Methemoglobinemia diagnostic study of choice: Difference between revisions

Jump to navigation Jump to search
VisualWikitext
No edit summary
No edit summary
Line 1: Line 1:
__NOTOC__
__NOTOC__
{{Methemoglobinemia}}
{{Methemoglobinemia}}
{{CMG}}; {{AE}}
{{CMG}}; {{AE}} {{AKS}}
== Overview ==
== Overview ==
The diagnostic study of choice for [[methemoglobinemia]] is direct measurement of [[methemoglobin]] by a multiple wavelength co-oximeter. Also clinical [[cyanosis]] in the presence of normal arterial oxygen tensions is highly suggestive of methemoglobinemia.


== Diagnostic Study of Choice ==
== Diagnostic Study of Choice ==


=== Study of choice ===
=== Study of choice ===
[Name of the investigation] is the gold standard test for the diagnosis of [disease name].
Direct measurement of [[methemoglobin]] by a multiple wavelength co-oximeter is the gold standard test for the diagnosis of [[methemoglobinemia]].
 
OR
 
The following result of [gold standard test] is confirmatory of [disease name]:
* [Result 1]
* [Result 2]
 
OR
 
[Name of the investigation] must be performed when:
* The patient presents with [symptom/sign 1], [symptom/sign 2], and [symptom/sign 3].
* A [name of test] is positive for [sign 1], [sign 2], and [sign 3] in the patient.
 
OR


[Name of the investigation] is the gold standard test for the diagnosis of [disease name].
'''Co-oximetry'''


OR
The [[co-oximeter]] is the most accurate device to measure [[methemoglobin]]. The newer generation devices can actually differentiate between [[methemoglobin]], [[carboxyhemoglobin]], [[oxyhemoglobin]], [[deoxyhemoglobin]], and also [[sulfhemoglobin]].<ref name="pmid20007731">{{cite journal| author=Feiner JR, Bickler PE, Mannheimer PD| title=Accuracy of methemoglobin detection by pulse CO-oximetry during hypoxia. | journal=Anesth Analg | year= 2010 | volume= 111 | issue= 1 | pages= 143-8 | pmid=20007731 | doi=10.1213/ANE.0b013e3181c91bb6 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20007731  }} </ref>
 
 
The diagnostic study of choice for [disease name] is [name of the investigation].
 
OR
 
There is no single diagnostic study of choice for the diagnosis of [disease name].  
 
OR
 
There is no single diagnostic study of choice for the diagnosis of [disease name], but [disease name] can be diagnosed based on [name of the investigation 1] and [name of the investigation 2].
 
OR
 
[Disease name] is primarily diagnosed based on the clinical presentation.
 
OR
 
Investigations:
* Among the patients who present with clinical signs of [disease name], the [investigation name] is the most specific test for the diagnosis.
* Among the patients who present with clinical signs of [disease name], the [investigation name] is the most sensitive test for diagnosis.
* Among the patients who present with clinical signs of [disease name], the [investigation name] is the most efficient test for diagnosis.


==== The comparison of various diagnostic studies for [disease name] ====
==== The comparison of various diagnostic studies for [disease name] ====
Line 55: Line 23:
! style="background: #4479BA; color: #FFFFFF; text-align: center;" |Specificity
! style="background: #4479BA; color: #FFFFFF; text-align: center;" |Specificity
|-
|-
! style="background: #696969; color: #FFFFFF; text-align: center;" |Test 1
! style="background: #696969; color: #FFFFFF; text-align: center;" |Co-oximetry
| style="background: #DCDCDC; padding: 5px; text-align: center;" |...%
| style="background: #DCDCDC; padding: 5px; text-align: center;" |100%
| style="background: #DCDCDC; padding: 5px; text-align: center;" |...%
| style="background: #DCDCDC; padding: 5px; text-align: center;" |100%
|-
|-
! style="background: #696969; color: #FFFFFF; text-align: center;" |Test 2
! style="background: #696969; color: #FFFFFF; text-align: center;" |Pulse-oximetry
| style="background: #DCDCDC; padding: 5px; text-align: center;" |...%
| style="background: #DCDCDC; padding: 5px; text-align: center;" |85%
| style="background: #DCDCDC; padding: 5px; text-align: center;" |...%
| style="background: #DCDCDC; padding: 5px; text-align: center;" |85%
|}
|}
<small> [Name of test with higher sensitivity and specificity] is the preferred investigation based on the sensitivity and specificity</small>
<small> [Co-oximetry] is the preferred investigation based on the sensitivity and specificity</small>


===== Diagnostic results =====
===== Diagnostic results =====
The following finding(s) on performing [investigation name] is(are) confirmatory for [disease name]:
In [[methemoglobinemia]] patients, we often see the so called “[[saturation gap]]” which can help us diagnose the condition. The gap is calculated by subtracting the [[oxygen]] percentage from the [[ABG analysis]] (typically normal in [[methemoglobinemia]] patients 100%) from the percentage of [[oxygen saturation]] given by the [[pulse oximeter]] (always ~85% in [[methemoglobinemia]] patients). [[Saturaion gap]] more than 5% is significant.
* [Finding 1]
* [Finding 2]


===== Sequence of Diagnostic Studies =====
The following finding on performing [[saturation gap]] is confirmatory for [[methemoglobinemia]]:
The [name of investigation] must be performed when:
* [[Saturaion gap]] more than 5%.
* The patient presented with symptoms/signs 1, 2, and 3 as the first step of diagnosis.
* A positive [test] is detected in the patient, to confirm the diagnosis.


