Middle ear cholesteatoma resection under general anesthesia in patients with congenital methemoglobinemia: A case report.

RATIONALE: Congenital methemoglobinemia is a rare cyanosis cause that can be manifested in affected individuals. We report a case of congenital methemoglobinemia after middle ear cholesteatoma resection under general anesthesia. PATIENT CONCERNS: The primary concern of the patient is to safely perform cholesteatoma resection of the middle ear to reduce the pain associated with years of surgery and to survive the perioperative period. DIAGNOSES: Congenital methemoglobinemia type 1. INTERVENTIONS: The patient underwent general anesthesia and cholesteatoma resection of the middle ear. OUTCOMES: The patient successfully underwent cholesteatoma resection in the middle ear under general anesthesia and went through the perioperative period smoothly, and successfully returned to society. LESSONS: For patients requiring general anesthesia complicated with rare methemoglobinemia, we improve the awareness of crisis and make comprehensive preparation and monitoring, learn the pathophysiological mechanism related to the disease, so as to protect the operation of methemoglobin patients under general anesthesia.

A Curious Case of Methemoglobinemia Complicating a Pediatric Live Donor Liver Transplantation Surgery.

BACKGROUND: Pediatric live donor liver transplantation (LDLT) surgery is by itself a complicated surgery. Added to the difficulty in the operative technique are the complex preoperative work-up, optimization, and postoperative treatment. Intraoperative events and immediate postoperative recovery are important in graft function and the patient's overall recovery. Intraoperative greenish-blue urine and hypoxia are seldom seen during this period in the case of LDLT. Knowing the differential diagnosis and treatment are of predominant importance. METHODS: A case of decompensated chronic liver disease due to Wilson's disease underwent routine LDLT. Here we describe an uncommon complication, methemoglobinemia, which complicated this patient's recovery. The case is presented for the condition's rarity and the confusing clinical picture it produced. RESULTS: Observations of greenish-blue urine, ascites, serum, gastric aspirate, bile, maroon or brown-colored blood, and hypoxia with normal PaO2 were made in this case. Timely diagnosis of suspected drug-induced methemoglobinemia and treatment, which led to the uneventful recovery of the patient, are explained. CONCLUSION: Even though methemoglobinemia does not have a direct graft effect, it can affect the graft oxygen perfusion and the overall oxygenation of the postoperative patient, causing adverse impacts if not detected and treated promptly. No such association of methemoglobinemia with Wilson's disease or during transplantation has been reported in the literature so far.

Acquired methemoglobinemia: A systematic review of reported cases.

INTRODUCTION: Acquired methemoglobinemia may cause cyanosis and tissue ischemia unresponsive to oxygen supplementation. METHODS: We performed a literature search to identify cases of acquired methemoglobinemia published between 1980 and 2020. Clinical, diagnostic, and treatment details were extracted from eligible cases. RESULTS: A total of 76 reports involving 87 cases were analyzed. The median age at presentation was 32.5 with male to female ratio of 1.6. Cyanosis and SpO2 <90 % were reported in 82 % and 60 % of cases, respectively. Dapsone or cocaine-based anesthetics were causative in 52 % of cases; most anesthetic-related cases occurred in the peri-procedural setting. Methylene blue (MB) and red cell transfusion were given in 71 % and 10 % of cases, respectively. Compared to MB untreated patients, MB treated patients were more likely to be cyanotic (91.9 % vs 54.2 %), had higher proportions (%) and levels (g/dL) of methemoglobin (MetHb) - 33.2 % vs 15.3 % and 3.1 g/dL vs 1.2 g/dL, respectively. We found that among cyanotic cases, the median MetHb level was 3.0 g/dL (0.4-12.3 g/dL) with 74 % of values ≥ 1.5 g/dL. An SaO2:SpO2 ratio of >1 was not universally present, but always coincided with an [SaO2-SpO2] delta value greater than zero. CONCLUSIONS: Cyanosis and hypoxemia were not universal findings of acquired methemoglobinemia in our series. In addition, not all patients had cyanosis at MetHb ≥ 1.5 g/dL or an SaO2:SpO2 ratio of >1. All those with an SaO2:SpO2 >1 did, however, have a delta value greater than zero - a finding not previously reported which we feel holds diagnostic value.

Methemoglobinemia due to Hemolysis Secondary to Infection in a Child: A Case Report.

