Transcript Pediatric Care - Children`s of Alabama

Antithrombotic Therapy for
Pediatric VAD Patients
Meloneysa Hubbard, MSN, CRNP, CCTC
Director of Heart Transplant Services
Children’s of Alabama
Disclosure Statement
I do not have any relevant
financial relationships with any
commercial interests to
disclose.
Objectives ?
 Discuss the use of ventricular assist device (VAD) support
in the pediatric population
 Identify indications for antithrombotic therapy
 Describe basic coagulation components
 Discuss anticoagulation medications
 Review our strategy for monitoring anticoagulation
Pediatric Ventricular Assist Devices
 Berlin Heart EXCOR
 FDA approved pediatric VAD
 Pulsatile flow device
 RVAD, LVAD, BiVAD
 Thoratec PVAD
 HeartWare, HeartMate II
 SynCardia
 PumpKIN Trial
Berlin Heart Implants
Almond et al. Circulation 2013;127:1702-1711
Morbidity and Mortality
Almond et al. Circulation 2013;127:1702-1711
这是凝血过程是很容
易理解是否你一定要
把它理解成你的理解。
Coagulation Cascade
• Feedback process of
plasma protein activation
• Results in converting
prothrombin to thrombin
• Thrombin
• converts
fibrinogen to fibrin
• Activates platelets
Balance
Thrombosis
Bleeding
Hemostasis
Considerations
Ventricular Support
Device
Antithrombotic Medications
Considerations of Hemostasis
Immature coagulation
vWB factor deficiency
Heparin induced thrombocytopenia
Baseline hematology
Current hematology
Changes in patient status
Changes in nutrition
Laboratory Monitoring
 Anti Xa
 PTT
 INR
 TEG
 Platelet Mapping / Platelet Aggregation
Thromboelastogram
Thromboelastogram
Maximum amplitude (MA)
-body of the clot formation
-represents the ultimate clot strength
-indicative of platelet activity
-target range 55-73
Platelet Mapping
 Platelet Mapping
 Represents the inhibition present between
clot fibrin and thrombin
 Agent specific
 ADP – clopidogrel, dipyridamole
 AA - aspirin
 Inhibition 70-95%
Platelet Mapping
Antithrombotic Agents
 Unfractionated heparin
 Antithrombin
 Acetylsalicylic acid (ASA)
 Dipyridamole
 Clopidogrel
 Low molecular weight heparin (enoxaparin)
 Warfarin
 Adjunctive Medications
Anticoagulation Therapy
 Heparin
 Catalyzes the interaction between thrombin and
antithrombin
 Requires adequate ATIII level <70%
 Initiated 24-48 hours after implant
 Platelet count 50,000
 TEG MA >56
 No significant bleeding
 Therapeutic monitoring with anti Xa
Heparin Target Dosing
Stage
Age
(months)
I
Therapeutic
Range
All
II
Adjustment
<3 mo
Max PTT
85 sec
Anti-factor XA
(u/ml)
PTT (sec)
Infusio
n rate
Hold
UFH
%Rate
Change
<0.1 (<50)
No
+15%
4hrs
0.1-0.34 (50-59)
No
+10%
6hrs
0.35-0.50 (60-
No
0
As per guideline
No
-10%
6hrs
0.71-.89(96-120)
30 min.
-10%
4hrs
≥ 0.90 (>120)
60 min.
-15 %
4hrs
<0.1 (<50)
No
+15%
4hrs
0.1-0.34 (50-59)
No
+10%
6hrs
0.35-0.70 (6095)
0.71-.89(96-120)
No
0
As per guideline
30 min.
- 10%
4hrs
≥ 0.90 (>120)
60 min.
-15 %
4hrs
10-20
u/kg/h
Repeat
Anti-Xa
(or PTT)
After 6hrs
85)
0.51-0.70 (8695)
II
Adjustment
≥ 3 mo
Max PTT
95 sec
Long Term Anticoagulation
 Low molecular weight heparin
 Catalyzes the interaction between thrombin and
antithrombin
 Monitor anti-Xa for target 0.6-1.0
Anti-Factor Xa
level u/ml
Hold Next Dose?
Dose Change
No
No
No
No
Increase by 25%
Increase by 15%
Increase by 10%
No
4 hours after next dose
4 hours after next dose
4 hours after next dose
4 hours after next dose
1.1 - 1.25
No
Decrease by 20%
4 hours after next dose
1.26 - 1.5
1.6 – 2.0
No
Yes, for 3 hours
Decrease by 30%
Decrease by 40%
Yes, until anti-factor Xa
level is ≤ 0.6 u/ml
Decrease by 50 %
4 hours after next dose
Before next dose then 4 hours
after next dose
Before next dose, if anti-Xa level
>0.6 U/ml, repeat level q12h until
≤0.6 U/ml before re-starting at
50% of previous dose
< 0.35
0.36 - 0.45
0.46 - 0.59
6.
> 2.0
1.
0
Repeat Anti-Factor Xa
Long Term Anticoagulation
 Warfarin
 Vitamin K antagonist
 Monitor INR for target 2.5-3.5
Stage
INR
Day 1
1.0 – 1.8
1.1 – 1.3
1.4 – 1.9
2.0 – 3.0
3.1 – 3.5
> 3.5
1.1 – 1.9
2.0 – 2.6
2.7 – 3.5
3.6 – 4.0
Day 2-4
Maintenance
≥ Day 5 and long
term
4.1 – 5.0
Action
0.2 mg/kg orally
Repeat day 1 loading dose
50% of day 1 loading dose
50% of day 1 loading dose
25% of day 1 loading dose
Hold dosing until INR is < 3.5
Increase dose by 40 – 50%
Increase dose by 20 – 30%
No change
Administer next dose at 50%, then restart at 20% less
maintenance dose
Hold one dose then repeat INR; if 2-3 decrease dose 50%
Antiplatelet Therapy
 Aspirin
 Blocks arachidonic acid pathway of platelet
activation
 Usually started >48 hours after implant
 Monitored by TEG and platelet mapping or aggregate
studies
 May be indicated bid
Arachidonic acid
platelet inhibition
0-30%
31-50%
51-69%
70-95%
96-100%
100% and patient is
bleeding
Hold next
dose?
No
No
No
No
No
Yes
Dose change?
Increase 100%
Increase 50%
Increase 25%
No
Decrease 10%
Hold next dose until bleeding
stops, decrease 50%
Repeat AA Test?
Next day
Next day
48 hours
As per guideline
48 hours
Next day
Antiplatelet Therapy
 Clopidogrel / Dipyridamole
 Binds to adenosine di-phosphate receptors and
prevents uptake
 Initiated after POD 4
 Monitored by platelet mapping or aggregate studies
ADP platelet
inhibition
0-30%
31-50%
51-69%
70-95%
96-100%
100% and patient is
bleeding
Hold next
dose?
No
No
No
No
No
Yes
Dose change?
Increase 100%
Increase 50%
Increase 25%
No
Decrease 10%
Hold next dose until bleeding
stops, decrease 50%
Repeat AA Test?
Next day
Next day
48 hours
As per guideline
48 hours
Next day
Anticoagulation
Question
 A 2 month old patient
supported with Berlin Heart
LVAD is stable with no signs
of active bleeding or pump
fibrin deposits.
 Anticoagulation
 ASA 5mg/kg
 clopidogrel 0.2mg/kg
 Warfarin 0.5mg/kg
 Labs
 TEG/PM: MA 68; AAI
80%; ADPI 53%
 INR 2.1
What would you anticipate for
this patient?
a) continue to monitor
b) increase warfarin
c) increase warfarin and
clopidogrel
d) increase warfarin and
decrease aspirin
Anticoagulation Guidelines




