Haematology AS Flashcards
What values define anaemia?
Males: Hb 140 (<14g/L)
Females: Hb <120 g/L (<12g/L)
Or 125 g/L (<12.5g/dL) in adults.
What are the symptoms of anaemia?
Fatigue Dyspnoea Faintness Palpitations Headache Tinnitus
What are the signs of anaemia?
Pallor Hyperdynamic circulation - Tachycardia - Flow murmur: apical ESM - Cardiac enlargement
Ankle swelling with heart failure.
What are the causes of a microcyctic anaemia?
Haem defect
- Iron deficiency anaemia
- anaemia of chronic disease (because of reduced iron, inadequate secretion of EPO for erythropoiesis, reduced red cell survival). Ferritin is acute phase reactant. Iron is not released from stores therefore despite having low circulating iron, total iron body stores are increased so transferrin is reduced, meaning TIBC is reduced.
- Sideroblastic/lead poisoning
Globin defect
- Thalassaemia
What are the causes of a macrocytic anaemia?
Megaloblastic
- Vit B12 or folate
- Anti-folate drugs (phenytoin, methotrexate)
- Cytotoxic: Hydroxycarbamide
Non-megaloblastic
- Reticulocytosis
- Alcohol or liver disease
- Hypothyroidism (stimulatory effect of thyroid hormones on erythropoiesis).
- Myelodysplasia
What are the causes of a normocytic anaemia ?
- Recent blood loss
- Bone marrow failure
- Renal failure
- Early ACD
- Pregnancy (increased plasma volume)
In Haemolytic Anaemia what are the signs of increased red cell breakdown?
- Anaemia with increased MCV + polychromasia = reticulocytosis
- Increased unconjugated bilirubin
- Increased urinary urobilinogen
- Increased LDH
- Bile pigment stones
What are the signs of intravascular haemolytic anaemia?
- Haemoglobinaemia
- Haemoglobinuria
- Decreased haptoglobins
- Increased urine haemosiderin
- Increased MCHC
- Methaemalbuminaemia
What sign indicated extravascular haemolytic anaemia?
Splenomegaly (phagocytosis of red blood cells).
What are the acquired haemolytic anaemias?
Immune-mediated DAT +ve
- AIHA: warm, cold,
- Drugs: penicillin, quinine, methyldopa
- Allo-immune: acute transfusion reaction, HDFN.
Non-Immune (DAT -ve) - PNH Mechanical - MAHA: DIC, HUS, TTP - Heart Valve
Infections: Malaria
Burns
Hereditary
- Enzyme: G6PD and pyruvate kinase deficiency
- Membrane: HS, HE
- Haemoglobinopathy: SCD, thalalassaemia
What are the signs of iron deficiency anaemia?
- Koilonychia
- Angular Stomatitis/cheiolsis
- Post-cricoid Web: Plummer-Vinson (IDA, Dysphagia, Oesophageal webs)
What are the causes of IDA?
Increased loss: Menorrhagia, GI bleeding, Hookworms
Decreased intake: Poor diet
Malabsorption: Coeliac, Crohn’s
What are the investigations of IDA?
- MCV
- Reticulocytes
Haematinics:
- decreased ferritin (correlates with iron stores), - increased TIBC (High as this reflects low iron stores),
- decreased transferrin saturation (not saturated as free)
- high transferrin (to bind and carry iron)
Film:
Anisocytosis (size) , poikilocytosis (Shape), pencil cells, hypochromic
Men of any age with a Hb below 110 should be referred for upper and lower GI endoscopy as a 2WW.
- Upper and Lower GI endoscopy
- Coeliac screen
- H.pylori
Management of IDA?
Ferrous Sulphate 200mg PO TDS
IV iron for those with Iron deficiency anaemia prior to surgery when oral iron can’t be tolerated or not enou
- SE: GI upset
What is sideroblastic anaemia
- Body has enough Iron, but unable to make haemoglobin.
- Ineffective erythropoiesis
- Increased iron absorption
- Iron loading in BM –> ringed sideroblasts. (Granules of iron in mitrochondria)
- Haemosiderosis: endo, liver, cardiac damage.
What are the causes of sideroblastic anaemia
Congenital
Acquired
- Myelodysplastic/myeloproliferative disease
- Drugs: Chemo, anti-TB, lead.