OR


===== Sequence of Diagnostic Studies =====
The various investigations must be performed in the following order:
The various investigations must be performed in the following order:
* [Initial investigation]
* [direct measurement with co-oximetry]
* [2nd investigation]
* [calculation of the saturation gap]
 
* The [[pulse oximetry]] in [[methemoglobinemia]] patients is inaccurate and unreliable, and will always show a value around  85%, regardless of the level of [[MetHb]] in the blood. This is very importan tot know as this value can be misleading especially in patients with very high [[MetHb]] levels. Fortunately new [[multiwavelength pulse oximeters]] have been developed recently and they can detect the levels of [[MetHb]] more accurately. <ref name="pmid29060914">{{cite journal| author=Van Leeuwen SR, Baranoski GVG, Kimmel BW| title=Three-wavelength method for the optical differentiation of methemoglobin and sulfhemoglobin in oxygenated blood. | journal=Conf Proc IEEE Eng Med Biol Soc | year= 2017 | volume= 2017 | issue=  | pages= 4570-4573 | pmid=29060914 | doi=10.1109/EMBC.2017.8037873 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=29060914  }} </ref>
=== Name of Diagnostic Criteria ===
=== Name of Diagnostic Criteria ===


'''It is recommended that you include the criteria in a table. Make sure you always cite the source of the content and whether the table has been adapted from another source.'''
There are no established criteria for the diagnosis of [[methemoglobinemia]].
 
[Disease name] is primarily diagnosed based on clinical presentation. There are no established criteria for the diagnosis of [disease name].
 
OR
 
There is no single diagnostic study of choice for [disease name], though [disease name] may be diagnosed based on [name of criteria] established by [...].
 
OR
 
The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].
 
OR
 
The diagnosis of [disease name] is based on the [criteria name] criteria, which includes [criterion 1], [criterion 2], and [criterion 3].
 
OR
 
[Disease name] may be diagnosed at any time if one or more of the following criteria are met:
* Criteria 1
* Criteria 2
* Criteria 3
 
OR
 
'''IF there are clear, established diagnostic criteria'''
 
The diagnosis of [disease name] is made when at least [number] of the following [number] diagnostic criteria are met: [criterion 1], [criterion 2], [criterion 3], and [criterion 4].
 
OR
 
The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].
 
OR
 
The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].
 
OR
 
'''IF there are no established diagnostic criteria'''
 
There are no established criteria for the diagnosis of [disease name].


==References==
==References==

Revision as of 14:23, 15 August 2018

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 diagnostic study of choice On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Methemoglobinemia diagnostic study of choice

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Methemoglobinemia diagnostic study of choice

on Methemoglobinemia diagnostic study of choice

Methemoglobinemia diagnostic study of choice in the news

Blogs on Methemoglobinemia diagnostic study of choice

Directions to Hospitals Treating Methemoglobinemia

Risk calculators and risk factors for Methemoglobinemia diagnostic study of choice

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

Overview

The diagnostic study of choice for methemoglobinemia is direct measurement of methemoglobin by a multiple wavelength co-oximeter. Also clinical cyanosis in the presence of normal arterial oxygen tensions is highly suggestive of methemoglobinemia.

Diagnostic Study of Choice

Study of choice

Direct measurement of methemoglobin by a multiple wavelength co-oximeter is the gold standard test for the diagnosis of methemoglobinemia.

Co-oximetry

The co-oximeter is the most accurate device to measure methemoglobin. The newer generation devices can actually differentiate between methemoglobin, carboxyhemoglobin, oxyhemoglobin, deoxyhemoglobin, and also sulfhemoglobin.[1]


The comparison of various diagnostic studies for [disease name]

Test Sensitivity Specificity
Co-oximetry 100% 100%
Pulse-oximetry 85% 85%

[Co-oximetry] is the preferred investigation based on the sensitivity and specificity

Diagnostic results

In methemoglobinemia patients, we often see the so called “saturation gap” which can help us diagnose the condition. The gap is calculated by subtracting the oxygen percentage from the ABG analysis (typically normal in methemoglobinemia patients 100%) from the percentage of oxygen saturation given by the pulse oximeter (always ~85% in methemoglobinemia patients). Saturaion gap more than 5% is significant.

The following finding on performing saturation gap is confirmatory for methemoglobinemia:


Sequence of Diagnostic Studies

The various investigations must be performed in the following order:

  • [direct measurement with co-oximetry]
  • [calculation of the saturation gap]
  • The pulse oximetry in methemoglobinemia patients is inaccurate and unreliable, and will always show a value around 85%, regardless of the level of MetHb in the blood. This is very importan tot know as this value can be misleading especially in patients with very high MetHb levels. Fortunately new multiwavelength pulse oximeters have been developed recently and they can detect the levels of MetHb more accurately. [2]

Name of Diagnostic Criteria

There are no established criteria for the diagnosis of methemoglobinemia.

References

  1. ↑ Feiner JR, Bickler PE, Mannheimer PD (2010). "Accuracy of methemoglobin detection by pulse CO-oximetry during hypoxia". Anesth Analg. 111 (1): 143–8. doi:10.1213/ANE.0b013e3181c91bb6. PMID 20007731.
  2. ↑ Van Leeuwen SR, Baranoski GVG, Kimmel BW (2017). "Three-wavelength method for the optical differentiation of methemoglobin and sulfhemoglobin in oxygenated blood". Conf Proc IEEE Eng Med Biol Soc. 2017: 4570–4573. doi:10.1109/EMBC.2017.8037873. PMID 29060914.

Template:WH Template:WS

Retrieved from "https://www.wikidoc.org/index.php?title=Methemoglobinemia_diagnostic_study_of_choice&oldid=1490596"