CVS IM Flashcards
What does reticulocyte count reflect?
Bone marrow production activity
Benchmark for adequate BM response to mild/moderate anemia?
Above 2.5% correct reticulocyte count
Suggests patient’s anemia is due to blood loss OR hemolytic destruction
What does macrocytic or microcytic anemia suggest?
Reflect RBC maturation defects
What does Normocytic anemia reflect?
Decrease in RBC proliferation
Does haemoglobin level fall with blood loss immediately?
No, only after fluid resuscitation
Fixed amount of RBC is diluted by higher plasma volume
Commonest presentation of chronic blood loss?
Asymptomatic iron-deficient anemia.
Reticulocytes <2.5% and low MCV
Commonest cause of Fe-deficiency is chronic occult GI bleeding, which depletes iron stores. do endoscopy!!!
Etiologies of microcytic anemia?
Iron-deficiency
Thalassemia
Chronic disease
Sideroblastic anemia
Sideroblastic anemia is defective incorporation of iron into heme. Due to lead poisoning/drugs/congenital wtv. Rare!!
How does FBC present if thalassemia is likely in microcytic anemia?
Thalassemia: RBCs are very small with MCV in 60s and uniform (low RDW)
Fe deficiency: MCVs in 70s unless severely deficient, less uniform with higher RDW
What does an inflammatory state do to ferritin?
Inflammation raises ferritin 3x.
In inflammatory state, up to 100mcg/L can mean Fe deficiency
What does transferrin saturation show?
Amount of iron binding to Fe-binding proteins.
Below 16% suggests Fe defiency.
Cut-off is higher for pregnancy, renal disease etc etc
Confirmatory tests for Thalassemia?
Beta = Haemoglobin electrophoresis finds HbF and HbA2
Alpha = Haem electrophoresis shows low HbH
What is Red Cell Distribtion Width?
Measures heterogeneity of cell size in peripheral blood.
Low in thalassemia, high in Iron deficiency
What to exclude for in macrocytic anemia?
Reticulocytosis!
Reticulocytes are larger than mature RBCs, and can raise MCV.
Etiology of B12/folate deficiency?
GI malabsorption (gastrectomy, IBD, ileal resection, pernicious anemia)
Dietary insufficiency in vegans
Etiology of macrocytic anemia?
Megaloblastic anemia - B12 deficiency
Alcohol and NASH
HypoThyroidism
Drugs
Myelodysplastic syndrome
Initial studies for isolated anaemia?
Reticulocytes
Serum creatinine
Calcium
Iron studies
What does profound anemia with very low reticulocyte suggest?
Red Cell aplasia.
Workup usu includes BM aspirate.
Consider what etiologies if renal impairment is present in normocytic anemia?
CKD
Multiple myeloma
2nd line considerations are: Early Fe deficiency, Anaemia of chronic disease, myelodysplasia, idiopathic
How to divide mechanisms of pancytopenia?
BM infiltration
Aplasia
Blood cell destruction
What is in Iron study panel?
Serum iron
Transferrin
Ferritin
Total iron binding capacity
What emergencies to consider in pancytopenia?
Miroangiopathic hemolytic anaemia
Leukemia
Marrow infiltration
Etiology of pancytopenia?
Megaloblastic anaemia
Drugs (e.g. cytotoxic drugs)
Cirrhosis with hypersplenism
Autoimmune conditions
Infection e.g. Malaria, HIV, EBV, hepatitis
Which drugs can cause pancytopenia?
Abx - Linezolid, cotrimoxazole etc
Anti-epileptics
Anti-Thyroid meds
Immunosuppressants
Evidence of mechanical hemolysis?
Presence of schistocytes
Non-MAHA causes of mechanical red cell fragmentation?
Malignant HTN
Hemodynamic turbulence around prosthetic intravascular material e.g. leaky prosthetic valves
March hemoglobinuria
Commonest congenital etiologies of hemolytic anemia?
Thalassemia
G6PD
Sickle Cell disease
Hereditary Spherocytosis
Hypoxia is a physiological trigger of ____?
Hypoxia can trigger raised erythropoietin and polycythaemia.
What is secondary polycythaemia?
Elevated erythryopoietin level drives RBC overproduction
What gene is mutated in Primary polycythaemia?
JAK-2 is mutated in 90% of cases
Complications of Polycythaemia Vera?
Hyperviscosity symptoms
Thrombosis
Bleedin
Transformation to leukemia or secondary myelofibrosis
How to use splenomegaly to differentiate between myeloproliferative disorders?
With splenomegaly = Chronic myeloid leukemia, Primary Myelofibrosis
Without = Polycythemia vera, Myelodysplastic syndromes, Essential Thrombocytosis
Can extreme thrombocytosis cause bleeding?
Yes
Sinus tachycardia is usually a response to?
Usu a response to non-cardiac disease. E.g. pain, infection, hypovolemia, anemia, hyperT, PE, anxiety.
Multifocal atrial tachycardia tends to occur in patients with what comorbids?
Usu in pts with lung disease (e.g. COPD / pneumonia) or heart disease with pulmonary HTN
Endocrine disorders that can case sinus Tachy?
HyperT
Hypoglycemia
Phaeochromocytoma
What is resistant HTN?
HTN above target with optimal doses of 3 anti-hypertensives from different classes, including a diuretic
What is pericardial fat pads?
Normal structures in cardiophrenic angle.
Adipose tissue that surrounds heart.
More prominent in obese patients
NYHA classification for Heart Failure?
Stage 1 = No symptoms, no limits to activitty
Stage 2 = mild symptoms, mild limits to ordinary activity
Stage 3 = Limited activity. Only comfortable at rest
Stage 4 = Severely limited activity. Symptoms even at rest
What is Electrical Alternans on ECG? What condition does it show?
Alternatingly high and low QRS complexes. 1 high, then 1 low.
This means Pericardial effusion or tamponade
What causes Pulsus Paradoxus?
Cardiac tamponade, possibly lesser degree constrictive pericarditis.
Often due to pericardial disease
When diagnosis is uncertain for cardiac chest pain, how often to test ECG and Troponin?
Without certain diagnosis, repeat ECG and Cardiac troponin as often as needed!
Troponin within 2 hrs, ECG as often as every 5 mins if u suspect STEMI
If suspected STEMI, do you wait for troponin to do angiogram?
No!! Troponin takes 4 hrs to rise. Do angiogram asap without caring.
but actl now got super sensitive trops test that detects within 1hr lmao