Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3865_Библиотеки_им_академика_М_И_Перельмана
.pdf
410 Anticoagulation Therapy
https://t.me/med1917
(continued)
ACT is the most commonly utilized monitoring parameter.
4,9,13,19-23
Anticoagulant Therapy Specific Considerations
Therapy
Indication For Anticoagulation or Antiplatelet Therapy
Device Antiplatelet
Temporary Support Devices
TABLE 17-3: Anticoagulation Strategies by Device
VA ECMO None Heparin
The Purge solution of heparin with dextrose can vary between 5% and 40% dextrose, but
commonly initiated at 5% dextrose and modified based on device-specific parameters. It
is important to note that the device controls the rate of solution into the device, thereby
changing the rate of heparin administration. Typically, additional heparin will need to be
administered systemically to achieve therapeutic goals.
Titrated to institution-
specific ACT goals
and
Systemic heparin—high
dose
Titrated to institution-
None Heparin—purge solution
Impella (several
types)
Impella RP: This is placed on the right side of the heart, and goals will be different. Heparin
specific ACT (low range),
50 units/mL may be recommended, and it is important to avoid compounding different
heparin concentrations. The type of Impella catheter should be clearly identified and
potential confusion on the heparin concentrations and type of Impella identified with
management.
No anticoagulation recommendations provided by manufacturer, although a localized
heparinized infusate (45,000 units/500 mL NS) is infused into the device at 10 mL/hr for
local anticoagulation in the pump housing. Additional heparin will need to be administered
systemically to achieve therapeutic goals.
Anticoagulation started after hemostasis achieved following implant.
APTT, or anti-Xa goals
Titrated to institution-
specific ACT (low range),
APTT, or anti-Xa goals
Titrated to institution-
specific ACT (low range),
TandemHeart None Heparin— high dose
Thoratec PVAD None Heparin—high dose
APTT, or anti-Xa goals
MECHANICAL CIRCULATORY SUPPORT DEVICES 411
Indication for Anticoagulation or Antiplatelet Therapy
Intra-aortic balloon
Durable Support Devices
Heartware HVAD
https://t.me/med1917
(continued)
Choice to anticoagulate is institution-specific. Thrombosis risk increases with decrease in
frequency of counterpulsation (1:1 vs 1:2 vs 1:3, etc.) where the balloon is immobile for
Anticoagulation started after hemostasis achieved following implant.
Anticoagulant Therapy Specific Considerations
Device Antiplatelet
TABLE 17-3: (Continued)
Titrated to institution-
Therapy
BVS 5000 None Heparin—high dose
Higher thrombotic risk than other devices due to pulsatile flow.
specific ACT (low range),
APTT, or anti-Xa goals
Titrated to institution-
specific ACT (low range),
APTT, or anti-Xa goals
AB 5000 None Heparin—high dose
longer periods of time.
needed, see special
considerations)
None Heparin— low dose (if
pump
Also causes platelet destruction and thrombocytopenia, which will contribute to
coagulopathy during therapy.
Anticoagulation started after hemostasis achieved following implant
Titrated to institution-
specific ACT (low range),
APTT, or anti-Xa goals
Centrimag None Heparin—high dose
The decision to use heparin in the early postoperative period is institution-specific and may
lead to more bleeding events. Patients who are unable to take oral medications for more
than a few days postoperatively may need parenteral anticoagulation therapy.
Warfarin
INR Goal 2–3
Aspirin 325 mg PO
daily
412 Anticoagulation Therapy
Indication for Anticoagulation or Antiplatelet Therapy
ACT: activated clotting time, APTT: activated partial thromboplastin time, hr: hour, INR: international normalized ratio, PO: by mouth, TAH: total artificial heart, TEG:
thromboelastography, VA ECMO: veno-arterial extracorporeal membrane oxygenation
https://t.me/med1917
The decision to use heparin in the early postoperative period is institution-specific and may
lead to more bleeding events. Patients who are unable to take oral medications for more
than a few days postoperatively may need parenteral anticoagulation therapy.
Many centers will have other monitoring goals other than INR (i.e., TEG parameters).
