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Flashcards in Haematology Deck (37):
1

A 65-year-old man who has smoked heavily all his life presents with lymph node over sub-mandibular gland.
Which of the following is the most likely diagnosis?
(Please select 1 option)
Cancer of the floor of maxilla
Cancer of the lateral anterior two thirds of tongue
Cancer of the mandible
Cancer of the pancreas
Testicular teratoma

Cancer of the lateral anterior two thirds of tongue

Seventy five per cent of lingual cancers arise on the anterior two thirds of the tongue.

Metastasis occurs unilaterally to the submental, submandibular and then the lower deep cervical lymph nodes.

Rare posterior third tumours spread bilaterally and have a poor prognosis due to their late presentation.

2

A 30-year-old woman is seen in the haematology clinic for follow up of a coagulation defect of the extrinsic pathway.
Which of the following factors is likely to be affected as part of her condition?
(Please select 1 option)
Factor VII
Factor VIII
Factor IX
Factor XI
Factor XII

FVII

Factor VII and tissue factor are involved in the extrinsic pathway of the coagulation cascade whereas the intrinsic pathway is dependent on factors XII, XI, IX and VIII.

A defect in the extrinsic pathway will show as a prolonged prothrombin time whereas an activated partial thromboplastin time (APTT) will be prolonged with a defect of the intrinsic pathway.

3

A 28-year-old female attends clinic with a history of multiple venous thromboses.
You suspect she has a prothrombotic disorder.
Which one of the following disorders is most likely to be responsible?
(Please select 1 option)
Antithrombin III deficiency
Disseminated intravascular coagulation (DIC)
Thrombocytopenia
Vitamin C deficiency
Vitamin K deficiency

Antithrombin III deficiency is an autosomal dominant disorder.

Less than 70% of the normal value increases the risk of venous thrombosis because of the role of antithrombin in the inactivation of thrombin, factors VIIa, IXa, Xa, XIa, kallikrein and plasma.

DIC is a systemic thrombohaemorrhagic disorder with variable clinical presentation. Most patients present with easy bruising and haemorrhage and this results from serious underlying disease, such as obstetric complications or massive trauma.

Thrombocytopenia and vitamin K deficiency are types of acquired bleeding disorders.

Vitamin C deficiency can result in an acquired vascular defect.

4

A 27-year-old woman undergoes excision of a lipoma on the day list and is surprised how quickly the wound heals.
Which cell type is involved almost immediately in wound healing following tissue injury?
(Please select 1 option)
Basophils
Fibroblasts
Macrophages
Monocytes
Platelets

Platelets This is the correct answerThis is the correct answer
Damage to blood vessel walls during tissue injury leads to the rapid formation of a platelet plug to prevent bleeding.

Vasodilation and increased vascular permeability is then followed by the influx of inflammatory cells and fibroblasts.

Neutrophils initiate phagocytosis and are the predominant cell type in the first 24 hours.

Macrophages secrete cytokines and continue phagocytosis as they become the predominant cell type after 48 hours.

5

On an evening ward round you glance at the blood results of a patient from another team.
The results show an increased prothrombin time (PT), an increased activated partial thromboplastin time (APPT), an increased thrombin time (TT) and a low platelet count.
Which of the following is the most likely underlying explanation for this set of blood results?
(Please select 1 option)
Disseminated intravascular coagulation (DIC)
Haemophilia
Heparin
Liver failure
Warfarin

DIC is a systemic thrombo-haemorrhagic disorder with variable clinical presentation.

There is activation of the coagulation process with consumption of platelets and coagulation factors with thrombin formation overwhelming the normal inhibition system and resulting in systemic fibrin deposition.

Most patients present with easy bruising and haemorrhage as a pathological response to serious underlying disease.

Conditions associated with DIC include

Malignancy
Massive tissue injury and trauma
Obstetric complications and infections.
Liver disease can result in a similar pattern of blood results but the thrombin time is usually normal.

6

A 70-year-old gentleman was admitted with difficulty swallowing, abdominal pain and vomiting.
Past medical history included a gastrectomy for carcinoma.
Initial investigations showed a macrocytic anaemia and thrombocytopenia.
Of the following, which is the likely diagnosis?
(Please select 1 option)
B12 deficiency
Iron deficiency anaemia
Pernicious anaemia
Sickle cell anaemia
Sideroblastic anaemia

B12

Intrinsic factor of Castle which is produced by the parietal cells is required for the normal absorption of vitamin B12.

