Fluid & Electrolyte Imbalances Flashcards
What are the two main things that can cause fluid and electrolyte imbalances?
Illness and therapeutic measures
Which electrolyte is the primary determinant of ECF osmolarity?
Sodium
Sodium is important in (2) - other than osmoarity
generation + transmisison of nerve impulses
regulation of acid-base balance
Sodium leaves the body through (3)
urine, sweat, feces
Which organ is the primary regulator of sodium balance, under the influence of what hormone?
The kidneys under the influence of ADH
Serum sodium levels become elevated as a result of __ __ or __ __
water loss or sodium gain
Since sodium is the major determinant of ECF osmolarity, hypernatremia causes ___, shifting water out of the cells, causing cellular ___
Hyperosmolarity, causing cellular dehydration
Hypernatremia is not a problem in a person who is __ and has access to __ and is able to __
Alert
Water
Swallow
What type of patients are at risk for hypernatremia?
Unconscious patients and certain cognitively impaired patients
Clinical states that can produce water loss and hypernatremia
Dysfunctional ADH
Osmotic diuretics
Hyperglycemia from uncontrolled diabetes
Excessive sweating & increased sensible losses from high fever
Causes of sodium gain
IV administration of hypertonic saline
Use of sodium-containing drugs
Excessive oral intake of sodium (ingestion of seawater)
Primary aldosteronism
Main thing of treatment of hypernatremia
Treat the underlying cause
Treatment of Hypernatremia: Primary Water Deficit
+ Caution with rapid correction
Replace fluid orally or through IV infusion with isotonic fluids
Correct hypernatremia slowly prevents a rapid shift of water into cells, which can cause cerebral edema
Patients with long-standing hypernatremia (over several days or longer) are at higher risk of complications from overly rapid correction
Treatment of Hypernatremia: Sodium Excess
Dilute the sodium concentration using salt-free IV fluids, such as 5% dextrose in water (D5W).
Promote sodium excretion by administering diuretics.
Restrict dietary sodium intake as needed.
Treatment of Hyponatremia: Water Excess
Restrict fluids are often all that is needed.
If severe symptoms (seizures) develop, small amounts of IV hypertonic saline solution are administered to restore the serum sodium level while the body is returning to normal water balance.
Treatment of Hyponatremia: Sodium Loss
+ Important consideration
The nurse must monitor serum sodium levels and the patient’s response to treatment to avoid rapid correction or overcorrection.
Rapidly increasing levels of sodium can cause osmotic demyelination syndrome with permanent damage to nerve cells in the brain.
Causes of sodium loss of hyponatremia
GI losses
- diarrhea
- vomiting
- NG suction
Renal losses
- diuretics
- adrenal insufficiency
Skin losses
- burns
- wound drainage
Causes of water gain of hyponatremia
SIADH
Heart failure
Excessive hypotonic IV fluids
Primary polydipsia
Causes of water deficit of hypernatremia
Increased insensible water loss or perspiration (high fever, heatstroke)
Diabetes insiders
Osmotic diuretics
Causes of sodium gain of hypernatremia
IV hypertonic NaCl
IV sodium bicarbonate
IV excessive isotonic NaCl
Primary hyperaldosteranism
Saltwater near-drowning
Clinical manifestations of Hyponatremia
Decreased ECF volume - sodium loss
Irritability, apprehension, confusion
Postural hypotension
Tachycardia
Rapid, thready pulse
Decreased CVP
Decreased jugular venous filling
N+V
Dry mucous membrane
Weight loss
Tremors and seizures
Clinical manifestation of Hypernatremia
Decreased ECF volume - water loss
Intense thirst; dry, swollen tongue
Restlessness, agitation, twitching
Seizures and coma
Weakness
Postural hypotension
Decreased CVP
Weight loss
Fancy term for ECF volume deficit
Hypovolemia, low blood volume
Fancy term for ECF volume excess
Hypervolemia, high blood volume
Causes of hypovolemia
Abnormal loss of body fluids
- diarrhea
- hemorrhage
- polyuria
Decreased intake of fluids
Plasma-to-Interstitial Fluid Shift: Movement of fluid from the vascular space to the interstitial space.
Third spacing
Fluid volume deficit vs dehydration
Fluid volume deficit - loss of water with electrolytes
Dehydration - loss of pure water
Treatment of hypovolemia
Correct underlying cause
Replace both water and electrolytes using:
Balanced IV solutions: Lactated Ringer’s solution.
Isotonic NaCl (0.9%): For rapid volume replacement.
Blood transfusions: When volume loss is caused by blood loss
Causes of hypervolemia
Excessive intake of fluids.
Abnormal retention of fluids: Conditions like heart failure or renal failure.
Treatment of hypervolemia
Treat underlying cause
Remove sodium and water: diuretics and fluid restriction
I&O: Intake includes
Oral
IV
Tube Feedings
I&O: Output includes
Urine
Excess perspiration
Wound/tube drainage
Vomitis
Diarrhea
Fluid deficit vs hypovolemia
Fluid deficit - general state of dehydration/insufficient fluid in the body
Hypovolemia - low blood volume
Signs and symptoms of fluid excess and deficit are reflected in changes in (3)
Blood pressure
Pulse force
Jugular vein visibility
Compensatory mechanisms (consequences) for mild to moderate fluid deficit
stimulation of the sympathetic nervous system causes
- Increased heart rate to maintain cardiac output.
- Peripheral vasoconstriction to maintain blood pressure.
(cardiac) Consequences for severe fluid deficit
Recumbent hypotension (low bp even when lying down)
Wak and thread pulse
This can lead to shock
Signs and symptoms of fluid excess (cardiac)
Increased blood pressure
Bounding pulse
Jugular vein distension
(cardiac) Potential complications of fluid excess
Pulmonary edema
Congestive heart failure
Respiratory changes in fluid excess
Pulmonary congestion
Pulmonary edema
Shortness of breath
Crackles on auscultation
Respiratory changes in fluid deficit
Increased respiratory rate due to decreased tissue perfusion and resultant hypoxia
Neurological consequences of hyponatremia (high water, low sodium)
Swelling of brain cells resulting in confusion and seizures
Neurological consequences of hypernatremia (low water, high sodium)
Shrinkage of brain cells resulting in irritability, restlessness, and even lethargy and coma
Assessment of neurological function includes evaluation of:
Level of consciousness x3
Pupillary response
Voluntary movement of the extremities
For fluid status, the skin is inspected for __ and __
Turgor (elasticity)
Mobility
Integumentary Findings in Fluid Volume Deficit
Diminished skin turgor
Dry skin
Dry mucous membranes
Integumentary Findings in Fluid Volume Excess
Edematous skin
Cool to the touch
