Download Infectious diseases/ Haematology/ Rheumatology/ Dermatology

Infectious diseases/ Haematology/ Rheumatology/ Dermatology
Haematological
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Interpretation of haematological investigations***
Anaemia**
Abnormal haemoglobins*
Disorders of haemostasis and coagulation***
Anticoagulant agents**
Antiplatelet agents**
Neutropaenia**
Thrombocytopaenia**
Thrombocytosis*
Disorders of white cells*
Myelodysplastic disorders*
Paraproteinaemia*
Rheumatology
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Rheumatoid arthritis**
Gout*
Septic arthritis ***
Urgencies and emergencies in systemic rheumatic diseases**
Thoracic and lumbar pain syndromes**
Neck pain*
Shoulder pain*
Tendonitis and tenosynovitis*
Repetitive strain injury and overuse syndromes*
Regional pain syndromes*
Tunnel syndromes*
Complications of drugs used in rheumatic diseases*
Dermatology in emergency care
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Dermatitis and eczema*
Urticarial and allergic rashes**
Viral exanthems*
Macular rashes*
Maculopapular lesions**
Papular and nodular rashes*
Petechial and purpuric rashes**
Vesicular and bullous rashes**
Ulceration*
Cellulitis**
Dermatological manifestations of underlying systemic disease**
Dermatological manifestations of neoplastic disorders*
Infectious disorders
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Universal precautions*
Protection of staff from infectious disease*
Isolation of patients with infectious disease*
Infection control in the ED**
Needlestick injury ***
Vaccination in the ED **
Reportable communicable diseases*
Antibiotic use in the ED**
Outpatient antibiotic therapy**
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Febrile infant management ***
Historical*
SIRS ***
Sepsis, severe sepsis and septic shock ***
Multiple organ dysfunction***
Toxic shock syndrome**
Infections in the returned overseas traveller***
Bacterial - Meningococcal ***. Rest *-**
Viral - HIV and Herpes **. Rest *
Mycoplasma infections*
Fungal infections*
Protozoal infections*
Tick-born infections*
Infections from human bites**
Infections from animal bites**
Infection from a marine source**
Infection in a burns patient**
Biologic weapons*
Haematology
Haematological Investigations
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Hemoglobin - <14g/dl – anemia, >18g/dl – polycythemia
MCHC – elevated in hereditary spherocytosis
Hematocrit = (0.0485 x Hb + 0.083) x 100
Hyperlipemic plasma may elevate Hb falsely
Very high WCC can falsely elevate Hb
Leukocytosis - >11 x 109 /L
Neutrophilia – elevation of neutrophilic fraction of leucocytes, very non-specific finding in ED
Causes
o Hemorrhage
o Drugs/toxins
o Acute stress response
o Infections – toxic cell changes more specific
o Severe pain
o Vomiting
o Inflammation
Lymphocytosis - > 4x109/L
o Causes
o Viral infections – EBV,CMV, HIV, HSV etc
o Other infections – TB, toxoplasmosis, syphilis
o Autoimmune diseases
o >20x109/L usually CLL
o Atypical lymphocytes in EBV sensitive
Eosinophilia
o Causes
o Allergic diseases
o Asthma
o ADR
o Parasitic infections
o Uncommon – Hodgkin’s, vasculitis, primary eosinophilic syndromes
Leukopenia
o Causes
o Pancytopenia due to immunosuppression, aplasia, chemotherapy
o Neutropenia in severe sepsis
The blood film examination
Red cell morphology
 Anisocytosis – unequal cell sizes – macrocytosis
 Poikilocytosis – irregular shapes of RBC – dyserythropoiesis
 Hypochromia – iron deficiency
 Target cells – central loss of staining
o Occurs in
o Severe iron deficiency
o Liver disease
o Sickle cell disease
o Thalassemia
o Post-splenectomy
