List I - Act Core Conditions Flashcards
1
Q
What is anaemia?
A
- Low (Hb) due to either low RBC mass (low production/increased loss) or
- Increased plasma volume (e.g. pregnancy - haemodilution as increased plasma volume > increased RBC)
2
Q
What are the normal values of Hb?
A
- Males - 13-18g/dL
- Females - 11.5-16g/dL
Higher in neonates, lower in younger children
3
Q
How much iron is contained within the blood?
A
- 1mL blood contains 0.5mg iron
- Body stores are regulated by absorption (duodenum, jejunum)
- No active excretion occurs (small daily losses in the urine, faeces and sweat)
4
Q
What are the daily requirements of iron?
A
- Adults
- Males - 1 mg
- Females - 2 mg if menstruating, 3 mg if pregnant
- Absorption
- Haem iron in meat readily absorbed, but in vegetables/cereals is part of amino/organic acid complex requiring release/reduction from Fe3+ to Fe2+ for absorption (promoted by gastric HCl acid and ascorbic acid in food)
5
Q
What are the causes of iron deficiency anaemia?
A
- Chronic blood loss - menorrhagia, (occult) GI bleeds (PUD, colonic angiodysplasia, gastric/colorectal Ca)
- Increased requirements - childhood, pregnancy
- Poor diet (developing countries) - usually babies, children, special diets, poverty (rarely adults)
- Malabsorption (causes refractory IDA) - gastrectomy, coeliac disease
- Malnutrition, hookworm - most common in the tropics
6
Q
How common is iron deficiency anaemia?
A
- Common (up to 14% of menstruating females)
- Most common cause of anaemia worldwide
- F>M
7
Q
What is the pathophysiology of iron deficiency anaemia?
A
- Latent iron deficiency (initial depletion of iron stores is asymptomatic)
- Iron deficiency anaemia (when reticuloendothelial stores - haemosiderin/ferritin - are completely depleted)
- Symptomatic (only when Hb falls)
- Leads to tissue hypoxia (rate of development and commorbidity reflects severity)
- Acute IDA has worse severity as there is no time for the body to compensate for reduced O2 carrying capacity
8
Q
What are the presenting clinical symptoms of IDA?
A
- Symptoms
- Acute IDA - SOB, faintness, palpitations, headache, tinnitus, anorexia, angina/claudication (if occult co-existent disease)
- Chronic IDA - fatigue, dysphagia (if post-cricoid mucous web), restless leg syndrome
- PMH - menorrhagia, GI bleeds, pregnancy, gastrectomy, coeliac disease
- SH - food diary
- DH - PPI (can also lead to IDA)
9
Q
What are the presenting clinical signs of IDA?
A
- Signs
- Mild to moderate - may be absent (even in severe), palmar/conjunctival pallor
- Severe (signs of hyperdynamic circulation) - bounding pulse, tachycardia, ejection systolic flow murmur (loudest over apex), cardiac enlargement, retinal haemorrhage (rare), heart failure (later: rapid transfusion may be fatal)
- Chronic IDA - koilonychias, atrophic glossitis, angular chelitis (painful cracking at corners of mouth), oesophageal / post cricoid web (Plummer-Vinson Syndrome)
- Examination - always do GI examination and include PR
10
Q
What is Plummer-Vinson Syndrome?
A
- Triad of the following:
- Dysphagia (secondary to oesophageal/cricoid webs)
- Glossitis
- Iron deficiency anaemia
- Associated with chronic IDA
- Treatment includes iron supplementation and dilation of the webs
11
Q
What does FBC demonstrate typically in IDA?
A
- Hypochromic microcytic anaemia
12
Q
What are the other blood pictures of IDA?
A
- Low MCV (microcytic)
- Low iron (hypochromic)
- High total iron-binding capacity (TIBC)/transferrin -reflects low iron stores
- Low transferrin saturation
- Low serum ferritin - correlates with iron stores
- Blood film - anisopoikilocytosis (RBC’s of different sizes and shapes), target cells, ‘penicil’ poikilocytes
13
Q
What are the differential diagnoses of IDA?
