FN: Hyponatraemia Flashcards
Presentation
.
Presentation
.
Causes
Hypovolaemia
Hypervolaemic
Euvolaemic
Hypovolaemia
U Na >20 mM (=renal loss)
U Na >20mM (=extra-ranal loss)
U Na >20 mM hypovolaemia = renal loss causes
Diuretics
Addisons
Osmolar diuresis (e.g. glucose)
Renal failure (diuretic phase)
Hypervolaemia hyponatraemia causes
Cardiac failure
Nephrotic syndrome
Cirrhosis
Renal failure
Hypervolaemia hyponatraemia causes
Cardiac failure
Nephrotic syndrome
Cirrhosis
Renal failure
Causes
Hypovolaemia
Hypervolaemic
Euvolaemic
Hypovolaemia
U Na >20 mM (=renal loss)
U Na >20mM (=extra-ranal loss)
U Na >20 mM hypovolaemia = renal loss causes
Diuretics
Addisons
Osmolar diuresis (e.g. glucose)
Renal failure (diuretic phase)
U Na >20 mM hypovolaemia = extra renal loss
Diarrhoea Vomiting Fistula SBO Burns
Hypervolaemia hyponatraemia causes
Cardiac failure
Nephrotic syndrome
Cirrhosis
Renal failure
Euvolaemic U osmolality >500
SIADH
Euvolaemia U osmolality
Water overload
Severe hypothyroidism
Glucocorticoid insufficiency
Management
- correct underlying cause
- Replace Na and water at the same rate they were lost
- asymptomatic chronic hyponatraemia - fluid restrict
-S ymptomatic/acute/dehydrated - cautious rehydration with 0.9% Ns
If hypervolaemia consider frusomide
Emergency seizures/coma: consider hypertonic saline (e.g. 1.8%)
Replace sodium too fast
central pontine myelinolysis
Chronic Na loss replacement
10mM/d
Acute Na loss replacement
1mM/hr
SIADH
- Concentrated urine: Na>20mM, osmolality >500
- Hyponatraemia or plasma osmolality
SIADH causes
Resp: SCLC, pneumonia, TB
CNS: meningoencephalitits, head injury, SAH
Endo: hypothyroidism
Drugs: cyclophosphamide, SSRIs, CBZ
SIADH Rx
Treat cause and fluid restrict
Vasopression recepto antagonists
Vasopressin receptor antagonist name (2)
- Demclocycline
- Vaptans