Methemoglobinemia is a rare condition characterised by hypoxic state manifesting as headache, nausea, fatigue, and confusion. We report a 2-year-old boy presenting with fever and cough for 7 days with an episode of hypoxia as the saturation declined and did not improve on face mask oxygenation. On further evaluation, acute intravascular hemolysis was established following decreased haemoglobin level, increased levels of lactate dehydrogenase, and unconjugated bilirubin in the setting of documented infection. Assessment of arterial blood gas showed a significantly raised saturation gap and detection of methemoglobin confirmed the diagnosis. He was managed conservatively with packed red blood cells transfusion following which hypoxia was corrected. Methemoglobinemia as a result of hemolysis can be a non-cardio-respiratory cause of hypoxia and inciting aetiology needs to be addressed. Keywords: case reports; hemolysis; hypoxia; infection; methemoglobinemia.

Fatal methemoglobinemia in three suicidal sodium nitrite poisonings.

Nitrites are chemicals that are abundant in the environment, widely used as preservatives for meat, and in pharmaceuticals. Volatile products containing nitrites have been used recreationally for the euphoric effect associated with mild hypoxia. Dietary exposure to small amounts is considered harmless. Deaths by ingestion of nitrite salts are not common, but accidental exposure and as suicidal and homicidal agents have been noted. Death is a consequence of oxidation of hemoglobin ferrous (Fe+2 ) iron (Hb) to the ferric (Fe+3 ) form (methemoglobin, MetHb), causing a reduction in the oxygen-carrying capacity of the blood. We report three cases of ingestion of sodium nitrite in two college students (one mildly decomposed) and one adult in early middle age. All of the decedents in these cases developed fatal methemoglobinemia. Sodium nitrite in chemical form was found near the bodies. MetHb was detected in the postmortem blood of each decedent. The MetHb concentrations in the two decedents with a short postmortem interval were less than MetHb concentrations reported in the current literature. The MetHb concentrations reported in the mildly decomposed person were greater than for the other two, but still less than the concentration previously considered lethal. The data from these cases indicate that levels of MetHb can vary widely in fatal cases, and should not be used as the sole criterion for determination of a death caused by sodium nitrite. Following a discussion of the cases, there is a review of the pathophysiology of MetHb production and a current literature review.

Hemolysis and methemoglobinemia in a child with left ventricular assist Levitronix PediMag.

A 5-month-old male was treated with left ventricular assist device due to cardiac failure secondary to dilated cardiomyopathy. The patient developed acute severe intravascular hemolysis with methemoglobinemia and renal failure, related to a mechanical problem due to pump cylinder misalignment. Secondary severe methemoglobinemia has not been previously described in patients undergoing ventricular assist device. Early detection of the signs and symptoms of hemolysis is crucial to prevent further complications.

High dose vitamin C induced methemoglobinemia and hemolytic anemia in glucose-6-phosphate dehydrogenase deficiency.

Investigational use of intravenous vitamin C has been on the rise, but its side effects may be underreported. A 75-year-old woman presented with acute onset of jaundice, dark urine and shortness of breath after receiving 30 g of vitamin C infusion as an unconventional therapy for her hemifacial spasm. Diagnosis of methemoglobinemia and hemolytic anemia was made clinically and confirmed on laboratory tests. She recovered with supportive treatment and packed cell transfusion. Her previously unrecognised underlying condition of glucose-6-phosphate dehydrogenase (G6PD) deficiency was confirmed months after the initial presentation. This is the first reported case of methemoglobinemia and hemolytic anemia induced by high dose vitamin C in a female patient with G6PD deficiency. The dosage of vitamin C administered was also relatively low compared with previous adult reports. When administered at physiological dose, vitamin C can be used as an alternative to methylene blue in treatment of methemoglobinemia in patients with G6PD deficiency. However at supraphysiological dose vitamin C can paradoxically lead to hemolytic anemia in the same group of patients. Physicians should be alert of these potential complications of high dose vitamin C.

Whole bowel irrigation in dapsone intoxication with persistent methemoglobinemia.

Dapsone intoxication can be a life-threatening condition due its enterohepatic recirculation pharmacokinetics, and therefore, persistent methemoglobinemia development. We describe a case of a 17-year-old girl who was admitted 4 h after ingesting 5 g of dapsone. She presented methemoglobinemia (39%) and showed clinical signs of toxicity (cyanosis and altered mental status) despite mechanical ventilation. Multiple activated charcoal dosis and methylene blue infusions were performed. Notwithstanding initial improvement, a pattern of peaks and valleys was observed in serial methemoglobinemia measurements, with cyclic states of hypoxemia. On account of enterohepatic recirculation pharmacokinetics, clearance was enhanced by whole bowel irrigation. After 7 days of hospitalization, she was discharged in good general condition.

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

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.

Fatal Methemoglobinemia Due to Acute Inhalation of Methyl Nitrite in an Industrial Accident.

