Closure Time

Source	Blood
Mnemonic	CLT
Specimen Requirements	Adult: 1 x 5 mL blue top sodium citrate tube (4.5 mL draw) Pediatric: 1 x short-draw (2.7 mL draw) blue top sodium citrate tube Whole blood DO NOT combine other coagulation tests on this tube. PSC:DO NOT collect. Refer patient to RRL Outpatient Laboratory. (If patient is unable to go to RRL, contact Special Coagulation.) RRL: Collect Monday to Friday 0700h-1300h No collections on statutory holidays When using a winged blood collection set (butterly needle) a discard tube must be used to remove the air in the tubing, if only a citrate tube is drawn or is the first tube drawn.
Specimen Handling	DO NOT centrifuge. Indicate test clearly on specimen. Place in individual collection bag, adhere prepared label stating "Send to DSC Special Coagulation. DO NOT CENTRIFUGE". Indicate STAT on specimen bag and place Stat label on transport container. DO NOT transport samples through pneumatic tube system. Send to Special Coagulation within 2 h of collection. Include copy of original requisition.
Additional Information	If for any reason sample must be collected after stated hours, before collecting sample, phone Special Coagulation (770-3598/ 770-3599) to ensure test can be performed. Notify Special Coagulation before sending sample. Hematologist approval is required for testing after 1600 hours.
Testing Location	Special Coagulation
Testing Frequency	Weekdays
Alternate Name(s)	Replaced Bleeding time
Reference Interval

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