Lack of intrinsic factor may arise from deficient production by parietal cells due to antiparietal cell antibodies in pernicious anaemia or following gastrectomy.

In the absence of intrinsic factor vitamin B12 will not be absorbed in the terminal ileum, and megaloblastic anaemia will result.

7

An 80-year-old lady with a history of ischaemic heart disease is transfused three units.
Following this she starts complaining of increasing shortness of breath. It is noted that her saturations have dropped and on examination she had bilateral basal crackles.
Of the following, which is the likely diagnosis?
(Please select 1 option)
Air embolism
Anaphylaxis
Circulatory overload
Hyperkalaemia
Thrombophlebitis

Circulatory overload

In elderly patients fluid overload is a potential complication following a transfusion.

Furosemide may be given in these cases to reduce the risk.

8

A 75-year-old lady who has had four units of blood prior to surgery is found to have peaked T waves and a slightly prolonged QRS complex on an ECG.
What is the cause of her condition?
(Please select 1 option)
Anaphylaxis
Haemolytic reaction
Hyperkalaemia
Iron overload
Thrombophlebitis

Hyperkalaemia

The most common changes associated with hyperkalaemia are

Tall peaked T-waves
Reduction in amplitude
and eventually

Loss of the P-wave and
Bizarre widening of the QRS interval.

9

A 60-year-old gentleman is transfused two units prior to surgery.
Within thirty minutes of its commencement he starts complaining of feeling generally unwell with back pain and shortness of breath.
Observations reveal hypotension, reduced saturations and pyrexia.
What is the cause of his condition?
(Please select 1 option)
Air embolism
Haemolytic reaction
Hyperkalaemia
Iron overload
Thrombophlebitis

Haemolytic reaction

Acute haemolytic reactions may occur after infusion of a small volume of incompatible blood.

It is associated with a high morbidity and mortality and occurs soon after the start of transfusion.

The patient feels unwell and agitated and symptoms include back pain and pain at infusion site with associated shortness of breath and rigors.

Management includes discontinuation of the transfusion and fluid resuscitation.

10

A 30-year-old gentleman of African origin was admitted with severe back pain.
Investigations revealed a normocytic normochromic anaemia with a high reticulocyte count.
Which of the following is the likely diagnosis?
(Please select 1 option)
B12 deficiency
Iron deficiency anaemia
Pernicious anaemia
Sickle cell anaemia
Sideroblastic anaemia

Sickle cell anaemia is a disorder of varying degrees.

It may present in childhood with anaemia and mild jaundice. In the older patient, vaso-occlusive problems occur due to sickling in the small vessels of any organ, mimicking many medical and surgical emergencies.

Typical infarctive sickle crises include

Bone pain
Pleuritic pain
Hemiparesis
Fits
Splenic infarcts and
Priapism.

11

A 20-year-old Caucasian man presents with a six month history of upper abdominal pain and leg ulcers.
He was noted by his family to be jaundiced.
Investigations showed a slight rise in bilirubin and mild anaemia.
An ultrasound scan of the abdomen showed evidence of splenomegaly.
Of the following, which is the likely diagnosis?
(Please select 1 option)
Hereditary spherocytosis
Iron deficiency anaemia
Sickle cell anaemia
Sideroblastic anaemia
Thalassaemia

Hereditary spherocytosis is the most commonly inherited haemolytic anaemia in northern Europe, affecting 1 in 5000.

It is inherited in an autosomal dominant manner but in 25% of patients neither parent is affected.

It may present with jaundice at birth however sometimes it is delayed for many years and some patients may go through life with no symptoms.

The patient may eventually develop anaemia, splenomegaly and ulcers on the leg.

12

A 65-year-old gentleman was admitted with a two month history of jaundice, pale stool, dark urine and bruising following minimal trauma.
A coagulation screen revealed a prolonged APTT and PT.
Which of the following is the likely diagnosis?
(Please select 1 option)
DIC
Ehlers-Danlos syndrome
Haemophilia A
Vitamin K deficiency
von Willebrand disease

Vitamin K is necessary for the y-carboxylation of glutamic acid residues on factors II, VII, IX and X and on proteins C and S.

