Haematology Flashcards
1
Q
Causes of relative polycythaemia
A
- Dehydration
- Diuretics
2
Q
Causes of true polycythaemia
A
- EPO or red cell transfusion
- Androgens
- Malignancy - polycythaemia vera
3
Q
Causes of microcytic anaemia
A
- Iron deficiency anaemia
- Thalassemia
4
Q
Causes of normocytic anaemia
A
- Anaemia of chronic disease
- Bone marrow failure
- Haemodilution (IV fluids)
- EPO insufficiency (renal failure)
5
Q
Causes of macrocytic anaemia
A
- Haematinic deficiency (B12 and folate deficiency)
- Haemolysis
- Altered lipid content in red cell membrane e.g. alcohol, liver disease, hypothyroidism, drugs
6
Q
Iron study results in a patient with iron deficiency anaemia
A
- Low serum iron AND high transferrin
OR
- Low ferritin
7
Q
Ferritin levels may be falsely ??? during the acute phase response
A
Raised
8
Q
Treatment of a patient with iron deficiency anaemia
A
PO ferrous sulphate 200mg tads until FBC normal then continue for 3 months to replenish iron stores
9
Q
When would you consider looking for causes of iron deficiency anaemia?
A
Iron deficiency in a non-menstruating women - consider upper GI endoscopy and colonoscopy
10
Q
FBC results in thalassemia
A
MCV much lower than haemoglobin
11
Q
Most common cause of normocytic anaemia
A
Anaemia of chronic disease
12
Q
Iron study results in a patient with anaemia of chronic disease
A
- Normal/high ferritin
- Low serum iron
- Low transferrin
13
Q
Causes of bone marrow failure
A
- Malignancy e.g. blood cancers
- Drugs e.g. chemotherapy, cytotoxic, antibiotics
- Infection e.g. HIV
- Nutritional
- Radiation
- Poisons
- Congenital
14
Q
Causes of haematinic deficiency
A
- Dietary choices e.g. veganism
- Pernicious anaemia (autoimmune destruction of intrinsic factor)
- Ileal disease e.g. Crohn’s
15
Q
Treatment of haematinic deficiency
A
- Folate: oral replacement
- B12: IM injections
16
Q
Never replace ??? before checking ??? is normal as this can precipitate subacute combined degeneration of the spinal cord
A
- Folate
- B12
17
Q
Causes of haemolysis
A
- Sickle cell disease
- Thalassemia
- GPD6 deficiency
- Hereditary spherocytosis
- Autoimmune haemolysis
- Haemolytic transfusion reaction
- DIC
- Eclampsia
- Malaria
- Toxins
18
Q
Clinical features of haemolysis
A
- Signs of anaemia
- Jaundice
- Dark urine/pale stool
- Splenomegaly (chronic)
19
Q
Investigations which would indicate haemolysis is occurring
A
- FBC: macrocytic anaemia, Reticulocyte response, increased LDH
- LFTs: unconjugated bilirubinaemia
- Consumption of haptoglobin
20
Q
Investigations to perform to work out cause of haemolysis
A
- Blood film
- Coomb’s test
21
Q
Commonest inherited single gene conditions
A
Haemoglobinopathies
22
Q
Pathophysiology of sickle cell disease
A
Single nucleic acid substitution (GAG to GTG) in the beta global gene leading to synthesis of structurally abnormal haemoglobin.
This causes HbS to polymerise and form crystals when it becomes deoxygenated at low oxygen tensions, causing haemoglobin to clump and become ‘sickled’ in shape, meaning RBCs are much more easily damaged in the capillaries.
Originally the sickling is reversible but becomes irreversible over time.
23
Q
Inheritance pattern of sickle cell disease
A
Autosomal recessive
24
Q
Factors which increase sickling of RBC in sickle cell disease
A
- Hypoxia
- Infection
- Acidosis
- Cold temperatures
- Medications e.g. ibuprofen
- Low levels of HbF (higher levels are protective)
25
Clinical features & investigation results of a patient with sickle cell TRAIT
- Asymptomatic
- Normal FBC (no anaemia)
- Normal blood film
- Abnormal HbS detected on HPLC (HbA and HbS)
26
Treatment required in sickle cell trait
None - patient's are asymptomatic and don't experience anaemia
27
What are the two main complications of sickle cell disease?
