Posterior Pituitary Gland Disorders

Posterior Pituitary Gland Disorders

Diabetes Insipidus

Insufficient ADH(vasopressin)

Functions of ADH:Secreted when ECF volume deficit or an increased osmolality (increased solutes).Promotes water reabsorption from the distal tubules of the kidneys. Helps to restore blood pressure when systolic blood pressure falls below 90mm Hg or when the Right Atrium is underfilled

Neurogenic: Not enough ADH

Nephrogenic: Normal ADH- renal tubules fail to respond

Signs & Symptoms:*Polyuria; Urine output may be as high as 20 L/24 hours*Urine is dilute, with a specific gravity of 1.002 or less *weight loss *Thirst *weakness *dehydration

ADH : *responds to thirst *fluid losses : IE- hemorrhage, which lowers blood pressure. *ADH also raises blood pressure by signaling the peripheral arterioles to constrict; hence, its alternative name, vasopressin.

Diagnostics:Fluid deprivation test:Urine concentrates with IV desmopressin is neurogenic.Urine specific gravity:Urine is dilute; 1.002 or less

Medical Management: Drug therapy: Desmopressin (DDAVP) nasal solution and lypressin (Diapid) nasal spray IV fluidsthiazide diuretic: hydrochlorothiazide (Hydrodiuril): nephrogenicLow sodium/Low Protein dietpotassium-sparing diureticsAnti-inflammatory drug: indomethacin (Indocin): inhibits prostaglandin production.

Syndrome of Inappropriate ADH Secretion

Continued release of ADH

Renal resbsorption of H2O rather than normal excretion.

Signs & Symptoms:*Hyponatremia*Water retention; headaches*Muscle cramps; anorexia *Changes in LOC*Serum sodium levels and serum osmolarity are decreased *Urine Sodium and osmolarity levels are high.

Medical Management: Treat the causeOsmotic diuretics: mannitol (Osmitrol)loop diuretics: furosemide (Lasix)IV administration: 3% hypertonic sodium chloride solution

Nursing Management:Monitor fluid intake+ output vital signsHyponatremia Assess LOC;Teaching about meds and to never omit a dose

Nursing Management:Correcting fluid volume deficitMeasure I and O; daily weights (gain or loss) Medication: Adherence to drug and diet therapyAvoid Strenuous activityAvoid Heat to prevent thirst and fluid loss

Reference: Timby, B.K., & Smith, N.E. (2010) Introductory Medical Surgical Nursing, (10th Ed). Philadelphia, PA: Lippincott.