The prothrombin time (PT) and activated partial thromboplastin time (APTT) are prolonged and there may be bruising, haematuria and gastrointestinal or cerebral bleeding.

13

A 30-year-old gentleman was in an industrial accident leading to 60% burns requiring intensive care and surgery.
A coagulation screen revealed a prolonged APTT, PT and low levels of fibrinogen.
Which of the following is the likely diagnosis?
(Please select 1 option)
DIC
Haemophilia A
Haemophilia B
Vitamin K deficiency
von Willebrand disease

Disseminated intravascular coagulation (DIC) is an acquired syndrome characterised by the intravascular activation of coagulation with loss of localisation arising from different causes.

It can originate from and cause damage to the microvasculature which can produce organ dysfunction.

DIC is seen in sepsis, major trauma, and placental abruption.

14

An 18-year-old boy was admitted with RIF pain.
On a recent visit to the dentist he had problems with bleeding after a tooth extraction. A clotting screen was requested which showed a prolonged APTT, normal PT and bleeding time. A further coagulation screen showed low levels of factor VIII.
Which of the following is the correct diagnosis?
(Please select 1 option)
DIC
Ehlers-Danlos syndrome
Haemophilia A
Haemophilia B
von Willebrand disease

Haemophilia A is an X linked disorder. The clinical features depend on the level of factor VIII.

Levels of less than 1% are associated with frequent spontaneous bleeding from early life.

Levels of less than 5% are associated with severe bleeding following injury and occasional spontaneous episodes.

Levels above 5% produce mild disease, usually with bleeding after injury or surgery.

15

A 36-year-old female who is on warfarin after suffering a deep vein thrombosis, presents with an INR of 8.2 and a conjunctival haemorrhage.
The blood pressure is 125/55 mmHg, heart rate is 65 bpm and the ECG reveals a normal sinus rhythm.
Which of the following is the most appropriate treatment for this patient?
(Please select 1 option)
Factor VII
FFP
Oral vitamin K 1 mg
Prothrombin complex concentrate
Stop warfarin only

oral vit K 1mg

A conjunctival bleed is defined as a minor bleed, and current guidelines suggest that oral or IV vitamin K together with the omission of warfarin, is the treatment of choice. Local guidelines should also be available.

One must always weigh up the risks and benefits of reversing the anticoagulation. The patient described is at low risk if the warfarin-induced coagulopathy is reversed. There is no suggestion from the ECG and the haemodynamic status that there is pulmonary embolus.

Major bleeds are defined as

Intraorbital
Intracranial
Retroperitoneal or
Muscular bleeding
causing compartment syndrome.

Any acute bleeding with BP less than 90 mmHg, oliguria or Hb drop to less than 9 g/l, also count as major bleeding episodes and require aggressive reversal of the coagulopathy with vitamin K, stopping warfarin and prothrombin complex concentrate or fresh frozen plasma (FFP).

16

A 78-year-old female who is on warfarin for atrial fibrillation presents with melaena.
Her blood pressure is 90/60 mmHg and heart rate is 100 bpm.
Investigations show:
Haemoglobin 9 g/L (12-16)
MCV 87 fL (83-95)
INR 7.2 (

Stop warfarin and give IV vitamin K and prothrombin complex concentrate This is the correct answerThis is the correct answer
This patient is hypotensive and tachycardic with melaena suggesting a major bleeding episode on warfarin.

In these circumstances guidelines suggest stopping warfarin, giving IV vitamin K, and either fresh frozen plasma (FFP) or prothrombin complex concentrate.

Local guidelines will be available and if in doubt consult with the haematologist on call. FFP may not completely reverse the effects of warfarin so it may now be preferable to consider prothrombin complex concentrate (PCC) if available.

The rate of fatal haemorrhage in patients receiving warfarin approaches 1%.

