Fluid and electrolyte problems can result from a number of reasons.
Dehydration caused by vomiting, diarrhea, decreased intake, and excessive
perspiration are but a few. Medical problems of cardiac and kidney disease
interfere with fluid and electrolyte regulation. Medical treatments and
therapy may cause or aggravate fluid and electrolyte balance problems.
1. Principles related to normal fluid and electrolyte balance
(e.g., anatomical. physical, and chemical principles relating to
fluid compartments and the movement of substances across
semipermeable membranes; the role of specific electrolytes in
normal body function; homeostatic mechanisms controlling the
levels of fluids and electrolytes in the body)
The body cells and tissue require a stable fluid composition in order to
function effectively. Homeostasis maintains this through a normal equal
intake and output of fluid and electrolytes.
Water (H20) is the solute for the dissolved electrolytes, as well as the other
substances of the body, the non electrolytes. Electrolytes are substances
that break their electrical bonds when dissolved in water, making an
positive and negatively charged .... The non electrolyte substances include
dextrose, urea, and creatinine. Protein and fat also....
The fluid volume of the body is first divided into intracellular and
extracellular, and then the extracellular is further divided into the
interstitial and the intravascular, or just vascular, compartments. These are
referred to as the three compartments.
The extracellular fluid is the environment that needs to be maintained
constant for proper cell function, and it is the extracellular fluid that
serves as the transport medium for substance movement to and from the
cell. The intracellular fluid provides the environment necessary for the
chemical reactions of life.
A "third compartment shift," or a "third spacing," is when the normal
distribution of fluid changes increasing the interstitial fluid???
transcellular??? This fluid becomes trapped, thus unable to return to the
vascular compartment and the circulation. This fluid shift occurs in
conditions such as high capillary pressure in heart failure (peripheral
edema and pulmonary edema), low plasma protein, lymphatic problems,
and increased capillary permeability. MORE...
Of note is the small component of the extra cellular fluid that is found as
cerebrospinal fluid, synovial fluid, and the pleural and peritoneal fluid, as
well as in the intraocular compartment.
The electrolytes of note are potassium, phosphate, sodium chloride, calcium
and sulfate. Non electrolytes are glucose, creatinine, and urea. These form
the solute portion of the body fluids. Although these are the solutes for all
the compartments, the concentration of the various electrolytes vary
between compartments.
Potassium is the major intracellular cation, with phosphate the anion. The
intracellular compartment also contains magnesium, protein and small
amounts of sodium, calcium, chloride and bicarbonate.
The extracellular compartment contains sodium as the major cation, with
chloride as the anion. Also...
For the intravascular and interstitial fluid, the major variance is the higher
protein concentration in the plasma. Interstitial fluid is usually low in
protein. Electrolyte concentration is the same.
Cellular process, such as the sodium potassium pump, maintain the
electrolyte concentration relationship between compartments.
Overall fluid balance, and electrolyte concentration is regulated by mainly
kidneys, as well as the GI tract, skin and lungs. In respect to the kidneys,
this involves the autoregulation of the glomerular filtration rate and the
renin angiotensin aldosterone system, and the hormones aldosterone and
antidiuretic hormone (ADH).
Fluid moves between compartments as a result of diffusion, osmotic
pressure, active transport of electrolytes, and capillary pressures. Fluid
will move from a compartment with lower osmotic pressure to one with
higher osmotic pressure. This is osmosis, there molecules pass through the
semi permeable membrane of the cell and vascular wall which are
normally impermeable to large protein molecules. A balance is usually
maintained, with the blood serum osmolality of between 275 and 290
mOsm/kg. A blood serum osmolality below 275 mOsm/kg. may indicate
fluid overload and dilute intravascular fluid. Values over 290 mOsm/kg.
may indicate dehydration and hemoconcentration.
2. Common disturbances of fluid balance (e.g., dehydration,
hypovolemia, hypervolemia, edema, ascites, fluid shifts, acid-
base balance)
Normally the body maintains equilibrium between fluid intake and output.
Fluid is taken in as water or other liquids and in food. Fluid is produced
through food oxidation and from body tissue. Loss is incurred through the
lungs, skin and feces, with most excess fluid excreted by the kidneys as
urine. Normally xxxx is taken in, xxx as moisture in food, xxx aiaiaidjf;. Loss
through respiration accounts for.... feces.... perspiration.... with usually xxx
ml per day excreted as urine. This works out to .... per hour, with this
hourly urine output value being important to remember for assessing
kidney perfusion and overall fluid status.
Excessive fluid loss can occur through such mechanisms as diarrhea,
vomiting, diaphoresis and blood volume loss. Factors that affect fluid
balance are;
age
environment and body temperature - hot dry locations, fever
diet and exercise -
physiological factors - anxiety and stress
surgery and medical procedures - gastric suctioning, ileostomies
disease - renal disease, cancer, cardiovascular disease
trauma - burns crush injuries hemorrhage
medications - diuretics
Hypovolemia. Total volume deficit occurs when an insufficient amount of
water exists within the extracellular compartment, resulting in the
compartment becoming contracted. Hypovolemia may be caused by
gastrointestinal losses of vomiting and diarrhea, excessive use of diuretics,
diabetes insipidus, diabetic ketoacidosis, third spacing, and plasma loss
from burns, as well as loss of both cellular material and water in
hemorrhaging.