What are the investigations for Sideroblastic anaemia?
- Microcytic anaemia not responsive to oral iron
- Increased ferritin, increased serum iron, normal TIBC
Management of sideroblastic anaemia?
Remove cause
- Pyridoxine may help
What is the pathophysiology of Thalassaemia?
Point mutations/deletions –> Unbalanced production of globin chains
–> Precipitations of unmatched globin
Membrane damage –> haemolysis while still in BM and removal by the spleen.
What is the epidemiology of thalassaemia?
Common in Mediterranean and Far East (Egyptian girl/Greek man)
What is B-Thalassemia Trait?
- B normal/B + or B/B0 (no production).
- Mild anaemia usually harmless.
- Decreased MCV (too low for the anaemia) - <75
- Increased HbA2 (a2delta 2) and increased HbF (a2y2).
- HbA2 (>3.5%)
However, there is no history to suggest this and the microcytosis is disproportionately low for the haemoglobin level. This combined with a raised HbA2 points to a diagnosis of beta-thalassaemia trait
Normally seen when fetal haemoglobin transitions to adult haemoglobin.
What is B-Thalassaemia Major?
- Ineffective B-chain therefore severe deficiency in most red-blood cells.
- Features develop from 3-6 months:
Severe anaemia
Jaundice
Failure to Thrive
Extramedullary erythropoiesis - Frontal bossing
- Maxillary overgrowth
- Hepatosplenomegaly
Haemachromatosis after 10yr (transfusion)
What are the investigations for B-thalassaemia major
- Decreased Hb (microcytic) - haemoglobin problem.
- Decreased MCV
- Very high HbF
- V high HbA2
- High reticulocyte
Film: Target cells (Thalassaemia) and nucleated RBC
Electrophoresis
- Fast migrating are Hb H and Barts.
Management of B-Thall major?
- Life-long transfusion
- SC- desferrioxamine Fe Chelation
- Splenectomy
- BM transplant may be curative
What is a-thalassaemia trait?
–/aa or a-/a-
Asymptomatic
Hypochromic microcytes
What is HbH disease
–/a-
Moderate anaemia: May need transfusion
Haemolysis: HSM, jaundice
What is Hb Barts
–/–
Hydrops fetalis –> Death in utero
What is the investigations for macrocytic anaemia?
Film
- B12/Folate
Hypersegmented polymorphonuclear leucocyte
Oval macrocytes
- Alcohol/Liver
Target cells.
Blood
- LFTS: mild increased bili in B12/folate deficiency
- TFTs
- Se B12 (<200 pg/ml deficiency)
- Red Cell Folate: reflects body stores over 2-3 months.
- Normally low reticulocytes
Biopsy
- If cause not revealed by above tests
Megaloblastic erythropoiesis
Giant metamyelocytes
What are sources of folate?
Green veg, nuts and liver
How long do you have stores of folate?
4 months
Where is folate absorbed
Proximal jejunum
Causes of folate deficiency?
- Decreased intake (poor diet)
- Increased demand
Pregnancy
Haemolysis
Malignancy - Malabsorption
Coeliac
Crohn’s - Drugs
EtOH
Phenytoin
Methotrexate
Management of folate deficiency?
- Assess for underlying cause
- Give B12 first unless B12 level known to be normal
May precipitate or worsen SACD - Folate 5mg/d PO.
What are the sources of B12?
Source: meat, fish and dairy (vegans get deficiency)
Stores: 4 yrs
Absorption: Terminal ileum bound to intrinsic factor (released from gastric parietal cells).
Role: DNA and myelin synthesis.
What are the causes of B12 deficiency?
Decreased Intake - Vegan
Decreased intrinsic factor: Pernicious anaemia, post-gastrectomy
Terminal ileum - Crohn’s ileal resection, bacterial overgrowth.
What are the features of B12 deficiency?
General
- Symptoms of anaemia
- lemon tinge: pallor + mild jaundice
- glossitis (beefy, red tongue)
Neuro
- Paraesthesia
- Peripheral neuropathy
- Optic Atrophy
- SACD
What is subacute combined degeneration of the cord?
- Usually only caused by pernicious anaemia
- Combined symmetrical dorsal column loss and corticospinal tract loss.
