Diabetes insipidous Flashcards
What is happening in Diabetes Insipidous
Suppression of ADH producing large amount of dilute urine
Describe primary DI
Irreversible damage due to neurohypophosis
Describe nephrogenic DI
Damage to renal tubules due to drugs, genetics, or acquired
What happens in secondary DI
Polydipsea
Describe the three subcategories of polydipsea DI
Dipsogenic DI: inappropriate thirst d/t underlying secondary disease
Psychogenic: psychosis or OCD
Iatrogenic: increased intake d/t health reasons
What medical conditions can cause pituitary DI
Trauma, surgery, cancer, inflammation, chemical toxins (snake venom), vascular conditions, congenital, genetic
S/s of DI
Dehydration, polydipsia, polyuria
What is the urine vs serum osmo in DI
Urine: <300
Serum: >290
What is the total volume of daily urine in DI
> 40mls/kg/day
How do you find the difference between nephrogenic, polydipsea, vs central DI
ADH levels
Nephrogenic: >1pg/ml
Central/Polydipsia: <1pg/ml
How do you tell the difference between central DI and polydipsia DI
Brain MRI: pituitary bright spot only present in polydipsia DI
At what rate do you want to correct the sodium in DI
10-q2 mEq/l/day
Pituitary DI treatment
Desmopressin or DDAVP IV, SQ, nasal inhalation, or PO
• Dosing vary widely depending on route
• 1-2 mcg QD/BID via IV/SQ
• 10-20 mcg BID/TID via intranasal
• 100-400 mcg BID/TID via PO
Primary polydipsia DI treatment plan
Patient education
Replete lost volume
Nephrogenic DI treatment plan
Thiazide diuretic or amiloride
• Low Na+ diet
• Indomethacin
