HIT Flashcards
what is the lab test that can be done to determine if pt has HIT?
ELISA
a strongly positive ELISA of what can reliably confirm the dx of HIT?
OD >1
what are the treatment options for HIT if it is a NON-surgrical patient
Fondaparinux
Direct Oral Anticoagulants
what is the treatment options for HIT for surgical pts?
Argatroban
what is the treatment options for HIT for pts undergoing cardiac surgery?
Bivalirudin
How long should the length of treatment be for pts with Isolated HIT? (HIT without Thrombosis?)
4 wks
How long should the length of treatment before pts with HITT (HIT with thombosis)
3 mths then assess risks vs benefits
what are some common drugs that can cause thrombocytopenia?
Carbamazepine
vancomycin
quindine
when should you order ELISA test?
after you do the 4 T score and pt has high or moderate suspicion of HIT
what are the 2 other tests that can be done if ELISA is not working or need additional test to confirm HIT?
SRA (serotonin release assay) - looks for heparin dependent Ab
P-Selectin Expression Assay (PEA)
what are the 4 steps that need to be done for all pts with suspected or confirmed HIT dx?
- discontinue all heparin (including flushes)
- dsicontinue/reverse warfarin with phytonadion
- obtain bilateral US for DVT
- start non-heparin anticoag immediately upon ELISA confirmation or if we are awaiting SRA/PEA results
what is the dose of argatroban for pts with normal hepatic function?
2mcg/kg/min
what is the goal APTT for argatroban for pts with normal hepatic function for HIT?
1.5-3x baseline APTT (max 100secs)
when should you measure APTT for argatroban?
every 2 hours after initiation or at any rate adjustment
once 2 consecutive APTTs are at target range then you can check daily
in what situation would you consider Bivalirudin for HIT?
pt to have urgent cardiac surgery with actue or subacute HIT or Cardiac Cath or PCI
what is the dose of bivalirudin for HIT? if CrCl is greater than 60ml/min?
0.15mg/kg/hr
NO BOLUS NEEDED EVER
what is the dose of bivalirudin for HIT if Crcl is 30-60ml/min?
0.08mg/kg/hr
what is the dose of bivalirudin for HIT if CrCl is less than 30
0.05mg/kg/hr
what is the goal APTT for Bivalirudin for pts with normal hepatic function for HIT?
1.5-2.5 x baseline
when should you measure APTT for bivalirudin?
every 2 hours if within therapeutic range x2 then check every 12 hours
when transitioning from argatroban to warfarin what target INR should you aim for?
there is a false elevation of INR therefore target INR of 4 after a minimum of 5 days on dual anticoag therapy.
you can then stop infusion but if INR falls sub then restart infusion at previous rate - repeat daily until INR is therapeutic on only warfarin
what can you define as plt recovery in HIT and how often do you monitor?
100-150
Monitor daily until they reach this normalize level
If pt does not have planned surgery in the next 24 hours, but crCL is less thatn 30ml/min what agent would you recommend for HIT?
argatroban
what is the agent of choice in pregnant women with HIT?
fondaparinux
what is the agent of choice in pts mechanical valves or pediatrics?
Direct thrombin inhibitors (argatroban or bivalirudin)
how much of a dose reduction do you need for HIT in pts with liver failure for argatroban?
1/4 the dose of argatoban is used
which DOAC has the most evidence for HIT
Rivaroxaban
isolated HIT: 15mg BID until plts have recovered then 20mg daily
HITT: 15mg BID x 21 days then 20mg daily for at elast 3 months