Anticoagulant Therapy Specific Considerations
Warfarin
INR Goal 2–3
Heparin—very low dose
(early post op)
Warfarin (INR goal 2.5–3.5)
Therapy
daily
Device Antiplatelet
TABLE 17-3: (Continued)
Heartmate II Aspirin 81 mg PO
daily
Dipyridamole 100
mg PO q 6–8hr
Pentoxifylline 400 mg
PO q 8hr
SynCardia TAH Aspirin 81 mg PO
MECHANICAL CIRCULATORY SUPPORT DEVICES 413
https://t.me/med1917
MONITORING PARAMETERS
•
Choice of monitoring should depend on local availability and provider experience with different parameters.
•
Frequency of monitoring is institution-specific, but should be at least daily in
temporary support devices.
•
Some parameters are not routinely checked unless a clinical situation (i.e., suspicion of pump thrombosis) is suspected. Alternatively, for patients on temporary
support devices where thrombus formation may not be easily recognized, routine
surveillance may be warranted (Table 17-4).
TABLE 17-4: Antithrombotic Monitoring Parameters Used in
Mechanical Circulatory Support Devices
Test Device Type Utility
PT/INR Temporary and
aPTT* Temporary and
ACT* Temporary POC test most commonly used in ECLS since the
Anti-Xa activity* Temporary and
Fibrinogen Temporary Protein used in clot formation, level indicates
Antithrombin activity Temporary Used to determine the availability of antithrombin.
Platelet function
testing
durable
durable
durable
Durable When patients have device-related thrombosis
Warfarin monitoring
Monitoring of extrinsic pathway and hepatic
function
Heparin or DTI monitoring
value is rapidly available.
Pharmacodynamic marker of heparin activity
availability of protein for clot formation
Evaluation for DIC
A low antithrombin may be a cause of heparin
resistance.
Note: In ECLS, AT replacement may not change
heparin dosing.
despite optimal anticoagulation parameters,
testing for aspirin resistance may be indicated
to optimize antiplatelet therapy (i.e., increasing
dosage or adding a second agent such as
dipyridamole).
Platelet mapping is another option.
9,21,22,24
Thromboelastography Temporary and
durable
Requires specialized equipment and personnel
trained on interpretation.
May be used when patient has bleeding or
thrombotic events despite adequate levels of
anticoagulation as determined by standard tests.
(continued)
414 Anticoagulation Therapy
https://t.me/med1917
TABLE 17-4: (Continued)
Test Device Type Utility
Lactate
dehydrogenase
Plasma free
hemoglobin
CBC Temporary and
*The preferential test between ACT, aPTT, or anti-Xa activity for managing heparin in ECLS is
institution specific. Correlation between the tests is poor and outcome data on which may be
optimal is limited. See Chapters 3 and 21.
ACT: activated clotting time, aPPT: activated partial thromboplastin time, CBC: complete
blood count, DIC: disseminated intravascular coagulation, DTI: direct thrombin inhibitor, ECLS:
extracorporeal life support, ECMO: extracorporeal membrane oxygenation, INR: international
normalized ratio, POC: point of care, PT: prothrombin time
Durable Marker of hemolysis and possible thrombosis
Temporary Marker of hemolysis and possible thrombosis
durable
formation in durable support devices.
Levels >600 units/L are associated with higher risk
of thrombus formation.
formation in temporary support devices.
High bilirubin levels may interfere with test
accuracy.
Levels >30 mg/dL are associated with hemolysis
and possible thrombus formation.
Evaluate platelet quantity and early detector of
anemia.
MANAGEMENT OF COMPLICATIONS
•
Complications following device implant are common.
•
The most common complications during the first 60 days are bleeding, infection, and arrhythmia.
•
Signs and symptoms are numerous and vary by device (Table 17-5).
26
25,26
TABLE 17-5: Signs and Symptoms of Device Complications
Temporary Devices Durable Devices
Visualization of clot in device
Sudden decrease in oxygen saturation
(ECMO)
Plasma free hemoglobin >30 mg/dL
Acute decrease in cardiac output
ECMO: extracorporeal membrane oxygenation, LDH: lactate dehydrogenase, UOP: urine output
20,34,35
Signs of heart failure:
• Pulmonary edema
• Low cardiac output
• Hypoperfusion (jaundice, decreased UOP,
mental status changes)
Signs of pump thrombosis:
• Amber colored urine
• Low hemoglobin/hematocrit
• LDH >3 x upper limit of normal
• Increased pulsatility from frequent aortic
valve opening
• Power elevations (spikes)
MECHANICAL CIRCULATORY SUPPORT DEVICES 415
https://t.me/med1917
Bleeding
•
Bleeding is the most common complication following LVAD placement.
