data interpretation

Question 1

Causes of microcytic (low MCV) anaemia

Answer 1

• Iron deficiency anaemia
• Thalaseamia
• Sideroblastic anaemia

Question 2

Causes of normocytic (normal MCV) anaemia

Answer 2

• **Anaemia of chronic disease
• acute blood loss**
• haemolytic haemia
• renal failure (chronic)

Question 3

Causes of macrocytic (high MCV) anaemia

Answer 3

• **B12/folate deficiency
• Excess alcohol
• liver disease**
• hypothyroidism
• haematological diseases beginning with ‘M”: myeloproliferative, myelodyspastic and multiple myeloma

Question 4

causes of hypokalaemia

Answer 4

DIRE:
* drugs (loop and thiazide diuretics)
* Inadequate intake or intestinal loss (diarrhoea or vomiting)
* renal tubular acidosis
* Endocrine (Cushings and Conns syndromes)

Question 5

Causes of hyperkalaemia

Answer 5

DREAD:
* Drugs (potassium sparing diuretics and ACEi)
* Renal failure
* Endocrine (addisons)
* Artefact (due to clotted sample)
* DKA

Question 6

causes of hypernatraemia

Answer 6

causes all begin with ‘d’:
* dehydration
* drips (i.e. too much IV saline)
* drugs (e.g. effervescent tablet preparations or intravenous preparations with a high sodium content)
* diabetes insipidus (which is effectively the opposite of syndrome of inappropriate antidiuretic hormone (SIADH).

Question 7

High neutrophils causes

Answer 7

• Bacterial infection
• tissue damage (inflammation/infarct/malignancy)
• steroids

Question 8

low neutrophils causes

Answer 8

• viral infection
• chemotherapy or radiotherapy
• Clozapine (antipsychotic)
• Carbimazole (antithyroid)

Question 9

high lymphocytes

Answer 9

• viral infection
• lymphoma
• chronic lymphocytic leukaemia

Question 10

causes of low platelets (thrombocytopenia)

Answer 10

Reduced production:
* infection (usually viral)
* drugs (esp. penicillamine (e.g. in rheumatoid arthritis treatment))
* myelodysplasia, myelofibrosis, myeloma

Increased destruction:
* heparin
* hypersplenism
* disseminated intravascular coagulation (DIC)
* idiopathic thrombocytopenic purpura (ITP)
* haemolytic uraemic syndrome/thrombotic thrombocytopenic purpura

Question 11

causes of high platelets (thrombocytosis)

Answer 11

Reactive:
* bleeding
* tissue damage (infection/inflammation/malignancy)
* postsplenectomy

Primary:
* myeloproliferative disorders

Question 12

Causes of hyponatraemia

Answer 12

Fluid status:

Hypovolaemic
* Fluid loss (especially diarrhoea/vomiting)
* Addisons disease
* Diuretics

Euvolaemia
* SIADH
* Psychogenic polydipsia
* hypothyroidism

Hypovolaemic
* Heart failure
* Renal failure
* Liver failure
* Nutritional failure
* thryoid failure

Question 13

raised urea indicated

Answer 13

AKI or upper GI haemorrhage (normal creatinine in the latter)

Question 14

Biocehmical disturbance in prerenal AKI (70%)

Answer 14

Urea rise&raquo_space;creatinine rise,
e.g.: Urea 19 (3–7.5 mmol/L), Creatinine 110 (35–125 μmol/L)

Question 15

Causes of pre-renal AKI

Answer 15

Dehydration (or if severe, shock) of any cause, e.g. sepsis, blood loss.
Renal artery stenosis (RAS)

Question 16

biocehmical abnormalities in intrinsic renal AKI

Answer 16

Urea rise «creatinine rise, bladder or hydronephrosis not palpable,
e.g.: Urea 9 (3–7.5 mmol/L) Creatinine 342 (35–125 μmol/L)

Question 17

causes of intrinsic AKI (10%)

