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Dr.niarna Lusi Diabetes Insipidus

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diabetes insipidus

Text of Dr.niarna Lusi Diabetes Insipidus

  • Disorders of the Posterior Pituitary

    Diabetes Insipidus

    Syndrome of Inappropriate Antidiuretic Hormone (SAIDH)

  • Posterior Pituitary

    Posterior pituitary hormones are actually produced in the hyopthalamus and only stored in the posterior pituitary

    Posterior pituitary hormones

    Antidiuretic hormone (ADH)

    Oxytocin

    The hormones secreted by the posterior pituitary are Antidiuretic hormone (ADH) (Also call vasopressin)and oxytocin.

    ADH contributes to fluid balance by Controlling renal reabsorption of free water It also has potent vasoconstrictive properties.

  • Posterior PituitaryAntidiuretic hormone (ADH) (Also called vasopressin)

    Disorders/diseases resulting from dysfunction

    Excess: Syndrome of Inappropriate ADH secretion (SIADH)

    Deficiency: Diabetes Insipidus

  • SIADHPosterior Pituitary Hypersecretion

  • SIADH - Syndrome of Inappropriate Hormone Secretion

    ADH (anti-diuretic hormone) is a hormone made in the pituitary gland.

    ADH does what the name says - it stops urination - diuresis

    Slowing or stopping urine production leads to fluid retention.

    That in turn causes a dilution of body sodium

  • SIADH - Syndrome of Inappropriate Hormone Secretion

    Depending on the rapidity & the extent of the sodium drop, a battery of S/S appear.

    Lethargy, weakness, & foggy thinking are common. Personality changes can happen.

    Low sodium levels often make pt nauseated

    If the situation is not corrected, seizures, coma, & even death can follow.

  • Syndrome of Inappropriate Antidiuretic Hormone Secretion - SIADHSIADH occurs when there is too much vasopression (ADH) with inappropriate water retention and decreased blood Na levelsResults from many different conditions and drugsMay be produced by certain tumors such as lung cancer or may result from chronic lung diseases. Medicines associated with SIADH include common meds as antidepressants, antianxiety agents, antipsychotic agents, seizure meds, and desmopressin (DDAVP)

  • Syndrome of Inappropriate Antidiuretic Hormone Secretion - SIADH

    Results fromInability to produce & secrete dilute urineWater retentionIncreased extra cellular fluid volumeHyponatremia Diseases that affect the hypothalamus

  • Dx of SIADHThe following criteria should be fulfilled before a diagnosis of SIADH can be made:

    persistent excretion of concentrated urine with no reason for ADH release

    normal renal and adrenal function

    no edema or hypovolaemia should be present

    the urine osmolarity should be greater than the serum osmolarity

  • Physical Assessment of SIADHInitially, S/S are R/T retention of water.

    Most common complaintsGI disturbances-loss of appetite, N,V

    Nurse Weighs pt & documents any recent weight gainChecks pt extremities for presence of edema

    Pt with SIADH have free water, not salt, that is retained & edema is not usually present due to intracellular free water

  • Assessment-Clinical Manifestations of SIADHWater retention, hyponatremia, & resulting fluid shifts have an effect on CNS function, especially when serum sodium level drops. Normal serum Na 135-145. S/S occur when serum Na level drops below 125, and especially below 115Clinical S/SLethargy, headaches, hostility, uncooperativeness, disorientationEarly sign -Change in LOCNeurological S/S can progress from lethargy and headaches to decreased responsiveness, seizures, and coma.Nurse assess deep tendon reflexes, which are often < or sluggishV/S changes-tachycardia associated with increased fluid volume & hypothermia associated with CNS disturbance

  • Normal Lab Values

    serum osmolality (285-295 mOsm/kg)sodium (Na 135-145 mEq/L)

    chloride (95-105 mEq/L)Urine osmolality - -24 hr specimen 500-800 mOsm/kg H20 -Random specimen: 50-1200 mOsm/kg/H20

    Osmolality is measures in milliosmoles per kilogram of water (mOsm/kg). The major determinants of plasma osmolality are Na, glucose, & ureaUrine specific gravity1.003-1.0301.002-1.035High=dehydrationLow=diabetes insipidusconcerntrated urine > than 50-100 mOsm/kg with normal vascular volume and normal renal function

  • Lab Assessment in SIADHExtracellular fluid volume expansion affects electrolyte levels in the serum and the urine

    Elevated urine sodium levels and specific gravity reflect an increased concentration of the urine

    Serum sodium levels are decreased, often as low as 110 mEq/L (normal serum sodium 135-145 mEq/L) due to extracellular volume expansion and increased Na excretion

    Fluid retention causes changes in both plasma and urine osmolality

    Plasma osmolality is decreased, and the urine is hyperosmolar in relation to the plasma

  • Osmolality Urine osmolality -24 hr specimen 500-800 mOsm/kg H20Random specimen: 50-1200 mOsm/kg/H20 Osmolality is measures in milliosmoles per kilogram of water (mOsm/kg). The major determinants of plasma osmolality are Na, glucose, & urea.

