Anticoagulation

Question 1

Presentation of large and small PEs

Answer 1

Large saddle embolus- sudden onset sob, hypertension and collapse
Small- tachycardia, chest pain, haemoptysis

Question 2

Investigations for suspected DVT

Answer 2

D diner
ECG
VQ scan
CTPA
CXR
ECG - S1Q1T3

Question 3

Immediate management of DVT

Answer 3

Thrombolysis

Thrombolectomy

Question 4

Short term and long term management DVT

Answer 4

ST - heparin

LT - warfarin

Question 5

Indications for warfarin

Answer 5

Previous DVT
Cancer
Known thrombophilia
Male with DVT
D diner positive throughout therapy

Question 6

Why start heparin and warfarin simultaneously

Answer 6

Warfarin takes time to take effect and has prothrombotic effects until then
If no overlap,at very high risk of microemboli and warfarin skin necrosis in high fat areas

Question 7

HASBLED score

Answer 7

Risk for major bleeding
Hypertension
Abnormal renal or liver function
Stroke
Bleeding
Labile INR
Elderly
Drugs or alcohol

Question 8

Heparin characteristics, including UFH and LMWH

Answer 8

Promotes Antithrombin 3 and factor 10a inhibitors
Weight-based dosing and effect, must up dose in obesity to 0.75mg/kg
Unfractionated - must monitor PTT. For patients at risk of bleeding because of protamine sulphate. Can get heparin-induce thrombocytopenia (also in LMWH due to cross reactivity, but much less than in UFH)

Question 9

Prerequisite for warfarin therapy

Answer 9

Must be able to go to INR clinic

INR checked every 4 weeks

Question 10

INR at risk of bleeding

Answer 10

> 4

Question 11

Warfarin MOA and antidote

Answer 11

Works on vitamin K hydroxide

Vit K antidote

Question 12

Interactions with warfarin

Answer 12

NSAIDs - inhibit PGE–> PUD and bleeding (hidden)
Alcoholics -
A. Risk of liver disease - raised INR
B. Risk of gastritis - bleeding
C. Alcohol induces warfarin - increases concentration
D. Increase risk of falls

Therefore patients must abstain, start PPIs

Question 13

Process of initiating warfarin therapy

Answer 13

Start warfarin 6 hours after heparin
Wait 4 hours for INR to become stable
Stop heparin once second INR is therapeutic.

Question 14

Management of high INR

Answer 14

Stop warfarin
Resus if bleeding - give vit K, cryoprecipitate , FFPs, clotting factors (7,8,9)
If low risk bleed - give low dose oral vit k, drink if diluted

Question 15

Risk factors for DVT

Answer 15

Previous DVT 
Pregnancy
Recent long distance travel
Cancer
Surgery
Bed bound
Haemophilia and thrombophilia
Drugs - HRT, COC, steroids, tamoxifen