Transcript Fluid and Electrolytes: Balance and Disturbances

Fluid and Electrolytes:
Balance and Disturbances
Jimmy Durbin, MSN, RN
Body Fluids
• Factors that influence body fluid
• 60% of our body is fluid (water and
electrolytes.
• Perform numerous functions (what
electrolytes do)
– Promote neuromuscular irritability
– Maintain body fluid osmolality
– Regulates acid/base balance
– Regulate distribution of body fluids among
body fluid compartments
Nursing Implications with
Electrolytes
• Must assess fluid and electrolyte balance by doing
daily I&O
• Assess LOC
• Evaluate sensory and motor function and
neuromuscular irritability
• Monitor VS and electrolytes
• Look at EKG to detect changes
• Assess the nutritional status (b/c electrolytes are
obtained thru food intake)
• Evaluate the health history for medical conditions
that might alter these fluid and electrolytes
• Evaluate medication history for prescriptions or
OTC meds that can affect lytes
Body Fluid Shit
• Younger ppl have a higher percentage of
body fluid than old ppl
• Men more body fluid than women
• Obese people have less fluid than those
who are thin (b/c fat cells contain very little
water)
• Bone has a lower water content
• The highest amt of water is found in
muscle, skin, and blood
ICF vs. ECF
• Intracellular space (fluid in the cells) and
Extracellular space (fluid outside a cell)
• 2/3rd located in ICF and is usually in
skeletal mass.
• 1/3rd located in ECF.
ICF vs. ECF
• ECF further divided
– Intravascular-contains plasma
• Plasma is 3 L of the 6 L of blood in your body. Plasma is half
of the blood in your body
– Interstitial-fluid that surrounds the cell
• Lymph and lymph system. About 11-12 L of this in the body
– Transcellular
• 1 L in the body. This consists of cerebrospinal fluid,
pericardial fluid, synovial fluid (in your joints), interoccular
fluid, and pleural fluids.
• Shifting of fluid
– Normal (keeps normal balance)
• Third spacing
– Anything inside the cells is referred to as this. When
it’s in the cell it’s not useable.
Third Spacing
• Manifestations
– ↓Urine output (even tho they’re drinking
adequately, b/c the fluid is unuseable)
Other s/s
– ↑Heart rate
– ↓BP, ↓CVP (central venous pressure), edema
– ↑Body weight
• Imbalances in I/O
Electrolytes
• Active chemicals in body fluids
– Cations (+ charge)
• Na+, K+, Ca++, Mg+, H+
• Sodium, potassium, calcium, magnesium, and
hydrogen
• Sodium concentration effects the overall concentration
of the extracellular fluid. It’s the most important in
regulating the volume of body fluid
– Anions (- charge)
• Cl-, HCO3, Phos.
• Chloride, bicarbonate, and phosphorus
Regulation of Fluid
• Osmosis and Osmolality
– Osmosis: the movement of a pure solvent, such as water, thru a
permeable membrane from a solution with lower solute (or
concentration) to a higher solute (or concentration) It’s trying to
even out
• Diffusion
– Particles in a fluid move from an area of higher concentration to
an area of lower concentration resulting in even distribution. The
body always wants to be in homeostasis
• Filtration
– Separate out an unwanted material
• Sodium-Potassium Pump
– Protein that transports sodium and potassium ions across
membranes against their concentration gradient. In other words,
it doesn’t naturally move that way, but the protein assists in
moving it against the grain.
Routes of Gains & Losses
• Kidneys
– Lose in the form of urine
• Skin
– Sweat, visible loss.
• Lungs
– Moisture you breathe out in a vapor. Usually
lose 400 mL of water Fever can greatly
increase this.