–> Distal sensory loss: esp joint position and vibration
Leads to ataxia with wide-gait and +ve Romberg’s test (balance and closing eyes)
What neuro signs do you see in SACD?
Mixed UMN and LMN signs
- Spastic paraparesis
- Brisk knee jerks
- Absent ankle jerks
- Upgoing plantars
Pain and temperature remain intact
What are the investigations to do for B12 Deficiency?
- May have decreased WCC and plats if severe
- Serum B12
- Intrinsic factor Abs: specific but lower sensitivity
- Parietal cells Abs: 90% +ve in PA but less specific.
Management of B12 deficiency ?
- Malabsorption –> parenteral B12 (hydroxocobalamin)
- Replenish: 1mg/48hr IM
- Maintain: 1mg IM every 3 months.
- Dietary –> oral B12 (cyanocobalamin)
- Parenteral B12 reverses neuropathy but not SACD (injection)
Pernicious Anaemia what is it?
- Autoimmune atrophic gastritis caused by autoabs vs parietal cells or IF –> achlorhydria and decreased IF.
- Usually >40yr, increased incidence with blood group A
Associated
- AI: thyroid disease, Vitiligo
- Ca: 3 risk of gastric adenocarcinoma
What are the AutoImmune Haemolytic Anaemias?
Warm = Due to SLE, RA.
Cold
Paroxysmal Cold Haemoglobinuria
Drug: methyldopa, penicillin
What is warm AIHA?
- IgG mediated bind @ 37 C
- Extravascular haemolysis and spherocytes where it is warm. Occur in the spleen.
- Ix: DAT +ve, raised LDH = haemolytic anaemia.
- Causes: idiopathic, SLE, RA, CLL
- Management: immunosuppression, splenectomy
What is cold AIHI?
- IgM-mediated, binds @ <4C.
- Often fix complement –> intravascular haemolysis
- May cause agglutination –> acrocyanosis or Raynaud’s
- Ix: DAT +ve for complement alone. Causes a macrocytosis due to reticulocytosis.
- Causes: idiopathic, mycoplasma, background of lymphoma is a risk factor.
- Rx: avoid cold, rituximab.
What is paroxysmal nocturnal haemaglobinuria?
- Absence of RBC anchor molecule (GP1) –> decreased cell-surface complement degradation proteins –> Intravascular Lysis. (activation of complement on blood cells lacking Complement defence proteins) - exaggerated at night.
- Affects stem cells and therefore may also –> Decreased platelets and decreased PMN.
What are the features of PNH?
Visceral venous thrombosis (hepatic, mesenteric, CNS) - Budd-Chiari,
- IV haemolysis and haemoglobinuria
What are the investigations of PNH?
- Anaemia + thrombocytopenia ± neutropenia
- FACS: decreased CD55 and Decreased CD59
Management of PNH?
- Chronic disorder therefore long-term anticoagulation
- Eculizumab (prevents complement MAC formation) and controls haemolysis
- RBC transfusion for underlying aplastic anaemia
- Erythropoiesis stimulation+ iron tabs.
What are the key features of HUS?
E.coli O157
- Bloody diarrhoea + abdo pain precedes:
- MAHA
- Thrombocytopenia
- Renal failure
Ix: Schistocytes, decreased platelets, normal clotting.
Rx:
- Usually resolves spontaneously
- Exchange transfusion or dialysis may be needed.
What is Thrombotic Thrombocytopenia Purpura (TTP)
Genetic or acquired deficiency of ADAMTS13
Leads to unusually large VWF multimers - lead to platelet aggregation + Subsequent thrombocytopenia.
- Features Adult females Pentad: Fever CNS sign: confusion, seizures MAHA Thrombocytopenia Renal failure
Ix: schistocytes, decrease platelets, normal clotting
Management - Plasmapheresis, immunosuppression, splenectomy.
What is hereditary spherocytosis?
Commonest inherited haemolytic anaemia in N.europe
Pathophysiology of HS?
- Autosomal dominant defect in RBC membrane.
- Spherocytes get trapped in spleen –> Extravascular haemolysis.
What are the features of HS?
Splenomegaly
Pigment gallstones
Jaundice
Complications of HS?
Aplastic crisis
Megaloblastic crisis
- Leads to a haemolytic criss. Can be caused by erythema infectiosum - due to parvovirus.
What are the investigations of HS?