1) Chronic haemolytic anaemia (due to damage and breakdown of RBCs) - Hb 70-90g/l
- leads to jaundice and bilirubinaemia
- leads to reticulocytosis (as bone marrow try to compensate for anaemia)
2) Acute faso-occlusive crisis
- often presents with bony pain
28
Acute complications of sickle cell disease
- Infection
- Acute anaemia - splenic/hepatic sequestration, aplastic crisis (associated with parvovirus), haemolytic crisis
- Chest crisis
- Stroke
- Priapism
- Avascular necrosis of the hip or shoulder
29
Management of complications in sickle cell disease
- Infection - prophylactic penicillin and vaccinations
- Stroke - chronic transfusion in high risk patients
- Avoid precipitating factors e.g. cold, excessive exercise, dehydration
- Crisis prevention, analgesia and supportive care
- Transfusion - intermittent top up transfusion or exchange transfusion (to reduce HbS%) OR chronic transfusion and chelation
- Hydroxycarbamide (increases HbF%)
- Bone marrow transplant (curative)
30
Chronic complications of sickle cell disease
- Chronic anaemia
- End-organ damage e.g. renal failure, pulmonary hypertension, cerebrovascular disease, heart failure, splenic atrophy
- Immunocompromise and increased risk of infection with encapsulated organisms
- Transfusion-related complications e.g. iron overload, allo-antibody formation
31
How would you detect HbS in a patient with suspected sickle cell disease?
HPLC
32
Management of a painful vaso-occlusive episode in a patient with sickle cell disease
- Adequate pain control within 60 mins of presentation e.g. IV morphine
- Ensure adequate hydration e.g. IV fluids
- Avoid/treat hypoxia e.g. oxygen
- Examine/investigate for/treat infection e.g. antibiotics
33
How are newborns screened for sickle cell disease?
Guthrie heel prick test
34
Current life expectancy in sickle cell disease
50-60 years
35
Pathophysiology of thalassemia
Reduced rate of normal beta globin chain synthesis
36
If a patient has 1 or 2 abnormal alpha globin genes they will have ...?
Alpha thalassemia trait
37
If a patient has 3 or 4 abnormal alpha globin genes they will have...?
Alpha thalassemia major (not usually compatible with life)
38
If a patient has 1 abnormal beta globin gene they will have...?
Beta thalassemia trait
39
If a patient has 2 abnormal beta globin genes they will have...?
Beta thalassemia major
40
Risk factors for thalassemia trait
- Family history
| - Ethnicity
41
Investigation results in a patient with alpha thalassemia trait
- Mild anaemia or no anaemia
- Normal HPLC
- Normal ferritin
Alpha thalssemia trait is a diagnosis of exclusion.
42
Investigation results in a patient with beta thalassemia trait
- Anaemia
- Elevated HbA2
- Normal ferritin
- Very low MCV
43
Clinical features and investigation results in a patient with beta thalassemia major
- Splenomegaly
- Bony changes (e.g. skull bossing)
- Failure to thrive
- Jaundice
- Gallstones
- Severe hypochromic microcytic anaemia
- Increased reticulocytes
- HPLC: elevated HbA2, HbF and reduced HbA
44
Management of a patient with beta thalassemia trait
None needed if patient asymptomatic (avoid unnecessary iron supplementation)
45
Management of a patient with beta thalassemia major
- Chronic transfusions + chelation therapy
| - Bone marrow transplant
46
Complications of beta thalassemia major
- Iron overload - leads to cardiac failure, liver failure, endocrine problems e.g. diabetes
- Allo-antibody formation
47
Current life expectancy for patients with beta thalassemia major
40-50 years
48
Commonest severe inherited bleeding disorder
Haemophilia
49
Inheritance pattern of haemophilia
X-linked recessive - carrier mothers have a 50% chance of each son being affected and each daughter being a carrier
50
Factor affected in Haemophilia A
Factor VIII
51
Factor affected in Haemophilia B
Factor IX
52
Investigation results in a patient with Haemophilia
- Isolated prolonged APTT (factors VIII and IX both part of intrinsic pathway)
- Normal PT
- Normal fibrinogen
53
Clinical features in a patient with haemophilia
- Family history e.g. carrier mother, history of bleeding problems on haemostatic challenges
- Birth history of bleeding on delivery
- Prolonged bleeding, re-bleeding or excess bruising
- Unusual surgical bleeding
- Bleeding with IM injections, vaccinations or heel prick test
54
Categories of haemophilia
- <1% factor VIII/IX = severe
- 1-5 factor VIII/IX = moderate
- 6-49% factor VIII/IX = mild
(50-150% = normal)
55
Symptoms of mild haemophilia
- Bleeding with surgery or dental work
| - Bleeding with major trauma
56
Symptoms of moderate haemophilia
- Bleeding with minor trauma - SC or IM bleeds
| - Occasionally spontaneous bleeds
57
Symptoms of severe haemophilia
- Recurrent spontaneous joint bleeds leading to joint damage
| - Spontaneous intra-cranial bleeds
58
Management of haemophilia
Recombinant synthetic factor VIII or IX
Tranexamic acid
Physiotherapy
59
Commonest inherited bleeding disorder
Von Willebrand disease
60
Clinical features of von Willebrand disease
- Mucosal bleeding
- Easy bruising
- Dental bleeding
- Epistaxis
- Menorrhagia
- Surgical and post-traumatic bleeding
61
Malignant cells in leukaemia are???