17

A 17-year-old girl with mild von Willebrand's disease is scheduled for dental extraction.
A previous dental extraction resulted in bleeding that had required two unit transfusion.
What is the most appropriate treatment prior to dental surgery?
(Please select 1 option)
Cryoprecipitate
DDAVP
Fresh frozen plasma
High purity factor VIII concentrate
Recombinant factor VIII concentrate

DDAVP is the choice treatment for mild von Willebrand's disease, which would include type I, and the majority of type II, although there is some controversy in type II B as it is thought that DDAVP can exacerbate thrombocytopenia that can accompany this type of von Willebrand's.

It is of no use in type III - severe von Willebrand's disease. The history tells us that she has mild disease.

You would not use cryoprecipitate or fresh frozen plasma in these patients in this era due to potential viral transmission risk from blood products.

For severe disease you would use a von Willebrand factor concentrate, not factor VIII concentrate.

18

A 25-year-old female with a history of type 1 von Willebrand's disease (vWD) is referred for an opinion.
She is to have a cervical cone biopsy and the admitting team are concerned about her clotting.
You find that she has a past history of menorrhagia and has had two dental extractions as an adolescent that were uncomplicated.
What is the most useful test to assess her bleeding tendency?
(Please select 1 option)
Activated partial thromboplastin time
Bleeding time
Plasma factor VIII activity
Platelet aggregation
Prothrombin time

Plasma factor VIII activity

In type I vWD the prothrombin time (PT) and platelet aggregation will be normal.

Bleeding time, partial thromboplastin time (APTT) and factor VIII-coagulant (FVIIIc) are likely to be abnormal.

The bleeding time would be a good screening test but as we already know she has type I vWBD it will not give a quantitative measurement of her bleeding tendency.

Similarly APTT will not be that useful.

The most useful test in practice is to do the vWB antigen and activity (RICOF); but you would also do FVIIIc as this is also low in vWD.

19

You are asked to provide advice on a 35-year-old woman who is admitted under the maxillo-facial surgeons for extraction of wisdom teeth.
The only concern was that she had developed prolonged bleeding following a tooth extraction 10 years previously and had required suturing. Besides this, she gave no other history of bleeding.
What is the most likely diagnosis?
(Please select 1 option)
Factor V Leiden
Factor IX deficiency
Factor XII deficiency
Primary antiphospholipid syndrome
von Willebrand's disease

von Willebrand's disease This is the correct answerThis is the correct answer
Not that much is given away by this history just the issue of a prolonged bleed after prior dental extraction.

The most likely diagnosis when considering this patient is von Willebrand's disease which is an autosomal dominant condition and is one of the commonest bleeding disorders. Most cases are mild, with bleeding after only mild injury, particularly mucosal membrane injuries.

The condition is due to a reduction or structural abnormality of von Willebrand's factor, which has the dual role of promoting normal platelet function and stabilising coagulation factor VIII.

von Willebrand's disease can give normal results on screening tests and diagnosis may require specialist investigation.

Most patients with mild disease respond to desmopressin (DDAVP) but clotting factor concentrates are needed for a minority.

20

In transfusion, which of the following is a clinically important blood group?
(Please select 1 option)
Kell
Lewis
Li
Lutheran
Scianna

Kell

n addition to the ABO and rhesus systems, another eight blood group systems have been identified.

The Kell, Duffy and Kidd systems can cause both haemolytic transfusion reactions and the haemolytic disease of the newborn.

The P and MN systems can also cause both of these reactions, but they are rare events.

The Lutheran, Lewis, Scianna and Li systems are clinically of less importance, since they do not cause the haemolytic disease of the newborn, and are unlikely (or rarely) to cause haemolytic transfusion reactions.

21

Which of the following is true of low molecular weight (LMW) heparin?
(Please select 1 option)
Exerts its anticoagulant effect by binding with Factor VIII
Has a more potent effect on platelets than does unfractionated heparin
Inactivates thrombin more readily than unfractionated heparin
Is excreted in the urine
Is less efficacious compared with unfractionated heparin

Is excreted in the urine

By binding to antithrombin low molecular weight heparin (LMWH) creates a complex which then binds with and inactivates Xa.

LMWH binds less to platelets, endothelium and von Willebrand factor, hence less bleeding risk.

The shorter chains are less likely to bind both antithrombin and thrombin (LMW binds Xa more readily). LMHW is excreted in the urine (and partly by hepatic metabolism, though less so than unfractionated). This needs monitoring in renal impairment.

