Methemoglobinemia natural history, complications and prognosis

Jump to navigation Jump to search

Methemoglobinemia Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Methemoglobinemia from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings

Chest X Ray

CT

MRI

Ultrasound

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Methemoglobinemia natural history, complications and prognosis On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Methemoglobinemia natural history, complications and prognosis

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Methemoglobinemia natural history, complications and prognosis

on Methemoglobinemia natural history, complications and prognosis

Methemoglobinemia natural history, complications and prognosis in the news

Blogs on Methemoglobinemia natural history, complications and prognosis

Directions to Hospitals Treating Methemoglobinemia

Risk calculators and risk factors for Methemoglobinemia natural history, complications and prognosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Template:Aksiniya K. Stevasarova, M.D.

Overview

Congenital (Hereditary) Methemoglobinemia

There are three main congenital conditions that lead to methemoglobinemia:

1. Cytochrome b5 reductase deficiency and pyruvate kinase deficiency

2. G6PD deficiency

3. Presence of abnormal hemoglobin (HbM)


Acquired or Acute Methemoglobinemia

Some of the most common causes include different oxidant drugs, toxins and chemicals.

Natural History

Patients with hereditary forms of methemoglobinemia are generally asymptomatic, with the exception of having chronic cyanosis. Unfortunately, despite the benign nature of the congenital methemoglobinemia, people with type IIb5 cytochrome-reductase deficiency have poor prognosis and shorter lifespan, mainly due to neurologic complications.

In acquired methemoglobinemia, depending on the amount and duration of toxin exposure, the levels of MetHb in the blood will be different. As a result we expect different outcomes, which are as follows: MetHb of 15% presents with skin and blood color changes at levels; levels above 15% will result in hypoxia and levels above 70% can lead to death. [1] [2]

  1. {{Rev Bras Anestesiol. 2008 Nov-Dec;58(6):651-64. Methemoglobinemia: from diagnosis to treatment. [Article in English, Portuguese] do Nascimento TS1, Pereira RO, de Mello HL, Costa J. pmid=19082413}}
  2. {{Toxicol Rev. 2003;22(1):13-27. Occupational methaemoglobinaemia. Mechanisms of production, features, diagnosis and management including the use of methylene blue. Bradberry SM1. pmid=14579544}}

Complications

Death is the most serious complications of methemoglobinemia especially when MetHb levels approach 70%. In severely sick patients death may occur even with lower levels of MetHb. Other complications include myocardial infarction, seizure and coma. [1]


  1. {{Toxicol Rev. 2003;22(1):13-27. Occupational methaemoglobinaemia. Mechanisms of production, features, diagnosis and management including the use of methylene blue. Bradberry SM1. pmid=14579544}}

Prognosis

Depending on the anoxic end-organ damage caused by MetHb, the prognosiss varies between mild an fatal. [1]

  1. {{Rev Bras Anestesiol. 2008 Nov-Dec;58(6):651-64. Methemoglobinemia: from diagnosis to treatment. [Article in English, Portuguese] do Nascimento TS1, Pereira RO, de Mello HL, Costa J. pmid=19082413}}

References

Template:WS Template:WH