F/E balance Flashcards
constant stability; body fluids are in constant motion transporting nutrients, electrolytes and oxygen to cells while carrying away waste products
Homeostasis
Primary fluid in the body; most important nutrient
-carries nutrients and waste products
-participates in metabolic reactions, food digestion
-solvent for minerals, vitamins, glucose
-lubricant and cushion for the joints, eyes, spinal cord
-aids in regulation of body temp
-maintains blood volume
60% of an adult’s body weight
Water; H2O
problem before the kidneys
pre-renal
30-60 ml/hr
normal urine output
found in food
-daily need 2000-3000 ml
-1 L of H2o weighs 1 kg
Sudden change in body weight is a great indicator of fluid volume
Fluids (H2O) needed
liquids (1500 ml/day)
solid foods (800 ml/day)
Metabolism (300 ml/day)
Intake Sources of fluids
Kidney (1200-1500 ml/day) Skin (500-600 ml/day) Lungs (400 ml/day) GI tract (100-200 ml/day) Drainage from Fistulas/drains, GI suction, salivation
Fluid Loss routes
oral fluid, tube feedings
parenteral fluid
enemas
retained irrigation fluid
Measurable fluid Intake
urine
emesis
feces
drainage from body cavities
Measurable fluid output
Solid foods
Metabolism
Non-measurable intake
sweating
vaporization through lungs
sensible loss
not measurable
chemicals dissolved in the body fluid, distribution affects fluid balance.
Regulates by intake, output, acid-base balance, hormones, and cell integrity
Electrolytes
Major extracellular electrolyte
controls and regulates water balance
Sodium
Major intracellular electrolyte
Helps maintain intracellular H20 balance
Transmit nerve impulses to muscles and contracts skeletal and smooth muscles
Potassium
mostly found from food;
kidneys excrete
electrolytes
135-145 mEq/L
determines whether water is retained, excreted or moved.
imbalance cause neuro problems
Sodium Na
3.5-5.5
increased with poor kidney function
decreased with excessive urination, diarrhea, vomitting
-imbalances cause cardiac problems
Potassium K
95-105; important in acid-base balance
-works with sodium to maintain osmotic pressure
increased with poor kidney function
decreased with excessive vomitting/ or diarrhea
Chloride Cl
9-11 ionized or serum 4.25-5.25
transmission of nerve impulses
heart and muscle contractions, blood clotting, formation of teeth and bone
Requires Vit D for absorption
Calcium Ca
balance is interwinded with Ca
Major anion of ICF. but found in ECF too.
Bone, skeletal muscle, and nerve tissue.
2.5-4.5 mg/dL
Functioning of muscles, nerves, & RBC’s.
Involved in metabolism of protein, fat and Carbohydrates
absorbed in intestine. all animal products, milk products, legumes, bread,
Phosphate PO4
6-20
BUN
0.6-1.3
Creatinine
42-52% Males
37-47% Females
Hematocrit
7.35-7.45
pH
35-45 mmHg
PaCO2
75-100% mmHg
PO2
24-28mEq/L
HCO3; bicarbonate
hematocrit normal is 3x the hemoglobin (10-14 normal)
H, H
indicates the H2O balance of the body
-serum osmo is 285-295 mOsm/kg
high is H2O deficit (concentrated)
low is H2O excess (dilute)
Serum Osmolarity
500-1200 mOsm/kg
avg 500-800 mOsm/kg
Urine Osmolarity
Together are used to determine what is causing a sodium imbalance.
- solute to h2o ration
- how well the kidneys are working
Serum and Urine Osmolarity
K, PO4; intracellular 2/3 body fluids
Na, Cl; extracellular 1/3 body fluids; interstitial (lymph) and transcellular (cerebrospinal, pleural, peritoneal, synovial fluids) and intravascular (blood plasma)
Distribution of body fluids & electrolytes
extracellular (33%)
-interstitial 25%
-intravascular (blood plasma) 8%
Intracellular (66%)
body water distribution
JG cells
- sense low Na, low volume
- release of renin
- converts angiotensinogen to angiotensin I which converts to angiotensin II
- stimulates release of aldosterone (RAAS)
Kidneys JG cells
adrenal cortex
- senses low serum osmo or low Na
- releases aldosterone
- reabsorbs Na into the blood, increases K excretion in the urine
- increases serum osmo
Kidneys Adrenal Cortex
senses high serum osmo or high Na
- stimulates thirst
- triggers release of ADH (vasopressin) from posterior pituitary
- retains h2o in the blood
- concentrates urine
- mildly constricts blood vessels
- decreases serum osmo
Hypothalamus
senses high volume through stretch receptors in the right atrium
- secretes ANP, BNP
- inhibits ADH
- stops the RAAS
- increases Na excretion through the urine
- dilates blood vessels
- decreases serum osmo
Heart
concentrates urine
raises Bp
H2O level down
ADH up
Antidiuretic hormone ADH
1st spacing normal
2nd spacing; edema, dehydration
3rd spacing; ascities, burn edema
capillary, interstital pressure changes, fluids shifts from 1 space to another. decreased protein causes 3rd spacing
Fluid spacing
fluid trapped and can’t be easily exchanged to other spacing.