HeartWare HVAD
Berlin Heart EXCOR
Heparin Drip
 Inhibits coagulation pathway
 started 24-48 hours after implant
 Titrated to goal Anti Xa 0.35-0.5 U/mL
 Stopped once Coumadin is therapeutic

Coumadin
 Inhibits coagulation pathway
 Started once bleeding resolved and
tolerating PO
 Titrated to goal INR 2.5-3.5

Aspirin
 Blocks arachidonic acid pathway of
platelet activation
 Dosed for goal AA inhibition 70-95 %

Clopidogrel (Plavix)
 Blocks adenosine di-phosphate pathway of
platelet activation
 Dosed for goal ADP inhibition 70-90%
 May be used as long-term therapy

Heparin Drip

Inhibits coagulation pathway

started 24-48 hours after implant

Titrated to goal Anti Xa 0.35-0.5 U/mL

Stopped once Coumadin is therapeutic
Coumadin

Inhibits coagulation pathway

Started once bleeding resolved and tolerating
PO

Titrated to goal INR 2.0-3.0
Aspirin

Blocks arachidonic acid pathway of platelet
activation

Dosed for goal AA inhibition 70-95%
Clopidogrel (Plavix)

Blocks adenosine di-phosphate pathway of
platelet activation

Dosed for goal ADP inhibition 70-90%

Stopped once Coumadin is therapeutic
Patient Assessment
 Pump function
 Flows/Parameters
 Chamber
assessment
 Physical assessment
Patient Care Education
 Medication
 Indication
 Administration/dosage
 Side effects
 Monitoring
 Interactions
 Physical Activity Precautions
 Dietary Considerations
 Illness effects
 Complications of device support/anticoagulation
 Home monitoring
Question
 Do you utilize INR Patient Home Monitoring for
pediatric VAD patients?
a) yes
b) no
Quality of Life
References





Almond, C., Morales, D., Blackstone, E., Turrentine, M., Imamura, M., Massicotte, P.,
Jordan, L., Devaney, E., Ravishankar, C., Kanter, K., Holman, W., Kroslowitz, R.,
Tjossem, C., Thuita,
L., Cohen, G., Buchholz, H., St. Louis, J., Nguyen, K.,
Neibler, R., Walters, H., Reemtsen, B., Wearden, P., Reinhartz, O., Guleserian, K.,
Mittchell, M., Bleiweis, M., Canter, C., Humpl, T., (2013). Berlin Heart EXCOR
pediatric ventricular assist device for bridge to heart transplantation in US children.
Circulation, 127:1702-171
Zafar, F., Chasleberry, C., Khan, M., Mehta, V., Bryant, R., Lorts, A., Wilmot,I., Jefferies, J.,
Chin, C., Morales, D., (2015). Pediatric heart transplant waiting list mortality in the
era of ventricular assist devices. Journal of Heart and Lung Transplantation, 34:1, 82-86.
Drews, T., Kupper, F., Stiller, B., Hubler, M., Weng, Y., Berger, F., Hetzer, R., (2007). Coagulation
management in pediatric mechanical circulatory support. ASAIO Journal, 53: 640-645.
Moffett, B., Gabrera, A., Teruya, J., Bomgaars, L., (2014). Anticoagulation therapy trends in
children supported by ventricular assist devices: a multi-institutional study. ASAIO
Journal, 60:2, 211-215
Massicotte, M., Bauman, M., Murray, J., Almond, C., (2015). Antithrombotic therapy for
ventricular assist devices in children: do we really know what to do?, (2015). 13, S343345.