A
- Anaemia of chronic disease (same but with high ferritin)
- Serum iron low <15
- TIBC High
- Ferritin High
- Chronic haemolysis
- Serum iron High
- TIBC Low
- Ferritin High
- Haemochromatosis
- Serum iron High
- TIBC Low / Normal
- Ferritin High
- Pregnancy
- Serum iron High
- TIBC High
- Ferritin Normal
- Sideroblastic anaemia
- Serum iron High
- TIBC Normal
- Ferritin High
14
Q
What can cause ferritin to rise?
A
- Inflammation
- Infection
- Malignancy
15
Q
What can cause variation in RBC size (anisocytosis)?
A
- IDA
- Thalassaemia
- Megaloblastic anaemia
16
Q
What can cause variation in RBC shape (poikilocytosis)?
A
- IDA
- Thalassaemia
- Myelofibrosis
17
Q
What is the clinical manifestation of haemolytic anaemia in blood?
A
- Jaundice
18
Q
What is the clinical manifestation of B12 deficiency?
A
- Neurological symptoms/signs
19
Q
What can cause a rise in platelets?
A
- Acute blood loss
* Anaemia of chronic disease (due to inflammatory process)
20
Q
What can cause a fall in platelets?
A
- Bone marrow failure/megaloblastic anaemia (WCC fall)
21
Q
What are the appropriate blood investigations of IDA?
A
- Bloods
- FBC (Hb low, MCV low, MCH low, MCHC low, normal WCC/platelets
- Ferritin low
- Serum iron low
- TIBC (total Fe-binding capacity) high
22
Q
What imaging can be done for IDA?
A
- Barium enema
23
Q
What special tests should be done to investigate IDA?
A
- PR examination
- Endoscopy
- Gastroscopy (OGD)
- Colonoscopy (or sigmoidoscopy)
- Stool for OC and P (ova: hookworm, cysts, parasites)
- Bone marrow aspiration - rare
24
Q
What is the conservative approach to management of IDA?
A
- Conservative - management with dietary intake increase e.g. dark green leafy vegetables, meat, iron fortified bread
25
What is the medical management of IDA?
* Treat underlying cause if found
* Oral iron supplements
- If MCV low and good history of menorrhagia - ferrous sulphate 200mg/8h PO
- Each tablet contains 67mg iron
- SE's - nausea, diarrhoea, constipation, abdo discomfort, black stools
- If not tolerated can try ferrous fumarate or SR preparations
- Aim for increase in Hb by 1g/dL/week (with modest reticulocytosis
- Continue until Hb is normal for at least 3 months to replenish stores
* IV iron (risk anaphylaxis) - only use if oral not possible/ineffective (functional Fe deficiency in CKD - inadequate mobilisation of iron stores in response to acute demands of EPO therapy
* Packed cell transfusion - if significant blood loss (Hb <7-8/severely symptomatic
26
What are the complications of IDA?
* Prognosis is good once there is resolution of the cause
27
What is a group and save?
* Sample tested for ABO/Rhesus group and standard Ab screen (available for cross match if required)
28
What is a cross match?
* ABO/Rhesus group and standard Ab screen performed and blood is made available
29
For how long are group and save and cross match samples valid?
* Up to 3 months (if no prior transfusion)
| * 3 days (if transfused in the last 3 months or pregnant)
30
What is a massive transfusion?
* Replacement of the entire blood volume (>10U) in 24 hrs
| * Complications include low platelets, low calcium, low clotting, high potassium, low temperature
31
What are the requirements for FFP/cryoprecipitate/platelets?
* Needs to have been grouped previously
* Telephone requests accepted
* Allow for thawing (with cryoprecipitate/FFP)
* Allow for delivery if platelets
32
What are the blood transfusion related complication types?
* Immunological
- Acute haemolytic
- Non-haemolytic febrile
- Allergic/anaphlaxis
* Infective
* Transfusion related acute lung injury (TRALI)
* Transfusion associated circulatory overload (TACO)
* Others
- Hyperkalaemia
- Iron overload
- Clotting
33
What are the features of a non-haemolytic febrile reaction?
