sodium-chlorate and Methemoglobinemia

Topics: Adult; Child, Preschool; Chlorates; Cyanosis; Dapsone; Emergency Medical Services; Emergency Nursing; Fatal Outcome; Female; Follow-Up Studies; Humans; Infant; Infant, Newborn; Male; Methemoglobinemia; Risk Assessment; Spectrophotometry; Suicide, Attempted

Chlorate poisoning as a cause of methemoglobinemia is regarded in current literature to be resistant to treatment by methylene blue due to the oxidizing and denaturing properties of the chlorate anion, and often leads to severe renal and hematological complications with a high mortality rate. Recent case studies suggest practitioners have eschewed the use of methylene blue in such situations.. This report describes a case of chlorate poisoning presenting as severe methemoglobinemia successfully treated with methylene blue alone, believed to be a first in reported literature.. A 34-year-old male construction worker presented 4 h after accidental ingestion of an industrial chemical, with giddiness and breathlessness. Physical examination did not reveal any abnormal cardiorespiratory findings, although arterial blood gas analysis and pulse oximetry revealed an "oxygen saturation gap." Methemoglobin levels were found to be severely elevated at 66.8% 6 h after ingestion, and the patient was promptly treated with methylene blue. Clinical examination and laboratory tests suggested the absence of hemolysis at the time of treatment. The patient was discharged after a brief and uneventful hospital stay. Subsequent tests revealed the chemical ingested to be sodium chlorate.. The successful outcome in our case suggests that a window of opportunity as long as 6 h may exist during which treatment of chlorate poisoning with methylene blue may be of clinical value. We postulate that the absence of significant hemolysis and hematological alterations at the time of antidote administration may be a necessary prerequisite for treatment success.

Topics: Accidents, Occupational; Adult; Chlorates; Enzyme Inhibitors; Herbicides; Humans; Male; Methemoglobinemia; Methylene Blue; Poisoning

Topics: Acute Kidney Injury; Aged; Anemia, Hemolytic; Chlorates; Exchange Transfusion, Whole Blood; Female; Herbicides; Humans; Hyperbaric Oxygenation; Methemoglobinemia

Topics: Adult; Chlorates; Female; Herbicides; Humans; Male; Methemoglobinemia; Middle Aged

A case of severe sodium chlorate poisoning was observed within 5 h after suicidal ingestion of 150-200 g of the herbicide. Methaemoglobinaemia was the early symptom of the intoxication. Treatment with methylene blue and ascorbic acid could not prevent a massive haemolysis with disseminated intravascular coagulation. Hypercoagulation and hyperfibrinolysis could be treated successfully with exchange transfusions, heparin and fresh plasma. During the first hours, 70 mmol chlorate were excreted before complete renal failure occurred which required haemodialysis for several weeks. Clinical observations and in vitro experiments provide evidence that methylene blue is effective only in the very early stages of chlorate poisoning. Consequently, the following treatment is suggested: gastric lavage, exchange transfusion, bicarbonate infusion, haemodialysis, anticoagulation with heparin and substitution of clotting factors if necessary.

Topics: Adult; Blood Proteins; Chlorates; Female; Hemoglobins; Humans; Kidney Function Tests; Liver Function Tests; Methemoglobinemia; Suicide; Time Factors