NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Sodium assays are important in assessing acid-base balance, water balance, water intoxication, and dehydration.
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Potentiometric, Indirect Ion-Selective Electrode.
Also available as part of an Electrolyte Panel.
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
K and Na (Potassium and Sodium) Plasma or Serum (ORDER 8468)
K+ and Na+ (ORDER 8468)
Na+ and K+ (ORDER 8468)
K+ and Na+ (ORDER 8468)
Na+ and K+ (ORDER 8468)
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 0.5 mL
Additional Information: Patient's age and sex are required.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild OK; Gross reject
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Serum||Refrigerated (preferred)||14 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Sodium is the primary extracellular cation. Sodium is responsible for almost one half the osmolality of the plasma and therefore plays a central role in maintaining the normal distribution of water and the osmotic pressure in the extracellular fluid compartment. The amount of sodium in the body is a reflection of the balance between sodium intake and output.
Hypoatremia (low sodium) is a predictable consequence of decreased intake of sodium, particularly that precipitated or complicated by unusual losses of sodium from the gastrointestinal tract (e.g., vomiting and diarrhea), kidneys or sweat glands. Renal loss may be caused by inappropriate choice, dose or use of diuretics; by primary or secondary deficiency of aldosterone and other mineralocorticoids; or by severe polyuria. It is common in metabolic acidosis. Hyponatremia also occurs in nephrotic syndrome, hypoproteinemia, primary and secondary adrenocortical insufficiency and congestive heart failure. Symptoms of hyponatremia are a result of brain swelling and range from weakness to seizures, coma and death.
Hypernatremia (high sodium) is often attributable to excessive loss of sodium-poor body fluids. Hypernatremia is often associated with hypercalcemia and hypokalemia and is seen in liver disease, cardiac failure, pregnancy, burns, and osmotic diuresis. Other causes include decreased production of ADH or decreased tubular sensitivity to the hormone (i.e., diabetes insipidus), inappropriate forms of parenteral therapy with saline solutions, or high salt intake without corresponding intake of water. Hypernatremia occurs in dehydration, increased renal sodium conservation in hyperaldosternism, Cushing's syndrome, and diabetic acidosis. Severe hypernatremia may be associated with volume contraction, lactic acidosis and increased hematocrit. Symptoms of hypernatremia range from thirst to confusion, irritability, seizures, coma and death.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
> or =12 months: 135-145 mmol/L
Reference values have not been established for patients that are less than 12 months of age.
Symptoms of hyponatremia depend primarily upon the rate of change in sodium concentration, rather than the absolute level. Typically, sodium values less than 120 mEq/L result in weakness; values less than 100 mEq/L in bulbar or pseudobulbar palsy; and values between 90 and 105 mEq/L in severe signs and symptoms of neurological impairment.
Symptoms associated with hypernatremia depend upon the degree of hyperosmolality present.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
It is important to remember that whole blood sodium values determined by direct potentiometry-ion selective electrode will be higher in specimens with high protein and lipid concentrations than the corresponding serum specimen that is assayed by an indirect potentiometric method. The whole blood sodium values are the correct values.
Ion selective electrodes are selective but not absolutely specific for the ion in question. Other monovalent cations may react with the electrode but not in the physiologic range.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Tietz Textbook of Clinical Chemistry, Edited by Burtis and Ashwood. WB Saunders Co, Philadelphia, PA, 1994
Method Description Describes how the test is performed and provides a method-specific reference
Ion selective electrode (indirect potentiometry). The ISE module of the P-Module performs indirect measurement of electromotive for (EMF). The ISE module measure the EMF difference between an ion selective electrode and a reference electrode. The EMF of the ion selective electrode is dependent on the ion concentration of the sample. The EMF of the reference electrode is constant. The P-Module uses an electronic calculation circuit to convert the EMF of the sample to the ion concentration of the sample. (Boehringer Mannheim ISE reagent package insert; Indianapolis, IN 46256, 1997)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Sunday; Continuously
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Same day/1 day
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|