- EMA binding test - amount of fluorescence derived from individual red cells.
- Increased osmotic fragility test no longer recommended.
Normally clinical with spherocytes, raised MCHC. - Spherocytes
- DAT -ve
What is the management of HS?
Folate and splenectomy (after childhood). This is primarily an extravascular haemolysis therefore splenomegaly.
What is hereditary eliptocytosis?
Autosomal dominant defect –> elliptical RBCs
Most pts are asymptomatic
Rx: folate, rarely splenectomy
G6PD deficiency - pathophsyiology?
- X-linked disorder of pentose phosphate shunt
- decreased NAPDH production - RBC oxidative damage
- Affects mainly mediterranean and mid/far east.
- Therefore turkish and G6PD.
What are the triggers for G6PD
Broad (Fava) beans
Mothballs (naphthalene)
Infection
Drugs: antimalarials, dapsone, henna, sulphonamides.
Made worse by fava beans, beans means Heinz and you bite beans so you get bite cells.
Invx for G6PD?
Film
- Irregularly contracted cells
- Bite cells
- Heinz bodies (haemolytic anaemia)
- May have spherocytes as a result of MAHA.
G6PD assay after 8 weeks (reticulocytes have high G6PD).
What is the management of G6PD?
- Treat underlying problem
- Stop and avoid precipitant
- Transfusions may be needed.
What is pyruvate kinase deficiency?
AR defect in ATP synthesis
–> rigid red cells phagocytosed in the spleen
triggers in times of stress.
Features: Splenomegaly, anaemia ± jaundice
Ix: PK enzyme assay
Rx: often not needed or transfusion ± splenectomy
What is Sickle Cell anaemia
- Point mutation in B globin gene –> Glu to valine.
SCA: HbSS
Trait: HbAS - HbS insoluble when deoxygenated –> Sickling
- Sickle cells have decreased life-span –> haemolysis
- Sickle cells gets trapped in microvascular –> Thrombosis
What are the investigations for SCD?
- Hb 6-9, increased reticulocytes, increased bilirubin. Therefore low haemoglobin, normal MCV, raised reticulocytes. Normocytic anaemia as destruction
- Film: Sickle cells and target cells. Howell-Jolly Bodies.
- Hb electrophoresis
Dx at birth with neonatal screening.
Triggers in Sickle Cell Disease
- Clinical features manifest from 3-6 months due to decreased HbF
- Triggers
Infection
Cold
Hypoxia
Dehydration
Presentation in SCD?
Splenomegaly: may –> sequestration crisis
- Infarction: stroke, spleen, AVN, leg ulcers, BM
- Crises: pulmonary, mesenteric, pain
Thrombotic crises
- Painful or vaso-occulisve crises due to infection, dehydration deoxygenation.
- Infarcts occur in various organs including the boen (avascular necrosis of hip, hand-foot syndrome, lungm spleen)
Sequestration crisis
- Sickling within organs such as spleen or lungs poolign blood with worsening anaemia.
Acute chest syndrome
- Dyspnoea, chest pain, pulmonary infiltrates, low pO2.
Most common cause of death after childhood.
Aplastic crises
- Sudden fall in haemoglobin, associated with parvovirus
Haemolytic crisis
- Rare
- Fall in haemoglobin due to icnreased ate of haemolysis.
- Kidney Disease
- Liver, lung disease
- Erection
- Dactylitis
Complications of Sickle Cell disease?
Sequestration crisis
- Splenic pooling –> Shock and severe anaemia (trapping of RBC)
- Splenic infarction:atrophy
- Increased infection: osteomyelitis
- Aplastic crisis: due to parvovirus B19 infection
- Gallstones
Management of Chronic SCD?
- Pen V BD prophylaxis + immunisations
- Folate
- Hydroxycarbamide if frequent crises (in children). Shown to decrease frequency of pain episodes.
- Consider bone marrow transplant
- Blood
Management of an acute crises?
General
- Analgesia: opioids IV
- Good hydration
- O2
- Keep warm
Investiation
- FBC, U+E, reticulocytes, cultures
- Urine Dip
- CXR
Management
- Blind Abx: ceftriaxone
- Transfusion: Exchange if severe
What pathway does APTT test and which factors?
