3. Data interpretation Flashcards
What are the causes of microcytic anaemia?
Microcytic: TAILS
Thalassaemia, Anaemia of chronic disease, Iron-deficiency, Lead poisoning, Sideroblastic)
What are the causes of normocytic anaemia?
Normocytic: Anaemia of chronic disease, acute blood loss, haemolytic, renal failure
What are the causes of macrocytic anaemia?
Macrocytic: B12/folate, alcohol, hypothyroidism, myelo- conditions
What are the causes of high neutrophils?
Bacterial infection
Tissue damage (inflammation, infarct, malignancy)
Steroids
What are the causes of low neutrophils?
Viral infection
Clozapine
Carbimazole
Chemo/radiotherapy
What are the causes of high lymphocytes?
Viral infection
Lymphoma
CLL
What are the causes of high platelets?
Reactive: Bleeding, tissue damage
Primary: Myeloproliferative disorders
What are the causes of low platelets
Reduced production: Drugs (penicillamine), infection, myelo issues
Increased destruction: Heparin, DIC/ITP/TTP/HUS/TTP
What are the causes of hypovolaemic hyponatraemia?
Fluid loss (inc D+V)
Diuretics
Addison’s Disease
Causes of euvolaemic hyponatraemia?
SIADH
Psychogenic polydipsia
Hypothyroidism
Causes of hypervolaemic hyponatraemia?
Heart failure
Renal failure
+ liver/nutritional/thyroid failure
What are the causes of SIADH?
SCLC
Infections
Abscess
Drugs (antipsychotics, carbamazepine)
Head injury
Causes of hypokalaemia?
DIRE
Drugs (loop and thiazide)
Intestinal loss (D+V)
RTA
Endocrine (Cushings and Conns)
Causes of hyperkalaemia?
DREAD
Drugs (ACEIs, K+-sparing)
Renal failure
Endocrine (Addison’s)
Artefact (clotted sample)
DKA (can go hypo once insulin given)
How can you distinguish between pre, intra and post renal AKI?
Prerenal: rise urea > creatinine
Intra: rise creat > urea
Post: rise creat > urea + palpable bladder/hydronephrosis
Causes of pre-renal AKI
Dehydration (inc RAS)
Causes of intrinsic AKI
INTRINSIC
Ischaemia
Nephrotoxics
Radiological contrast
Injury (rhabdomyolysis)
Negative crystals (gout)
Syndromes (glomerulonephritis)
Inflammation
Cholesterol emboli
Causes of post-renal AKI?
Obstructions in lumen, wall or externally
How can severe pre-renal AKI be differentiated from intrinsic/post?
If urea x 10 > creat = severe pre-renal
How can AKI and UGI bleed be differentiated?
UGI bleed will have low Hb
What are the common nephrotoxics?
Renal drugs
NSAIDs
Antibiotics: gent, vanc, tetracylcines
How do you assess hepatic function
Albumin, PT, bilirubin and gluocse
How can pre, intra and post-hepatic jaundice be determined from LFTs
Raised bilirubin for all with
Pre: insignificant rises in both ALT and ALP
Intra: ALT rises > 10x and ALP rises < 3x
Post: ALT rises < 10x and ALP rises >3x
How can LFTs distinguish between pathological and drug induced intrahepatic jaundice?
ALT associated with liver disease
AST associated with alcohol
Causes of pre-hepatic jaundice?
Haemolysis
Causes of intrahepatic jaundice
Damage within the liver (hepatitis, cirrhosis, malignancy)
Causes of post-hepatic jaundice
Obstruction in lumen, wall or surrounding
Distinguish between primary and secondary
a) hypothyroidism
b) hyperthyroidism
a) Low T4 with raised / low TSH
b) High T4 with low / raised TSH
What causes primary and secondary hypothyroidism?
1: Hashimoto’s, drug induced
2: Pituitary pathology
What causes primary and secondary hyperthyroidism?
1: Graves, toxic nodular goitre, drugs
2: Pituitary tumour
What TSH dictates an increase or decrease in levothyroxine
decrease < 0.5-5.5 < increase
How is CXR quality assessed>
PRIM
Projection: AP heart size > PA
Rotation: Distance between clavicles
Inspiration: Is the 7th anterior rib visible?
Markings: additional things the radiographer has seen
Outline the ABCDE approach for CXR interpretation
Airway: trachea, carina, bronchi, hilar
Breathing: Lungs and pleura
Cardiac: Heart size and borders
Diaphragm: inc costophrenic angles
Everything else: bones, soft tissues, tubes, pacemakers etc
How does a normal airway look on CXR?
Trachea central/slightly right
Bronchi division visible, right bronchus stockier than left
What problems can be seen with airways on CXR?
Tracheal deviation: Pushed away (cancer, effusion), towards (tension pneumothorax)
Hilar enlargement: Unilateral (malignancy), bilateral (sarcoidosis)
How do you assess the lung fields?
Check upper middle and lower zones have lung markings throughout
Pleura should be non visible (thickening suggests mesothelioma, reduced extension suggests pneumothorax
How do you assess the heart on CXR
<50% thoracic width on PA, if not then consider congestive, structural or effusion
How do you assess the diaphragm on CXR?
Should be indistinguishable from liver
If separated, free gas could be present so urgent senior review (likely perforation)
Blunted costophrenic angles mean fluid or consolidation
What are the features of pulmonary oedema?
Alveolar oedema
B-lines
Cardiomegaly
Diversion to upper zones (vessels bigger here)
Effusions
How can you differentiate between oedema and pneumonia?
ABCDE and bilateral for oedema, unilateral (usually) for pneumonia
How do you account for Pa02 for someone on O2 therapy?
% O2 -10 = normal kPa
(if on 50% then kPa should be 40)
How can you distinguish between T1 and T2 resp failure?
T1: low/Normal PaCO2 (fast/shallow breathing so blowing off CO2)
T2: High PaCO2 (slow breathing: blue bloaters, NM failure)
Outline how PaCO2, HCO3- and pH are interpreted for acid-base status
Raised PaCO2: resp
Raised HCO3: metabolic
Both up/down + normal pH: compensation
Causes of
Resp acidosis
Metabolic acidosis
Resp alkalosis
Metabolic alkalosis
Resp acidosis: T2RF
Metabolic acidosis: Lactic acidosis, DKA, renal failure
Resp alkalosis: rapid breathing, anxiety
Metabolic alkalosis: vomiting, diruretics, Conn’s Syndrome
How do you manage a paracetamol overdose
Acute: Check normogram after 4hrs + administer NAC if above/fluids if below line
Staggered: NAC
What is INR? What does it indicate?
Patient PT/population PT
Higher means longer clotting time .’. bleed risk
Treat the following INRs for patients on warfarin
<6
6-8
>8
Major bleed (low BP, confined space eg brain, eye)
<6: reduce dose
6-8: Omit 2 days then reduce
>8: Omit + give 1-5mg oral vitamin K
Major: omit + 5-10 vit K IV + PT complex
