Exam 1: Sodium Imbalances Flashcards
Most abundant electrolyte in ECF?
Na
Concentration of Na?
135-145
Primary role of Sodium?
Controlling water distribution throughout body, because it doesd not easily cross the cell wall membrane.
What is Sodium regulated by?
ADH, Thirst, and RAAS
Loss or gain or sodium is usually accompanied by?
Loss or gain of water
SIADH may be associated with?
Sodium imbalance
When is Arginine Vasopressin (AVP) released?
When there is a decrease in the circulating plasma osmolality, blood volume, or blood pressure
What can oversecrection of AVP cause?
SIADH
Sodium Deficit name?
Hyponatremia
Sodium Excess Name?
Hypernatremia
Hyponatremia Contributing Factors?
Loss of Sodium through diuretics, renal disease, gain of wwater, and disease states associated with SIADH
Hyponatremia Signs/Symptoms
Anorexia, Nausea and Vomiting, Headache, Decreased BP/Pulse, Dry Skin, Weight Gain, Edema
Hyponatremia Labs Indicate
Decreased Serum and Urine Sodium
Decreased Urine Specific Gravity and Osmolality
Hypernatremia Contributing Factors
Fluid deprivation in patients who don’t respond to thirst.
Diabetes Insipidus
Watery Diarrhea
Hypernatremia Signs/Symptoms
Thirst, Elevated Body Temperature, Seizures, Increased BP and Pulse
Hypernatremia Labs Indicate
Increased Serum Sodium
Decreased Urine Sodium
Increased Urine Specific Gravity and Osmolality
Decreased Central Venous Pressure
Hyponatremia refers to serum sodium level that is
less than 135 mEq / L
Acute Hyponatremia is commonly the result of
a fluid overload in a surgical patient
Chronic hyponatremia is more frequently
in patients outside a hospital setting, has longer duration
Low Urine Sodium occurs as
the kidneys retains sodium to compensate for nonrenal fluid loss (vomiting, diarrhea, sweating)
High Urine Sodium concentration is associated with
renal salt washing
What medications increase the risk of hyponatremia?
Anticonvulsants, Oxcarbazepine, Levetiracetam, SSRIs, SErtraline, Paroxetine, or Desmopressin Acetate
Neurologic changes of hyponatremia?
Altered mental status, status epilepticus and coma
Hyponatremia: What happens as extracellular sodium level decreases?
The cellular fluid becomes relatively more concentrated and pulls water into the cells.
Acute decreases in sodium may be associated with?
Brain herniation, and compression of midbrain strcutres
What signs can ocur when Serum Sodium levels decreases to less than 115 mEq/L?
Signs of increasing intracranial pressure, such as lethargy, confusion, muscle twitching, focal weakness, hemiparesis, seizures, or death
Sodium level in hyponatremia?
Less than 135 mEq/L
Sodium level in SIADH?
May be lower than 100 mEq/L
When hyponatremia is due primarily to sodium loss, the urinary sodium content is
less than 20 mEq/L, suggesting proximal reabsorption of sodium secondary to ECF volume depletion
Hyponatremia SpG?
1.002 to 1.004
Urinary Sodium Content and SpG when Hyponatremia due to SIADH?
Greater than 20 mEq.L and urine specific gravity is usually greater than 1.012
Most common treatment for hyponatremia is?
Careful administration of sodium by mouth, nasogastric tube, or parenteral route
Sodium replacement for patients who can eat and drink?
Sodium easily replaced because it is consumed abundantly in a normal diet
Sodium replacement for those who cnanot consume sodium?
Lactated Ringer solution or isotonic saline (0.9% sodium chloride)
usual daily sodium requirement in adults?
Approximately 100 mEq
In patients with normal or excess fluid volume, hyponatremia is usually treated effectively by
restricting fluid
Hyponatremia: Pharmacologic Therapy treatments?
AVP Receptor Antagonists
Vaprisol
Tolvaptan
What do AVP Recceptor Antagonists do?
Pharmacologic agents that treat hyponatremia by stimulating free water excretion
What does Vaprisol do?
Limited to hospitalized patients. May be useful therapy for those patients with moderate to severe symptomatic hyponatremia, but not those with seizures or in a coma
What does Samsca do?
Oral medication for clinically significant hypervolemic and euvolemic hyponatremia
Hyponatremia is a frequently overlooked cause of what?
Confusion in older patients who are at increased risk because of decreased renal function
What should a nurse monitor?
I/O, Weight, and be alert for GI Manifestations
Hypernatremia is
a serum sodium level higher than 145 mEq/L
How is Hypernatremia caused?
By a gain of sodium in excess of water or by a loss of water in excess of sodium
Hypernatremia can occur in patients with
normal fluid volume, or those with FVD or FVE
Hypernatremia, what happens in water loss?
Patient loses more water than sodium, as a result, the sodium concentration icnreases and the increased concentration pulls fluid out of the cell
Common cause of hypernatremia?
Fluid deprivation in patients who cannot respond to thirst.
Less common causes of hypernatremia??
Heat Stroke, NEar Drowning in Sea Water, and Malfunction of hemodialysis or peritoneal dialysis systems
Clinical manifestations of hypernatremia?
Are owing to increased plasma osmolality causedby an increase in plasma sodium concentration. Water moves out of the cell into the ECF
Serum Sodium levels in hypernatremia?
> 145 mEq/L
Serum Osmolality in Hypernatremia?
300 mOsm / kg
Urine SpG and Urine Osmolality in hypernatremia?
Increased as kidneys attempt to converse water.
Treatment of hypernatremia consists of
gradual lowering of the seurm sodium level by the infusion of a hypotonic electrolyte solution (0,3% sodium chloride) or an isotonic nonsaline solution (dextrose 5% in water).
Why is Hypotonic thought to be safer than Isotonic?
Allows gradual reduction in the serum sodium level, thereby decreasing the risk of cerebral edema
How should a nurse prevent hypernatremia?
By providing oral fluids at regular intervals
How should a nurse prevent hypernatremia if patient unconscious?
By enteral feedings or by the parenteral route.
