Diabetes Insipidus Flashcards
Pathophysiology of Diabetes Insipidus: Pituitary consists of 2 lobes: \_\_\_\_\_\_\_ aka (\_\_\_\_\_\_): Secretes Growth hormone (somatotropin) Prolactin Thyroid-stimulating hormone Follicle-stimulating hormone Luteinizing hormone \_\_\_\_\_\_\_\_\_\_ Posterior Pituitary > adenohypophysis
Adrenocorticotropic hormone (ACTH)
Pathophysiology of Diabetes Insipidus: Pituitary consists of 2 lobes: \_\_\_\_\_\_\_ Aka (\_\_\_\_\_\_) : Secretes Oxytocin \_\_\_\_\_\_\_
Anterior Pituitary > neurohypophysis Antidiuretic hormone (ADH, vasopressin)
Pathophysiology of Diabetes Insipidus:
These hormones are produced in the hypothalamus and are ______ in the Posterior Pituitary until their release is triggered by the appropriate stimuli.
Hormones secreted by the ______ Pituitary gland regulate growth, metabolism, pigment changes, and sexual development. These functions are affected when the pituitary gland secretes too much or too little of one or more hormones.
The _______ Pituitary gland secretes vasopressin, also known as antidiuretic hormone (ADH).
stored
Anterior
Posterior
Pathophysiology of Diabetes Insipidus:
______ is the single most important hormone responsible for fluid balance by either increasing the rate of water reabsorption (recovery) from the renal tubules (collecting ducts in the kidney) or decreasing the rate of water reabsorption (elimination). It also stimulates peripheral blood vessels to constrict.
Anti-Diuretic Hormone (ADH)
Pathophysiology of Diabetes Insipidus:
________ Pituitary problems result in fluid and electrolyte imbalances. ADH causes reabsorption of water improves low BP and low blood volume. This hormone also contributes to control of the sodium level in the ECF by control of plasma osmolality ADH is released to stimulate fluid reabsorption thus retaining water and maintain NA balance which results in dilution of Extra Cellular Fluid. Blood ______ is the most important stimulus to increase ADH secretion (a measure of solute concentration of circulating blood) this is used to compensate for hyperosmolar blood.
Posterior
osmolality
Diabetes Insipidus Defined: DI is a condition which is caused by a deficiency of production or secretion of ADH or a decreased ____ response to the secretion of ADH which results in the inability of the body to concentrate or retain water. ADH deficiency results in the excretion of large volumes of dilute urine resulting in ______. The amount of urine excreted may vary from ___ to ___ liters per day. This results in fluid and electrolyte imbalances caused by the increased DILUTE urine output, decreased urine specific gravity, decreased urine osmolality and increased blood plasma osmolality.
renal
polyuria
4 to 20 Liters
Types of Diabetes Insipidus: This is the Most common. __________- Insufficient production of ADH by the hypothalamus or ineffective secretion by the posterior pituitary. Examples: Brain tumors, CNS infections, brain lesions, head injury.
Central DI (Neurogenic)
Types of Diabetes Insipidus: _________- Inadequate renal response to ADH despite presence of adequate ADH. Can be drug induced such as Lithium or can be secondary to renal disease such as polycystic kidney disease or chronic renal insufficiency. Can be secondary to hypercalcemia and hypokalemia, or with disease of the renal tubules.
Nephrogenic DI
Types of Diabetes Insipidus: Rare. Excessive water intake as in water toxicity. Lesion in the thirst center or psychiatric disorder.
Psychogenic DI
Diabetes Insipidus Pathophysiology:
Diabetes insipidus is caused by decrease in the functioning and levels of antidiuretic hormone (ADH), also known as _______. Manufactured in the ________ and stored in the pituitary gland, ADH helps to regulate the amount of fluid in the body.
vasopressin
hypothalamus
Diabetes Insipidus Pathophysiology:
In healthy NORMAL individuals, when the bodily fluids are LOW, ADH is released from the pituitary gland which ______ the excretion of fluids from the body in the form of urine. ADH acts on the ______ to increase water permeability and reabsorption in the collecting duct and distal convoluted tubule and water is reabsorbed. In an unhealthy ABNORMAL condition of low ADH this results in _____ of tubular reabsorption of water in the kidneys leading to polyuria and dehydration. Dehydration increases plasma osmolality which stimulates osmoreceptors. This increases thirst. If thirst mechanism is ______ severe dehydration and death can occur.
prevents
kidneys
failure
absent
Diabetes Insipidus Pathophysiology:
In ______ diabetes insipidus, the production or release of ADH is too low to stop the kidneys from passing dilute urine, which results in an increased loss of water or polyuria.
