investigations Flashcards
What are haematinics?
Haematinics are the nutrients needed by the bone marrow to make blood cells in the process of haematopoiesis. Without adequate amounts of these nutrients, cytopenia(s) and related symptoms can develop.
clinical signs of anaemia on examination
General and conjunctival pallor
Atrophic glossitis
Angular cheilitis
Koilonychia (spoon-shaped nails) – less common
What is Ferritin?
Ferritin is an intracellular protein complex that binds iron and is responsible for most iron storage in the body.
How is Ferritin related to iron storage?
Small amounts of ferritin are released into the serum to transport and absorb excess iron and therefore act as a surrogate serum marker for body iron storage.
There is a direct correlation between serum ferritin levels and overall iron stores in health. However, serum ferritin is an acute-phase protein, and so increases in inflammatory states, chronic kidney disease, liver disease, and malignancy.
What level of ferritin indicates IDA?
The British Society for Haematology (BSH) guidelines suggest a serum ferritin level of <15 μg/l is indicative of an iron deficiency in those aged >5 years.
A level of <150 μg/l should act as a trigger to consider further investigations for potential iron deficiency if a patient has a concurrent inflammatory condition (acute or chronic) or renal impairment.
What is transferrin saturation?
Transferrin saturation is the ratio of total serum iron (or the total iron-binding capacity) to transferrin expressed as a percentage.
Transferrin is the primary serum iron transporter molecule in the body. In an iron-deficient state, the body produces more transferrin to increase the total iron-binding capacity and so acquire more iron for its cells.
what would be seen on a blood film in iron deficiency anaemia?
Blood film features which make iron deficiency more likely include anisocytosis, microcytosis, hypochromia, pencil cells, target cells, and elliptocytes.
serum iron….
Serum iron only measures a fraction of the iron in the blood. It can only measure the ferric form (Fe3+) and not the iron incorporated in haemoglobin molecules.
Serum iron levels show diurnal variation and are sensitive to recent iron intake therefore, measuring serum iron in isolation has no role in determining a patient’s iron stores.
What is total iron binding capacity?
The TIBC is calculated by taking a serum sample and adding excess iron to fully saturate the iron carrying molecules.
The TIBC is a measurement of the total iron concentration in the sample when fully saturated.
TIBC can rise in an iron-deficient state, but specificity is poor. Hence, BSH does not recommend routinely using this to assess iron stores.
Transferrin…
Transferrin is the main serum iron transporter molecule which can be measured in a patient’s serum.
Like TIBC, transferrin can rise in iron deficiency as the body tries to increase the total iron-binding capacity. However, transferrin is a negative acute-phase protein and so decreases in inflammatory states.
causes of B12 deficiency ?
Malabsorption: pernicious anaemia, Crohn’s, coeliac disease, gastric/bariatric surgery, atrophic gastritis
Dietary: vegetarians/vegans
Infection: H.pylori, giardia, tapeworm
Infants: congenital causes
What antibodies should you test for in b12 deficiency ?
Anti-intrinsic factor antibodies (Anti-IF)
Anti-gastric parietal cell antibodies
How to interpret a CXR?
Dr S ABCDE
Details - name, DOB, sec, PA/AP, inspiratory, date time
Ripe - assess the image quality
rotation, inspiration (5-6 anterior ribs in MCL or 8-10 posterior ribs above the diaphragm), Picture (straight vs oblique, entire lung fields), Exposure (penetration - IV disc spaces, spinous processes to ~T4, L) hemidiaphragm visible through cardiac shadow.)
Soft Tissue and bones - Ribs, sternum, spine, clavicles – symmetry, fractures, dislocations, lytic lesions, density.
Airway - trachea, paratracheal/mediastinal masses or adenopathy, Carina and RMB and LMB, mediastinal width, aortic know left hilum is usually higher (2cm) and squarer than the V-shaped right hilum.
Breathing - Lung fields
Vascularity, pneumothorax, lung field outlines - abnormal opacity/lucency, atelectasis, collapse, consolidation, bull. Horizontal tissue on the right lung, pulmonary infiltrates, cavitary lesion.
Pleural reflections, pleural thickening
Circulation
Heart size, heart borders, heart shape, aortic shape
Heart borders – R) border is R) atrium, L) border is L) ventricle & atrium
Diaphragm
Diaphragm shape/contour
Cardiophrenic and costophrenic angles – clear and sharp
Gastric bubble / colonic air
Subdiaphragmatic air (pneumoperitoneum)
Extras
ETT, CVP line, NG tube, PA catheters
ECG electrodes, PICC line, chest tube
PPM, AIDC, metalwork
Abdominal XR interpretation?
BBC
Bowel and other organs: small bowel, large bowel, lungs, liver, gallbladder, stomach, psoas muscles, kidneys, spleen and bladder.
Bones: ribs, lumbar vertebrae, sacrum, coccyx, pelvis and proximal femurs.
Calcification and artefact (e.g. renal stones)
how to differentiate small and large bowel types on AXR?
The small bowel usually lies more centrally, with the large bowel framing it.
The small bowel’s mucosal folds are known as valvulae conniventes and are visible across the full width of the bowel.
The large bowel wall features pouches or sacculations that protrude into the lumen, known as haustra. In between the haustra are spaces known as plicae semilunaris. The haustra are thicker than the valvulae conniventes of the small bowel and typically do not appear to completely traverse the bowel. This distinction is unfortunately unreliable as dilated large bowel can have a haustral pattern that does, in fact, traverse the bowel.
Faeces have a mottled appearance and are most often visible in the colon, due to trapped gas within solid faeces.
