Download Diabetes Insipidus and SIADH

Diabetes Insipidus and SIADH
Charnelle Lee RN, MSN
Diabetes Insipidus
Hyposecretion of ADH
• Description
– Insufficiency or hypofunction of antidiuretic
hormone (ADH)
– ADH stimulates kidney tubules to be
permeable to water, so that water is
reabsorbed back into the bloodstream
– Inadequate ADH means that large quantities
of dilute urine are passed
• Hypotension and hypovolemic shock
Diabetes Insipidus
Hyposecretion of ADH
• Etiology
– 3 types
• Central DI
– Primary
– Secondary
• Nephrogenic DI
• Psychogenic DI
Diabetes Insipidus
Hyposecretion of ADH
• Assessment and Diagnosis
– Urine
• Urine output may be > 300 ml/hr
• Low urine osmolality
• Urine is “insipid” or tasteless (not sweet)
– Laboratory Tests
•
•
•
•
Serum osmolality
Urine osmolality
Sodium
Serum ADH
Types of Diabetes Insipidus
Central
• ADH deficit
• Neurosurgery, TBI, tumors, Increased ICP, brain
death, infections
Nephrogenic
• Kidneys ignore ADH
• Kidney disease, drugs such as lithium
Psychogenis
• Rare form of DI
• Compulsive water drinking up to 5 liters/day
Pathophysiology
ADH deficit
Hypovolemic
shock
Hypernatremia
Excessive
diuresis
Increased
serum
osmolarity
• Polyuria without
• Diuretics
• Fluids
• hyperglycemia
Diagnosis
Pituitary
dysfunction
• Assess underlying
cause
• Replace ADH
• Treat the reason
• ADH is not
indicated
Increased ICP
Level above 145
mEq/L
DI + Laboratory
Studies
Sodium
Osmolarity
greater than 320
mOsm/L
Serum
Osmolarity
Low Urine
osmolarity < 300
mOsm/L
Urine Osmolarity
Diabetes Insipidus
Hyposecretion of ADH
• Medical Management
– Diagnose and treat cause of DI
– Medications to manage Central DI
• Vasopressin (Pitressin)
• DDAVP
• Lypressin
– Medications to manage Nephrogenic DI
• Thiazide diuretics
Diabetes Insipidus
Hyposecretion of ADH
• Nursing Management
– Fluid status
– Laboratory studies
– ADH replacement
– Elimination issues
– Patient education
Syndrome of Inappropriate Secretion
of ADH (SIADH) Hyper-secretion of ADH
• Description
– Opposite of DI
– Too much ADH
– Kidneys reabsorb too much water
– Dilutional hyponatremia
Syndrome of Inappropriate Secretion
of ADH (SIADH) Hyper-secretion of ADH
• Etiology
– Head / CNS injury
– Malignant bronchogenic oat cell carcinoma
– Other conditions
– PEEP with mechanical ventilation
Syndrome of Inappropriate Secretion
of ADH (SIADH) Hyper-secretion of ADH
• Pathophysiology
– ADH released by posterior pituitary gland
– ADH regulates water and electrolyte balance
– Excessive ADH
• Overhydration
• Low sodium (dilutional)
• Concentrated urine
Syndrome of Inappropriate Secretion
of ADH (SIADH) Hyper-secretion of ADH
• Assessment and Diagnosis
– Clinical presentation in SIADH relates to water
and sodium imbalance
– Lethargy
– Anorexia
– Mental confusion
– Seizures, coma, death
Syndrome of Inappropriate Secretion
of ADH (SIADH) Hyper-secretion of ADH
• Assessment and Diagnosis
– Serum Laboratory Values
• Serum ADH
• Serum Osmolality
– Urine Laboratory Values
• Serum Sodium
• Urine Osmolality
• Urine Specific Gravity
Syndrome of Inappropriate Secretion
of ADH (SIADH) Hyper-secretion of ADH
• Medical Management
– Secondary disease
– Fluid restriction
– Sodium replacement
– Medications
• Stop drugs that may cause SIADH
• Vasopressin receptor antagonists
Syndrome of Inappropriate Secretion
of ADH (SIADH) Hyper-secretion of ADH
• Nursing Management
– Hydration status
• Fluid restriction
– Neurologic status
– Parental therapy
– Patient education
Summary (Cont.)
• Pituitary: DI and SIADH
– Central DI occurs when ADH is not released from
the posterior pituitary gland. Excretion of large
quantities of hypotonic urine creates alterations in
serum and urinary laboratory values.
– SIADH occurs when excess ADH is released from
the posterior pituitary gland. This stimulates
kidney tubules to retain water, resulting in fluid
overload and hyponatremia manifested by
alterations in serum and urinary laboratory values.
Copyright © 2014, 2010 by
Mosby, an imprint of Elsevier
Inc.
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