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Test Code HMET24 Heavy Metals Screen, with Reflex, 24 Hour, Urine

Important Note

Mayo Test Code; HMU24

Additional Codes

Sunrise Clinical Manager (SCM) Orderable:  

Heavy Metals, Urine 24 Hour

AllScripts (AEHR) Orderable

Heavy Metals, Urine 24 Hour


Specimen Required


Patient Preparation:

1. High concentrations of gadolinium and iodine are known to interfere with most metals tests. If either gadolinium- or iodine-containing contrast media has been administered, a specimen should not be collected for 96 hours.

2. Patient should not eat seafood for a 48-hour period prior to start of, or during, collection.

Supplies: Urine Tubes, 10 mL (T068)

Collection Container/Tube: Clean, plastic aliquot container with no metal cap or glued insert

Submission Container/Tube: Plastic, 10-mL urine tube

Specimen Volume: 10 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. Refrigerate specimen within 4 hours of completion of 24-hour collection.

3. See Trace Metals Analysis Specimen Collection and Transport in Special Instructions for complete instructions.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.


Useful For

Detecting arsenic, cadmium, mercury, and lead exposure and toxicity using 24-hour urine specimens

Profile Information

Test ID Reporting Name Available Separately Always Performed
ASHU Arsenic, 24 Hr, U Yes, (order ASU24) Yes
CDHMU Cadmium, 24 Hr, U Yes, (order CDU) Yes
HGHU Mercury, 24 Hr, U Yes, (order HGU) Yes
PBHU Lead, 24 Hr, U Yes, (order PBU) Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
ASFR Arsenic Fractionation, 24 Hr, U Yes No

Testing Algorithm

If arsenic concentration is greater than or equal to 35 mcg/L, then fractionation will be performed at an additional charge.

Method Name

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)

Reporting Name

Heavy Metal Scrn w/Reflex, 24 Hr, U

Specimen Type

Urine

Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 7 days
  Frozen  7 days

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Arsenic:

Arsenic is a naturally occurring element that is usually found in the environment combined with other elements such as oxygen, chlorine, and sulfur. Arsenic combined with these elements is called inorganic arsenic. Arsenic combined with carbon and hydrogen is referred to as organic arsenic. The organic forms (eg, arsenobetaine and arsenocholine) are relatively nontoxic, while the inorganic forms are toxic. The toxic inorganic forms are arsenite (As[3+]/As[III]) and arsenate (As[5+]/As[V]). Inorganic As(V) is readily reduced to inorganic As(III) which is then primarily broken down to less toxic methylated metabolites monomethylarsinic acid (MMA) and subsequently dimethylarsinic acid (DMA).

 

People are exposed to arsenic by eating food, drinking water, or breathing air. Of these, food is usually the largest source of arsenic. The predominant dietary source of arsenic is seafood, followed by rice/rice cereal, mushrooms, and poultry. While seafood contains the greatest amounts of arsenic, for fish and shellfish, this is mostly in an organic form of arsenic called arsenobetaine, which is much less harmful. Some seaweed may contain arsenic in the inorganic form, which is more toxic. In the United States, some areas also contain high natural levels of arsenic in rock, which can lead to elevated levels in the soil and drinking water. Occupational (eg, copper or lead smelting, wood treating, or pesticide application) exposure is another source where people may be introduced to elevated levels of arsenic. Lastly, hazardous waste sites may contain large quantities of arsenic and if not disposed of properly may get into the surrounding water, air, or soil.

 

A wide range of signs and symptoms may be seen in acute arsenic poisoning including headache, nausea, vomiting, diarrhea, abdominal pain, hypotension, fever, hemolysis, seizures, and mental status changes. Symptoms of chronic poisoning, also called arseniasis, are mostly insidious and nonspecific. The gastrointestinal tract, skin, and central nervous system are usually involved. Nausea, epigastric pain, colic abdominal pain, diarrhea, and paresthesias of the hands and feet can also occur.

 

Since arsenic is excreted predominantly by glomerular filtration, measurement of arsenic in urine is the most reliable means of detecting arsenic exposures within the last several days.

 

Cadmium:

The toxicity of cadmium resembles the other heavy metals (arsenic, mercury, and lead) in that it attacks the kidney; renal dysfunction with proteinuria with slow onset (over a period of years) is the typical presentation. Measurable changes in proximal tubule function, such as decreased clearance of para-aminohippuric acid also occur over a period of years, and precede overt renal failure.

 

Breathing the fumes of cadmium vapors leads to nasal epithelial deterioration and pulmonary congestion resembling chronic emphysema.

 

The most common source of chronic exposure comes from spray painting of organic-based paints without use of a protective breathing apparatus; auto repair mechanics represent a susceptible group for cadmium toxicity. Another common source of cadmium exposure is tobacco smoke, which has been implicated as the primary source of the metal leading to reproductive toxicity in both males and females.

 

The concentration of cadmium in the kidneys and in the urine is elevated in some patients exposed to cadmium.

 

Mercury:

The correlation between the levels of mercury (Hg) excreted in the urine and clinical symptoms, is considered poor. However, urinary Hg is the most reliable way to assess exposure to inorganic Hg.

 

Lead:

Increased urine lead excretion rate indicates significant lead exposure. Measurement of urine lead excretion rate before and after chelation therapy has been used as an indicator of lead exposure. An increase in lead excretion rate in the post chelation specimen of up to 6 times the rate in the prechelation specimen is normal. Blood lead is the best clinical correlate of toxicity.

Reference Values

ARSENIC:

0-17 years: not established

≥18 years: <18 mcg/24 hour

 

CADMIUM:

0-17 years: not established

≥18 years: <0.6 mcg/24 hour

 

MERCURY:

0-17 years: not established

≥18 years: <2 mcg/24 hour

Toxic concentration: >50 mcg/24 hour

 

The concentration at which toxicity is expressed is widely variable between patients. 50 mcg/24 hour is the lowest concentration at which toxicity is usually apparent.

 

LEAD:

0-17 years: not established

≥18 years: <1 mcg/24 hour

Day(s) and Time(s) Performed

Monday through Saturday; 7 p.m.

Analytic Time

1 day

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

82175

82300

83825

83655

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HMU24 Heavy Metal Scrn w/Reflex, 24 Hr, U 94575-8

 

Result ID Test Result Name Result LOINC Value
8678 Cadmium, 24 Hr, U 5612-7
48539 Arsenic, 24 Hr, U 5587-1
92408 Mercury, 24 Hr, U 6693-6
92409 Lead, 24 Hr, U 5677-0
TIME4 Collection Duration 13362-9
92215 Arsenic Concentration w/Reflex 21074-0
VL16 Total Volume 3167-4

NY State Approved

Yes

Urine Preservative Collection Options

Note: The addition of preservative or application of temperature controls must occur within 4 hours of completion of the collection.

Ambient

No

Refrigerate

Preferred

Frozen

OK

50% Acetic Acid

OK

Boric Acid

No

Diazolidinyl Urea

No

6M Hydrochloric Acid

OK

6M Nitric Acid

No

Sodium Carbonate

No

Thymol

No

Toluene

OK

Northwell Health Laboratories Additional Information:

Computer Interface Code

   PDM # 5902461