•
Arteriovenous malformations and acquired von Willebrand syndrome are thought
to be contributing factors to the increase in bleeding in continuous flow devices.
•
Bleeding types (percentages specific to Heartmate II [HMII]) in one report
Thoracic and mediastinal (42.1%)
Anemia of undetermined source (20%)
Lower gastrointestinal tract (12.4%)
Central nervous system (CNS) (6.9%)
Epistaxis (3.4%)
•
Patients who have a gastrointestinal (GI) bleed are more likely to have recurrent bleeds.
•
Nonpulsatile devices experience more bleeding events than do pulsatile
devices.
Interventions
•
Hold all anticoagulation and antiplatelet therapy until bleed resolves.
•
Transfusion of packed red blood cells (PRBCs) is based on variables such as
hemoglobin, platelet, INR, and mixed venous oxygen saturation (SvO2) thresh
olds; they are determined by the surgeon.
•
Vitamin K, recombinant fact VII activated (rVIIa), and prothrombin complex
concentrate (PCC) use are controversial due to the risk of pump thrombosis.
•
Octreotide may be used to control GI bleeds.
•
Restart anticoagulation when bleed is controlled or resolved.
28,29
Therapeutic options:
Medical intervention
Surgical intervention
Lower target goals or reduce the number of agents
Proton pump inhibitors should be started and continued
indefinitely for upper gastrointestinal bleeds
30
If utilized, consider low doses and titrate to goals to limit prolonged
effects.
29,31,32
Holding anticoagulation for short periods of time does not put the
patient at higher risk for thrombosis.
When to restart warfarin depends on severity of bleed and patient
33
status.
Lower INR target may be considered and then revised as necessary.
27
-
20
Hemolysis and Thrombosis
See Table 17-6.
•
Hemolysis refers to the destruction of red blood cells, which can occur with or
without thrombosis; however, during MCS it is more likely an early marker of
thrombosis.
416 Anticoagulation Therapy
https://t.me/med1917
Consideration can be given to the addition of second antiplatelet
medication.
(hemolysis, power spikes, and/or heart failure symptoms).
Not routinely recommended; conflicting data regarding benefit with
Consider initiation in patients with early markers of thrombosis (hemolysis,
increased risk of bleeding.
INR goal should be increased upon resolution of findings of hemolysis,
power spikes, and/or heart failure symptoms). Heparin alone is typically not
power spikes, and/or heart failure symptoms.
(continued)
Consider in patients with persistent hemolysis, power spikes, and/or heart
failure symptoms.
Direct thrombin inhibitors may be more effective than heparin as they bind
both free and clot-bound thrombin.
Direct thrombin inhibitors may be an effective alternative to heparin when
antithrombin deficiency or other sources of heparin resistance are present
effective; combination with increased aspirin doses of 325 mg PO daily or
add-on therapy with clopidogrel 75 mg daily may be reasonable.
In selected situations, anti-Xa activity or ACT may be alternatives to the
aPTT.
(if not a laboratory testing method issue). See Chapters 3 and 5.
Eptifibiatide 180 mcg/kg IV bolus
Dipyridamole 75 mg PO TID
Addition of second
Increased aspirin Aspirin 325 mg PO Aspirin should be up titrated to 325 mg upon findings of thrombosis
Increase
Strategy Intervention Regimen Considerations
TABLE 17-6: Interventions for Device Thrombosis
antiplatelet medication
34-38
antiplatelet
over 1-2 minutes followed by
Clopidogrel 75 mg daily
0.1–2 mcg/kg/min (dose adjust in
Glycoprotein IIb/IIIa
inhibitor infusion
± 0.5
renal dysfunction)
Increased INR goal Warfarin titrated to goal INR of 2.5
34,35,39-41
Increased
anticoagulant
Bivalrudin titrated to goal aPTT of
1.5–2.5 x normal level (dose adjust
in renal dysfunction)
Aragtroban titrated to 1.5–3 x
depending on MCS device
Intravenous direct thrombin
Intravenous heparin Heparin drip titrated to goal aPTT
inhibitors
normal level (dose adjust in hepatic
dysfunction)
MECHANICAL CIRCULATORY SUPPORT DEVICES 417
Pump modification
Pump exchange
ACT: activated clotting time, aPTT: activated partial thromboplastin time, INR: international normalized ratio, IV: intravenous, MCS: mechanical circulatory support, NA: not
applicable, PO: by mouth, TEG: thromboelastography , x: times
https://t.me/med1917
Subxiphoid approach with right anterior thoracotomy
Subxihoid approach with small left anterior thoracotomy
Full redo sternotomy
•
•
May be given systemically or intraventricularly depending on patient risk
for bleed.
