Calcium, Ionized, Serum/Plasma

Sunquest Code:ICAW  
Epic Code:LAB3077Epic Name:Calcium Ionized
Order Instructions:Order ICAW for whole blood and ICA for plasma/serum.
Synonyms:Ionized Calcium
Methodology:Ion selective electrode
Turnaround Time:Performed and reported 24 hours/day.

Collection Instructions

Optimal Volume:1 mL
Minimum\Peds Volume:0.5 mL
Container:St Johns/St Joseph/Woodwinds-Green (lithium heparin, no gel), Dry heparin syringe (Capillary (lithium heparin) gas tube, Green (lithium heparin, gel), Green (lithium heparin) on ICE)
Collection Instructions:
  • Do not remove stopper.
  • Place sample on ice and deliver to laboratory for processing within 1 hour of collection.
  • Acceptable without ice if received within 30 minutes of collection.
  • If unprocessed samples cannot be delivered to the laboratory within 1 hour of collection, a whole blood ionized calcium testing should be requested. Whole blood samples are stable on ice for 4 hours.
Causes for Rejection:Sample exposed to air during collection or transport not analyzed within 1 hour of collection, specimen on ice not received within 1 hour of collection, room temperature specimen not processed within 30 minutes of collection.

Processing and Shipping

Specimen Processing:
Centrifuge with stopper in place within one hour of collection. Do not open the tube or split the sample. Store in refrigerator.

If collected in a red top (plain) tube, allow the sample to clot for 15 minutes before centrifuging; do not remove stopper.
Whole blood specimens collected on ice and maintained anaerobically may be analyzed within 4 hours using test code ICAW. SI Unit Conversion Factors: mg/dl x 2.5 = mmol/L. See ICAW.
Shipping Instructions:Ship unopened (anaerobically) at refrigerated temperature.
Stability:Centrifuged, refrigerated specimens are acceptable for 7 days if stopper is not removed. Specimens that have been exposed to air should be analyzed within 1 hour if pH is 7.35-7.45; otherwise recollect. Whole blood samples on ice are stable for 4 hours. See ICAW.
Test Performed at or Referral Lab Chemistry  (UMMC-East Bank, Lakes, Ridges, Northland, Southdale, UMMC/UMMCH-West Bank, UMMC NICU, M Health Clinic and Surgery Center, St. Joseph's, St. John's, Woodwinds)


Critical Range:St Johns/St Joseph/Woodwinds:  N/A

All other sites:
0-11 mo Less than 3.5 mg/dL and greater than 7.0 mg/dL
1 y & older Less than 3.0 mg/dL and greater than 7.0 mg/dL
Reference Range:St Johns/St Joseph/Woodwinds:  N/A

All other sites:
0-11 mo 5.1-6.3 mg/dL    
1 y & older    4.4-5.2 mg/dL
  To convert mg/dL to mmol/L, divide by 4.
To convert mmol/L to mg/dL, multiply by 4.
  1. Suspect hypocalcemia or hypercalcemia
  2. Monitor treatment for calcemic disorder.

Click HERE to Report test errors or omissions.
*If no email program is associated with this computer, please contact: for TestID: 1233"