Intrinsic: 12,11,9,8. Common: 10, 5, 2, 1 Assessing secondary haemostasis Increased: - Lupus anticoagulant (Anti-PL) - Haemophilia A or B - vWD (carries factor 8) - Unfractionated heparin - DIC - Hepatic failure
Which pathway does PT test and which fators?
Extrinsic: 7
Common: 10, 5, 2, 1
Increased:
- Warfarin/ Vit K deficiency
- Hepatic failure
- DIC
What does the Bleeding Time test?
Platelet function - primary haemostasis - Increased in: Decreased platelet numbers or function -vWD - Aspirin - DIC
What does Thrombin time test?
Fibrinogen function - Increased Quantitive/qualitative fibrinogen defect - DIC, dysfibrinogenaemia - Heparin
What are the features of a vascular or platelet disorder?
Bleeding into skin: petechiae, purpura, ecchymoses.
Bleeding mucus membranes: Epistaxis, menorrhagia, gums.
Immediate, prolonged bleeding from cuts.
What are the features of coagulation disorders?
- Deep bleeding: muscles, joints, tissues.
- Delayed but severe bleeding after injury.
What are congenital vascular disorders?
HHT
Ehler’s Danlos (Easy bruising)
Pseudoxanthoma elasticum (elastic fibre disorder)
What are the acquired vascular disorders
Vasculitis e.g HSP Steroids Infection e.g meningococcus Vit C deficiency Senile purpura
How can you classify platelet disorders?
Thrombocytopenia
- Increased destruction
- Decreased production
- Spleening pooling
Functional defects
What causes a decreased production of platelets?
- BM failure: aplastic, infiltration of bone marrow, drugs (ETOH, cyto) )
- Megaloblastic anaemia
What causes increased destruction of platelets?
- Immune: ITP, SLE, CLL, heparin, Viruses.
- Non-immune: DIC, TTP, HUS, PNH, anti-phospholipid
What causes splenic pooling leading to thrombocytopaenia?
Portal HTN
SCD
Which anticoagulant do you give for ACS?
1st line: Aspirin (lifelong) and ticagrelor 12months
2nd line: if CI aspirin, given clopidogrel lifelong
Which anticoagulant do you give for PCI?
1st line: Aspirin (lifelong) and ticagrelor 12months or prasurgrel
2nd line: if CI aspirin, given clopidogrel lifelong
Which anticoagulant do you give for TIA?
1st line: Clopidogrel
2nd line: aspirin and dipyridamole
Which anticoagulant do you give for Ischaemic Stroke?
1st line: Clopidogrel
2nd line: aspirin and dipyridamole
Which anticoagulant do you give for Peripheral arterial disease?
1st line: Clopidogrel (lifelong)
2nd line: Aspirin (lifelong)
What is Immune thrombocytopenia purpura?
Children: commonly post
Acute: More commonly seen in children, equal sex incidence, may follow an infection or vaccination, usually runs a self-limiting course over 1-2 weeks.
Chronic ITP: more common in young/middle-aged women. Tends to run a relapsing-remitting course.
Evan’s syndrome: ITP in association with autoimmune haemolytic anaemia (AIHA).
- URTI, self-limiting.
- Adults:F>M, long-term
- Ix: Anti-platelets Abs present
- Management is conservative with steroids if necessary, consider IVIG/Splenectomy.
What platelet functional defects can lead to a bleeding diatheses?
Drugs: aspirin, clopidogrel 2ndry: paraproteinaemia, uraemia Hereditary - Bernard-Soulier: GpIb deficiency - Glanzmann's: GpIIb/IIIa deficiency.
What can cause an acquired coagulation disorder?
- Severe liver disease
- Anticoagulants
- Vitamin K deficiency
What is Haemophilia A: F8 deficiency
No Factor 8
- X-linked, affects 1/5000 males
- Presentation: Hemarthrosis, bleeding after surgery/extraction.
- Ix: Increased APTT, normal PT, decreased F8 assay.
- Mx
Avoid NSAIDs and IM injection
Minor bleeds: desmopressin + transexamic acid (control mucosal bleeding - antifibrinolytic)
Major bleeds: rhF8.
What is Haemophilia B: F9 deficiency?
No Factor 9
X-linked 1/20,000 males.
Consider infusion of IX concentrate.
Antifibrinolytic and pain medication.
