Hyponatremia ☺️ Flashcards
Presentation
- early
- late
Early
- headache
- fatigue
- N+V
- confusion
- cramps
Severe
- seizures
- coma
- resp arrest
What would the U&Es show if a patient had SIADH
What other signs and symptoms might they have?
- Na => low
- Plasma osmolality => low
- Urine Na, osmolality => high
Urea, creatinine => normal, not dehydrated
No postural hypotension (characteristic of Addisons)
Nausea, weakness, dizziness
Normal TFT, adrenal function
Possible causes
Hypo hypo
- diuretic
- Addisons
Normo hypo
-SIADH (antipsychotics, mood stabilisers, lung cancer, infections)
Hyper hypo
-CF, LF, nephrotic
How would you manage hyponatremia caused by SIADH
Fluid restriction
Demeclocycline - block ADH
Tolvaptan - ADH antagonist
Investigations and diagnosis
- hypovolemic
- normovolemic
- hypervolemic
Hypovolemic Urine Na 20+ -diuretics -Addisons -CKD
Urine Na U20 - extrarenal loss
-diarrhoea, vomit, sweat, burns
Euvolemic - urine Na 20+
- SIADH
- hypothyroid
Hypervolemia - urine Na U20
- HF, cirrhosis
- nephrotic
- excess fluids
- psychogenic polydipsia
Consequences of
- untreated severe hyponatremia
- overrapid correction
Cerebral edema => brain herniation
Osmotic demyelination syndrome
Management for chronic without severe symptoms
- hypovolemic cause
- normovolemic cause
- hypervolemic cause
Hypo - isotonic saline
- if serum Na rises => hypo hypo
- if serum Na falls => SIADH
Normo - fluid restriction
-address underlying cause
Hyper - fluid restriction, loop diuretics, vaptans
-address underlying cause
Management for acute with severe symptoms
HDU/ICU monitoring
Hypertonic saline