Blood loss anaemia

Question 1

classifications of post-partum hemorrhage

Answer 1

• Minor: 500-100mL lost
• major: >1000mL
  • moderate: 1000-2000ml
  • severe: >2000mL

Question 2

What happens when you lose:
~20% blood
~40% blood
~50% blood

Answer 2

~20% = toleratable
~40% = hypovolemic shock
~50% = death

Question 3

Response to acute blood loss

Answer 3

Plasma volume expansion to compensate for blood loss = dilutes RBC fraction
=> Inc EPO bc of hypoxia => releases reticulocytes

Question 4

What assays to take if there’s a problem w/ patient’s plts?

Answer 4

• Plt count
• Plt functional assay
• Plt morphology

Question 5

What assays to take if patient has an inherited coagulopathy?

Answer 5

• PT
• aPTT
• Factor assays

due to single factor deficiency - detectable if has a history o bleeding

Question 6

What cond would you suspect if patient has several Vit K dependent factors? and what assay/s to take

Answer 6

Suspect warfarin therapy OR liver disease => purpura & petechia

PT, aPTT, factor assays, TT, Fibrinogen

Question 7

What assays to take if you suspect anticoag. present? & give e.g of anticoag

Answer 7

• aPTT w/ Heparin neutralising agent = for heparin

- aPTT w/ excess phosplolipid = for lupus anti-coag

Question 8

What assays to take if patient has consumptive coagulopathy like DIC?

Answer 8

DIC screen

Plt count, PT, aPTT, D-dimer

Question 9

briefly describe the PFA-100 Plt function analyser

Answer 9

• membrane coated w/ collagen & agonist (epinephrine, ADP)

- recorded time it takes for membrane to be occluded

Question 10

briefly describe the Plt aggregometry

Answer 10

• measure change in optical density, when agonist added in PRP
• from platelet poor plasma (100%) to plt rich plasma (0% light transmitted)

Question 11

list 4 plt agonist

Answer 11

• ADP
• collagen
• epinphrine
• ristocetin

Question 12

Which tests assess:

a) total amount of VWF
b) functionality of VWF
c) Components of VWF

Answer 12

a) VWF Ag measured by ELISA
b) Ristocetin cofactor assay - ristocetin + vWF = agglutinate
c) multimeric analysis

Question 13

Describe how you form fibrin from fibrinogen w/ thrombin

Answer 13

thrombin cleaves Fibrino peptides on E domain of fibrinogen => E domain is +ve charged & D domain is -ve

Question 14

Describe Thromboplastin Time (PT) aka One stage PT

Answer 14

• measures clotting time of re-calcified plasma

- assess extrinsic (& common) path : VII (X, V, II, I)

Question 15

reasons for protlonged PT

Answer 15

• Warafin treatment
• Liver disease
• Vit. K deficiency (depended by Prothrombin)
• Factor VII (X, V, II, I) deficeint
• DIC

Question 16

Describe Activated Partial Thromboplastin Time (aPTT)

Answer 16

• measures clotting time after activated by phospholipid & CaCl2
• assess intrinsic (& common) path : XII, XI, IX, VIII (X, V, II, I)

Question 17

reasons for protlonged aPTT

Answer 17

• Heparin treatment
• DIC
• Liver disease
• Circulating anticoag (inhibitor)
• Inherited factor deficiency

Question 18

Describe Thrombin Time (TT)

Answer 18

• measures clotting time after thrombin added to plasma
• affected by
  • [fibrinogen]
  • presence of inhibitory substances

Question 19

reasons for protlonged TT

Answer 19

• DIC
• Heparin treatment
• Hypoalbuniaemia
• paraproteinemia
• Hypofibrinodenaemia
• increased fibrin degradation products (FDP)

Question 20

what is Fibrinolysis & Describe process

Answer 20

a. digestion of fibrin clot

b. plasminogen activated to plasmin => digest fibrinogen & fibrin

Question 21

Plasmin digestion of
a) fibrinogen
b) X-linked fibrin
& the test to asses fibrinolysis

Answer 21

a) Early FDP: X & Y
Late FDP: D & E
b) D-dimers = Dx factor ofr fibrinolysis
c) latex agglutination method