 Burr cells – spiky projections – uremia and red cell trauma
 Basophilic stipling – RNA granules in cytoplasm, indicated damaged young red cells
o Severe anemia
o Lead poisoning
o Thalassemia
 Polychromasia – reticulocytosis
 Howell-Jolly bodies – remanants of nuclear material – post-splenectomy
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Schistocytes – fragmented RBCs
o Post splenectomy
o DIC
o TTP
o Mechanical trauma – prosthetic valve, march
 Tear drop cells – myelofibrosis, extramedullar hematospoiesis
 Heinz bodies – denatured Hb – hemolytic anemias
White cell morphology
 Toxic granulation – lysosomal granules in neutrophil cytoplasm
 Band forms – unsegmented nuclei
 Leuko-erythroblastic picture – large number of immature precursors
 Causes
o Ca prostate
o Extensive bony metastases
o Myeloma
o Hodgkin’s disease
o Myelofibrosis
o Glycogen storage diseases
Reticulocyte count – raised in
 Hemolytic anemias
 Severe bleeding
 Nutritional anemias recovery
Erythrocyte sedimentation rate – clumping of RBC to form rouleaux in inflammatory states raised in
 Bacterial infection - >30mm/hr
 Normal pregnancy – 80mm/hr
 Anemia
 Rheumatic fever
 Lipidemia
 Hyperfibrogenemia
 Hyperglobulinemia
 Severely raised in – SLE, rheumatoid arthritis, temporal arteritis, polymyalgia rheumatic
Evaluation of Anemia
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Classified into microcytic, macrocytic and normocytic types depending on MCV
Microcytic - <80fl
o Iron deficiency
o Thalassemia
o Sideroblastic anemia
o Multiple myeloma
o Chronic systemic illness
Macrocytic – MCV>100fl
o Vitamin B12 deficiency
o Folate deficiency
o Chronic alcoholism
o Chronic liver disease
o Hypothyroidism
o Myelodysplastic syndrome
o Aplstic anemia
o >115fl – always due to Vitamin B12 or folate deficiency
Normocytic normochromic –
o Early stages of most anemias
o Myelodysplastic syndrome
o Bone marrow infiltration
o Chronic systemic disease
o Prolonged critical illness
o
o
Hemolysis
Congenital – e.g. Diamond-Blackfan syndrome
Hemolytic anemias
Extracorpuscular
defects
Corpuscular
defects
Membrane
defects
spherocytosis
elliptocytosis
Hemoglobinopa
thies
Thalassemia
Enzyme
defects
Autoimmune
Mechanical
G6PD deficiency
Incompatible
blood
transfusion
Long distance
runners
PNH
SLE, RA, UC
prosthetic heart
valves
HbS
Penicillin
lymphoma, CLL
Intravascular Hemolysis
Extravascular hemolysis
• Microangiopathic hemolytic
anemia
• DIC, TTP, HUS, preeclampsia,
vasculitis
• March hemoglobinuria
• Cardiac valve / IABP
• Paroxysmal nocturnal
hemoglobinuria
• Autoimmune diseases
• Rh incompatibility
Laboratory features
 Reticulocytosis – increased MCV
 Heinz bodies seen on film
 Increased unconjugated bilirubin
 Increased LDH
 Decreased haptoglobin
 Presence of methemoglobin in severe cases
Glucose 6-phosphate dehydrogenase (G6PD) deficiency
 X linked inherited disorder – common in African-Caribbean
 Hemolysis due to oxidative stress in presence of low levels of reduced glutathione
 Usual precipitants – drugs and viruses
 Drugs commonly responsible
o Sulphonamides
o Nitrofurantoin
o Anti-malarials
o Methylene blue
o Naphthalene
o Vitamin K
o Aspirin
Petechiae
Palpable petechiae due to
 Vasculitis
 Subacute bacterial endocarditis
 Rheumatoid arthritis
 SLE
 Cryoglobulinemia
Causes of Paetechiae
 Thrombocytopenia
o Platelet dysfunction
 Congenital
 Aspirin, NSAID
 Myeloproliferative disorders
 Dysproteinemia
 Fat embolism
 Small vessel disease
o Infection
 SBE
 Vasculitis
 Meningococcal
 Measles
o Drugs
 Steroids
o Scurvy
 Cushing’s syndrome
 Polyarteritis nodosa
 Henoch Schonlein purpura
Neutropenia
Treatment