LMWH have been shown to be as efficacious, safer and have improved inpatient stay and hospital cost.

22

A prolonged thrombin clotting time may occur in which of the following?
(Please select 1 option)
Disseminated intravascular coagulation
Presence of factor V Leiden
Prothrombin deficiency
Renal disease
Warfarin therapy

DIC

Thrombin time compares a patient's rate of clot formation to that of a sample of normal pooled plasma. Thrombin is added to the samples of plasma. If the plasma does not clot immediately, a fibrinogen deficiency is present.

If a patient is receiving heparin, a substance derived from snake venom called reptilase is used instead of thrombin. Reptilase has a similar action to thrombin but, unlike thrombin, it is not inhibited by heparin.

Thrombin is added to platelet-poor plasma at 37°C; the clotting time is recorded. Typically 14-16 seconds is the normal time. It is prolonged in

Afibrinogenaemia
Hypofibrinogenaemia
Dysfibrinogenaemia.
It is prolonged by

Heparin (corrects with protamine)
Fibrinogen degradation product (FDP)
Paraproteins (partial correction with protamine).

23

A young man has undergone splenectomy five years ago for traumatic splenic rupture.
What blood picture would be expected on examination of the peripheral blood film?
(Please select 1 option)
Auer's bodies
Eliptocytosis
Howell-Jolly bodies
Microcytosis
Thrombophilia

Howell Jolly bodies

Splenectomy is associated with:

Howell-Jolly bodies
Thrombocytosis
Macrocytosis (persistence of larger red blood cells [RBCs])
Acanthocytes
Target cells
Leucocytosis.
Auer's bodies are inclusions in leukaemic white cells and are pathogonomic of leukaemia.

24

Which of the following conditions is not associated with an increased tendency to thrombosis?
(Please select 1 option)
Behçet's disease
Homocystinuria
Kawasaki disease
Metastatic malignancy
von Willebrand disease

von Willebrand disease This is the correct answerThis is the correct answer
Other acquired causes include

Congestive cardiac failure (CCF)
Trauma
Surgery
Myeloproliferative disorders
Oral contraceptives.
Other inherited causes include

Antithrombin III/protein C/protein S deficiency
Factor V Leiden
Dysplasminogenaemia
Dysfibrinogenaemia
Heparin cofactor II deficiency.
von Willebrand disease (vWD) is a congenital or acquired condition. It arises from a deficiency of von Willebrand factor (vWF), a protein that is required for platelet adhesion.

25

Splenectomy is not of recognised value in the management of patients with which of the following?
(Please select 1 option)
Auto-immune (idiopathic) thrombocytopenic purpura
Hairy cell leukaemia
Hereditary spherocytosis
Hodgkin's disease
Polycythaemia rubra vera

Polycythaemia rubra vera This is the correct answerThis is the correct answer
Indications for splenectomy include

Trauma
Haematological disorders
Lymphoma.
The second option may change with improvements with interferon Rx.

26

Upon the occurrence of which of the following events is the erythrocyte sedimentation rate (ESR) increased?
(Please select 1 option)
Following the infusion of high molecular weight dextran
In childhood
In men compared with women
In polycythaemia rubra vera
When plasma fibrinogen concentrations increase

When plasma fibrinogen concentrations increase This is the correct answerThis is the correct answer
ESR is elevated in inflammatory disease processes such as

Rheumatoid arthritis/systemic lupus erythematosus (SLE)/polymyalgia rheumatica (PMR) (associated with other raised inflammatory markers - fibrinogen)
Malignancy (myeloma).
It increases with age (roughly, normal ESR is age divided by two) and tends to be higher in females.

In polycythaemia, the ESR is low.

27

Which of the following is correct regarding erythropoietin?
(Please select 1 option)
Decreases red cell destruction
Decreases red cell production
Is produced by the kidneys
Is produced by the lungs
Is secreted in response to a high kidney tissue PCO2

Is produced by the kidneys

Erythropoietin is produced predominantly by the kidneys and is not secreted by the lungs. It acts by stimulating the stem cells in the bone marrow.

Secretion of erythropoietin is inversely related to kidney tissue PO2.

