Correcting High K Time on Thromboelastography (TEG)

Understanding K Time on TEG

K time measures the time from clot initiation to reach a clot width of 20mm, representing clot kinetics or the speed of clot formation 2, 3
Prolonged K time indicates delayed clot formation, which is often associated with fibrinogen deficiency or dysfunction 3
K time correlates strongly with fibrinogen levels, with a significant inverse relationship (r = -0.84, P = .0001) demonstrated in clinical studies 4

The American Society of Anesthesiologists recommends administering fibrinogen concentrate as first choice at 4g for adults or 70 mg/kg for children under 12 years 1
Target a fibrinogen level of at least 1.5-2.0 g/L in bleeding patients, with higher targets (>2.0 g/L) recommended in obstetric hemorrhage 5, 1

Consider FFP (10-15 mL/kg) if fibrinogen concentrate or cryoprecipitate is unavailable 1, 3
For massive transfusion scenarios, maintain a 1:1:1 ratio of packed RBCs, FFP, and platelets 1

Consider platelet transfusion if TEG shows that platelet contribution to clot strength is reduced (rTEG MA – FF TEG MA <45 mm or EXTEM CA5 – FIBTEM CA5 <30 mm) 5
Maintain platelet count >50,000/mm³ for patients with significant bleeding 1

Repeat TEG 15-30 minutes after intervention to assess response 3
Continue monitoring fibrinogen levels, as fibrinogen is often the first coagulation factor to reach critically low levels during major bleeding 1

In pregnancy, baseline TEG parameters reflect a hypercoagulable state with shorter K times; therefore, a "normal" K time may actually represent coagulopathy in this population 4, 3
In liver disease, TEG may provide more valuable information than standard coagulation tests 6, 1

Do not rely solely on conventional coagulation tests (PT, aPTT) as they may not correlate well with clinical bleeding or TEG parameters 1
Remember that TEG functional fibrinogen levels (FLEV) may overestimate fibrinogen compared to the Clauss method, potentially leading to undertreatment 4
Do not delay treatment while waiting for laboratory results in cases of severe bleeding 1
Recognize that anemia can paradoxically show hypercoagulable TEG results due to decreased blood viscosity, potentially masking coagulopathy 3