* Thought to be caused by anti-bodies reacting with white cell fragments in the blood product and cytokines that have leaked from the blood cell during storage
* Features - fever, chills
* Incidence - 1-2% in red cell transfusion, 10-30% in platelet transfusion
* Management - slow or stop the transfusion, give paracetamol, monitor the patient
34
What are the features of a minor allergic reaction to blood transfusion?
* Thought to be caused by foreign plasma proteins
* Features - pruritis, urticaria
* Management - temporarily stop the transfusion, give anti-histamine, monitor the patient
35
What are the features of anaphylaxis related reaction to blood transfusion?
* Can be caused by patients with IgA deficiency who have anti-IgA anti-bodies
* Features - hypotension, dyspnoea, wheezing, angioedema
* Management - stop the transfusion, IM adrenaline, ABC support, anaphylaxis protocol, O2, fluids
36
What are the features of acute haemolytic reaction to ABO incompatibility?
* Features - Fever, abdominal pain, hypotension
* Management - stop the transfusion, check the identity of the patient/name on blood product, send for direct Coombes test, repeat typing and cross-matching , supportive care, fluid resuscitation
37
What are the features of transfusion related circulatory overload?
* Excessive rate of transfusion, pre-existing heart failure
* Features - Pulmonary oedema, hypertension
* Management - slow or stop the transfusion, consider IV loop diuretic e.g. furosemide and oxygen
38
What are the features of transfusion related acute lung injury?
* Non-cardiogenic pulmonary oedema thought to be secondary to increased vascular permeability caused by host neutrophils that become activated by substances in donated blood
* Features - hypoxia, pulmonary infiltrates on chest x-ray, fever, hypotension
* Management - stop the transfusion, give oxygen and supportive care
39
Why could CMV be a risk in blood products?
* Cytomegalovirus (CMV) is transmitted in leucocytes
* Most blood products are now leucocyte depleted therefore CMV products are rarely required
* Exception to this is granulocyte transfusions
40
Why are blood products irradiated?
* To deplete them of T-lymphocytes to avoid transfusion associated graft versus host disease (TA-GVHD) caused by viable donor T lymphocytes
41
Which situations require CMV negative blood products?
* Pregnancy: Elective transfusions during pregnancy (not during labour or delivery)
* Neonates up to 28 days post exposure date of delivery
* Intra-uterine transfusions
* Granulocyte transfusions
* HIV?
42
Which situations require irradiated blood products?
* Patients with/previous Hodgkins Disease
* Immunocompromised (e.g. chemotherapy or congenital)
* Bone marrow /stem cell transplants
* Neonates up to 28 days post exposure date of delivery
* Intra-uterine transfusions
* Granulocyte transfusions
* HIV?
43
If a patient refuses a blood transfusion e.g. Jehovah's Witnesses, what are the alternatives that can be offered?
* Intra-operative cell salvage / post-operative cell salvage (may not be acceptable to some Jehovah's Witnesses)
* Anaesthetic techniques such as induced hypotension
* Surgical techniques such as argon beam diathermy
* Radiology guided arterial occlusion (pre or post operative)
* Anti-fibrinolytics such as tranexamic acid
* Clotting promotors such as Desmopressin
* Prothrombin Concentrate Complex e.g. Octaplex to reverse warfarin
* Local haemostatics such as Fibrin glue and sealants (Tisseel)
* Volume expanders such as crystalloids or some colloids
* Pharmaceutical options such as EPO, ferrous sulphate, B12 and / or folic acid
44
What are the risks of receiving a blood transfusion?
* Receiving incorrect blood (normally due to failure of the patient ID check at the bedside) 1/13000
* Contracting HIV 1/5.9 million donations
* Contracting Hep. B 1/2.2 million donations
* Contracting Hep. C 1/39 million donations
* Risk of HTLV (Human T-Lymphotrophic Virus - rare, no cases since before 1996
* Syphilis - extremely low
* Contracting vCJD extremely low 4 cases, the last being 1999
* TAGvHD (transfusion associated graft versus host disease - only 14 cases since 1996
* Context - in the UK there are around 2.6 million units of blood transfused each year
45
How are the risks of transfusion managed?