What is vWD?
- Commonest inherited clotting disorder (mostly AD)
- vWF
Stabilised F8
Binds pats via GpIb to damaged endothelium.
Ix: If mild, APTT and bleeding time may be normal.
- Increased APTT, Increased Bleeding Time, normal platelets, decreased vWF AG.
Management - Desmopressin and tranexamic acid. Consider VIII concentrate.
What is the presentation of DIC?
Acquired syndrome - activation of coagulation pathways, resulting in formation of intravascular thrombi + depletion of platelets + coagulation factors.
Coagulation = fibrinogen to fibrin = fibrin clot.
Fibrinolytic system = breaks down fibrinogen + fibrin. Through generating plasmin in the presence of thrombin to cause lysis of the clot.
Once DIC is triggered, TF present on surface of many cells and is not normally in contact with circulation. When exposed to cytokines lead DIC due to TF binding with coagulation fator + triggering extrinsic pathway.
Thrombin leads to vascular obstruction.
Thrombosis and Bleeding
- Increased PT, increased APTT, increased TT, decreased platelets, decreased fibrinogen, increased FDP.
- Schistocytes (MAHA)
- Thrombosis and bleeding
- Causes: Sepsis, malignancy, trauma, obs.
- Management: FFP, Platelets, heparin.
What is the definition of thrombophilia?
Coagulopathy predisposing to thrombosis, usually venous.
What are the inherited coagulopathies?
Factor V Leiden
Prothrombin gene mutation
Protein C and S deficiency
Antithrombin III deficiency
What is Factor V Leiden
Most common thrombophilia - present in 5% of UK population.
Gain of function mutation in the Factor V Leiden protein. Results in a mis-sense mutation means that Factor V is inactivated 10 times more slowly by activated protein C. (activated Protein C resistance). Resistance to action of protein C.
Heterozygotes have 4-5x risk of VTE.
Homozygotes have 10x risk of venous thrombosis.
Protein C and S deficiency?
Heterozygotes for either have increased risk of thrombosis
- Skin necrosis occurs - especially with warfarin.
Heterozygotes –> neonatal purpura fulminans.
Antithrombin III deficiency?
- AT is heparin co-factor –> thrombin inhibition
- Deficiency affects 1/500.
- Heterozygotes have high risk of thrombosis risk.
- Homozygosity is incompatible with life.
Acquired thrombophilia from where?
- Progesterone in OCPs, HRT, raloxifen, tamoxifen, antipsychotic (olanzapine).
- Anti-phospholipid syndrome CLOTs: venous and arterial Coagulation defect: - increased APTT - Livido reticularis - Obstetric complications: recurrent 1st trimester abortion - Thombocytopenia.
Indications for a thrombophilia screen?
- Arterial thrombosis <50yrs
- Venous thrombosis <40yrs with no RFs
- Familial VTE
- Unexplained recurrent VTE
- Unusual site: portal, mesenteric
- Recurrent foetal loss
- Neonatal
Investigations for thrombophilia screen?
- FBC, clotting, fibrinogen concentration.
- Factor V Leiden, APC resistance
- Pupus anticoagulant and anti-cardiolipin As
- Assays for AT, protein C and S deficiency
- PCR for prothrombin gene mutation
What is the management of thrombophilia?
- Manage acute thrombosis as per normal
- Anticoagulate to INR 2-3
- Consider lifelong warfarin
- If recurrence occurs on warfarin increased INR to 3-4.
How do you prevent thrombophilia?
- Lifelong anticoagulation not needed if asymptomatic
- Increased VTE risk with OCP or HRT
- Prophylaxis in high risk situations
Surgery
Pregnancy
What products can you use for blood transfusion?
- Packed Red cells
- Fresh Frozen Plasma
- Cryoprecipitate
- Platelet rich plasma
- Platelet concentrate
- Human Albumin Solution
What are packed red cells used for?
- Stored @ 4C. Less chance of developing an infection.
- Hct ~70%
- Use to correct anaemia or blood loss (cases where infusion of large volumes of fluid may result in cardiovascular compromise)
- 1u → ↑Hb by 1-1.5g/dL
What is platelet rich plasma used for?
- Usually administered to patients who are thrombocytopaenic and are bleeding or require surgery. It is obtained by low speed centrifugation.
What are platelet concentrate used for?
