Methemoglobinemia


Epidemiology


Etiology

Hereditary/Congenital Methemoglobinemia

Hemoglobin M Disease

Hemoglobin E Disease

NADH Cytochrome b5 Reductase (cyb5R) Deficiency

NADPH-Flavin Reductase Deficiency

Cytochrome b5 Deficiency

Anesthetics

Nitrites and Nitrates (see Nitrites and Nitrates, [[Nitrites and Nitrates]])

Anti-Malarials

Anti-Neoplastic Agents

Other Drugs/Toxins

Miscellaneous Other Conditions


Physiology

Normal Methemoglobin Physiology

Pathophysiology in Patient with Methemoglobinemia

Predisposition of Premature Neonates and Infants to Methemoglobinemia


Diagnosis

Pulse Oximetry

Arterial Blood Gas (ABG)

Evelyn-Malloy Assay of Methemoglobin

Potassium Cyanide Test

Drop Test

Aeration of Tube of Blood with 100% Oxygen

Hemoglobin Electrophoresis


Clinical Manifestations

Congenital Methemoglobinemia

Type I Cytochrome b5 Reductase Deficiency-Related Methemoglobinemia

Type II Cytochrome b5 Reductase Deficiency-Related Methemoglobinemia

Acquired Methemoglobinemia

General Comments

Cardiovascular Manifestations

Neurologic Manifestations

Pulmonary Manifestations

Renal Manifestations


Treatment

Treatment of Congenital Methemoglobinemia

Treatment of Hemoglobin M Disease-Associated Methemoglobinemia

Treatment of Acquired Methemoglobinemia

Withdraw or Avoid the Drug or Offending Agent

Supplemental Oxygen

Dextrose-Containing Intravenous (IV) Fluid

Correction of Metabolic Acidosis

Methylene Blue (see Methylene Blue, [[Methylene Blue]])

Ascorbic Acid (Vitamin C) (see Vitamin C, [[Vitamin C]])

Hyperbaric Oxygen (see Hyperbaric Oxygen, [[Hyperbaric Oxygen]])

PRBC Transfusion/Exchange Transfusion (see Packed Red Blood Cells, [[Packed Red Blood Cells]])

Other Agents


References