Hypervolemia. Fluid volume excess can occur as a result of the diseases
process in renal, cardiac, or hepatic diseases. Overhydration through
administration of intravenous fluids can occur easily in infants and the
elderly, and with general excessive administration.
One liter of water weighs one kilogram, thus an increase of one kilogram of
body weight may indicate retention of one liter. Daily weight measurement
is important in fluid balance monitoring. Serial weight measurements can
indicate overhydration. Other signs are distended neck veins, moist rales in
the lungs, a full bounding pulse, and peripheral edema. A decreased BUN
and hemocrit are associated with hypervolemia.
3. Common disturbances of electrolyte balance: deficits and
excesses of sodium, potassium, calcium, and magnesium
Electrolyte Balance
Sodium - Hyponatremia and hypernatremia.
Sodium serum value is normally 135 to 145 mEq/L.
4. Factors affecting fluid and electrolyte balance
a. Developmental level: infancy through senescence
b. Individual preferences and patterns (e.g., excessive salt intake, NPO
status)
c. Physical condition (e.g., general adaptation syndrome, altered level of
consciousness, vomiting, diarrhea, increased body temperature, renal
and cardiac status)
d. Ethnic and cultural factors (e.g., diet, religious restrictions)
e. Socioeconomic factors (e.g., income level)
f. Environmental factors (e.g., hot climate)
g. Psychological factors (e.g., stress)
5. Theoretical basis for interventions to promote fluid and
electrolyte balance
a. Dietary modifications (e.g., encourage fluid intake, maintain dietary
restrictions)
c. Medications (e.g., diuretics, electrolyte supplements, exchanges resins)
B. Nursing care related to theoretical framework
1. Assessment: gather and synthesize data about the patient's
fluid and electrolyte status in relation to the patient's
functional health patterns
a. Obtain the patient's history relative to fluid and electrolyte balance
(e.g., urinary elimination patterns; dietary habits; symptoms of
imbalance such as lethargy, thirst, and muscle weakness)
b. Assess factors affecting fluid and electrolyte balance (see IVA4)
c. Obtain objective data (e.g., skin turgor, body weight, intake and
output, weight changes, twitching, fatigue, vital signs, increased
abdominal girth, edema, dehydration, Trousseau's sign, Chvostek's sign)
d. Review laboratory and other diagnostic data (e.g., hematocrit, serum
electrolyte levels, specific gravity of urine, blood urea nitrogen [BUN])
2. Analysis: identify the nursing diagnosis (patient problem)
and determine the expected outcomes (goals) of patient care
a. Identify nursing diagnoses (e.g., fluid volume excess related to high
sodium intake, fluid volume deficit related to diarrhea, activity
intolerance related to potassium loss from diuretic therapy, fluid
volume deficit related to alterations in renal function associated with
aging)
b. Set priorities and establish expected outcomes (patient-centered
goals) for care (e.g., patient will identify foods that are high in sodium,
infant's fontanelle will regain normal contours, patient's serum
potassium level will be within normal limits, patient will drink four to
six 8-oz glasses of water a day)
3. Planning: formulate specific strategies to achieve the
expected outcomes
a. Incorporate factors affecting fluid and electrolyte status in planning
the patient's care (e.g., establish a pattern of fluid intake based on an
older adult's preferences and physical needs, replace fluid and
electrolyte for a patient with gastrointestinal fluid loss) (see IVA4)
b. Plan nursing measures on the basis of established priorities to help
the patient achieve the expected outcomes (e.g., plan instruction
regarding the sodium content of prepared foods, monitor the
administration of oral rehydration solutions, administer prescribes
potassium as ordered, plan instruction regarding the need for additional
fluids)
4. Implementation: carry out nursing plans designed to move
the patient toward the expected outcomes
a. Promote fluid and electrolyte balance (e.g., assist with food and fluid
selection, adapt measures to patient's development level)
b. Use nursing measures appropriate to fluid and electrolyte deficits
1) Natural replacements of fluids (e.g., establish daily fluid
regimen with patient)
2) Artificial replacement of fluids (e.g., assist with parenteral
administration of fluids, which includes calculating flow rate,
monitoring flow rate adding a new IV solution)
3) Natural replacement of electrolytes (e.g., modify dietary intake)
4) Artificial replacement of electrolytes (e.g., administer
parenteral or oral potassium chloride)
5) Prevention of excessive fluid and electrolyte loss (e.g.,
administer antiemetics, antipyretics, antidiarrheal agents; alter
room temperature as needed)
c. Use nursing measures appropriate to fluid and electrolyte excesses
1) Dietary restrictions (e.g., limit PO intake to 1,000 ml/day, limit
sodium intake)
2) Medications (e.g., administer thiazide diuretics, administer
sodium polystyrene sulfonate [Kayexalate])
3) Parenteral therapy (e.g., monitor for signs of fluid excess)
d. Provide information and instruction regarding fluid and electrolyte
requirements (e.g., instruct the patient receiving a loop diuretic to
increase dietary intake of oranges and bananas, provide instruction
regarding increased intake of salt prior to strenuous exercise in hot
weather)
5. Evaluation: appraise the effectiveness of the nursing
intervention relative to the nursing diagnosis and the
expected outcomes
a. Record and report patient's response to nursing actions (e.g., weight
changes, altered hematocrit levels, altered urine specific gravity,
alterations in output, increased energy level, adverse effects, signs or
symptoms of untoward reactions)
b. Reassess and revise patient's plan of care as necessary (e.g.,
recommend that the patient further increases intake of foods high in
potassium)