For nonsurgical candidates who have failed medical management.
TEG may be one means to assess the level of thrombolysis.
Consider following fibrinogen levels with prolonged infusions.
For Left Ventricular Device thrombosis, follow the Power and trend lactate
dehydrogenase if elevated.
See Chapter 6
• Isolated subxiphoid
•
Thrombolytic Multiple published regimens:
42-44
Thrombolysis
Strategy Intervention Regimen Considerations
TABLE 17-6: (Continued)
Alteplase 1 mg/min
intraventricularly over 20–50 min
under direct visualization or 1 mg/
hr until normalization of hemolysis
or pump parameters
Systemic: Alteplase 10-100 mg IV
bolus
Correct malpositioning NA
Replace thrombosed pump NA Four approaches:
45
418 Anticoagulation Therapy
https://t.me/med1917
•
Thrombosis of a MCS device may result in device malfunction and/or systemic
embolism (Figures 17-2 and 17-3).
•
VA-ECMO carries the additional risks of intra-cardiac or aortic root thrombus
due to stagnant blood flow during support.
Elevation of the lactate dehydrogenase (LDH) over a period of time
has been associated with increased incidence of LVAD thrombosis.
•
General treatment principles of thrombosis typically include intensification of the
antiplatelet/anticoagulant regimen. This may or may not include antifibrinolytic
therapy (Figure 17-4).
•
When pharmacologic treatments are ineffective or when device thrombosis has
caused device failure, device exchange or removal is indicated.
FIGURE 17-2. Pump Thrombosis in the Outflow Bearing of a
Heartmate II LVAD
FIGURE 17-3. ECMO Oxygenator with Clot Formation
Isolated LD
Unloading,
Dehydrogenas
New CHF Symptoms
Consider
https://t.me/med1917
3
MECHANICAL CIRCULATORY SUPPORT DEVICES 419
of CHF and Hemolysis
• Evaluate Other Causes
Yes
No
LV Unloading?
Consider Surgical
Diuresis as Needed
Yes
• ICU – Add Inotropes,
Consider:
•Direct Thrombin Inhibitors
No
No
Inflow Cannula
No
?
4
Resolved
No
Surgical
Resolved?
Candidate?
Compromise
Yes
• Chest CT Angiogram
•Consider IV Heparin
•Monitor LDH, pfHgb, indirect bili
•CXR
•Echocardiogram (± Pump Speed Changes), Consider RHC
Yes
No
Yes
Yes
•Admit to Hospital
Evidence of Hemolysis
2
Pump Exchange or Urgent
Recovery
No
Hemolysis?
Isolated LDH Rise
Speed Changes)
•
• Check Serum Indices of Hemolysis
Late
1
Early
Early or Late?
• Consider Echocardiogram (± Pump
•
Echocardiogram (± Pump
Speed Changes)
LV Unloading?
No
Yes
LV Unloading?
Yes
platelet Agent
•
• ASA 325 mg
• Increase INR
:
e; pfHgb, Plasma-free Hemoglobin; RHC,
and No Clinical Evidence of Hemolysis
•LDH > 3x ULN and pfHgb > 40
Resolved: Normal Powers, Normal LDHs, Sufficient LV
Right Heart Cath; CXR, Chest X ray
Close Follow Up
H Rise:
• Sustained (>24hrs) Power > 10W; or
•Clinical Diagnosis; or
•LDH > 3x Upper Limit of Normal (ULN)
• Sustained (> 24hrs) Power Increase > 2W from Baseline
Hemolysis:
FIGURE 17-4. Algorithm for the Diagnosis and Management of
Pump Thrombosis
Source: Reprinted with permission from Goldstein DJ, John R, Salerno C, et al.
Algorithm for the diagnosis and management of suspected pump thrombus. J Heart
Lung Transplant. 2013;32:667-670.
Соседние файлы в папке Библиотека им академика М.И. Перельмана