New Coagulation Normal Ranges, Heparin Protocol for APTT, and Critical Values

Premier Pulse     January 2019

The Miami Valley Hospital laboratory system – Miami Valley Hospital, Miami Valley Hospital South, Miami Valley Hospital North, Jamestown Emergency Center, and Austin Emergency Center – will be going live with new coagulation instrumentation January 30, 2019.

Through a large group effort including collaboration with pharmacy, we have studied the normal ranges for PT, APTT, Fibrinogen, and D-dimer testing. The laboratory has also studied very closely the Heparin Protocol for APTT. Based on these studies and the change in instrument method, new normal and critical ranges are required. Please see new normal and critical value ranges below.


PT (Partial Thromboplastin Time) = 11.7-13.9 seconds

APTT (Activated Partial Thromboplastin Time) = 24.5-35.2 seconds

FIBRINOGEN = 208-491 mg/dl

D-DIMER = <0.50 ug/ml FEU cut-off. This will be a unit of measure change for Miami Valley Hospital North only.

HEPARIN PROTOCOL FOR APTT (Therapeutic Range) = 74.0-110.0 seconds


INR > 5.0

APTT (Activated Partial Thromboplastin Time) >60.0 seconds

FIBRINOGEN < 75 mg/dl

HEPARIN PROTOCOL FOR APTT <74.0 or >110.0 seconds 

For questions or concerns, please call Catherine Hoesl, MT, system technical director of hematology and coagulation, at (937) 297-8209(937) 297-8209.

Back to the January 2019 issue of Premier Pulse

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