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22397 Calcium, Ionized, Blood

Calcium, Ionized, Blood
Test Code: IC
Synonyms/Keywords
IC, Ionized Calcium, Free Calcium​, i-Stat Ionized Calcium
Useful For
It is useful in evaluation of renal function and endocrine disorders, during cardiac surgery, and in neonatology.​
Specimen Requirements
 
 
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
No​
Whole Blood 
Low- or balanced-Heparin Blood Gas syringe
For Newborns: balanced-Heparin capillary tube
Full Li Heparin no gel tubeFull syringe, capillary tube or Li Heparin no gel tubeFull syringe, capillary tube or Li Heparin no gel tube
​No​Whole Blood

For Marshfield only:

Serum Separator Tube (SST)

For Marshfield only: ​

Red Top Tube (RTT)

​5 to 10 mL tube filled completely​5 to 10 mL tube filled completely
​No​Serum

For Marshfield only: ​

Serum Separator Tube (SST)

For Marshfield only

Red Top Tube (RTT) 

​Full aliquot, amount depends on size of the container​​Full aliquot, amount depends on size of the container
Collection Processing Instructions

Marshfield Medical Center collected & performed IC samples:                                                                       

Collect heparinized whole blood, either venous or arterial, anaerobically in a low- or balanced-heparin blood gas syringe, capillary tube, or Li-Heparin no gel tube. Upon receipt in the lab, do no centrifuge. Deliver to the blood gas testing section for analysis.                                                        

Alternatively, collect specimen anaerobically in a 5-10 mL SST or RTT completely filled.  Upon receipt in the lab, centrifuge, but DO NOT REMOVE CAP FROM THE TUBE. Deliver spun SST or RTT to the blood gas testing section for analysis.                                                                       

 

Other Marshfield Medical Center sites that collect & perform IC testing:                                                                   

Collect heparinized whole blood, either venous or arterial, anaerobically in a low- or balanced-heparin blood gas syringe, capillary tube, or Li-Heparin no gel tube. Upon receipt in the lab, do not centrifuge. Deliver to the blood gas testing section for analysis.                                                                       

 

All Marshfield Medical Center sites that collect & perform IC testing:                                                            

Surgery patients:  Whole blood without anticoagulant is acceptable from pre-heparinized heart surgery patients, collected in a syringe devoid of any externally added heparin.  Upon receipt in the lab, deliver to the blood gas testing section for analysis.                               

Newborns:  Preferred specimen is a balanced-heparin capillary tube.  Other types of capillary tubes or collection containers are unacceptable.  Transport to laboratory within 30 minutes of collection, preferred transport is on ice-pack.  Upon receipt in the lab, deliver to the blood gas testing section for analysis.                                                               

Pediatric samples where only serum is available and a dedicated red top is not feasible due to excessive sample volume, draw red top tube and following centrifugation, remove serum and rapidly transfer to a small polypropylene tube (i.e. Sarstedt) aliquot container, FILLING THE CONTAINER IN ITS ENTIRETY (to avoid any air exchange). Cap the filled container immediately and store refrigerated (or frozen) prior to and during transport. Send to Marshfield.                                                              

                                                           

Other sites sending IC to Marshfield Medical Center Laboratory:                                                                   

Collect specimen anaerobically in a 5 to 10 mL SST tube, filled completely, and centrifuged within 4 hours of collection.  (Centrifuged SST samples are preferred in case other tests are requested, but not required).  Alternatively, specimens collected anaerobically in a 5 to 10 mL un-centrifuged RTT are also acceptable, but less desirable.  DO NOT REMOVE CAP FROM THE TUBE.  Preferred is for the entire tube to be sent refrigerated.  If unique reasons preclude the entire tube from being sent, centrifuge the RTT or SST, then remove serum and rapidly transfer to a small polypropylene tube (i.e. Sarstedt) aliquot container, FILLING THE CONTAINER IN ITS ENTIRETY (to avoid any air exchange). Cap the filled container immediately and store refrigerated prior to and during transport.  These aliquots may also be frozen for transport.  If the only size aliquot container available does not allow to fill to its entirety, then add as much sample as is available, at least 0.5 mL, and freeze immediately.                                                          