Blasts/haematopoetic stem cells/early progenitor cells (acute leukaemia) or myeloid cells or lymphocytes (chronic leukaemia)
62
Clinical features of acute leukaemia
- Symptoms onset over days-weeks
- Bone marrow failure symptoms e.g. anaemia, bleeding, infection
- Hepatomegaly
- Splenomegaly
- Lymphadenopathy
63
Investigation results in acute leukaemia
- Blasts seen in blood
64
Clinical features of chronic leukaemia
- Symptoms onset over months-year
- Hepatomegaly
- Splenomegaly
- Lymphadenopathy
65
Investigation results in chronic leukaemia
- Leucocytosis
66
Laboratory definition of leukaemia
>20% blasts seen in bone marrow
67
Pathological hallmark of AML
Auer rods
68
Clinical features of AML
- Most common acute leukaemia in adults
- Middle-aged to elderly patients
- Short clinical history
- Bone marrow failure symptoms
- Infiltrates in liver, spleen and other tissue
69
Investigation results in AML
- WCC elevated or reduced
| - Coagulation disorders
70
Clinical features of ALL
- Most common childhood malignancy
- Children affected
- Short clinical history
- Bone marrow failure symptoms
- Infiltrates in lymph nodes, bone, liver, spleen and CNS
71
Investigation results in ALL
- WCC elevated or reduced
72
Investigations to consider in a patient with suspected leukaemia
- Urgent FBC - will be abnormal
AML/ALL: pancytopenia +/- circulating blasts
CML: neutrophils and myeloid precursors
CLL: lymphocytes
- Blood film to look for circulating malignant cells
- Urgent coagulation screen
73
Diagnostic test for leukaemia
Bone marrow aspirate and trephine from the posterior iliac crest
Can also do bone marrow examination under the microscope
Can do immunophenotyping to determine antigens on cell surface
Can do cytogenetic analysis to determine any genetic causes e.g. trisomy 8 (only present in blood cells)
74
Management of leukaemia
- Chemotherapy - intensive regimes with multiple drugs, oral, IV or IT
- Stem cell transplantation - allogenic transplant from sibling or unrelated donor
- Monoclonal antibodies - Imatinib targeted at Philadelphia chromosome in CML
```
- Supportive care e.g.
Infection prophylaxis and treatment
Blood transfusion - red cells or platelets
Coagulopathy management
Central venous access
```
75
Clinical features and investigation results for a patient with CML
- Age 40-60
- Abdominal discomfort
- Splenomegaly
- Very high WCC - mostly neutrophils and precursors
- Hyperviscosity - mucosal bleeding, shortness of breath, visual changes, neurological symptoms
76
Definitions of lymphomas
Malignancy of lymphocytes (T or B cells) in the lymph glands and other tissues
77
Pathological hallmark of Hodgkin's lymphoma
Reed-Sternberg cells
78
Most common haematological malignancy
Non-Hodgkin's lymphoma
79
Clinical features of Hodgkin's lymphoma
- Young adults and >50s
- More common in men
- Very aggressive symptoms
- Asymmetrical painless superficial lymphadenopathy (usually cervical)
- Organomegaly
- Constitutional symptoms e.g. drenching night sweats, fever, weight loss, itch
- Alcohol induced nodal pain
80
Clinical features of Non-Hodgkin's lymphoma
- 55-60 year olds
- Varying clinical course
- Lymphadenopathy
- Organomegaly
- Constitutional symptoms e.g. drenching night sweats, weight loss, fever, itch
- Extra-nodal involvement more common
81
Features of pathological lymphadenopathy
- >1cm in size
- Persistant
- Painless
- No reactive cause
- Rubbery/matted texture
82
FBC results in lymphoma
May be NORMAL - will only be abnormal if bone marrow is involved
83
Diagnostic test for lymphoma
Lymph gland biopsy
84
Lymphoma management
- Watchful waiting
- Chemotherapy e.g. CHOP therapy
- Targeted therapies e.g. Rituximab
85
Pathophysiology of multiple myeloma
Malignant proliferation of plasma cells within the bone marrow - these plasma cells secrete antibodies (para-proteins)
86
Main risk factor for multiple myeloma
Age
87
Clinical features of multiple myeloma
- Bone pain and pathological fractures
- Anaemia
- Recurrent infections
- Renal failure/AKI
