02 - Bleeding , 70 - rectal bleeding

Question 1

What are platelets called? What inhibites them in an intact endothelium ?
Which cell is their precursor?
Life span?
Activated by?
Do they need to be crossmatched before transfusion?

Answer 1

thrombocytes 
Nitric Oxide 
Megakaryocytes 
thrombin and exposed endothelial collagen 
8 days 
No

Question 2

Thrombocytopenia usually found when?

Causes?
Mx?

Answer 2

Usually silent and found on FBC
-Or bleeding esp from nose/gums
Pupura/petachae

leukemia, sepsis, Fanconi anemia, liver failure, aplastic anemia, ITP, TTP, haemolytic uraemic syndrome, DIC, drug side effects.

Treat underlying cause
Transfusion if severe

Question 3

Transfusion is CI in which cause of thrombocytopenia

Answer 3

Thrombotic thrombocytopenic purpura

Not sure i believe this based on evidence - But keep in back of mind

Question 4

key triggers of clotting cascade ? What is formed?

Answer 4

Endothelial injury + tissue factor

factor VII

(Cascade of protein cleavage and fibrin formation)

Question 5

How does heparin work

Answer 5

deactivates thrombin and factor Xa

Question 6

Main use of heparin? reversed with?

Answer 6

Treat and prevent DVT / PE

Reversed with protamine

Question 7

Egs of some LWMHs? Why beneficial to heparin?

Answer 7

enoxaparin, dalteparin and tinzaparin

Less effective but far less side effects (thrombocytopenia and osteoporosis)

Question 8

What is warfarin / how does it work?

How do you monitor?

Answer 8

Vit K inhibitor -> inhibits factor VII and prothrombin

INR and dietrary restrictions

Question 9

Heparin / warfarin in pregnancy

Answer 9

heparin is ok

Question 10

Eg of NOACs?

Vs warfarin

Answer 10

Rivaroxaban, dabigatran etc.

Just as effective as warfarin in preventing CVAs with AF.

Less bleeding events bar GI bleeds.

Are more expensive than warfarin, but you save money on bleeding events and community monitoring, so it balances out.

Question 11

which enzymes are key for fibrinolysis ?

Egs of drugs? Used when?

Answer 11

Plasmin enzymes

Plasminogen cleaved to Plasmin via urokinase and tissue plasminogen activator.
Plasmin degrades fibrin.

MI, ischaemic stroke and PE via streptokinase and other tPas (alteplase and reteplase)

Question 12

What is a major bleed? 4 stages?

When do you transfused packed cells?

Answer 12

50% volume in 3 hours / >150ml/min
(clinically if has lead to shock in excess of 90mmHg OR 110bpm

Like Tennis
15%, 30%, 40%, >40%

Stage 2

Question 13

What blood do you transfuse? Who gets something specific?

What risk with transfusion with relation to bleeding?

Answer 13

O

Females <50 get Rh-ve

Dilutional coagulopathy as with lots of resus fluid and red cells dilute clotting components

Question 14

Approx rise in Hb / unit of blood? What level before transfusion

Answer 14

1

<8

Question 15

Eg causes of upper GI bleed?
What interesting fact in Mx?
mX/

Answer 15

PUD, varices, etc.

Different to normal major haemorrhage in that transfusions worsen outcomes (unless patient is shocked)

Use terlipressin and PPIs instead.

Question 16

What is shock?
Features?
Types?

Answer 16

Inability to adequately maintain end organ perfusion

Low BP, high pulse, low urine, confusion, LoC, pallor, hypothermia etc.

Hypovolemic, Cardiogenic, Obstructive and Distributive.

Question 17

What is DIC? Initial Mx?

Answer 17

Pathological activation of the clotting cascade throughout the body, usually as a response to bacterial infection (from endotoxin

Clots formed in small vessels causing organ damage whilst coagulation products are consumed, leading to severe bleeding.

Treat underlying condition Eg sepsis / obstetirc, transfusion reaction, allergies….
Transfuse platelets as bleeding will kill first

Question 18

What is ITP ? Caused by? Mx?

Answer 18

Idiopathic thrombocytopenic purpura
Low platelet count with normal bone marrow. Diagnosis of exclusion.

May get purpuric rash / bleeding

Autoimmune response to platelet surface antigens

Conservative with steroids - can transfuse if needed

Question 19

What is TTP? 5 features?
Cause?
Mx?
What main issue with Mx?

Answer 19

Thrombotic thrombocytopenic purpura.

fever
renal failure
neuro symptoms (clots interrupting blood supply to the brain), 
haemolytic anaemi 
thrombocytopenia.

Spontaneous small vessle coagulation (Eg due to preg, drugs, Ca)

Plasmapheresis and corticosteroids

Transfusion worsens coagulopathy

Question 20

Haemophilia A vs B ?
Genetics?
Complications?

Answer 20

A is a Factor VIII deficiency.
B is a Factor IX deficiency.

Only seen in males (X-linked) two copies are not compatible with life.

Complications include haemarthrosis, internal bleeding, CVA, blood infections.

Question 21

Where is vWF found?

Answer 21

Epithelium basement membrane

Question 22

How does aspirin work? As a anticoagulative?
Clopidogrel?
More or less bleeding risk with clopidogrel?

Answer 22

irreversible COX inhibitor (cox 1 most) -
Prevents inflammation

Also prevents platelet aggregation via thromboxane inhibition
-Clopidogrel does this too via ADP inhibition

Less GI bleeding risk with clopidogrel

Question 23

Some DDx of rectal bleeding

Answer 23

Haemorrhoids 
fissue 
cancer
 IBD 
Angiodysplasia 
Meckles 
Intussusception

Question 24

what is meckels diverticulum?

Answer 24

Congenital diverticulum in small intestine. Remains of foetal vitelline duct.

Question 25

What is the rule of 2s with meckels

Answer 25

2 feet from ileocaecal valve, 2 inches long, in 2% of population, 2 years presentation, 2 types of tissue (gastric and pancreatic)

Question 26

Increased risk of what with meckels

Answer 26

hernias, volvulus, obstruction, intussusception

Question 27

Mx of meckels

Answer 27

resection