Answer 17

INTRINSIC:
* Ischaemia (due to prerenal AKI, causing acute tubular necrosis)
* Nephrotoxic antibiotics ∗∗
* Tablets (ACEI, NSAIDs)
* Radiological contrast
* Injury (rhabdomyolysis)
* Negatively birefringent crystals (gout)
* Syndromes (glomerulonephridites)
* Inflammation (vasculitis)
* Cholesterol emboli

Question 18

nephrotoxic antibiotics

Answer 18

gentamicin, vancomycin and tetracyclines

Question 19

biochemical abnormalities in postrenal AKI (20%)

Answer 19

Urea rise «creatinine rise, bladder or hydronephrosis may be palpable depending on level of obstruction,
e.g.: Urea 9 (3–7.5 mmol/L) Creatinine 342 (35–125 μmol/L)

Question 20

causes of postrenal AKI

Answer 20

In lumen: stone or sloughed papilla

In wall: tumour (renal cell, transitional cell), fibrosis

External pressure: benign prostatic hyperplasia, prostate cancer, lymphadenopathy, aneurysm

Question 21

Causes of raised ALP

Answer 21

A raised alk phos does not necessarily indicate posthepatic jaundice; common causes may be remembered using the mnemonic ALKPHOS:
* Any fracture
* Liver damage (posthepatic)
* K (for kancer)
* Paget’s disease of bone and Pregnancy
* Hyperparathyroidism
* Osteomalacia
* Surgery.

Question 22

pattern of LFT derangement in prehepatic

Answer 22

increased bilirubin, normal AST/ALT

Question 23

prehepatic causes

Answer 23

• Haemolysis
• Gilberts and Crigler-Najjar syndromes

Question 24

pattern of LFT derangement in intrahepatic

Answer 24

• increased bilirubin
• increased AST/ALT

Question 25

Causes of intrahepatic

Answer 25

* Fatty liver * Hepatitis ∗ * Cirrhosis ∗ * Malignancy (primary or secondary) * Metabolic: Wilson’s disease/haemochromatosis * Heart failure (causing hepatic congestion)

Question 26

LFT derangement in posthepatic

Answer 26

* increased bilirubin * increased ALP * normal AST/ALT

Question 27

Causes of posthepatic

Answer 27

In lumen: stone (gallstone), drugs causing cholestasis ∗∗ In wall: tumour (cholangiocarcinoma), primary biliary cirrhosis, sclerosing cholangitis Extrinsic pressure: pancreatic or gastric cancer, lymph node

Question 28

primary hypothyroidism TFTs

Answer 28

* T4 decreased * TSH increased

Question 29

causes of primary hypothyroidism

Answer 29

* hashimotos * drug induced

Question 30

TFTs in secondary hypothyroisism

Answer 30

* decreased t4 * decreased TSH

Question 31

# causes causes of secondary hypothyroidism

Answer 31

pituitary tumour or damage

Question 32

primary hyperthyroidism TFTs

Answer 32

* high t4 * low tsh

Question 33

causes of primary hyperthyroisism

Answer 33

* graves disease * toxic nodular goiter * drug induced

Question 34

secondary hyperthyroidism TFTs

Answer 34

* high 4 * high tsh

Question 35

causes secondary hyperthyroidism

Answer 35

pituitary tumour

Question 36

change in levothyroxine dose following TFT results

Answer 36

Question 37

Quality of Xray film

Answer 37

It is important to check that the film is PRIM: * Projection (e.g. posterioanterior (PA) (normally) or anterioposterior (AP). If AP, the heart will appear larger. If no label, then it is PA). * Rotation (e.g. if distance between spinous process and clavicles is equal, then no rotation). * Inspiration (e.g. if the seventh anterior (down-sloping) rib transects the diaphragm, then adequate). * Markings (if additional markings, e.g. ‘red mark’, then the radiographer has spotted an abnormality).