- Hypercalcemia
- Hyperviscosity
- Hyperuricaemia
- Spinal cord compression
88
Screening tests for multiple myeloma
1) Serum protein electrophoresis
2) Bence-Jones proteinuria
BOTH must be tested as some patients will have one and not the other
89
Diagnostic test for multiple myeloma
Bone marrow aspirate and trephine
90
Laboratory definition of multiple myeloma
>10% clonal plasma cells on bone marrow aspiration
91
Investigation results in multiple myeloma
- Raised serum protein electrophoresis
- Raised Bence-Jones proteinuria
- Anaemia on FBC
- AKI on U&Es
- Hypercalcemia
- Raised ALP
- Raised ESR
92
Definition of multiple myeloma
Evidence of multiple myeloma-related tissue impairment
93
Definition of smouldering myeloma
Confirmed diagnosis of multiple myeloma but no evidence of multiple myeloma-related tissue impairment
94
Management of multiple myeloma
- Chemotherapy - usually intensive therapy and autologous stem cell transplant
- Radiotherapy (bone pain and spinal cord compression)
- Bisphosphonates e.g. monthly IV Zolendronate (for hypercalcemia and bone protection)
- Adequate hydration e.g. 3l of 0.9% NaCl over 24 hours (to prevent renal failure)
- Haematopoetic stem cell transplantation
95
PT assesses the ??? pathway of the coagulation cascade
Extrinsic
96
APTT assesses the ??? pathway of the coagulation cascade
Intrinsic
97
A raised APTT and raised PT indicates a problem in the ??? pathway of the coagulation cascade
Common
98
A raised PT and normal APTT indicates a problem in the ??? pathway of the coagulation cascade
Extrinsic
99
A raised APTT and normal PT indicates a problem in the ??? pathway of the coagulation cascade
Intrinsic
100
Causes of a prolonged PT
- Deficiency/inhibition of factors II, V, VII, X or fibrinogen
- Warfarin use
- Vitamin K deficiency
- Liver disease (+++)
- DIC
101
Causes of a prolonged APTT
- Deficiency/inhibition of factor II, V, VIII, IX, X, XII or fibrinogen (e.g. Haemophilia A or B)
- Heparin therapy
- Lupus anticoagulant/antiphospholipid disease
- Liver disease (+)
- DIC
102
Causes of a raised fibrinogen
- Acute phase response
103
Causes of a lowered fibrinogen
- Severe sepsis
- DIC
- Rare congenital states
104
Risk factors for venous thromboembolism
- Personal history of VTE
- Pregnancy and puerperium
- Oestrogen-containing medication e.g. Tamoxifen, COCP
- Antiphospholipid antibodies (rare)
- Prolonged immobility e.g. surgery, travel
- Smoking
- Obesity
- Malignancy
- Recent surgery
- Family history
- IVDU
- Inherited thrombophilia
105
Mechanism of action of heparins
Binds to antithrombin causing a conformational change and potentiating the action of antithrombin which inhibits factor Xa and thrombin (factor IIa)
106
Administration method of unfractionated heparin
Continuous IV infusion
107
Indications for use of unfractionated heparin over other anti-coagulants
Rapid reversibility required e.g. high bleeding risk, severe hepatic/renal failure
108
Risk of heparins
- Bleeding
- Heparin-induced thrombocytopenia (risk lower in LMWH)
- Heparin-induced osteoporosis (risk lower in LMWH)
109
Monitoring of unfractionated hepatin
APTT ratio (compared to normal APTT) every 4-6 hours initially then daily once stable
110
Reversal of heparin can be achieved with ??
Protamine
111
Administration method of LMWH
Once daily SC injection
112
Indications for LMWH
- DVT
- Thromboprophylaxis
- Pregnancy
113
Contra-indications for LMWH
- eGFR <30
114
When is monitoring indicated whilst using LMWH?
- Pregnancy
- Renal failure
- In Children
115
How would you monitor LMWH?
- Anti-Xa assay
116
Mechanism of action of warfarin
Prevents vitamin K 'recycling' by inhibiting vitamin K reductase and vitamin K epoxide reductase so reduces the rate of synthesis of vitamin K dependent clotting factors
117
Drugs which interact with warfarin
- Antibiotics e.g. erythromycin, clarithromycin, ciprofloxacin
- NSAIDs
- Amiodarone
- Anti-epileptics
- Azole anti-fungals
- Statins
- H2 receptor antagonists and PPIs
118
How would you monitor a patient on warfarin?
