SIADH, DI Flashcards
Persistent ADH release independent of serum osmolality
SIADH
Main causes of SIADH
SAH, small cell lung cancer
Meds: SSRIs, HCTZ
Increased oral water intake makes patient symptomatic
SIADH
Dx for SIADH
Urine Osmolality > 100 (concentrated urine)
Urinary Na+ ≥ 20
Serum Na+, Serum Osm and Urine Osm in SIADH
Serum Na+ decreased
Serum Osmolality Decreased
Urine Osmolality Increased
Tx for SIADH
Fluid restriction
+/- Demeclocycline
IV Hypertonic Saline w/furosemuide if severe hyponatremia or intracranial bleed
Serum Na+ and Serum Osmolality relationship
Both either inc or dec
What is osmolality
particles/water
Decreased ADH production
DI
MC type of DI
Central
Caused by lithium
Kidney does not respond to ADH
Nephrogenic DI
S/S of DI
Polyuria
Polydipsia
Nocturia
Hypernatremia
Dx for DI
Hypernatremia (Increased Serum Osm)
What establishes the Dx for DI?
Fluid Deprivation Test: Decreased Uosm < 200, decreased specific gravity
What test differentiates Central vs Nephrogenic ADH
ADH stimulation test
Results of ADH stimulation test for Central DI
Decreased Urine Output
Results of ADH stimulation test for Nephrogenic DI
No response
Tx for central DI
DDVAP
Tx for nephrogenic DI
Na+ & protein restriction
HCTZ
