data interpretation Flashcards
Causes of microcytic (low MCV) anaemia
- Iron deficiency anaemia
- Thalaseamia
- Sideroblastic anaemia
Causes of normocytic (normal MCV) anaemia
- **Anaemia of chronic disease
- acute blood loss**
- haemolytic haemia
- renal failure (chronic)
Causes of macrocytic (high MCV) anaemia
- **B12/folate deficiency
- Excess alcohol
- liver disease**
- hypothyroidism
- haematological diseases beginning with ‘M”: myeloproliferative, myelodyspastic and multiple myeloma
causes of hypokalaemia
DIRE:
* drugs (loop and thiazide diuretics)
* Inadequate intake or intestinal loss (diarrhoea or vomiting)
* renal tubular acidosis
* Endocrine (Cushings and Conns syndromes)
Causes of hyperkalaemia
DREAD:
* Drugs (potassium sparing diuretics and ACEi)
* Renal failure
* Endocrine (addisons)
* Artefact (due to clotted sample)
* DKA
causes of hypernatraemia
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).
High neutrophils causes
- Bacterial infection
- tissue damage (inflammation/infarct/malignancy)
- steroids
low neutrophils causes
- viral infection
- chemotherapy or radiotherapy
- Clozapine (antipsychotic)
- Carbimazole (antithyroid)
high lymphocytes
- viral infection
- lymphoma
- chronic lymphocytic leukaemia
causes of low platelets (thrombocytopenia)
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
causes of high platelets (thrombocytosis)
Reactive:
* bleeding
* tissue damage (infection/inflammation/malignancy)
* postsplenectomy
Primary:
* myeloproliferative disorders
Causes of hyponatraemia
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
raised urea indicated
AKI or upper GI haemorrhage (normal creatinine in the latter)
Biocehmical disturbance in prerenal AKI (70%)
Urea rise»_space;creatinine rise,
e.g.: Urea 19 (3–7.5 mmol/L), Creatinine 110 (35–125 μmol/L)
Causes of pre-renal AKI
Dehydration (or if severe, shock) of any cause, e.g. sepsis, blood loss.
Renal artery stenosis (RAS)
biocehmical abnormalities in intrinsic renal AKI
Urea rise «creatinine rise, bladder or hydronephrosis not palpable,
e.g.: Urea 9 (3–7.5 mmol/L) Creatinine 342 (35–125 μmol/L)
causes of intrinsic AKI (10%)
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
nephrotoxic antibiotics
gentamicin, vancomycin and tetracyclines
biochemical abnormalities in postrenal AKI (20%)
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)
causes of postrenal AKI
In lumen: stone or sloughed papilla
In wall: tumour (renal cell, transitional cell), fibrosis
External pressure: benign prostatic hyperplasia, prostate cancer, lymphadenopathy, aneurysm
Causes of raised ALP
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.
pattern of LFT derangement in prehepatic
increased bilirubin, normal AST/ALT