    The Kidneys are mainly responsible for maintaining the concentration of body fluids within this range of osmolality.

    When the plasma osmolality becomes abnormal, changes in the level of antidiuretic hormones (ADH) cause the kidneys to conserve or increase the excretion of water to return the osmolality to normal

  • Posterior Pituitary hypersecretion - SIADH

    Symptoms - fluid retention low serum osmolality (normal285-295 mOsm/kg)

    dilutional low sodium (normal Na 135-145 mEq/L)

    low chloride (normal95-105 mEq/L)Causes-Diseases effect the hypothalmus

    pneumonia TB positive pressure ventilationTraumaconcerntrated urine (> than 50-100 mOsm/kg) with normal vascular volume and normal renal function

    muscle cramps & weaknesscerebral edema, lethargy, anorexia, headache, seizures, coma.

    AIDsdelirium tremensEctopic ADH secreting tumor

  • SIADH - Diagnostic TestsBlood & Urine tests

    Must have low serum sodium

    low plasma osmolality level

    Inappropriated concentrated urine (increased urine osmolality level)These tests indicate excess of body water relative to the amount of body sodium.In other words, ADH is inappropriately holding onto too much water.Important to eliminate other causes of a low sodium level, such as hypothyroidism or adrenal insufficiency, before settling on a dx of SIADHRx- removing the offending drug or tumor, & treat the underlying condition.

  • Posterior Pituitary: SIADH,DI*Affect kidneys ability to concentrate urine*

    Measured by urine specific gravityMeasures number and size of particles

    Normal: 1.003 - 1.030High = dehydrationLow = Diabetic Insipidus 1.001-1.005

    Concentrated urine: SIADHDilute urine: DI

  • Posterior pituitary: SIADHADH excess = water intoxication

    water is reabsorbed, so assess forincreased blood volume, fluid retentionconcentrated urine, low urine outputdilutional hyponatremia (same Na, more H20)muscle cramps and weaknessanorexia, n/v, irritable, confused, disorient, seizure

  • SIADH and HyponatremiaHyponatremia- a lower than normal concentration of sodium in the blood

    Caused by inadequate excretion of water of by excessive water in the circulating bloodstream

    In a severe case the pt may experience water intoxication, with confusion and lethargy, leading to muscle excitability, convulsions, and coma.

    Treatment: Fluid and electrolyte balance may be restored by IV infusion of a balanced solution or a fluid restricted diet.

  • SIADHDiagnosis & Treatment

    Diagnosis measure urine volumeand osmolality

    TreatmentIf Na280mmol/kgSG>1005low BUN, creatinine, Hb, Hct.

    Lasix if Na

  • SIADHDiagnostic StudyHyponatremiaDecreased plasma osmolalityUrine sodium and urine osmolality elevatedElevated ADH levels++++++Normal renal, adrenal, & thyroid functionsNursing Assessment

    Headache,Personality change, Confusion,Irrritability, Dysarthria(difficult, poorly articulated speech), Lethargy,Impaired memory

    Restless, weakness, fatigue, gait disturbances

    Weight gain+++++

  • SIADH TreatmentWater Restriction is the cornerstone of treatment

    Decreased water intake allows serum sodium level to rise normally.

    The maximum amount of water that pt with SIADH are allowed to drink is just slightly more that the amount of urine they produce

    Pt must have regular serum sodium measurements to ensure that the water restriction has been effective

    Dehydration- The most concerning potential side effect from treatment is dehydration.

  • SIADH treatmentRestrict fluid intake (800-1000 cc/day)Daily weight Strict I & OMonitor urine specific gravity0.9 NS infusion(to raise the serum Na level if water intoxication is severe) Monitor for hyponatremia Lasix may be admin to block circulatory overloadDrugs-demeclocyclin HCL & lithium-may be admin to block renal response to ADH, intereferes with action of ADHDrugs - Phenytoin - inhibits ADH releaseSurgery & Chemo -to remove or destroy neoplasms that may be the underlying cause of this syndrome

  • SIADH treatment

    Demeclocycline (Declomycin)Lithium

    Used for: Excess secretion of ADH or SIADHAction:Inhibits ADH action in kidneyBlocks renal response to ADH, interferes with action of ADHTherapeutic outcome:Decreased urin