Myoglobinuria diagnostic study of choice

The most important laboratory test is creatine kinase (CK) levels to assess for rhabdomyolysis.

Myoglobin is the first enzyme to increase, but it returns to normal levels within 24 hours after the onset of symptoms. The reason is that myoglobin is rapidly cleared by the kidneys from the serum into the urine. Serum CK levels may remain elevated after serum and urine test results for myoglobin have become negative. CK levels typically peak {1000 U/L) about 3 days after the onset of symptoms, and remain elevated for several days.

Acute renal insufficiency (elevated BUN and creatinine levels) is a sequel of severe myoglobinuria in which the globulin precipitates and blocks the urinary tubules.

Although both myoglobinuria and hemoglobinuria may cause a tea-colored appearance of the urine, and both can cause positive results on the urine dipstick for blood, myoglobinuria can be differentiated from hemoglobinuria by performing the following:

• Myoglobinuria is brown, and only a few RBCs are present in the urine.
• Red or brown urine with a negative dipstick result for blood indicates a dye in the urine.

Gold standard or study of choice:

The cardinal feature of an esophageal stricture is dysphagia

• [Name of the investigation] is the gold standard test for the diagnosis of [disease name].
• The following result of [gold standard test] is confirmatory of [disease name]:
  • Result 1
  • Result 2
• The [name of investigation] should be performed when:
  • The patient presented with symptoms/signs 1. 2, 3.
  • A positive [test] is detected in the patient.
• [Name of the investigation] is the gold standard test for the diagnosis of [disease name].
• The diagnostic study of choice for [disease name] is [name of investigation].
• There is no single diagnostic study of choice for the diagnosis of [disease name].
• 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].
• [Disease name] is mainly diagnosed based on clinical presentation.
• Investigations:
  • Among patients who present with clinical signs of [disease name], the [investigation name] is the most specific test for the diagnosis.
  • Among patients who present with clinical signs of [disease name], the [investigation name] is the most sensitive test for diagnosis.
  • Among patients who present with clinical signs of [disease name], the [investigation name] is the most efficient test for diagnosis.

The comparison table for diagnostic studies of choice for [disease name]

	Sensitivity	Specificity
Test 1	✔	...%
Test 2	...%	✔

✔= The best test based on the feature

Diagnostic results

The following result of [investigation name] is confirmatory of [disease name]:

• Result 1
• Result 2

Sequence of Diagnostic Studies

The [name of investigation] should be performed when:

• 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.

Diagnostic Criteria

• Here you should describe the details of the diagnostic criteria.
• Always mention the name of the criteria/definition you are about to list (e.g. modified Duke criteria for diagnosis of endocarditis / 3rd universal definition of MI) and cite the primary source of where this criteria/definition is found.
• Although not necessary, 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.
• Be very clear as to the number of criteria (or threshold) that needs to be met out of the total number of criteria.
• Distinguish criteria based on their nature (e.g. clinical criteria / pathological criteria/ imaging criteria) before discussing them in details.
• To view an example (endocarditis diagnostic criteria), click here
• If relevant, add additional information that might help the reader distinguish various criteria or the evolution of criteria (e.g. original criteria vs. modified criteria).
• You may also add information about the sensitivity and specificity of the criteria, the pre-test probability, and other figures that may help the reader understand how valuable the criteria are clinically.
• [Disease name] is mainly diagnosed based on clinical presentation. There are no established criteria for the diagnosis of [disease name].
• There is no single diagnostic study of choice for [disease name], though [disease name] may be diagnosed based on [name of criteria] established by [...].

• 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].
• The diagnosis of [disease name] is based on the [criteria name] criteria, which includes [criterion 1], [criterion 2], and [criterion 3].

• [Disease name] may be diagnosed at any time if one or more of the following criteria are met:
  • Criteria 1
  • Criteria 2
  • Criteria 3

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].
• The diagnosis of [disease name] is based on the [criteria name] criteria, which include [criterion 1], [criterion 2], and [criterion 3].
• The diagnosis of [disease name] is based on the [definition name] definition, which includes [criterion 1], [criterion 2], and [criterion 3].

IF there are no established diagnostic criteria: 

• There are no established criteria for the diagnosis of [disease name].