INR
119
How would you reverse the effects of warfarin?
Oral/IV vitamin K (takes 6-12 hours to have an effect)
Or
Prothrombin concentrate complex (mix of vitamin K dependent factors made from donor blood)
Or
Fresh frozen plasma
120
Contra-indications for warfarin
Pregnancy - warfarin is teratogenic
121
Complications of warfarin
- Bleeding
- Thrombotic complications if dose is sub-therapeutic
- Fetal toxicity
- Interactions with medication and alcohol
- Poor INR control in liver dysfunction
- Itchy maculopapular rash
- Alopecia
122
Mechanism of action of DOACs
Directly inhibit coagulation factors - either thrombin (Dabigatran) or factor Xa (Apixaban, Rivoroxaban, Edoxaban)
123
Advantages of DOACs compared to warfarin
- Rapid onset and offset of action
- Fewer drug interactions, no dietary interactions
- Fixed dosing
- No monitoring requirements
- Overall lower risk of major bleeding, particularly intra-cranial haemorrhage
124
Contra-indications to DOAC use
- Pregnancy
- End-stage cirrhosis
- Caution should be used in renal disease
125
Side effects of DOACs
- Bleeding complications
- GI upset
- Alopecia
126
Which anticoagulant should you use in a pregnant woman?
LMWH
127
Features of pseudomonas aeruginosa
- Small gram negative bacilli
- Aerobic
- Oxidase positive
- Produces diffusible pigments and appear green-blue colour on culture or when colonising wounds
- 'Freshly cut grass' odour
- Widespread in moist environments e.g. soil
- Colonises moist sites on humans e.g. groin, axilla, ear, perineum
128
Risk factors for pseudomonas infection
- Immunocompromise/ neutropenia
| - ITU admission
129
Potential infections caused by pseudomonas aeruginosa
- Line infection leading to bacteraemia
- Catheter-associated UTI
- Hospital/Ventilator acquired pneumonia
- Surgical site infections
130
Management of pseudomonas infection in Lothian
Vancomycin + Tazocin
131
Features of strenotrophomonas maltophilia
- Aerobic
- Gram negative bacilli
- Oxidase negative
- Pale yellow colour on culture
- Ammonia-like odour
132
Risk factors for infection with Strenotrophomonas
- Haematological malignancy
- Immunocompromise/prolonged neutropenia
- Prolonged treatment with carbapenems/Cephalosporins/Fluoroquinolone
- Lines/intravascular devices or catheters
133
Potential infections caused by strenotrophomonas
- Bacteraemia (often secondary to line infection)
- Respiratory infections
- UTIs
134
Antibiotics which strenotrophomonas is resistant to
- Beta-lactams
- Fluoroquinolones
- Aminoglycosides
- Carbapenems
(- Disinfectants)
135
Treatment of infection with strenotrophomonas in Lothian
Co-trimoxazole
136
Features of pneumocystis
- Unicelluar fungus
| - Lacks ergosterol in it's cell wall - so is resistant to many anti-fungals
137
Risk factors for pneumocystis
Immunocompromise:
- HIV patients
- Haematological and other malignancies
- Solid organ and bone marrow transplant recipients
- Collagen vascular disorders on immunomodulator therapy
138
Most common clinical presentation of pneumocystis infection
Pneumocystis pneumonia (from inhalation of cyst form of pneumocystis jirovecii:
- Progressive dyspnoea
- Fever
- Non-productive cough
- Tachycardia
- Tachypnoea
- Fine end inspiratory crackles
139
An immunocompromised patient has bilateral diffuse interstitial infiltrates extending from the peri-hilar region on CXR. What is the most likely causative organism?
Pneumocystis jirovecii
140
An immunocompromised patient has 'ground glass' changes in their lungs on high resolution CT scanning. What is the most likely cause of their pneumonia?
Pneumocystis jirovecii
141
What is the diagnostic test for pneumocystis pneumonia?
Induced sputum or bronchoscopic alveolar lavage for immunofluorescent antibody staining
142
Pneumocystis is easily cultured in the laboratory (true/false)?
False - pneumocystis can not be cultured in the lab
143
First line management of pneumocystis pneumonia in Lothian
High-dose Co-trimoxazole (+ prednisolone if pO2 <9.3 kPa) for 14-21 days in immunocompromised patients (21 days in HIV patients).