Specimen Stability Information
Specimen Type Temperature Time
Whole Blood - Syringe/non-gel GTT​  ​ ​Refrigerate ​ ​4 hours​
​Ambient​ 30 minutes
Whole Blood - SST/RTT Refrigerate 70 hours​
Ambient​ 6 hours​
Serum​​ ​ Frozen ​ 45 days
​Refrigerate ​ ​7 days
Rejection Criteria
Specimens exposed to air
Plasma separator tubes​
Other syringes than those listed​
​Capillary tubes other than balanced-heparin 
​Gross hemolysis
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Bloomer​ ​​Monday through Friday ​Less than 2 hours​ ​Ion-Selective Electrode Potentiometry/i-STAT
​Cadott ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Chetek ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Colby/Abbotsford ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Cornell ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Cumberland ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
Diagnostic Treatment Center ​Monday through Sunday​ ​Less than 2 hours​ ​Radiometer
​Eagle River​ ​Monday through Friday ​Less than 2 hours ​​​Ion-Selective Electrode Potentiometry/i-STAT
​Eau Claire ​​Monday through Sunday ​Less than 2 hours​ ​​Gem 4000
Hayward​ ​​​Monday through Friday ​​Less than 2 hours​ ​​​Ion-Selective Electrode Potentiometry/i-STAT
​MMC-Ladysmith​Monday through Sunday​Less than 2 hours​Gem 4000
MMC-Park Falls​​Monday through Sunday​Less than 2 hours​Gem 4000
​MMC-Rice Lake​Monday through Sunday​Less than 2 hours​Gem 4000
Marshfield​ Monday through Sunday​ Less than 2 hours​ Gem 4000
​Mercer ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Minocqua​Monday through Sunday​Less than 2 hours​Reference Electrode/Gem 4000
​Mosinee ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Oakwood ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
Phillips​ ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Rhinelander ​Monday through Friday ​Less than 2 hours ​​​Ion-Selective Electrode Potentiometry/i-STAT
​Stettin ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Wittenberg ​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
Test Information
​Analysis does not include a total calcium. The total calcium must be ordered as a separate test if needed.
When determining ionized calcium for diagnosis of a disorder in Ca metabolism, a four hour fasting sample is recommended.
Reference Range Information
Performing Location Reference Range
All Performing Sites 0-4 days: 4.3-5.5 mg/dL
5-29 days: 4.8-6.0 mg/dL
1 mo.-19 yrs.: 4.9-5.5 mg/dL
>=20 yrs.: 4.5-5.3 mg/dL ​

See Critical Value List for list of current critical values

Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
82330 ​
Synonyms/Keywords
IC, Ionized Calcium, Free Calcium​, i-Stat Ionized Calcium
Ordering Applications
Ordering Application Description
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
 
 
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
No​
Whole Blood 
Low- or balanced-Heparin Blood Gas syringe
For Newborns: balanced-Heparin capillary tube
Full Li Heparin no gel tubeFull syringe, capillary tube or Li Heparin no gel tubeFull syringe, capillary tube or Li Heparin no gel tube
​No​Whole Blood

For Marshfield only:

Serum Separator Tube (SST)

For Marshfield only: ​

Red Top Tube (RTT)

​5 to 10 mL tube filled completely​5 to 10 mL tube filled completely
​No​Serum

For Marshfield only: ​

Serum Separator Tube (SST)

For Marshfield only

Red Top Tube (RTT) 

​Full aliquot, amount depends on size of the container​​Full aliquot, amount depends on size of the container
Collection Processing

Marshfield Medical Center collected & performed IC samples:                                                                       

Collect heparinized whole blood, either venous or arterial, anaerobically in a low- or balanced-heparin blood gas syringe, capillary tube, or Li-Heparin no gel tube. Upon receipt in the lab, do no centrifuge. Deliver to the blood gas testing section for analysis.                                                        

Alternatively, collect specimen anaerobically in a 5-10 mL SST or RTT completely filled.  Upon receipt in the lab, centrifuge, but DO NOT REMOVE CAP FROM THE TUBE. Deliver spun SST or RTT to the blood gas testing section for analysis.                                                                       

 

Other Marshfield Medical Center sites that collect & perform IC testing:                                                                   

Collect heparinized whole blood, either venous or arterial, anaerobically in a low- or balanced-heparin blood gas syringe, capillary tube, or Li-Heparin no gel tube. Upon receipt in the lab, do not centrifuge. Deliver to the blood gas testing section for analysis.                                                                       

 

All Marshfield Medical Center sites that collect & perform IC testing:                                                            

Surgery patients:  Whole blood without anticoagulant is acceptable from pre-heparinized heart surgery patients, collected in a syringe devoid of any externally added heparin.  Upon receipt in the lab, deliver to the blood gas testing section for analysis.                               

