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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Potassium, Whole Blood

Test Code(s): WBK / HCWBK

CPT Code(s): 84132

Test Description: Included In: Electrolytes, Whole Blood

Methodology: Ion Selective Electrode

Request Form: UWHC DOWNTIME Laboratory Request Form (UWH IPDOWNTIME, 4004202); Write in test if not on form.

Days Performed: Daily, 24 hours.

Turnaround Time: Stat: Up to 30 minutes. All requests processed stat.

Specimen Requirements

Specimen: Arterial, venous, or capillary

Patient Preparation: None.  For venous samples on outpatients, send patient to UWHC Outpatient Phlebotomy to be drawn.

Collection Instructions: Radiometer "PICO"® syringes must be free of bubbles and clots. Two full Radiometer capillaries free of air bubbles and clots are needed for capillary blood. Do NOT place specimen on ice.

Collection Container: Preferred: Radiometer PICO® syringe
Also Acceptable: 2 full Radiometer capillary tubes, Green top

Collection Volume: Preferred: 1.5 mL
Pediatrics: 0.5 mL

Sample Analyzed: Whole Blood

Volume Required: Preferred: 1.5 mL
Pediatrics: 0.5 mL

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220) immediately.  Specimen must arrive in the UWHC Core Lab within 30 minutes of collection.

Unacceptable Criteria: Clotted specimens, iced specimens or specimens past stability time are not acceptable.

Stability: Ambient: 1 hour
Refrigerated: Not acceptable
Frozen: Not acceptable


Reference Interval:
 Age  mmol/L
 0-29 days  4.0-5.9
 30 days-11 months  4.0-5.3
 12 months and up  3.6-5.0


Critical Calls: View

Additional Information:

Whole blood specimens will not be inspected for hemolysis. Hemolysis, if present, will increase potassium results.

K, Whole Blood

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