144
Methods for preventing infection with pneumocystis pneumonia
- Primary or secondary chemoprophylaxis with co-trimoazole for as long as the patient is immunocompromised
- Prevention of transmission/exposure e.g. isolate patient in side room with respiratory precautions
145
Features of candida
- Yeasts
- Normal human commensal in skin, GI tract and GU tract
- Gram positive
- Small, thin-walled ovoid cells
- Appear smooth creamy-white glistening colonies on blood agar
- 5 species which most commonly cause invasive disease
1) Candida albicans
2) Candida glabrata
3) Candida tropicalis
4) Candida parapsilosis
5) Candida krusei
146
Risk factors for candidaemia
- Exposure to broad-spectrum antibiotics
- Presene of indwelling IV catheters
- Neutropenia
- Solid organ transplant recipients on immunosuppression
- TPN
- GI or thoracic surgery
147
How would you confirm a diagnosis of candidaemia?
Blood cultures (from central and peripheral venous access if possible)
148
Management of candidaemia
- Anti-fungal treatment (Fluconazole or Caspofungin) for a minimum of 14 days from the first set of negative blood cultures
- Repetition of blood cultures every 48 hours until cultures are negative
- Removal of all indwelling catheters
- Cardiology review and echocardiogram
- Ophthalmology review and dilated eye examination within 1 week of diagnosis
- Review potential sources of candidaemia e.g. GI and GU imaging
- Identification and management of risk factors e.g. stop or narrow spectrum of antibiotics
149
Complications of candidaemia
- Endocarditis
| - Endopthalmos and blindness
150
Features of VRE
- Gram positive cocci
- Enterococci resistant to Vancomycin
(Usually E. faecium or E. faceless)
151
Risk factors for VRE infection
- Broad spectrum antibiotic treatment
- IV lines/urinary catheter
- Haematological malignancy
- Increased age
- Diabetes
- Transplant recipient
- Surgery
- Long inpatient stay
- ICU stay
152
Potential infections caused by VRE
- UTI
- Bacteraemia
- Endocarditis
- Skin and soft tissue infections
- Intra-abdominal/pelvic infections
(VRE can be carried in the gut without symptoms)
153
Which antibiotics are VRE resistant to?
- Aminoglycosides
- Carbapenems
- Cephalosporins
- Macrolides
- Penicillins
- Quinolones
- Tetracyclines
154
Management options for VRE infections
- Linezolid
| - Daptomycin
155
VRE infection control and prevention measures
- Antimicrobial stewardship
- Patient isolation
- Contact precautions
- Dedicated single patient equipment
- Staff PPE and hand washing
- Daily and terminal decontamination of patient bed area, room and sanitary facilities
156
Main risk factors for line infections
Immunocompromise
157
Management of a line associated infection
- Blood cultures from line and peripheral sites
- Line removal
- Antibiotics (duration depends on organism cultured)
- Daily review of all exit sites
158
Interventions which reduce the infective complications of CVCs
- Removal of catheters discussed daily
- Early removal of unnecessary catheters
- Check list for CVC insertion and maintenance bundle
- Documentation of time and date of catheter insertion
- Hand washing, aseptic technique and PPE use during insertion
- Education
159
Features of Staph Aureus
- Coagulase positive
- Gram positive cocci
- Virulent - produces toxins
- Commensal which colonises 30% of the population - found in nose, respiratory tract and on skin
- Transmitted from person to person via contact
160
Which antibiotic is MRSA resistant to?
Flucloxacillin
161
Management of S. Aureus bacteraemia
At least 2 weeks IV Flucloxacillin
Vancomycin in patients with penicillin allergy or MRSA
162
Most common cause of line infections in patients with haematological malignancies
S. epidermidis (60% of line infections are coagulase negative Staphs)
163
Features of S. epidermidis
- Coagulase negative
- Gram positive cocci
- Less virulent than S. Aureus
- Forms biofilms on plastic devices
- Normal skin flora
- Can be pathogenic in immunocompromised hosts
164
Functions of the spleen
- Filtration of damaged cellular material, RBCs, antibodies, bacteria and parasites
- Regulation of inflammation
- Immunity - maturation of T and B-cells
- Haemostasis
165
Causes of asplenia
- Congenital
- Surgery
- Splenic infarction
166
Causes of acquired hyposplenia
- Sickle cell anaemia
- Graft vs Host disease
- Coeliac disease
- HIV
- ALD
- IBD (mainly UC)
- Primary amyloidosis
- SLE
167
Bacterial organisms most associated with post-splenectomy sepsis
Encapsulated bacteria e.g. Streptococcus Pneumoniae, Haemophilus influenzae type B and Neisseria meingitidis
168
Which of the following is LEAST likely to cause sepsis in a patient following a splenectomy?
