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Calcium, Ionized, post-filter

Item Value
Test Update Information Effective March 10, 2008, the volume of blood required for ionized calcium testing in venous blood will increase from approximately 100 microliters to 600 microliters. This will require that an additional full bullet tube sample be drawn on pediatric patients in whom other tests are being ordered in addition to ionized calcium.
Approval req'd? No
Available Stat? Yes
Utilization Guidelines This test should ONLY be ordered when testing post-filter samples in patients on dialysis with citrate anticoagulation. It should not be ordered for monitoring a patient's systemic ionized calcium level. See Calcium, Ionized, serum/plasma (CAI).
Test code PCAI
Test group Calcium
Performed by Parnassus & Mission Bay Chemistry
In House Availability Test available 24 hours per day 7 days per week
Method Ion selective electrode (ISE) - Nova 8 CRT
Collection Instructions Fill collection container completely. Deliver immediately to lab. Not acceptable as an "add-on" if tube has already been processed for other routine tests.

Note: Please submit sample in its own separate biohazard bag with Apex requisition before sending to the lab.
Container type Light green top preferred, Gold top acceptable
Amount to Collect 2 mL blood Click here for Microdetermination info
Sample type Plasma or serum
Preferred volume 1 mL serum or plasma
Min. Volume 0.3 mL serum or plasma Click here for Microdetermination info
UCSF Rejection Criteria Delivered to lab > 30 min after collection
Processing notes Do not centrifuge or open tube. Deliver immediately to Chemistry. Not acceptable as an "add-on" if tube has already been processed for other routine tests
Units mmol/L
Normal range
Synonyms iCa; Free calcium; Calcium, ionized; calcium, free; Ca; Ca++
Turn around times STAT 1 hour, Routine 3 hours
Additional information NOTE – the results for serum or plasma ionized calcium are adjusted (normalized) to a standard pH of 7.40. To obtain ionized calcium results that are not adjusted to a standard pH of 7.40, order whole blood ionized calcium (e.g., in patients with possible acid-base disturbances including those with symptoms of hypocalcemia suspected to be secondary to respiratory alkalosis).
CPT coding 82330
LOINC code 1995-0
LDT or Mod FDA? No
Last Updated 2/9/2017 12:11:46 PM
Entry Number 1456
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