Test Id : CAI
Calcium, Ionized, Serum
Useful For
Suggests clinical disorders or settings where the test may be helpful
Assessing calcium states during liver transplantation surgery,
Second-order test in the evaluation of patients with abnormal
Method Name
A short description of the method used to perform the test
Ion-Selective Electrode (ISE)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Ca (Calcium)
Calcium (Ca)
Free Calcium
Ionized Calcium, Serum
CA Ionized, Serum
Calcium Ionized, Serum
Specimen Type
Describes the specimen type validated for testing
Serum SST
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Container/Tube: Serum gel or serum gel microtainer
Specimen Volume: Full tube
Collection Instructions:
1. Allow blood to clot for 30 minutes.
2. Serum gel tube/microtainer must be centrifuged within 1 hour of collection. Centrifuge with stopper in place for 7 minutes at 3000 rpm to ensure that the gel barrier separates the serum and cells.
3. Keep specimen anaerobic; do not aliquot.
4. Test cannot be combined with other testing. Separate specimens must be submitted when multiple tests are ordered.
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
1.75 mL in a 3.5 mL (50% full) in serum gel tube or 1 full serum gel microtainer
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Tubes less than 50% full Specimens that have been aliquoted, opened, or poorly centrifuged | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum SST | Refrigerated | 7 days | SERUM GEL TUBE |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Assessing calcium states during liver transplantation surgery,
Second-order test in the evaluation of patients with abnormal
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Ionized calcium, which accounts for 50% to 55% of total calcium, is the physiologically active form of calcium.
Low ionized calcium values are often seen in kidney disease, critically ill patients, or patients receiving rapid transfusion of citrated whole blood or blood products.
Increased serum ionized calcium concentrations may be seen with primary hyperparathyroidism, ectopic parathyroid hormone-producing tumors, excess intake of vitamin D, or various malignancies.
Nomograms have been used to calculate ionized calcium from total calcium, albumin, and pH values. However, calculated ionized calcium results have proven to be unsatisfactory. A Mayo study of 114 patients found significant differences between ionized and total calcium in 26% of patients.
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.
IONIZED CALCIUM
< or =13 days old: Not established
14 days-<1 year: 5.21-5.99 mg/dL
1-<2 years: 5.04-5.84 mg/dL
2-<3 years: 4.87-5.67 mg/dL
3-23 years: 4.83-5.52 mg/dL
24-97 years: 4.57-5.43 mg/dL
> or =98 years: Not established
pH
< or =13 days old: Not established
14 days-97 years old: 7.35-7.48
> or =98 years old: Not established
For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.
Interpretation
Provides information to assist in interpretation of the test results
Serum ionized calcium concentrations 50% below normal will result
Ionized calcium values are higher in children and young adults.
Ionized calcium result has been adjusted to pH 7.40 to account for changes in specimen pH that may occur during transport. Ionized calcium concentration increases approximately 0.2 mg/dL per 0.1 pH unit decrease.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Proper specimen handling is necessary to ensure accurate results.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
Rifai N, Horwath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018
Method Description
Describes how the test is performed and provides a method-specific reference
The pH and ionized calcium sensors in the GEM Premier 3500 Analyzer are based on the principle of ion-selective electrodes; that is, an electrical potential can be established across a membrane that is selectively permeable to a specific ion.(Instruction manual: GEM Premier 3500 Analyzer Operator's Guide. Instrumentation Laboratory; 03/2015)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Sunday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
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
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
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 instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
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 Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
82330
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| CAI | Calcium, Ionized, S | 57333-7 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| CAIS | Calcium, Ionized, S | 57333-7 |
| PHCC | pH | 2753-2 |