4 - VTE: Special Patient Populations

why are ESRD pts at increased bleeding risk at baseline

• due to platelet dysfunction

• ACs accumulate in ESRD

why are ESRD pts at increased thrombotic risk

• chronic activation of clotting cascade

• increasing homocysteine

• decreased levels of protein C and S

are ESRD pts at increased bleeding risk, increased thrombotic risk, or both?

both

ESRD preferred (green) anticoags

A War Is Underway

• apixaban

• warfarin

• IV UFH → minimal renal metabolism/elimination

ESRD cautious (yellow) anticoags

Lookout Soldiers

• LMWH

• SQ UFH

ESRD anticoags to avoid (red)

Avoid RED Flags

• rivaroxaban

• edoxaban

• dabigatran

• fondaparinux → CI! primarily renally cleared

monitoring for enoxaparin (LMWH) in ESRD - when is steady state

4-5 doses

monitoring for enoxaparin (LMWH) in ESRD - dose

0.7-1.0 mg/kg/qd

monitoring for enoxaparin (LMWH) in ESRD

• check trough or peak?

• when do you check ^?

• goal for VTE tx?

• check a trough level

• check 30-60mins prior to next dose

• trough goal for VTE tx: less than 0.5 u/mL

if we’re checking a trough level, what are we worried abt?

poor CL

if we’re checking a peak level, what are we worried abt?

efficacy

preferred (green) anticoags in pregnancy

Pregnant Lions Isolate

• LMWH (enoxaparin)

• IV UFH

anticoags to be cautious with in pregnancy (yellow)

Caution With Fetal Safety

• SQ UFH

• Warfarin

  • assess risks/benefits

  • max 5mg dose

• fondaparinux

  • can cross placenta

  • only use if can’t take LMWH/UFH

anticoags to avoid in pregnancy (red)

DOACs (insufficient data)

enoxaparin monitoring in pregnancy - dosing

• start off with 1mg/kg q12h

• may need to increase to 8h dosing

enoxaparin monitoring in pregnancy

• check peak or trough?

• when do we check?

• peak

• ~4 hrs after dose (steady state)

when is steady state for enoxaparin

4-5 doses

preferred anticoags in cancer (green)

(including which is preferred in pts with and without GI lesions)

Cancer Is Ugly; either it Applies, or you Lie

• IV UFH

• apixaban

  • preferred for pts without GI lesions

• LMWH

  • preferred for patients with GI lesions

anticoags to be cautious with in cancer (yellow)

RED

• rivaroxaban

• edoxaban

• dabigatran

  • as effective as rivar/edoxaban as VTE recurrence prevention

  • but increases GI bleeds

anticoags to avoid in cancer (red)

warfarin

• if possible; may be cheapest option though :/

where are most coagulation cascade factors made

liver

which coagulation cascade factors are NOT made in the liver

factors VIII (8) and XIII (13)

factors that contribute to cirrhosis

• coagulation factor deficiencies

• vitamin K deficiencies → malnutrition

• thrombocytopenia

• reduced platelet function

• decreased protein C, S

• decreased AT

preferred anticoags in cirrhosis (green)

Cirrhosis Enters In Undetected

• enoxaparin

• IV UFH

anticoags to be cautious with in cirrhosis (yellow)

• warfarin

  • if INR is not significantly elevated at baseline

• fondaparinux

anticoags to avoid in cirrhosis (red)

• DOACs

  • very limited evidence

  • CYP (liver) metabolism

VTE risk factors in obese pts

• endothelial dysfunction

• platelet dysfunction

• stasis

• inflammation

preferred anticoags in obesity (green)

Obesity Is Underestimated And Really Widespread

• IV UFH

• apixaban

• rivaroxaban

• warfarin

anticoags to be cautious with in obesity (yellow)

FEED

• fondaparinux

• enoxaparin

• edoxaban

• dabigatran

monitoring for LMWH (enoxaparin) in obesity - dosing & max dose

• 0.7-1.0 mg/kg/q12h

• max dose = 120-150mg

monitoring for LMWH (enoxaparin) in obesity

• check peak or trough level?

• when do we check ^?

• goal for VTE tx?

• peak (worried abt efficacy)

• check 4 hrs after dose (steady state 4-5 doses)

• peak goal for VTE tx: 0.6-1 u/mL

why is there increased thrombotic risk in APS

APS ABs → endothelial damage

APS preferred (green) anticoags

APS Will Leave Us

• warfarin

• LMWH

• IV UFH

anticoags to be cautious with in APS (yellow)

fondaparinux

• limited data

anticoags to avoid in APS (red)

avoid DOACs

• increased thrombotic risk