* Blood is collected from unpaid volunteers who are in good health
* Each donated unit of blood is rigorously tested for: hepatitis B, hepatitis C, HIV, HTLV and syphilis
46
Which types of transfusion is transfusion related lung injury more likely to happen in?
* Plasma rich components such as Fresh Frozen Plasma (FFP) and / or platelets
47
What are the important details to cover when consenting a patient for blood transfusion?
* Is transfusion necessary and why?
* Can anaemia be corrected with iron / B12 / folic acid / EPO?
* Are there alternatives to transfusion for this particular patient?
* Have you stopped anti-coagulants?
* Have you considered Warfarin reversal therapy and or commenced tranexamic acid where necessary?
* Explain how the benefits outweigh the risks of transfusion for this particular patient in this situation?
* Explain the risks of transfusion
* Inform the patient that once transfused they will not be able to donate blood again
* Ensure the patient understands the above
48
What are the clinical features of acute haemolytic reaction to transfusion?
* Agitation, pain (abdominal/chest), flushed, increase temperature, low BP, oozing venepuncture sites, DIC
49
What are the clinical features of non-haemolytic febrile reaction to transfusion?
* (0.5-1 hr after starting transfusion): shivering / high temperature
50
What are the clinical features of anaphylaxis reaction to transfusion?
* Cyanosis, bronchospasm, low BP, soft tissue swelling
51
What are the clinical features of bacterial contamination reaction to transfusion?
* Rapid fever, low BP, rigors
52
What are the clinical features of allergic reaction to transfusion?
* Itch, urticaria, mild temperature rise
53
What are the clinical features of fluid overload reaction to transfusion?
* SOB, hypoxia, tachycardia, raised JVP, bi-basal lung crepitations
54
What are the clinical features of transfusion related lung injury reaction to transfusion?
* SOB, cough, chest x-ray 'white out'
55
What is the management of acute haemolytic reaction to transfusion?
* STOP transfusion
* Check patient details on unit
* Inform haematologist / blood bank
* Send Unit, giving set and FBC (platelets), U and E's (renal failure), clotting (DIC), cultures, urine (HB-uria)
* Keep IV line open with 0.9 % NaCl
* Supportive care
* DIC therapy - Platelets if <50, cryoprecipitate replaces fibrinogen, FFP replaces clotting factors
* Monitor urine output
56
What is the management of non-haemolytic febrile reaction to transfusion?
* STOP/SLOW transfusion
* Give antipyretic (paracetamol 1g)
* Monitor closely (if recurrent, use leucocyte depleted blood or WCC filter
* Exclude bleeding wound
* If no improvement, stop and get senior help
57
What is the management of anaphylaxis reaction to transfusion?
* STOP transfusion
* Maintain airway
* Give 100% O2
* Contact anaesthetist
* Give adrenaline 0.5ml 1:1000 IM
* Give chloramphenamine 10mg IV
* Give hydrocortisone 200mg IV
58
What is the management of a bacterial contamination reaction to transfusion?
* STOP transfusion
* Check the patient details on the Unit
* Inform haematologist
* Send the Unit and giving set
* Send FBC, U and E's, clotting, cultures, urine (Hb-uria)
* Start broad spectrum antibiotics
59
What is the management of an allergic reaction to transfusion?
* STOP/SLOW transfusion
* Give chloramphenamine 10 mg slow IV/IM
* Give hydrocortisone 200mg IV stat
* Monitor closely (more frequent obs)
60
What is the management of a fluid overload reaction to transfusion?
* STOP/SLOW transfusion
* Give O2
* Give diuretic (furosemide 40mg IV initially)
* Consider CVP line and exchange transfusion
61
What is the management of TRALI reaction to transfusion?
* STOP transfusion
* Give 100% O2
* Inform seniors/haematology/ICU (CPAP, mechanical ventilation circulatory support/nutritional support)
* Treat as ARDS
* Monitor ABGs
* Fluid resuscitate
* Remove donor from donor panel