3rd spacing
a solution that has the same osmo as body fluids.
-normal saline solution, 0.9% sodium chloride, D5W, LR
isotonic
keep fluids in the intravascular without causing any fluid compartment shift
crystalloids
refers to solutions that have a lower osmo than body fluids.
0.045%. 1/2 normal saline; hydrates cells
hypotonic
refers to solutions that have a higher osmo than body fluids
3%
D5 1/2 NS
D10W
hypertonic
colliods
plasmanate; replace body protein
lipids; IV therapy longer than 5 days
plasma expanders
percent of body weight of h2o is decreased
- structure changes in the kidney and decreased renal blood flow
- decreased GFR
- decreased creatinine clearance
- loss of ability to concentrate urine and thus conserve h2o
- decrease in renin and aldosterone
- increase in ADH & ANP
- Loss of subcutaneous tissue
- decrease in thirst mechanism
- musculoskeletal changes
- mental status changes
- incontinence; aging, body changes
- instead of skin turgor, use I & O’s and daily weights, mucous membranes
Gerontologic considerations
nurtrition, I & O’s, insensible losses, use of diuretics/laxatives, weight changes, kidney or endocrine disorders, LOC, mental status, depression, eating disorders, alcohol intake?
History; assessment considerations
hydration status, skin turgor, muscous membranes, I & O’s
physical assessment considerations
electrolyte levels, BUN, glucose, creatinine, pH, HCO3, osmolality, Hgb, Hct, urine dipstick, urine pH, urine specific gravity
Dx tests
substances such as lg protein molecules that do not readily dissolve into true solutions
colloids
concentrations of solutes in the body fluids is usually expressed in
osmolality
the power of a solution to draw h2o across a semipermeable membrane.
osmotic pressure
plasma proteins exert an osmotic draw, pulling h2o from the interstitial space into the vascular compartment
*important in maintaining vascular volume.
Colloid Osmotic Pressure or oncotic pressure
the continual intermingling of molecules in liquids, gases or solids brought about by the random movement of the molecules.
Diffusion
process whereby fluid and solutes move together across a membrane from one compartment to another.; movement from higher pressure to one of lower pressure
filtration
the pressure a fluid exerts within a closed system on the walls of its container.
hydrostatic pressure
When the hydrostatic pressure is greater than the osmotic pressure, the fluid filters out of the blood vessels; which can lead to swelling of the body tissues (excess fluid trapped)
Edema
substances can move cell membranes from a less concentrated solution to a more concentrated one.
- a substance combines with a carrier on the outside surface of the cell membrane, and together they move to the inside surface of the cell membrane.
- requires enzymes and energy is expended.
- Important in maintaining the differences in Na & K ion concentrations of ECF & ICF.
- Sodium Potassium pump; activated, moving sodium from the cells and K into the cells
Active transport
primary regulatro of fluid intake; located in the hypothalmus
Stimulating contributors:
-osmotic pressure of body fluids
-vascular volume
-angiotensin (hormone released in response to decreased blood flow to the kidneys)
Thirst mechanism
certain fluid losses are required to maintain normal body function. 500 ml must be excreted through kidneys ea. day to eliminate metabolic waste products from the body
- though skin
- respirations
- feces
obligatory losses necessary for temp regulation and elimination of waste products. total 1300 ml/day
as kidneys regulate and filter waste, they return electrolytes, ie, K, and Na to blood for use.
-The Cardiovascular and Respiratory systems ensure the body has an adequate O2 to function and use fluids and electrolytes appropriately.
maintaining homeostasis
ADH; antidiuretic hormone
RAAS; Renin-angiotension-adosterone system
ANF; atrial natriuretic factor
hormones involved in maintaing homeostasis
primary regulator of body fluids and electrolyte balance
-regulate the volume and osmolality of extracellular fluids by regulating water and electrolyte excretion.
135-180 L of plasma/day, 1.5 L of urine excreted
-balance maintained by selective retention and excretion
*play significant role in acid-base balance regulation; excreting hydrogen and retaining HCO3
Kidneys
regulates H20 excretion from the kidney, synthesized in the anterior portion of the hypothalamus and acts on the collecting ducts of the nephrons.
-increased serum osmolality rises, hormone produced (collecting ducts become more permeable to h20)
ADH
blood volume temp pain stress drugs, ie. opiates, barbiturates, and nicotine
Factors that affect ADH production
specialized receptors in the juxtaglomerular cells of the kidney nephrons respond to changes in renal perfusion.
;blood flow or pressure of kidney decreases, renin is released.