Question 38

when interpreting a CXR what are the main structures to be considered

Answer 38

* Heart, which should be less than 50% of the width of the lungs (in PA film); if more, then cardiomegaly should be considered.∗ * Lungs, where, if a white area is present, then effusion (seen as unilateral and solid), pneumonia (seen as unilateral and fluffy), oedema (seen as bilateral and fluffy∗), or fibrosis (seen as bilateral and honeycomb) should be considered. * Trachea, which should be central and if not, consider collapse (i.e. towards affected side) or pneumothorax (i.e. away from affected side). * Mediastinum, which if widened, consider right upper lobe collapse (with tracheal deviation) or aortic dissection (without tracheal deviation). * Bones, where it is important to look for rib fractures or lytic lesions (i.e. usually suggesting metastases). * Are the costophrenic angles sharp? If not then this suggests pleural effusion(s).∗ * Is there air under the right hemidiaphragm? This suggests bowel perforation or recent surgery. Under the left side is the gastric air bubble (which is normal). * Is there a triangle behind the heart (i.e. sail sign)? This suggests left lower lobe collapse. * Are the apices clear? If not, consider tuberculosis or an apical tumour.

Question 39

signs of heart failure on CXR

Answer 39

ABCDE signs of pulmonary oedema: * Alveolar oedema (bat wings) * Kerley B lines (interstitial oedema) * Cardiomegaly * Diversion of blood to upper lobes (where vessels in upper zone are larger than in lower zone), * pleural Effusions.

Question 40

causes of respiratory alkalosis

Answer 40

rapid breathing

Question 41

causes of respiratoey acidosis

Answer 41

t2rf

Question 42

causes of metabolic alkalosis

Answer 42

vomiting, diuretics, conns syndrome

Question 43

causes of metabolic acoidosis

Answer 43

lactic acidosis DKA renal failure diarrhoea ethanol intoxication

Question 44

Left or Right BBB?

Answer 44

WiLLiaM MaRRoW

Question 45

Elevated ST segment ECG causes

Answer 45

* infarction (ST segment flat and only raised in some leads), or * pericarditis (ST segment convex and raised in all leads).

Question 46

ST segment depression causes ECG

Answer 46

* ischaemia or infarction check troponin to distinguish (ST segment flat and only depressed in some leads); * digoxin treatment (ST segment down-sloping in all leads).

Question 47

tall tented T wave

Answer 47

Height: if more than two-thirds of the QRS height throughout the ECG then hyperkalaemia is likely present.

Question 48

T wave inversion

Answer 48

normal in aVR and I (top middle two) leads; in other leads suggests old infarction/LVH.

Question 49

drugs with narrow therapeutic index

Answer 49

* digoxin * theophyline * lithium * phenytoin * gentamicin * vancomycin

Question 50

Signs of digoxin toxicity

Answer 50

Confusion, nausea, visual halos, and arrhythmias

Question 51

signs of lithium toxicity

Answer 51

Early: tremor Intermediate: tiredness Late: arrhythmias, seizures, coma, renal failure and diabetes insipidus

Question 52

Signs of phenytoin toxicity

Answer 52

gum hypertrophy ataxia nystagmus peripheral neuropathy teratogenicity

Question 53

gentamicin toxicity

Answer 53

ototoxicity nephrotoxicity

Question 54

vancomycin toxicity

Answer 54

ototoxicity and nephrotoxicity

Question 55

Target INR on warfarin

Answer 55

2.5 unless recurrent thromboembolism then 3.5

Question 56

management of warfaring INR 5-8 or >8

Answer 56

Question 57

management of hyperkalaemia

Answer 57

"Dependent on K level, symptoms and ECG (see diagram): * insulin and dextrose infusion (in moderate-severe hyperkalaemia) - drives carbohydrates into cells and takes K with it * IV calcium gluconate (in severe kyperkalaemia or with ECG changes) - stabilises cardiac muscle cells Other options: * nebulised salbutamol - temporarily drives K into cells * IV fluids - increases fluid output, which encourages K loss * oral calcium resonium - draws K out of the gut and into stools (works slow) * sodium bicarbonate - drives K into cells * loop diuretics * dialysis Further management: * stop exacerbating drugs e.g. ACEi * treat underlying cause "