7.404, a partial pressure of CO2 (pCO2) of 40.6 mmHg, a partial pressure of oxygen (pO2) of 21.3 mmHg, a bicarbonate level of 24 mmol/L, and an oxygen saturation (SO2%) of 47.7%. CO-oximetry carried out simultaneously identified a methemoglobin level of 22%. MET was suspected, and oxygen via nasal cannula at a rate of 4 L/min was given with only a slight increase in oxygen saturation (96%). Slow intravenous injection of methylene blue 1 mg/kg over a period of 5 min was initiated. The peripheral oxygen saturation (SpO2) gradually improved to 100% over the next 20 min. Forty minutes later, venous blood gas analysis showed a methemoglobin level of 0.9% with a complete resolution of cyanosis; supplemental oxygen via nasal cannula was therefore discontinued. During the next 36 h, the patient remained hemodynamically stable with good oxygenation on room air. Conclusions: This case report shows that recognition of acquired MET in a child with sudden cyanosis onset requires a high index of suspicion. In daily activities, there is a need to pay particular attention when homemade vegetable soups for child alimentation are prepared. The consumption of vegetable soups must occur immediately after preparation. Storage in a refrigerator must last no more than 24 h and if longer storage is needed, vegetable soups should be frozen.

Genotype and Successive Harvests Interaction Affects Phenolic Acids and Aroma Profile of Genovese Basil for Pesto Sauce Production

“…However, scientific evidence regarding the correlation of nitrate consumption with chronic disease onset relegates it among the most widely recognized anti-nutritional compounds [ 25 ]. Usually, nitrate is safe due to its rapid excretion in the urine [ 42 ], but under specific conditions, it can be reduced to nitrite [ 43 ], which is acknowledged to play a crucial role in carcinogenesis and the incidence of blood diseases such as methemoglobinemia [ 27 ]. Given its well-documented hazardousness, nitrate is a potentially harmful anion that can affect horticultural produce quality since its raw consumption is the principal source of human dietary intake [ 26 ].…”

“…Although the regulation n° 1258/2011 of the European Commission has not set a threshold value for basil, its leaves can accumulate nitrate values higher than 5000 mg kg −1 of fresh weight [ 26 ]. Pharmacologically, nitrate has very low toxicity, but if ingested, it is reduced by saliva and digestive system into nitrite and N-nitrose compounds (e.g., nitrosamines), which oxidize hemoglobin into methemoglobin, interfering with oxygen transport and causing in children a pathology known as methemoglobinemia [ 27 , 28 ].…”

An acquired acute methemoglobinemia from dietary sources: Case reports and literature review

“…12 Children at higher risk of intoxication are those below the age of 6 months, due to the reduced gastric acid production, a gut microbiota rich in nitrate-reducing bacteria, an immature methemoglobin reductase system, and the presence of certain amount of fetal hemoglobin that is more easily oxidized. 13 Whereas in the second case described, both the age and the food history of the child quickly suggested the diagnosis, the first case that we described concerned a 10-years-old boy, which reminds us that, although unusual, this condition can occur at any age, especially in situations in which there is less availability of fresh food and therefore people consume more processed food.…”

Homozygous Methemoglobinemia Course in a 2-Year-Old Girl

“…В данном случае диагноз метгемоглобинемии был установлен случайно при обследовании в связи с травмой. Тем не менее, врачам следует проявлять клиническую настороженность в отношении длительного изолированного цианоза при отсутствии сердечной патологии, так как при своевременно начатом лечении можно избежать серьезных осложнений [8][9][10].…”