• Gastrointestinal Tract
– Poop and whatnot
Sodium
• Major electrolyte in ECF
• Normal: 135-145 mEq/L
• ECF levels effect ICF levels:
–  serum Na+ = dilute ECF
• H2O drawn into cells
–  serum Na+ = concentrated ECF
• H2O pulled out of cells
• Na+ into cell  K+ moves out of cell
• Low sodium is hyponatremia
• High sodium is hypernatremia
Function of Sodium
• Controls H2O distribution
• Determine ECF concentration
• Determine ECF volume (remember, where
Na goes, water follows)
• Electrochemical state for proper muscle &
nerve function
– Sodium is responsible for establishing the
electro chemical state necessary for muscle
contraction and the transmission of nerve
impulses
Serum sodium level decreases
(water excess)
Serum osmolality falls to less than
280 mOsm/kg
Thirst diminishes, leading
to decreased water intake
Antidiuretic hormone (ADH)
release is suppressed
Renal water excretion increases
Serum sodium level increases
(water deficit)
Serum osmolality rises to
more than 300 mOsm/kg
Thirst increases , leading to
Increased water intake
ADH release increases
Renal water excretion diminishes
Serum osmolality normalizes
Hyponatremia
• Sodium < 135 mEq/L
• Causes
– Excessive Na loss
– Excessive H2O gain (dilutes the Na we
already have, which lowers levels)
– Both water and Na levels increase in
ECF, but water is more impressive
(cause it can dilute the Na levels). This
can happen from HF, liver failure, or
admin of hypotonic IV fluids
Sodium Loss
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Loss of GI fluids or secretions
Excessive sweating
Medications
Addison’s Disease
–  adrenocorticoid &  aldosterone secretion
– Addison’s is a life threatening condition caused
by partial or complete failure of the adrenal
corticoid function resulting from autoimmune
processes and also result from infection (either
tubercular or fungal), a neoplasm, or
hemorrhage
Water Gain
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Excess IVF (hypotonic)
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SIADH (Syndrome of Inappropriate Anti-diuretic
Hormone)
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There’s excessive or inappropriate production of the ADH
(anti diuretic hormone) which results in a dilutional
hyponatremia due to abnormal retention of water. You’re
holding on to water which dilutes the Na you already have,
which lowers the Na levels
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Continuous bladder irrigation
•
Fresh H2O near drowning
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Psychogenic polydipsia – excessive water drinking
S/S Hyponatremia
• S/S depend on the cause, magnitude and speed
at which the deficit occurs. (if slowly, probably not
a lot of initial S/S, but rapid you get these quickly)
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Poor skin turgor
Dry mucosa
Headache
Decreased saliva production
Orthostatic fall in BP (you move them and their BP falls)
Nausea
Abdominal cramping
S/S Hyponatremia
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Neurological changes
– Altered mental status
– Status epilepticus
– Obtundation – deadening to pain or a reduced
irritation and it blocks the sensibility at some
level of the central nervous system. They are
just there, they don’t feel pain. You pinch
them and they don’t move.
The more rapid the loss, the more severe and
dangerous the signs.
S/S Hyponatremia
• Usually due to sodium loss
– Anorexia
– Muscle Cramps
– Lethargy
• Severity of the symptoms also depend on the
degree and speed in which it develops.
• Normally you won’t see S/S until the Na is
below 120. At levels of 115, signs of
increasing intracranial pressure are lethargy,
confusion, muscle twitching, weakness, and
they may even go into a coma.
Hyponatremia: Lab Data
• Serum Na+ < 135 mEq/L
• Serum osmolality < 280 mOsm/kg
– Normal serum osmolality is greater than 280
• Urinary Na+ < 20 mEq/L
• Urine specific gravity < 1.010
Medical Treatment for
Hyponatremia
• Na replacement by mouth, IV, or NG Tube
• Replacement depends on the rate lost
– Can use LR, NS
– When replacing Na, watch for signs of fluid
overload or pulmonary edema!
• Fluid overload S/S are: Tachypnea, tachycardia,
SOB, may hear crackles or rhonchi with
ascultation, and an increase in BP
• Rule of thumb: serum Na must not be
increased > 12 mEq/L in a 24 hour period.
– If you overcorrect this too quickly you can cause
neurological damage.