-promoting Na & h20 retention
-restore blood volume (renal perfusion) though Na and h20 retention
Renin-Angiotensin-Aldosterone System RAAS
peptide hormone released from cells in the atrium of the heart in response to excess blood volume and stretching of the atrial walls.
- ANF promotes Na wasting and acts as a potent diuretic; reducing vascular volume.
- Inhibits thirst, reducing fluid intake
Atrial Natriuretic Factor
- maintaining fluid balance
- contributing to acid-base regulation
- facilitating enzyme reactions
- transmitting neuromuscular reactions
- must be consumed daily
- K & Ca stored in the cells and bones; if serum levels drop, ions shift out of “storage”.
Electrolytes
promotes enzyme reactions during carbohydrate digestion
Mg
present in both ICF & ECF. primary function is regulating acid-base balance, as an essential component of the carbonic acid bicarbonate buffering system.
Extracellular bicarbonate levels regulated by the kidneys.
*produced through metabolic processes in adequate amounts
HCO3
fluids constantly being shifted from one compartment to another to compensate a fluid imbalance.
Compensation
rapid gains or losses (4-8%) of total body weight indicate moderate to severe fluid volume deficits or excesses
FVD
tachycardia
early sign of hypovolemia
elevated body temp
dehydration or FVD
pulse volume low;
FVD
high pulse volume
FVE
irregular pulse rate may occur
electrolyte imbalances
280-300 mOsm/kg
serum osmolality
CBC; H & H
hematocrit measures the volume of whole blood (RBC)
-measure of volume of cells in relation to plasma, it is affected by changes in plasma volume.
increase in Hct; severe dehydration
decrease in Hct severe overload
normal values; 40-54% men and 36-46% women
HCT/ CBC
doubling the serum Na and assoc Cl ions are the major determinants of serum osmolality
-measure of the solute concentration of the blood.
Osmolality
indicator of urine concentration
1.005-1.030
Urine Specific Gravity
- sodium chloride
- potassium chloride
Electrolyte supplement
- serum albumin
- dextran 40
Colloids
- furosemide
- hydrochlorothiazide
- spironolactone (Aldactone)
diuretics
- 5% dextrose and H20
- normal saline solution
- lactated ringers
- 5% dextrose and 1/2 normal saline
Crystalloids
when water and electrolytes are lost or gained in equal proportions so that osmolality of body fluids remain constant.
isotonic imbalance
involve the loss/gain of only water, so that the osmolality of the serum is altered
osmolar imbalance
FVD
dehydration (hyperosmolar imbalance)
FVE
overhydration (hypoosmolar imbalance)
4 types of imbalances
a decrease in intravascular, interstitial, and/or intracellular fluid in the body.
-common, can exist alone or in combo with other electrolyte or acid-base balance issues
FVD; fluid volume deficit
refers to loss of fluid alone, often interchangable with FVD
dehydration
decrease in circulating blood volume
hypovolemia
K lost, Na same, fluid drawn into the vascular compartments from the interstitial spaces as the body attempts to maintain tissue perfusion.
-severe fluid loss can lead to cardiovascular collapse.
isotonic fluid volume deficit
hyponatremic dehydration; greater loss of Na than H20. Serum Na below normal levels. Shifts for ECF and ICF to compensate leads to greater ECF dehydration.
Hypotonic dehydration
F/E balance
A shift of fluid from the vascular space into an area where it is not available to support normal physiological processes
-Trapped fluid represents a volume loss; unavailable for normal physiological processes.
In abdomen or bowel, or other areas, ie pleural or peritoneal space. or with in soft tissue; burn, trauma
Third spacing
Most common cause is excessive loss of GI fluids;
vomitting, diarrhea, or intestinal drainage, intestinal fistulas
-diuretics
renal disorders
endocrine disorders
H20 and Na loss; sweating excessive exercise
hemorrhage
chronic abuse of lax. and enemas
FVD
most common type seen in initial period after a burn. fluid leaks into interstitial spaces, causing edema and further FVD; lower urine output
Hypotonic dehydration
darkend urine decrease urine output confusion lethargy headache light headedness sunken eyes dry mucous membranes dry axillae long tongue furrows postural changes in pulse and blood pressure
symptoms of dehydration
hypertension tachycardia weak pulse tachypnea reduced urine output/concentrated urine with increased sp. gravity
Decreased cardiac output
dry, cracked skin dry mucous membranes increased hematocrit poor skin turgor weightloss
inadequate fluid supply to tissues
edema
symptoms of FVD
no weight loss
Third spacing
Bp down HR up pulse down resp normal jug vein flat edema rare skin turgor loose, poor output low, concentrated urine sp. gravity high weight loss
FVD
BP up HR up pulse up Resp crackles, wheezes jug vein distended skin turgor taut output low to normal urine sp grav. low weight gain
FVE