Newborns:  Preferred specimen is a balanced-heparin capillary tube.  Other types of capillary tubes or collection containers are unacceptable.  Transport to laboratory within 30 minutes of collection, preferred transport is on ice-pack.  Upon receipt in the lab, deliver to the blood gas testing section for analysis.                                                               

Pediatric samples where only serum is available and a dedicated red top is not feasible due to excessive sample volume, draw red top tube and following centrifugation, remove serum and rapidly transfer to a small polypropylene tube (i.e. Sarstedt) aliquot container, FILLING THE CONTAINER IN ITS ENTIRETY (to avoid any air exchange). Cap the filled container immediately and store refrigerated (or frozen) prior to and during transport. Send to Marshfield.                                                              

                                                           

Other sites sending IC to Marshfield Medical Center Laboratory:                                                                   

Collect specimen anaerobically in a 5 to 10 mL SST tube, filled completely, and centrifuged within 4 hours of collection.  (Centrifuged SST samples are preferred in case other tests are requested, but not required).  Alternatively, specimens collected anaerobically in a 5 to 10 mL un-centrifuged RTT are also acceptable, but less desirable.  DO NOT REMOVE CAP FROM THE TUBE.  Preferred is for the entire tube to be sent refrigerated.  If unique reasons preclude the entire tube from being sent, centrifuge the RTT or SST, then remove serum and rapidly transfer to a small polypropylene tube (i.e. Sarstedt) aliquot container, FILLING THE CONTAINER IN ITS ENTIRETY (to avoid any air exchange). Cap the filled container immediately and store refrigerated prior to and during transport.  These aliquots may also be frozen for transport.  If the only size aliquot container available does not allow to fill to its entirety, then add as much sample as is available, at least 0.5 mL, and freeze immediately.                                                          

Specimen Stability Information
Specimen Type Temperature Time
Whole Blood - Syringe/non-gel GTT​  ​ ​Refrigerate ​ ​4 hours​
​Ambient​ 30 minutes
Whole Blood - SST/RTT Refrigerate 70 hours​
Ambient​ 6 hours​
Serum​​ ​ Frozen ​ 45 days
​Refrigerate ​ ​7 days
Rejection Criteria
Specimens exposed to air
Plasma separator tubes​
Other syringes than those listed​
​Capillary tubes other than balanced-heparin 
​Gross hemolysis
Useful For
It is useful in evaluation of renal function and endocrine disorders, during cardiac surgery, and in neonatology.​
Reference Range Information
Performing Location Reference Range
All Performing Sites 0-4 days: 4.3-5.5 mg/dL
5-29 days: 4.8-6.0 mg/dL
1 mo.-19 yrs.: 4.9-5.5 mg/dL
>=20 yrs.: 4.5-5.3 mg/dL ​

See Critical Value List for list of current critical values

For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Bloomer​ ​​Monday through Friday ​Less than 2 hours​ ​Ion-Selective Electrode Potentiometry/i-STAT
​Cadott ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Chetek ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Colby/Abbotsford ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Cornell ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Cumberland ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
Diagnostic Treatment Center ​Monday through Sunday​ ​Less than 2 hours​ ​Radiometer
​Eagle River​ ​Monday through Friday ​Less than 2 hours ​​​Ion-Selective Electrode Potentiometry/i-STAT
​Eau Claire ​​Monday through Sunday ​Less than 2 hours​ ​​Gem 4000
Hayward​ ​​​Monday through Friday ​​Less than 2 hours​ ​​​Ion-Selective Electrode Potentiometry/i-STAT
​MMC-Ladysmith​Monday through Sunday​Less than 2 hours​Gem 4000
MMC-Park Falls​​Monday through Sunday​Less than 2 hours​Gem 4000
​MMC-Rice Lake​Monday through Sunday​Less than 2 hours​Gem 4000
Marshfield​ Monday through Sunday​ Less than 2 hours​ Gem 4000
​Mercer ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Minocqua​Monday through Sunday​Less than 2 hours​Reference Electrode/Gem 4000
​Mosinee ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Oakwood ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
Phillips​ ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Rhinelander ​Monday through Friday ​Less than 2 hours ​​​Ion-Selective Electrode Potentiometry/i-STAT
​Stettin ​​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
​Wittenberg ​Monday through Friday ​Less than 2 hours​ ​​Ion-Selective Electrode Potentiometry/i-STAT
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
82330 ​
For most current information refer to the Marshfield Laboratory online reference manual.