Blood - Level 3 Flashcards
Pathology of DIC?
o Widespread activation of coagulation pathways
From release of procoagulants, formation of intravascular thrombi (fibrin)
Depletion of platelets and coagulation factors
• Then increased risk of bleeding
Causes of DIC?
o Malignancy – leukaemia o Sepsis o Trauma o Obstetric events – placental abruption, eclampsia, HELLP o Incompatible blood transfusion o Transplant rejection o Pancreatitis
Signs of DIC?
o Bruising
o Bleeding from at least 3 unrelated sites
o Renal failure – oliguria
o Hypotension
o ARDS
o In chronic/subacute – thrombotic events may dominate - VTE
Bloods in DIC?
o FBC – low platelets
o Clotting – raised PT and APTT, low fibrinogen
o Raised D-dimer
Blood films in DIC?
o Broken RBCs (fragments, paucity of platelets, schistocytes)
What is DIC scoring system?
o Measures platelets, D-dimer, PT, fibrinogen
5 or more – overt DIC – repeat daily
<5 – non-overt DIC – repeat net 1-2 days
Management of DIC - if low risk of bleeding?
o Treat cause
Management of DIC - if high risk of bleeding?
o Treat underlying cause
o Replace platelets
o FFP
2nd line - Cryoprecipitate to replace fibrinogen
o Activated Protein C – severe sepsis and multi-organ failure
Management of DIC - if dominant thrombotic signs?
o Unfractionated Heparin may be used – controversial
Complications of DIC?
o Haemorrhage
o Acute renal failure
o Gangrene and loss of digits
Definition of sickle cell disease?
- Inherited (autosomal recessive) blood disorder in which red blood cells develop abnormally
PAthology of sickle cell disease?
o Mutation in 17th nucleotide of Beta-globin gene changed from thymine to adenine and glutamic acid replaced by valine at position 6 in beta globin chain
o Abnormal beta-globin chain that causes it to polymerize when deoxygenated, which distorts the erythrocyte into a sickle shape
o Deformed erythrocytes form clusters which block blood vessels – damage large and small vessels, sequestered in liver and spleen and cause anaemia, intense pain and infections
What is sickle cell disease and sickle cell trait?
- Sickle cell disease
o Inherit HbS haemoglobin and gene for abnormal haemoglobin variant from other parent (homozygous HbSS, HbSC) - Sickle cell trait
o Inherit HbS haemoglobin and normal HbA haemoglobin (HbAS)
Epidemiology of sickle cell disease?
- Most common haemoglobinopathies
- 1 in every 2000 live births in England, and it is now the most common genetic condition at birth
- Highest prevalence of sickle cell disease is among Black African and Black Caribbean people
- Mortality rate 3% in childhood
Inheritance of sickle cell disease?
- Genetic, autosomal recessive – can be carrier or homogenous
Symptoms of sickle cell disease?
Moderate anaemia, pallor, lethargy, growth restriction with jaundice
Acute crises symptoms of sickle cell disease?
Increased susceptibility to encapsulated organisms (pneumococci, haemophilus influenzae, OSTEOMYELITIS due to Salmonella )
Acute painful Crisis
- Precipitated by cold, dehydration, excessive exercise/stress, hypoxia or infection
- Pain affecting many organs
- Dactylitis with swelling in hands/feet
- Commonest in limbs and spine
Acute chest syndrome
o Severe hypoxia, need ventilation and transfusion
Avascular necrosis
Acute anaemic crises
Priapism
Acute renal impairment
Acute stroke, hemiparesis, speech problems, seizures
Splenomegaly
Investigations in sickle cell disease?
Blood Tests o FBC, reticulocyte count - Blood film o Sickling of red cells
Hb electrophoresis (HPLC)= definitive test
Baseline tests
- U&E, LFT, lung function tests
When to admit acute crisis in sickle cell disease?
- Admission if clinical features of sickle cell crisis and raised temperature
Management of acute crisis in sickle cell disease?
Analgesia within 30 minutes of presentation and monitor
Bolus morphine if severe pain
• Weak opioid if moderate pain
Offer laxative, anti-emetic and antipruritic
Regular paracetamol and NSAIDs in addition
Monitor BP, HR, O2, RR, temperature regularly
Management of acute chest syndrome in sickle cell disease?
o Oxygen
o CPAP
o IV antibiotics
Management of priapism in acute crisis of sickle cell disease?
o Hydration
o Analgesia
o Aspiration and irrigation of corpora cavernosa with adrenaline if prolonged
Management at home if person well with mild pain and no increased temperature - what management measures?
o Avoid other triggers such as cold weather and excessive physical activity.
o Use distraction techniques, such as games, computers, and television
o Increase fluid intake (150% IV or oral)
o Prescribe paracetamol and/or ibuprofen (avoid ibuprofen if the person has renal impairment or significant proteinuria). Add codeine phosphate if these are not effective
o Urgent assessment in hospital if not controlled by these measures
When to screen for sickle cell disease?
- All newborn infant – Guthrie test
- Pregnant women -in high prevalence areas and low prevalence areas if high risk in Family Origins Questionnaire (FOQ)
- High-risk groups undergoing anaesthesia
- Women investigated for infertility