a) S. Aureus
b) Streptococcus pneumoniae
c) Haemophilus influenzae type B
d) Neisseria meningitidis
a) S. Aureus - the others are all encapsulated organisms
169
Parasites most commonly associated with post-splenectomy sepsis
Red cell parasites:
- Babesia microtia
- Plasmodium falciparum
Anasplama/human granulocytic ehrlichiosis
170
Pathological hallmark of Babesia microtia infection
Maltese cross sign on histology
171
Risk factors for post-splenectomy sepsis
- Extremes of age
- Recent splenectomy (0-90 days)
- Indication for splenectomy (immune cytosine is higher risk than trauma)
- Haemoglobinopathies
- Lack of appropriate vaccinations pre-splenectomy
- Immunosuppressant treatment
- HIV
Amyloidosis/sarcoidosis
- Autoimmune disease
- Splenic radiation
172
Methods for prevention of post-splenectomy infection
1) Prophylactic antibiotics
- Penicillin V 250-500mg BD, lifelong OR
- Clarithromycin 250mg OD, life long
(Can consider rescue therapy instead in low risk patients)
2) Vaccinations
- Pneumococcal - ideally 4-6 weeks before splenectomy or 2 weeks after, repeated every 5 years
- Meningococcal
- Influenza (as soon as practicable pre- or post-splenectomy, repeated annually
3) Avoidance of parasite vectors in endemic regions
4) Avoidance of dog bites/scratches
173
Clinical features of an acute haemolytic transfusion reaction
- Collapse within a few minutes of starting transfusion
- Dark urine
- Renal failure
- DIC
174
Clinical features of delayed haemolytic transfusion reaction
- Occurs several days after transfusion
- Haemoglobin fails to rise after transfusion
- Patient becomes jaundices
- Dark urine
- Direct anti-globulin test
175
Clinical features of a minor allergic reaction
- Urticarial or itchy rash
- Respiratory wheeze
- More common after plasma or platelet transfusion
- History of other allergies or atopy
176
Clinical features of a minor febrile reaction
- Mild rise in temperature
- Rigors
- More common after RBC or platelet transfusion
(Much rarer now transfused blood is leucodepleted)
177
Clinical features of anaphylaxis after transfusion
- Presents suddenly immediately after transfusion
- Hypotensive shock
- Breathlessness
- Wheeze
- Laryngeal and facial oedema
178
Commonest cause of death related to transfusion
Transfusion associated circulatory overload
179
Risk factors for TACO
- Extremes of age
- Renal impairment
- Heart failure
180
Management of TACO
- Diuretics
181
Clinical features of TRALI
- Severe breathlessness
- Hypoxia
- Occurs with 6 hours
182
Typical CXR appearance of TRALI
Bilateral pulmonary infiltrates
183
Biggest risk factor for TRALI
Donor platelets from a women
184
Risk factors for TA GvHD
- Immunosuppression
| - HLA-matched/HLA similar
185
Investigations results which would indicate haemolysis is occurring
- Decreased haemoglobin
- Increased unconjugated bilirubin
- Increased LDH
- Increased reticulocytes
- Increased urinary urobilinogen
- Folate deficiency
- Thrombocytosis
- Neutrophilia
- Immature granulocytes
186
Differentials for spherocytes seen on blood film
- Autoimmune haemolysis
| - Hereditary spherocytosis
187
Differential for schistocytes seen on blood film
- Micro-angiopathic haemolysis
188
Causes of intra-vascular haemolysis
- ABO transfusion reactions
- Paroxysmal nocturnal haemolgobinuria
- Infections e.g. malaria, C. perfringens
- Heart valves
- DIC
- Enzymopathies e.g. G6PD deficiency
189
Intra-vascular haemolysis causes a ??? in haptoglobin
Decrease
190
Pathophysiology of inherited spherocytosis
Red cell membrane defect, meaning each time these cells pass through the spleen they lose some elasticity and lost membrane relative to cell volume, causing increased MCHC, abnormal cell shape and haemolysis
191
Inheritance pattern of inherited spherocytosis
Autosomal dominant
192
Investigation results seen in inherited spherocytosis
Mostly asymptomatic patients with compensated chronic haemolytic state:
- Spherocytes seen on blood film but Coomb's test NEGATIVE
- Reticulocytosis
- Mild hyperbilirubinaemia
- Pigmented gallstones
193
3 potential crises of inherited spherocytosis
1) Haemolytic crisis - severity of haemolysis increases, usually associated with infection
2) Megaloblastic crisis - follows development of folate deficiency, usually during pregnancy
3) Aplastic crisis - occurs with parvovirus - patients present with anaemia and low reticulocytes
194
Management of hereditary spherocytosis