Medical Treatment for
Hyponatremia
Water gain:
• Restrict H20 safer than giving Na
(800ml/24hr)
• Hypertonic solution 3%-5% NaCl
• Edema only-restrict Na
• Edema and Na- restrict both
• Loop Diuretics (lasix)
• With severe hyponatremia, goal is to
elevate Na level until the neurological signs
are gone
Nursing Interventions
• Identify pt. at risk
– Monitor labs, I&O, daily weight
• Review medications
• GI manifestations
• Monitor for S/S of hyponatremia
• Monitor for neurological changes (big
sign with hyponatremia)
• Oral hygiene (esp when they’re on fluid
restrictions or NG tubes)
SIADH
• Syndrome of Inappropriate Anti-Diuretic
Hormone
• Body secretes too much antidiuretic
hormone (ADH)
• Disturbs fluid and electrolyte balance
– Because you’re retaining fluid and dilutes your
levels of stuff
• Major cause of low sodium levels
SIADH
What happens:
• ADH increases the permeability of the renal tubules
• Increased permeability of renal tubules increases water
retention and extracellular fluid volume
• Leads to:
– Reduced plasma osmolality (less stuff in your plasma)
– Dilutional hyponatremia
– Dimished aldosterone secretion
– Elevated GFR (glomerular filtration rate)
• Increased sodium excretion and shifting of fluids into
cells
SIADH
Can result from:
• Sustained secretion of ADH from
Hypothalamus
• Production of ADH-like substance from a
tumor (remember, benign tumors like to
pop out stuff like hormones)
– Oat cell lung tumor
• Head injury, pulmonary disorders, physical
or psychological stress, or certain meds
S/S of SIADH
• Same as Hyponatremia
• Fingerprinting
– When the finger is pressed over a bony
prominence it leaves an indention. Leave an
indention similar to pitting edema, but just not
as dramatic
Lab Values of SIADH
• Low BUN and Creatinine
• Due to over hydration
– elevated urine sodium > 20 mEq/L
– elevated urine specific gravity > 1.012
Treatment of SIADH
• Treat the underlying cause
• Replace sodium
– Hypertonic solution (NS)
• NS cannot be used alone to treat hyponatrimia
caused by SIADH because excessive Na would be
excreted rapidly and your urine would be highly
concentrated with Na.
– Diuretic –Lasix
• If water restriction is difficult
– Use lithium or demeclocycline
Nursing Management of SIADH
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Monitor I/O
Daily weight
Monitor for Neurological symptoms
Monitor for lithium toxicity (if they’re on
lithium, of course)
Ensure adequate sodium intake
Avoid excess water supplements
Monitor urine specific gravity
Monitor serum sodium
Hypernatremia
• Na+ > 145 mEq/L
• Causes:
–  H2O intake
– Hypertonic tube feeding with  H2O
supplement(Na+ gain)
– IVF with  Na+
– H2O loss (thru GI, burns, heat)
– CAPD (Continuous Alternating Peritoneal
Dialasis. Tube in their abd and they run a
bag of fluid in. Works like a filtration or
something b/c their kidneys don’t work).
– Diabetes Insipidus
– Partial salt water drowning
S/S Hypernatremia
• Primarily neurological
• Moderate hypernatremia
– Restlessness, weakness, fatigue
• Severe hypernatremia
– Disoriented, delusional, hallucinations, may see some seizure
activity
• Dehydration
• Thirsty (all the time)
• One of the most important signs of hypernatrimia is
neurological b/c of the effect that fluid shifts have on brain
cells. Make sure you don’t give an IV that’s going to push fluid
into the cells of the brain and make them expand.
• If hyper is sever enough you can have brain damage.
• A healthy person that can drink usually won’t get into trouble
with this. But if their crazy or wandering the desert w/o water
this can happen.
S/S of Hypernatremia
• Dry, swollen tongue, sticky mucous
membranes
• Flushed skin
• Mild increase in temperature
• Peripheral and pulmonary edema
• Postural hypotension
• Increased deep tendon reflexes and nuchal
rigidity (your neck gets stiff)
Memory Jogger
• SALT. Remember, hypernatrimia is
caused by too much salt. S/S are as
follows:
• S = Skin Flushed
• A = Agitation
• L = Low grade fever
• T = Thirst (complain of intense thirst from
stimulation of hypothalumus b/c of the
increased serum osmolality)
Hypernatremia Lab Data
• Serum Na+ > 145 mEq/L
• Serum osmolality > 300 mOsm/L
• Urine specific gravity > 1.015
Hypernatremia Medical
Treatment
•  serum Na+ level gradually
– We already talked about how it can cause brain
damage if you do it too fast
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 approx. 0.5-1mEq/L/hr over 48 hrs
Monitor for neuro changes & cerebral edema
Hypotonic solution D5W or 0.45% NS
Desmopressin (DDAVP)
As Na levels rise in the blood, fluid shifts out of
the cells to dilute the blood and equalize the
concentration. If too much water is introduced
too quickly the water will move into the brain
cells causing cerebral edema
Hypernatremia Nsg
Interventions
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Identify pt at risk
Monitor fluid loss / gain
Neuro precautions and behavior changes
Monitor labs
Monitor oral Na intake
Offer fluids
Note medication with  Na+ content
Pt’s that are at risk for hyper are infants,
confused ppl that won’t take in any liquids,
immoble people, elderly, unconscious
people, and people post surgery procedures