- Not needed if count >20 or not actively bleeding
- Should be x-matched.
- Stored at room temperature and must be used soon after collection. Puts them at risk of culturing gram positive organisms.
Administered to patients who are thrombocytopenic.
What is FFP?
- Prepared from single units of blood.
- Contains clotting factors, albumin and immunoglobulin.
For patients with pT or APTT >1.5. - Unit is usually 200 to 250ml.
- Usually used in correcting clotting deficiencies in patients with hepatic synthetic failure who are due to undergo surgery, TTP, DIC.
- Usual dose is 12-15ml/Kg-1.
It should not be used as first line therapy for hypovolaemia. - Universal donor for FFP is AB blood because it lacks any anti-A or anti-B.
What is cryoprecipitate?
- Formed from supernatant of FFP.
- Used to replace fibrinogen <1.5g/L.
- Rich source of Factor VIII and fibrinogen, vWF, Factor XIII and fibronectin.
- Allows large concentration of factor VIII to be administered in small volume.
- EG - DIC, liver failure. Emergency for haemophiliacs and von Willebrand.
What blood products can be used in the reversal of warfarin?
- Stop Warfarin
- Vitamin K (reverse in 4-24hrs) (IV = 4-6hr, Oral = 24hr).
- 1st line: Human prothrombin complex (reversal within 1hr, Bereplex. Rapid action byt factor 6 short half life, therefore give with Vit K.
- FFP (less commonly 1st line). Need to give at least 1L of fluid in 70kg person.
What are the immediate transfusion reactions?
- Haemolytic
- Bacterial Contamination
- Febrile Non-haemolytic
- Allergic
- TRALI
- Fluid Overload
- Massive Transfusion
What is a haemolytic transfusion reaction?
- Occurs in: Minutes
- Clinical features:
Agitation, fever, abdo/chest pain, decreased BP, DIC (haemorrhage) renal failure. - Mechanism: ABO incompatibility –> IV haemolysis
- Management: Stop transfusion, tell lab, keep IV line open with NS generous saline, treat DIC.
What is the sign of bacterial contamination in a transfusion?
- Occurs in: <24hrs
- Clinical features: Increase in temp and rigors. BP down because of shock.
- Mechanism: Bacterial proliferation, esp platelets.
- Management: Stop transfusion, send unit to lab, Abx: Taz + gent.
What is febrile non-haemolytic transfusion reaction?
- Occurs in: <24hrs
- Clinical features: Fever, rigors, chills.
- Mechanism: Recipient anti-HLA abs.
- Management: Slow transfusion, Paracetamol 1g.
What is allergic transfusion reaction?
- Occurs in: Immediate
- Clinical features: Urticaria, itch, angioedema, anaphylaxis
- Mechanism: Recipient IgA deficiency Anti-IgA IgE
- Management: Slow, chlorphenamine 10mg IV/IM
Urticaria = antihistamine.
More severe allergic reaction = discontinue transfusion, IM adrenaline. Then antihistamine, corticosteroids and bronchodilators should be considered in these patients.
What is TRALI? Transfusion-related acute lung injury?
- Occurs in: <6hr
- Clinical features: ARDS, SOB, cough, bilateral infiltrates on CXR, fever, hypotension. - KEY IS HYPOTENSION
- Mechanism: Anti-WBC Abs in donor plasma.
- Management: Stop transfusion, manage ARDS.
What is TACO (Transfusion associated circulatory overload)
- Occurs in: <6hr
- Clinical features: CCF. Pulmonary oedema the patient may also by hypertensive, key difference from patients with TRALI.
- Mechanism:
- Management: Slow transfusion + 02 + frusemide 40mg IV
What are the delayed transfusion reactions?
Delayed haemolytic
Fe Overload
Post-transfusion purpura
GvHD
What is delayed haemolytic transfusion reaction?
- Occurs in: 1-7d
- Clinical features: Jaundice, Anaemia, decreased Hb, Fever, ± Haemoglobinuria.
- Mechanism: Recipient anti-Ph Abs + Extravas haemolysis.
- Management:
What is the Fe Overload symptoms?
- Occurs in: Chronic
- Clinical features: SCA or Thal Major, Haemochromatosis
- Mechanism: Chronic Transfusion:
- Management: Desferrioxamine SC