Anaemia is frequently a feature of chronic renal failure and is now frequently treated with recombinant erythropoietin (EPO).


28

Which of the following is true regarding patients with anaemia?
(Please select 1 option)
Each haemoglobin molecule has the potential to combine with eight molecules of oxygen to become fully saturated
Oxygen delivery to tissues does not appear to fall until the haemoglobin level falls below 5 g/dl
Oxygen extraction is improved by a shift in the oxyhaemoglobin curve to the left
There appears to be a decreased risk of tumour recurrence in patients who require transfusion
Treated with ferrous sulphate (200 mg tds), patients should see a rise in haemoglobin levels of 1 g/dl/week after two weeks in iron deficiency anaemia

Treated with ferrous sulphate (200 mg tds), patients should see a rise in haemoglobin levels of 1 g/dl/week after two weeks in iron deficiency anaemia This is the correct answerThis is the correct answer
Each Hb molecule has a binding site for four molecules of oxygen.

The critical level at which oxygen delivery is affected by anaemia is approximately 8 g/dl.

Oxygen retention by the Hb molecule is increased through a shift to the left of the oxygen dissociation curve. In anaemia the curve is shifted to the right. For a given partial pressure of oxygen there are fewer O2 molecules associated with haemoglobin. This means there is less saturation: the decreased affinity for O2 molecules increases oxygen delivery to the tissues.

A small but significant risk of tumour relapse exists in those subjects that require transfusion. This may be due to the advanced nature of their tumour (increased metabolic and inflammatory processes associated with greater dissemination).

In iron deficiency anaemia a rapid improvement in Hb may be expected with appropriate iron supplementation.

29

Which of the following is true of a patient of blood group A?
(Please select 1 option)
Can safely be transfused with blood group AB
Can safely receive a transfusion of blood group O
Cannot have children of blood group O
Irrespective of the blood group of her partner, all her children will be group A
Will only have offspring with blood group A if her partner also has blood group A

Can safely receive a transfusion of blood group O

The ABO blood group is co-dominantly inherited, so that AO or AA represents blood group A. If the patient were transfused with AB blood then the B antigens would set up an immune reaction.

Group O is the universal donor - no antigens present. If her partner were blood group A then, depending on her partner's genotype, she could have O or A offspring.

30

A 45-year-old female presents with tiredness and is found to be anaemic.
In which of the following diagnoses would oral iron be an inappropriate treatment?
(Please select 1 option)
Coeliac disease
Hereditary haemorrhagic telangiectasia (HHT)
Menorrhagia due to ovarian fibroids
Patterson Brown-Kelly (Plummer-Vinson) syndrome
Small bowel bacterial overgrowth

Small bowel bacterial overgrowth This is the correct answerThis is the correct answer
Coeliac disease is a cause of iron deficiency anaemia.

HHT is an autosomal dominant condition associated with telangiectasia of the gut and lungs. It can result in:

Epistaxis
Occult gastrointestinal blood loss, and
Haemoptysis.
Menorrhagia is a common cause of iron deficiency anaemia, as is ulcerative colitis (UC), with blood gut losses.

Patterson Brown-Kelly is iron deficiency anaemia with post-cricoid web.

Bacterial overgrowth, associated with conditions such as diabetes, is associated with malabsorption of B12 concentrations.

31

Which of the following is an abnormality not associated with recurrent thromboembolism?
(Please select 1 option)
Decreased levels of protein C
Elevated levels of antiphospholipid antibodies
Malignancy
Plasminogen deficiency
Substance P deficiency

Substance P deficiency This is the correct answerThis is the correct answer
Prothrombotic tendencies are associated with:

Antithrombin III deficiency
Factor S and C deficiencies
Factor V Leiden, and
Antiphospholipid syndrome (lupus anticoagulant).
These may be picked up through requesting a thrombophilia screen. This is an expensive test so must have clear clinical indications.

Malignancy can result in hypercoagulable states. Sometimes malignancy is associated with hypercoagulable states. Those with the factor V Leiden mutation on both chromosome 1s (homozygote) have a six-fold increase in the incidence of colorectal cancer (there is no increase in incidence with the heterozygote state).

Substance p is a neuropeptide (neurotransmitter and neuromodulator). Increased levels are found in fibromyalgia.