Central / Neurogenic
Diabetes Insipidus Pathophysiology:
People with ________ diabetes insipidus, have adequate amounts of ADH in the body but the kidneys fail to respond which again results in polyuria with a very low urine specific gravity (less than ____), and very low urine osmolality (less than _____mOsm/Kg). Loss of water by the kidney results in _______ which increases thirst. Dehydration and resulting in increased serum Na+ causes increased plasma osmolality (hyperosmolar) which in turn stimulates osmoreceptors which also stimulates the thirst center. Therefore, patient experiences severe _______. Signs and symptoms of dehydration and hypernatremia can be seen as clinical manifestations.
nephrogenic 1.005 100 mOsm/Kg hypernatremia polydipsia
Nursing Assessment of Diabetes Insipidus:
Most of the manifestations of DI are related to dehydration.
The key manifestations are an increase in the frequency of urination and excessive thirst. Urine output may be __ to ___ l/day or about ____ ml per hour. Patient can go into hypovolemic shock.
Although increased fluid intake prevent serious dehydration and volume depletion, the patient who is deprived of fluids or who cannot increase oral intake may develop shock from fluid loss.
Watch for manifestations of dehydration, such as poor skin turgor and dry or cracked mucous membranes or skin.
4 –20 liters per he
200
Nursing Assessment of Diabetes Insipidus:
S/S vary depending on the type/cause – to certain extent
___________ DI s/s occur suddenly.
Nephrogenic DI less dramatic than central
Increased thirst – compensation for water loss
Increased urination, nocturia
Large quantities of dilute urine 5 – 20 liters/day with ____ specific gravity (____ mOsm/Kg)
Dehydration
Central
low
295 mOsm/Kg
Nursing Assessment of Diabetes Insipidus:
Weight loss
Increased serum osmolality d/t hypernatremia d/t pure water loss from kidneys
Increased temperature
Electrolyte imbalances – serum ___ greater than 145 mEq/L
_________ – leads to hypovolemia – vascular collapse (which can happen if water loss is NOT replaced with fluids)
Sodium
Hypotension
Clinical Manifestations of Diabetes Insipidus: \_\_\_\_\_\_\_\_\_\_: Hypotension (postural) Decreased pulse pressure Tachycardia Weak peripheral pulses Hemoconcentration -Increased Hgb & Hct -Increased BUN
Cardiovascular
Clinical Manifestations of Diabetes Insipidus:
________:
Increased Urine Output : dilute, low specific gravity, hypo-osmolar
Renal
Clinical Manifestations of Diabetes Insipidus: \_\_\_\_\_\_\_\_: Dehydration Poor turgor Dry mucous membranes
Integumentary
Clinical Manifestations of Diabetes Insipidus: \_\_\_\_\_\_\_\_\_: Increased sensation of thirst Irritability, headache Decreased cognition Hyperthermia Lethargy to coma Ataxia Hypernatremia
Neurological
Diagnosis of SIADH:
A. History and Physical.
B. CT / MRI of brain
C. Water loss produces changes in blood and urine tests. The first step in diagnosis is to measure a ______ intake and output
D. Urine is dilute with a ____ specific gravity (less than 1.005) and ____ osmolality (less than 100 mOsm/kg)
24-hour
low
low
Diagnosis of SIADH:
Fluid Deprivation Test:
1. Baseline body weight, urine volume, urine osmolality and specific gravity.
2. NPO for __ to __ hours
3. Administer ______ via intranasally or subcutaneously
4. ___ to ___ minutes after administration, obtain urine and serum osmolality and compare to baseline if it is :
A. Central DI – If the urine MOsm is greater than ____and there is a decreased urine output
B. Nephrogenic DI – ____change in urine output
8 to 12 hours desmopressin (DDAVP) 30-60 minutes 300 NO ASK PROF PAUL? Is urine output increased or decreased in central DI?
Diagnosis of SIADH:
To differentiate between central and nephrogenic DI, 1st obtain baseline weight, urine specific gravity and osmolality and the volume is obtained. After 8 to 12 hours of being NPO, desmopressin is given SC or intra nasally. After 30 to 60 minutes, the urine output and osmolality is measured again. Both urine volume and specific gravity/ mOsm is increased significantly in ____ whereas not much change is seen in if the cause is ______.
central
nephrogenic
Management of Central Diabetes Insipidus:
Fluids are _____ restricted. Fluids are replaced both orally and by IV. In acute DI, the nurse will use _____ SOLUTIONS Ex. D5W or 0.45% NS is used. The volume of IVF is titrated depending on the urine output. Monitor blood ______ levels with dextrose solutions.
NOT
HYPOTONIC
glucose
