Fluid and Electrolytes: SIADH-Diabetes Insipidus Flashcards
What is Diabetes insipidus?
A disease that causes ADH insufficiency that leads to excess fluid excretion
What are the possible causes of Diabetes Insipidus?
- Injury to the hypothalamus
- Injury to the Pituitary Gland
- Certain medication adverse reactions
- Can be born with a deficiency
- Tumors or any obstruction
- Infection
- Stroke/Cerebral vascular diseases
- Renal Insufficiency
What are the manifestations of Diabetes Insipidus?
- hypotension
- tachycardia
- Weak peripheral pulses
- Hemoconcentration
- Increased urine output
- Dilute specific gravity
- Poor turgor
- Dry mucous membranes
- Decreased Cognition
- Ataxia (loss of control of body movements)
- Increased thirst
- Irritability
What serum labs are consistent with Diabetes Insipidus?
- low ADH level due to excessive water secretion
- Elevated Sodium levels due to concentration in blood
- Elevated Osmolality level due to concentration in blood
- Elevated BUN due to concentration in blood
- Elevated Hct due to concentration in blood
What urine labs are consistent with Diabetes Insipidus?
- Low sodium level
- Low osmolality level
- Low Specific Gravity level
What interventions should a nurse keep in mind for a person with Diabetes Insipidus because of fluid volume deficit?
- Monitor neuro status due to possible changes in mental status secondary to electrolyte imbalances
- Avoid foods/drinks that may have a diuretic effect such as caffeine
- add bulk, fiber, and juices to prevent constipation
- Monitor for VS and trends
- Monitor lab values and trends (sodium level, BUN, Hct, Serum Osmolality, low ADH, Specific Gravity
What neuro interventions should be included in care for Diabetes Insipidus?
- Maintain Seizure precautions due to hypernatremia which increases the risk for seizure
- besides electrolyte imbalances, a deficiency in ADH may be a cause of a head injury to the hypothalamus/pituitary causing neurologic changes
- Decreased Central Venous Pressure (CVP) increases the risk for altered mental status
What is the normal range for CVP (central venous pressure)?
1-8 mmHg
What is important to remember about sodium levels for patients with Diabetes insipidus?
In cases where a patient is placed on a sodium-restricted diet due to excessive sodium intake; the Diabetes insipidus patient is NOT placed on a sodium-restricted diet because their sodium level is due to the serum concentration, not intake
What are interventions for Hypovolemia with Diabetes Insipidus?
- monitor for sx
- Administer Vasopressin aimed at retaining water and constricting blood vessels
- Administer fluids to replace loss
- Daily weights to monitor fluid balance and monitor trends
- Intake and output to monitor balance
- Skin care due to possible skin dryness/cracking secondary to dehydration
- Oral care due to dry mucous membranes and excessive thirst (polydipsia)
What is classified as anuria?
0-100 ml/day (no urine)
What is classified as oliguria?
<500 mL/day (only a little urine)
What is the normal adult range for urine output per day?
1-2 L/day (at least 30ml/hr)
What is classified as polyuria?
> 2L/day
How much urine does someone with diabetes insipidus release each day?
5-20 L/day
What is SIADH?
Syndrome of Inappropriate Antidiuretic Hormone
What is the pathophysiology of SIADH?
ADH is normally not secreted when plasma osmolarity is decreased, but with SIADH, ADH is secreted when plasma levels are low or normal. This makes the body retain water which leads to a low serum sodium level
What are the effects of fluid retention due to SIADH?
- diluted serum sodium (hyponatremia)
- hypo-osmolality (over hydrated)
- weight gain
What malignancies can cause SIADH?
- small cell lung cancer
- Pancreatic, duodenal and GU carcinomas
- Thymoma
- Hodgkin’s Lymphoma
- Non-Hodgkin’s lymphoma
What CNS disorders can cause SIADH?
- trauma
- Infection
- Tumors (primary or metastatic)
- Strokes
- Porphyria
- Systemic Lupus Erythematosus
What pulmonary disorders can SIADH?
- viral and bacterial pneumonia
- Lung abscesses
- Active Tuberculosis
- Pneumothorax
- Chronic lung diseases
- Mycoses
- Positive-pressure ventilation
What medications can cause SIADH?
- exogenous ADH
- Chlorpropamide
- Vincristine
- Cyclophosphamide
- Carbamazepine
- Opioids
- Tricycle antidepressants
- General anesthetics
9 Fluoroquinolone antibiotics
What are the differences and similarities between Diabetes insipidus and SIADH?
Similarity: Both will present with excessive thirst
Diabetes Insipidus: High urine output, low levels of ADH, hypernatremia, dehydration, loss of too much fluid
SIADH: Low urine output, high levels of ADH, hyponatremia, Over hydrated, retain too much fluid
Symptoms of Fluid Volume Overload due to SIADH
- headache
- Bounding pulse
- Elevated blood pressure
- Anorexia, weakness, decreased DTR, decreased strength
- Elevated RR, DOE, orthopnea, crackles in lungs (prevent progression of respiratory distress and coma)
- Possible confusion, alterations in mental status
- nausea, vomiting, diarrhea, and muscle cramps
- Increased weight due to fluid retention
- Hyponatremia
- Decreased urine output, and increased thirst
What serum labs are consistent with SIADH?
- low sodium levels due to being diluted with retained water
- decreased osmolality level due to retained water
- Elevated ADH level
What urine labs are consistent with SIADH?
- elevated sodium level (more coming out of the body)
- Elevated osmolality level
- elevated specific gravity level
What are the respiratory interventions for SIADH?
- monitor lungs for adventitious sounds such as crackles or wheezing
- Monitor for cough, or pink tinged sputum due to pulmonary edema risk
- Monitor for Reports of SOA, DOE, orthopnea
- Elevate HOB
- Administer Oxygen and diuretics as ordered
- Skin color and temp monitoring
- Increase urine output/decrease urine specific gravity
What are the cardiovascular interventions for SIADH?
- administer vasopressin antagonists (promote water excretion without sodium loss)
- Provide periods of rest between activities
- Cardiac monitoring (rate and rhythm), pulses (peripheral and central), cap refill, edema, and VS
- Laboratory monitoring and trends (low serium sodium <135 mEq/L)
- May need to administer 200-300 mL of hypertonic (i.e. 3% NS) fluid-cautions due to already in overload
What are some general SIADH interventions?
- administer prescribed medications to decrease blood pressure and pulse
- Limit fluids to 500-1000mL/day aka “fluid restriction”
- Avoid high salt content foods that cause fluids to be retained.
- May include foods high in sodium, that do not retain water such as milk, condiments, and cheese.
- Daily weights (big indicator of fluid status/changes)
- Intake and output monitoring
- Monitor neuro status due to CVP elevation; at risk for seizures and altered mental status increasing risk for fall
