Chemical Pathology - Management

Question 1

Hypovolaemic hyponatraemia

Answer 1

Volume replacement with 0.9% saline

Question 2

Euvolaemic hyponatraemia

Answer 2

Fluid restriction

Treat underlying cause

Question 3

Hypervolaemic hyponatraemia

Answer 3

Fluid restriction

Treat underlying cause

Question 4

SIADH

Answer 4

Demeclocycline - reduces responsiveness of the collecting tubule cells to ADH.
Tolvaptan - V2 receptor antagonist.

Question 5

Hypernatraemia

Answer 5

Correct water deficit using 5% dextrose
Correct extracellular fluid volume depletion using 0.9% saline
Serial sodium measurements every 4-6 hours

Question 6

Osteoporosis

Answer 6

Lifestyle - smoking cessation, reduce alcohol intake, weight-bearing excercise
Vitamin D and calcium
Bisphosphonates (e.g. alendronate)
Teriparatide (PTH derivative)
Strontium
Oestrogens (HRT)
SERMs (e.g. raloxifene)

Question 7

Hypercalcaemia

Answer 7

Fluids (0.9% saline, 1L over 1 hour then re-assess)
Frusemide (avoid thiazides) to remove calcium via urine
Bisphosphonates (e.g. alendronate)
Treat underlying cause

Question 8

Hypocalcaemia

Answer 8

Calcium

(Activated) Vitamin D

Question 9

Paget’s disease of bone

Answer 9

Bisphosphonates (for pain)

Question 10

Hyperkalaemia

Answer 10

10ml 10% calcium gluconate (stabilises myocardium) - if potassium > 6.5mmol/L or with ECG changes
50ml 50% dextrose (or equivalent) with 10 units of insulin
Nebulised salbutamol
Treat underlying cause

Question 11

Hypokalaemia

Answer 11

Serum potassium 3.0-3.5mmol/L:
Oral potassium chloride
Re-check serum potassium

Serum potassium < 3.0mmol/L:
IV potassium chloride (maximum rate 10mmol/hour)
Treat underlying cause

Question 12

Prolactinoma

Answer 12

Dopamine agonists (to shrink it) - cabergoline or bromocriptine
Surgery
Radiotherapy

Question 13

Acromegaly

Answer 13

Octreotide/lanreotide - somatostatin analogues
Cabergoline/bromocriptine - dopamine agonists
Pegvisomant - GH antagonist
Surgery
Radiotherapy

Question 14

Phaeochromocytoma

Answer 14

Urgent alpha blockade (phentolamine/phenoxybenzamine/doxazocin)
Non-urgent beta blockade
Surgery (adrenalectomy)

Question 15

Post-renal AKI

Answer 15

Relieve the obstruction

Question 16

Renal bone disease (osteitis fibrosa cystica, osteomalacia, adynamic bone disease, mixed osteodystrophy)

Answer 16

Phosphate control - dietary or phosphate binders
Vitamin D receptor activators - 1-alpha calcidol or paracalcitol
Direct PTH suppression - cinacalcet

Question 17

Sarcoidosis

Answer 17

Steroids

Question 18

Hypoglycaemia (in adults)

Answer 18

Alert and orientated:
Oral carbohydrates - rapid acting (juice/sweets) and longer acting (sandwich)

Drowsy and confusion, with swallow intact:
Buccal glucose e.g. hypostop/glucogel
Consider IV access

Unconscious or concerned about swallow:
20% glucose IV

NOTE: If deteriorating, refractory, insulin-induced or difficult IV access - consider 1mg IM/SC glucagon.

Question 19

Paracetamol overdose

Answer 19

N-acetylcysteine

Question 20

Alcoholic hepatitis

Answer 20

Supportive
Stop alcohol
Nutrition - especially vitamin B1 (thiamine) replacement (pabrinex)
? steroids (reduce inflammation)

Question 21

Phenylketonuria (PKU)

Answer 21

Dietary advice - help to avoid phenylalanine.

Question 22

Hyperbilirubinaemia in a baby

Answer 22

Mild (above 350 in term baby, or 120 in premature) = phototherapy
Severe (above 450 in term baby, or 230 in premature) = exchange transfusion
Treat underlying cause

Question 23

Osteopenia of prematurity

Answer 23

Phosphate and calcium supplements

? 1-alpha calcidol

Question 24

Acute intermittent porphyria (HMB synthase deficiency)

Answer 24

Avoid precipitants for attacks (stress, reduced caloric intake, ALA synthase inducers (steroids, ethanol etc.))
IV carbohydrate - inhibit ALA synthase and turn off the haem synthetic pathway
IV haem arginate - giving haem reduces the need for the haem synthesis pathway

Question 25

Obesity

Answer 25

``` Diet and exercise Orlistat 120-360mg daily - inhibits pancreatic lipase, so fat doesn't get absorbed as well Bariatric surgery (if BMI > 40) - gastric banding, roux-en-Y gastric bypass, biliopancreatic diversion ```

Question 26

Acute gout

Answer 26

NSAIDs (e.g. diclofenac) Colchicine Glucocorticoids (if other measures are unsuccessful)

Question 27

Interval (between acute episodes) gout

Answer 27

Keep hydrated Reverse factors which increase rate (e.g. remove diuretics) Allopurinol - reduces synthesis of urate by inhibiting xanthine oxidase Uricosuric drugs (e.g. probenecid) - enhance tubular excretion of urate

Question 28

Hypothyroidism

Answer 28

Levothyroxine

Question 29

Acute hyperthyroidism (thyrotoxic crisis)

Answer 29

``` Propylthiouracil Propranolol IV hydrocortisone - inhibits peripheral conversion of T4 to T3 Rehydrate Treat underlying cause ```

Question 30

Hyperthyroidism

Answer 30

Antithyroid drugs - propylthiouracil or carbimazole Radioactive iodine Surgery

Question 31

Viral (De Quervain's) thyroiditis

Answer 31

NSAIDs Corticosteroids Thyroxine (in stage when thyroid function is low)