Methyl nitrite is suggested to cause methemoglobinemia by generating methemoglobin, which may be lethal when the methemoglobin concentration exceeds 70%. However, intoxication with methyl nitrite is seldom reported compared with that with other nitrites. Here, we present an industrial accident involving methyl nitrite inhalation during its synthesis process that resulted in three fatalities and one survivor. The autopsy revealed conspicuous blue-gray discoloration in various parts of the body, including the skin, airway mucosa, vessels, brain, heart, and among other areas. The toxicological tests on the deceased showed methemoglobin concentrations in the blood over the lethal level and increased nitrite ion levels in the blood, gastric contents, liver, and lung tissue compared with those in control samples. The cause of death was determined to be methemoglobinemia-induced hypoxia due to methyl nitrite inhalation. This report provides evidence that in methyl nitrite intoxication, exposure duration has a significant influence on the postmortem changes and likelihood of a fatal outcome may be related to the age of the victim. More attention is required regarding the industrial hazards of this substance.

Diabetic Ketoacidosis Revealing Severe Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD-D) Deficiency with Methemoglobinemia: A Case Report.

BACKGROUND Glucose-6-phosphate dehydrogenase deficiency (G6PD-D) is the most common red blood cell enzymopathy disorder. Severe hemolysis due to G6PD-D may rarely manifest as methemoglobinemia. Although acute hemolytic crises are usually induced by the exposure to certain oxidative stresses, diabetic ketoacidosis may also elicit hemolytic reactions in G6PD deficient persons. CASE REPORT A 17-year-old male with type 1 diabetes mellitus presented with diabetic ketoacidosis and features of hemolytic anemia which turned to be G6PD-D related. Interestingly, the arterial blood gas of the patient showed an elevated methemoglobin level (8.1%). CONCLUSIONS G6PD-D induced hemolysis is conventionally caused by oxidative stress, however, we report here a case of G6PD-D induced methemoglobinemia as a complication of diabetic ketoacidosis that has not been, as far as we know, previously reported.

Fatal inhalation of volcanic gases in three tourists of a geothermal area.

The study reports the environmental, toxicological and histopathological forensic investigations applied on three victims of accidental death (father, mother and son), due to the fall in a volcanic pothole, during the touristic visit of the "Solfatara park", near Naples (Italy). At autopsy greenish skin discolouration was observed and all bodies showed the classical signs of asphyxial deaths, such as cyanosis and hemorrhagic pulmonary edema. Focal micro-hemorrhages were found in the brain at intracranial and subpial levels. The hemogasanalysis and spectrophotometric test on blood for Methemoglobin (MetHb), Carboxyhemoglobin (HbCO) and Sulfhemoglobin (SHb) showed pCO2, SHb and MetHb above the physiological levels. On biological specimens, toxicological analyses performed by GC/MS revealed high concentrations of hydrogen sulfide (H2S) and of thiosulfate (TS), its main metabolite. The monitoring of toxic gases on the death scene showed an unsafe environment, into the pothole, able to cause the sudden loss of consciousness of the victims with subsequent asphyxiation (knockdown effect). In particular, at the bottom of the hole, the maximum levels of H2S and carbon dioxide (CO2) were 2200 ppm and 98% respectively. For the family members, the cause of the death was assessed as acute poisoning by H2S and CO2. The fatalities, happened in quick succession as for a domino effect, were pretty similar to the asphyxial deaths by confined spaces, frequently observed in occupational setting. Fatalities secondary to accidental volcanic gases inhalation, such as H2S and CO2 in geothermal areas, have been already described but often without a forensic approach. To the best of our knowledge this is the first case that reports the accidental poisoning by volcanic gases involving three people, with different caracteristic of age and sex, allowing the correlation between toxicological and pathological results with the true levels of asphyxiating gas, measured on the death scene.

Neutropenia, Hypoxia, and the Complexities of Emergency Medicine: A Case of Dapsone-Induced Methemoglobinemia.

BACKGROUND: Methemoglobinemia is a rare dyshemoglobinemia that can be difficult to diagnose due to its nonspecific symptomatology and infrequent occurrence. A number of commonly used medications have been known to contribute to this disease process that results in acute hypoxemia. CASE REPORT: A 60-year-old man with history of acquired immunodeficiency syndrome presented to the Emergency Department (ED) with asymptomatic hypoxia. Supplemental oxygen proves to be ineffective in treating his low oxygen saturation. Numerous testing modalities are performed in the ED focused on an infectious versus pulmonary etiology prior to coming to the conclusion that the source is methemoglobinemia induced by dapsone therapy. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This article discusses the basic pathophysiology of the disease and the expected clinical findings. Patient outcome is correlated with prompt identification and discontinuation of the offending agents leading to the excessive accumulation of methemoglobin in the circulatory system. This makes it crucial that emergency providers know the symptomatology of the disease to facilitate appropriate treatment therapy.