Robert F. Sidonio, Jr. MD, MSc.
Vanderbilt Pediatric Hematology Thrombolysis (tPA) Protocol
4/1/12
Yes
Acute venous or
arterial thrombosis
Obtain pediatric hematology
consult
Yes
Check baseline tPA labs:
CBC
PT/PTT
Fibrinogen activity
Plasminogen activity
D-dimer (quantitative)
FVIII activity
CMP
CRP
Does patient meet inclusion
and exclusion criteria for
tPA?
Is there an indication for thrombolysis?
Is there clinical concern for an anatomic
compressive syndrome or occlusive
iliofemoral or IVC
DVT?________________________________
____
Consider anatomic thrombotic obstruction:
May-Thurner Syndrome
-Acute occlusive iliofemoral vein/lower IVC
thrombosis in left lower extremity
Paget-Schroetter Syndrome
-Subclavian thrombosis with recent vigorous
exercise of upper extremity
(pitcher, drummer, etc.)
No
No
No
Indications for thrombolysis
Strong Indications
-Life, limb or organ-threatening thrombosis
-Arterial or venous thrombosis causing ischemia
-Superior Vena Cava Syndrome
-Massive PE with cardio instability
-Bilateral renal vein thrombosis
-Cerebral Sinovenous thrombosis with neurologic decline
-Large atrial thrombi (congenital heart disease)
Intermediate Indications
-Acute iliofemoral or IVC thrombosis
-May-Thurner Syndrome
-Paget-Schroetter Syndrome
Inclusion Criteria for tPA
-Symptoms present < 14 days
-Thrombus site and extent confirmed by
objective imaging
-No more than 48 hours of UFH
or LMWH for thrombus (systemic tPA only)
-Platelet count > 100,000/l
-Fibrinogen > 100 mg/dl
-No thrombus in previous site
Exclusion criteria for tPA
Baseline labs: CBC, PT, PTT, fibrinogen activity,
FVIII activity, D-dimer (quantitative) and CRP
-Defer hypercoaguability workup until outpatient
-Start UFH or Enoxaparin
____________________________________________
_
Start Enoxaparin:
<3 month old
1.7mg/kg/dose BID
3-12 months old 1.5mg/kg/dose BID
1-5 years old
1.2mg/kg/dose BID
6-18 years of age 1mg/kg/dose BID
-Notify Kathy Jernigan for teaching (pager 831-6629)
Goal anti-Fxa 0.5-1, 4-5 hours after second dose
____________________________________________
UFH (clinically unstable, expected surgery or postcardiac surgery) :
Load: 75 units/kg over 10 minutes (max 5000 units)
Maintenance:
< 1 year of age: 28 units/kg/hr
≥ 1 year of age: 20 units/kg/dose
Goal PTT 65-100 seconds (Consider only 24-72 hrs)
and anti-FXa inhibition 0.35-0.7
-Active bleeding
-Active seizures < 48 hours
-Invasive procedure < 3 days
(chest tube, lumbar puncture, liver biopsy
etc)
-Major surgery < 10 days
-CNS bleeding or surgery < 14 days
-History of HIT
-Allergic reaction to UFH, LMWH or alteplase
-Renal or liver failure
-Uncontrolled Hypertension
tPA labs
CBC
PT/PTT
Fibrinogen activity
D-dimer (quantitative)
BMP
-CMP if LFTS abnormal
at baseline
No clot lysis
Double tPA dose
Repeat U/S in 24hrs
>0-50% clot lysis
Increase tPA by 50%
Repeat U/S in 24hrs
Yes
Catheter-directed tPA
1) Contact Interventional Radiology for
catheter-directed tPA
2) Start therapeutic UFH gtt
3) Make NPO for procedure
4) Start mIVF
5) Lab goals: Platelet >100k
Fibrinogen >100mg/dL
6) CTA/V of affected area prior to
catheter-directed tPA
7) Once catheter tPA done:
a) Goal PTT 65-100 seconds x 48hrs
b) Check tPA labs q8h x 48 hrs
c) Convert to Enoxaparin after 48hrs
Systemic tPA
1) Begin systemic tPA:
- 0.06mg/kg/hr if <2 months of age
- 0.03mg/kg/hr if >2 months of age
2) Perform cranial U/S if <1 month old within 7days
3) Concurrent UFH gtt at 10 Units/kg/hr
-Do not adjust PTT to therapeutic goal
4) tPA labs q8hrs
5) Maintain fibrinogen and plt count >100
6) tPA x 24 hours and re-image with U/S
>50-95% clot lysis
Cont. same dose tPA
Repeat U/S in 24hrs
>95% clot lysis
Stop tPA
-Therapeutic UFH
x 48 hrs
- tPA labs x 48hrs
-Switch to Enoxaparin
0-50% clot lysis
Either the following:
-Continue same tPA dose and repeat U/S in 24hrs
>50-100% clot lysis
Either the following:
-Continue same tPA dose and repeat U/S in 24hrs
-Stop tPA
__________________________________________
Once tPA done:
Therapeutic UFH x 48 hrs, tPA labs x 48hrs
Switch to Enoxaparin
-Stop tPA
________________________________________
Once tPA done:
Therapeutic UFH x 48 hrs, tPA labs x 48hrs
Switch to Enoxaparin
Key
UFH: Unfractionated Heparin
LMWH: Low molecular weight Heparin
CNS: Central Nervous System
tPA: Tissue Plasminogen Activator (usually alteplase)
Gtt: drip
HIT: Heparin induced thrombocytopenia