ADH: Balances water & serum osmolality (amount of solutes in the bloodstream)
Posterior Pituitary Gland: Releases ADH & oxytocin
SIADH (Syndrome of inappropriate antidiuretic Diabetes Insipidus (DI)
hormone)
Overproduction of ADH Underproduction of ADH
-Release of ADH despite normal or low plasma osmolality -Deficiency of production or secretion of ADH
(low solutes) Or a decrease in renal response to ADH
-Reabsorbs water into circulation
Most common cause = small cell lung cancer Primary DI: results from excessive water intake
Other causes: (psychologic disorder)
-Other cancers (pancreatic, lymph, thymus, prostate) Central (neurogenic) DI: interference with ADH synthesis,
-Central nervous system disorders transport, or release
(head injury, stroke, brain tumors, infection, lupus) Nephrogenic DI: ↓ renal response despite adequate ADH
-Drug therapy & other conditions
S/S -Polydipsia
-Polyuria (2-20 L/day)
- Low urine output - Severe hyponatremia -Urine specific gravity of 1.005 or less
- ↑ body weight (↓ 120) (1.010-1.030 is normal)
- Initially ↑ thirst ● Vomiting -Urine osmolality of 100 mOsm/kg
- Dyspnea on exertion ● Abd cramps (300-900 mOsm/kg is normal)
- Fatigue ● Muscle twitching -Serum osmolality is normal or slightly ↑
- Mild hyponatremia If sodium continues to fall: (275-295 mOsm/kg is normal)
(↓ 130) ● Cerebral edema -Nocturia
● Muscle cramps ○ Lethargy -Generalized weakness
● Irritability ○ Confusion -Brain shrinkage & intracranial bleeding
● Headache ○ Seizures → If hypernatremia is left untreated
○ Coma
Dx Urine Osmolality = CONCENTRATED (opposite for DI) → -Dilute urine output greater than 200 mL/hr with specific gravity
Serum Osmolality = DILUTE (opposite for DI) → less than 0.005
Urine Specific Gravity -Water deprivation test (NPO 8-12 hrs, give DDAVP
(desmopressin)
→ drastic ↑ in urine osmolality (100 to 600)= central DI
→ ↑ urine osmolality no greater than 300 = nephrogenic DI
Nrsg -Monitor I & O, VS, heart & lung sounds, daily weight Central DI:
Care Observe for S/S hyponatremia: -IV/oral fluids (NS & D5W)
Seizures, headache, N/V, ↓ neurological function -Monitor BP, HR, urine output, glucose, LOC, urine
-D/C meds that stimulate ADH release specific gravity
-FR if Na+ is less than 125 -Assess for dehydration
-Lasix to promote diuresis -DDAVP (desmopressin acetate)
(may need to supplement K+)
-Fall/Seizure precautions Nephrogenic DI:
-IV 3% sodium chloride (give slowly in small amounts) -Hormone therapy ineffective
-Low-sodium diet
Meds Conivaptan (Vaprisol) Central DI:
Tolvaptan (Samsca) -Chlorpropamide (Diabinese) → ↓ thirst
-Neither medications can be gives to pts with liver failure -Carbamazepine (Tegretol) → ↓ thirst
Nephrogenic DI:
-Lasix → to promote diuresis -Thiazide diuretics
-demeclocycline → antibiotic, can cause diabetes insipidus -Indomethacin (Indocin)
Pt Ed. -Fluid restriction (800-1000 mL/day) -Maintain a low sodium diet
-Ice chips & chewing gum to help with dry mouth
-Daily weight
-K+ & Na+ supplements
(esp. If taking Lasix)
-Teach about S/S of K+ & Na+ imbalances
Posterior Pituitary Gland: Releases ADH & oxytocin
SIADH (Syndrome of inappropriate antidiuretic Diabetes Insipidus (DI)
hormone)
Overproduction of ADH Underproduction of ADH
-Release of ADH despite normal or low plasma osmolality -Deficiency of production or secretion of ADH
(low solutes) Or a decrease in renal response to ADH
-Reabsorbs water into circulation
Most common cause = small cell lung cancer Primary DI: results from excessive water intake
Other causes: (psychologic disorder)
-Other cancers (pancreatic, lymph, thymus, prostate) Central (neurogenic) DI: interference with ADH synthesis,
-Central nervous system disorders transport, or release
(head injury, stroke, brain tumors, infection, lupus) Nephrogenic DI: ↓ renal response despite adequate ADH
-Drug therapy & other conditions
S/S -Polydipsia
-Polyuria (2-20 L/day)
- Low urine output - Severe hyponatremia -Urine specific gravity of 1.005 or less
- ↑ body weight (↓ 120) (1.010-1.030 is normal)
- Initially ↑ thirst ● Vomiting -Urine osmolality of 100 mOsm/kg
- Dyspnea on exertion ● Abd cramps (300-900 mOsm/kg is normal)
- Fatigue ● Muscle twitching -Serum osmolality is normal or slightly ↑
- Mild hyponatremia If sodium continues to fall: (275-295 mOsm/kg is normal)
(↓ 130) ● Cerebral edema -Nocturia
● Muscle cramps ○ Lethargy -Generalized weakness
● Irritability ○ Confusion -Brain shrinkage & intracranial bleeding
● Headache ○ Seizures → If hypernatremia is left untreated
○ Coma
Dx Urine Osmolality = CONCENTRATED (opposite for DI) → -Dilute urine output greater than 200 mL/hr with specific gravity
Serum Osmolality = DILUTE (opposite for DI) → less than 0.005
Urine Specific Gravity -Water deprivation test (NPO 8-12 hrs, give DDAVP
(desmopressin)
→ drastic ↑ in urine osmolality (100 to 600)= central DI
→ ↑ urine osmolality no greater than 300 = nephrogenic DI
Nrsg -Monitor I & O, VS, heart & lung sounds, daily weight Central DI:
Care Observe for S/S hyponatremia: -IV/oral fluids (NS & D5W)
Seizures, headache, N/V, ↓ neurological function -Monitor BP, HR, urine output, glucose, LOC, urine
-D/C meds that stimulate ADH release specific gravity
-FR if Na+ is less than 125 -Assess for dehydration
-Lasix to promote diuresis -DDAVP (desmopressin acetate)
(may need to supplement K+)
-Fall/Seizure precautions Nephrogenic DI:
-IV 3% sodium chloride (give slowly in small amounts) -Hormone therapy ineffective
-Low-sodium diet
Meds Conivaptan (Vaprisol) Central DI:
Tolvaptan (Samsca) -Chlorpropamide (Diabinese) → ↓ thirst
-Neither medications can be gives to pts with liver failure -Carbamazepine (Tegretol) → ↓ thirst
Nephrogenic DI:
-Lasix → to promote diuresis -Thiazide diuretics
-demeclocycline → antibiotic, can cause diabetes insipidus -Indomethacin (Indocin)
Pt Ed. -Fluid restriction (800-1000 mL/day) -Maintain a low sodium diet
-Ice chips & chewing gum to help with dry mouth
-Daily weight
-K+ & Na+ supplements
(esp. If taking Lasix)
-Teach about S/S of K+ & Na+ imbalances