- Lifelong folic acid 5mg
- Consider splenectomy in severe haemolysis with complications
- Management of acute, severe haemolytic crisis with blood transfusion
195
Most common human enzymopathy
G6PD deficiency
196
Inheritance pattern of G6PD deficiency
X-linked - usually affects males
197
Clinical features of G6PD deficiency
- Acute drug induced haemolysis (aspirin, anti-malarials, antibiotics, quinidine, probenecid, vitamin K, dapsone)
- Chronic compensated haemolysis
- Infection or acute illness
- Neonatal jaundice
- Favism (acute haemolysis after eating broad beans)
198
Blood film features of G6PD deficiency
- Bite cells
- Blister cells
- Irregularly shaped small cells
- Polychromasia (reflecting reticulocytosis)
- Heinz bodies
199
Management of G6PD deficiency
- Avoid precipitants
| - Treat underlying infection
200
Pathophysiology of autoimmune haemolytic anaemia
Increased red cell destruction due to red cell autoantibodies - IgM or IgG, causing intravascular or extravascular haemolysis
201
Investigation results in autoimmune haemolytic anaemia
Blood film:
- Haemolysis
- Spherocytes
- Polychromasia
Direct Coomb's test:
- POSTIVE
202
Management of warm autoimmune haemolysis
- Treat underlying causes
- Stop implicated drugs
- Management of haemolysis
1) PO prednisolone then taper dose
2) Immunomodulation/suppression e.g. rituximab
3) Splenectomy
4) Transfusion in life-threatening problems
203
Pathophysiology of ITP
Immune-mediated disorder with autoantibodies directed against platelet membrane proteins IIb or IIIa which sensitise the platelet and result in it's premature removal from the circulation
204
Conditions associated with ITP
- Connective tissue disease
- HIV infection
- B-cell malignancies
- Pregnancy
- Drug therapy
205
Clinical features of ITP
- Spontaneous bleeding
- Easy bruising
- Epistaxis
- Menorrhagia
- Asymptomatic
206
Investigation results in ITP
- Normal FBC except thrombocytopenia
- Increased megakarocytes on bone marrow aspiration
- Autoantibodies (present in connective tissue disease)
207
Features which indicate no treatment is required in ITP
- Stable, compensated disease
| - Platelets >30
208
Management of ITP patients with spontaneous bleeding
1) High dose glucocorticoids
2) Plus IV immunoglobulins (in severe haemostatic failure, evidence of significant mucosal bleeding or slow response to steroids alone)
3) Plus platelet transfusion (in life-threatening bleeding)
209
Management of ITP relapses
1) Glucocorticoids
2) Thrombopoietin receptor agonists, splenectomy or immunosuppression (if >2 relapses or primary refractory disease present)
210
Pathophysiology of haemolytic disease of the newborn
IgG antibodies from the mother cross the placenta and attack the foetal red blood cells, causing haemolysis
211
Clinical features of haemolytic disease of the newborn
- Anaemia - heart failure, pallor, hepatosplenomegaly, oedema, respiratory distress
- Jaundice within 24 hours of birth
- Kernicterus
212
Investigations and potential results in haemolytic disease of the newborn
- Blood film: reticulocytosis, erythroblasts
- Positive direct Coomb's test
- LFTs: elevated cord bilirubin
- FBC: neutropenia, neonatal alloimmune thrombocytopenia
(Mother will have positive indirect Coomb's test)
213
Management options for haemolytic disease of the newborn (after birth)
- Temperature stabilisation
- Phototherapy
- IV immunoglobulin
- Transfusion with compatible packed red cells
- Exchange transfusion with blood type compatible with mother and infant
- Sodium bicarbonate to correct acidosis
214
Pathophysiology of DIC
Generalised activation of the clotting pathways, resulting in the formation of intra-vascular fibbing and thrombotic occlusion of small and medium vessels and end-organ damage
215
Causes of DIC
- Infection e.g. sepsis, Rocky Mountain spotted fever, malaria
- Obstetric complications e.g. miscarriage, amniotic fluid embolism, eclampsia
- Tissue trauma e.g. burns
- Malignancy
- Drugs e.g. quinine, cocaine
- Liver failure
- Acute pancreatitis
- Transfusion reactions
- Respiratory distress syndrome
216
Investigation results seen in DIC
- Prolonged APTT and PT
- Increased fibrin
- Decreased antithrombin or protein C
- Decreased fibrinogen
- Thrombocytopenia
- Schistocytes on blood film
217
Management options for DIC
- Treat underlying cause
- FFP and platelets
- Cryoprecipitate
- Antithrombin treatment
- Unfractionated heparin