32

Typical features of disseminated intravascular coagulation (DIC) include which of the following?
(Please select 1 option)
Decreased fibrinogen degradation products (FDP)
Increased plasma fibrinogen concentration
Normal prothrombin time (PT)
Pancytopenia
Prolonged activated partial thromboplastin time (APTT)

Prolonged activated partial thromboplastin time (APTT) This is the correct answerThis is the correct answer
DIC is associated with increased PT and APTT, anaemia and thrombocytopenia due to microvascular coagulation resulting in the consumption of coagulation factors and fibrinogen. Consequently there are increased FDPs.

Causes include leukaemias, serious infections (meningococcus/Escherichia coli) and obstetric emergencies.

33

In disorders of cell growth, which of the following is correct?
(Please select 1 option)
A hamartoma is the overgrowth, with disordered architecture of mature cells which are not normally found within the tissue
Aplasia is the failure of development of an organ or tissue
Dysplasia is neoplastic
Hyperplasia is an increase in cell size
Metaplasia is the irreversible replacement of one fully differentiated cell type with another fully differentiated cell type

Aplasia is the failure of development of an organ or tissue

Hyperplasia is an increase in cell numbers, hypertrophy is an increase in cell size.

Metaplasia is a reversible process.

Dysplasia is a premalignant condition with increased cell growth, cellular atypia and altered differentiation.

A hamartoma is the overgrowth of mature cells which are normally found in the tissue with disordered architecture.

34

Which of the following is correct regarding warfarin therapy?
(Please select 1 option)
Affects the intrinsic pathway by prolonging the the prothrombin time
Interferes with the production of factors III, VI, XI and XII
Is a vitamin K agonist
Is not safe to use in pregnancy

Is not safe to use in pregnancy This is the correct answerThis is the correct answer
Warfarin is a vitamin K antagonist and interferes with the production of factors II, VII, IX and X.

Its activity can be monitored by measuring the prothrombin time which tests the integrity of the extrinsic and final common pathways of the coagulation cascade.

Bleeding in a patient who is receiving warfarin therapy may be controlled with either fresh frozen plasma or vitamin K depending on the urgency.

Warfarin is teratogenic and should be avoided in the first trimester of pregnancy.

35

With which of the following is deep vein thrombosis (DVT) associated?
(Please select 1 option)
Early post-op mobilisation
Haemophilia A
Malignancy
Protein E deficiency
Vitamin K deficiency

Malignancy

Prolonged immobility results in venous stasis and an increased risk of DVT.

Protein C is a natural anticoagulant which degrades factors Va and VIIIa and inactivates plasminogen activator inhibitor I.

Patients with carcinoma of the breast, lung, pancreas, prostate and bowel have increased risk of venous thrombosis. Mucin from adenocarcinomas and proteases from bowel and breast cancers are capable of inactivating factor X.

Haemophilia A is an X-linked recessive deficiency of factor VIII.

Vitamin K deficiency results in a lack of factors II, VII, IX and X and subsequent increased likelihood of bleeding.

36

Which of the following exerts anticoagulant activity specifically through actions on factor Xa of the coagulation cascade?
(Please select 1 option)
Aspirin
Clopidogrel
Low molecular weight heparin
Unfractionated heparin
Warfarin

LMWH

Clopidogrel, an adenosine diphosphate (ADP) receptor blocker and aspirin, a prostaglandin inhibitor exert antiplatelet effects.

Warfarin is a vitamin K antagonist.

The low molecular weight heparins exert their effect principally through inhibiting factor Xa and so do not affect activated partial thromboplastin time (APTT).

Unfractionated heparins work on a number of factors and are monitored through effects on the APTT.

37

Which one of the following is not associated with a prothrombotic tendency?
(Please select 1 option)
Anti-thrombin III deficiency
Factor V leiden mutation
Factor IX deficiency
Lupus anticoagulant
Protein S deficiency

FIX

All the above are associated with a prothrombotic tendency except factor IX deficiency otherwise known as Christmas disease/haemophilia B.

Lupus anticoagulant is termed this because it causes a prolonged activated partial thromboplastin time (APTT) in vitro only but is associated with increased thrombotic tendency in vivo. It is associated with the antiphospholipid syndrome.