Methemoglobinemia: Living with Dormant Devil.

Area of Science:

• Biochemistry
• Hematology
• Genetics

Background:

• Methemoglobin is an oxidized form of hemoglobin.
• Methemoglobinemia results from NADH methemoglobin reductase deficiency or inactivity, leading to excessive methemoglobin accumulation.
• This condition can be congenital or acquired.

Observation:

• A case of dormant congenital methemoglobinemia was discovered during a routine preoperative assessment.
• The patient presented with low oxygen saturation even at 100% fraction of inspired oxygen (FIO2) and central cyanosis.
• The patient had 27.7% methemoglobin but had been asymptomatic throughout life.

Findings:

• Congenital methemoglobinemia can be asymptomatic and undetected until specific medical evaluations.
• Significant methemoglobin levels (27.7%) do not always correlate with clinical complications in all individuals.
• Successful surgical intervention (tympanoplasty and mastoidectomy) was achieved under local anesthesia with appropriate precautions.

Implications:

• Highlights the importance of thorough preoperative assessments, especially for unexplained cyanosis or hypoxia.
• Suggests that congenital methemoglobinemia may have a broader spectrum of clinical presentation than previously recognized.
• Emphasizes the need for individualized patient management, considering both methemoglobin levels and overall clinical status.