 Early recognition and treatment of bacterial infection
 Institution of supportive care to prevent progression to overwhelming sepsis and shock
 Empiric broad-spectrum antibiotic therapy after blood cultures drawn
 Ideally coverage for both gram negative and gram positive organisms; cover for gram positive cocci if
central line in situ
 Ticarcillin/clavulante + aminoglycoside ± Vancomycin
 Addition of anti-fungal if sepsis features continue despite above after 96hrs
Disposition
 Most neutropenic patient with/without fever will require admission
Thrombocytopenia
Decreased production
Increased destruction
Pseudothrombocytopenia
Management:
 ITP
o Immune modulation – IV glucocorticoids and IV Immunoglobulin
o Splenectomy for failure of medical therapy and ongoing bleeding
o Platelet transfusions only in case of life-threatening hemmorhages
 Drug-related
o Withdrawl of drug usually results in prompt recovery
 Thrombotic thrombocytopenic purpura
o Pentad of clinical findings
 Fever
 Thrombocytopenia
 Microangiopathic hemolytic anemia
 Neurologi abnormalities
 Renal involvement
o Causes
 Idiopathic
 Pregnancy
 Verotoxin producing E.coli and Shigella dysentery
 Malignancy
 Chemotherapy, BMT
o Treatment
 Plasma exchange – fall in mortality from 90% to <20%
Hemophilia
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Group of congenital disorders of blood coagulation due to deficiency of clotting factor proteins of
intrinsic coagulation pathway.
Hemophilia A –
o Commoner form (80%), 1-8000 male live births, female carriers
o Deficiency of factor VIII
o X-linked pattern of inheritance
Hemophilia B –
o Less common (20%), 1-25000 live male births
o Deficiency of factor IX (Christmas disease)
o X-linked pattern of inheritance
Severity of disease
o Mild (6-30% activity) – persistent post-op bleeding, spontaneous bleeding does not occur
o Moderate (1-5% activity) – bleeding into joints and muscles post minor trauma + excessive
bleeding after asurgeries
o Severe (<1% activity) – spontaneous joint and muscle bleeding and all of above
Common presentations
o Hemarthrosis – knee, elbows, ankles, shoulders, hips and wrists
o Soft tissue hematomas
o Gum bleeding
o Superficial bruising
o CNS bleeding
o Retroperitoneal bleeding
Investigations
o General investigations in c/o severe bleeding
o Coagulation studies
 PT – measure factor II, VII, V and X activity thus normal
 PTT – measures all factors’ activity but not VIII so may be normal if activity >30%
 Specific factor assays indicated when suspected
Treatment
o R-rest, I-Ice, C-gentle compression bandage, E-elevation, S-splint
o Analgesia – oral and parenteral, PCA (avoid aspirin, NSAID)
o IM injections contra-indicated, limit skin punctures.
o Surgery for compartment syndrome
o Early consultation and multi-disciplinary approach
o If >10% factor VIII activity – desmopressin may be tried, especially if past h/o response
o Follow specialized treatment plans usually available with patient
o Factor VII infusions – 3500IU bolus then 1750 IU 12hrly in severe bleeds, titrate smaller doses
for less severe bleeding after discussions with specialist
Indications for hospital admission – most patients self-administer factor VIII at home
o ICH
o Large bleed or bleed in close compartment – head, neck, throat
o Compartment syndrome
o Analgesis requirements
o Social constraints
o Bleeding in iliopsoas, hip or intra-abdominal
o Antifibrinolytic therapies – tranexamic acid and aminocaproic acid for GI/mucosal bleeding
Blood and blood product transfusions
1 Estimated fluid and blood losses (70Kg man)
2 Guidelines for transfusion of blood products
Adverse reactions to transfusions