




Homeostasis
o Body simply does not reach a state of equilibrium and remain there, small changes
constantly occur in response to physiological processes.
o Maintaining homeostasis is essential to life
Chemical Organization
o Matter is anything that occupies space and possesses mass
o Elements are made of tiny units called atoms, atoms of each element are alike
o Atom is the smallest unit of chemical structure, and no chemical change can alter it
o Atoms of the same element that have different atomic weights are called isotopes
o Radiation from isotopes can be in alpha, beta, or gamma rays, useful for biological
markers
o Atoms of the same element can unite to form molecule, for example two hydrogen
elements combine to form hydrogen molecule
o When atoms of two different element combine, they form a compound
o When water and salt is mixed, it is called mixture
o Two or more atoms bond and form a more complex molecule is called synthesis
o When bonding between atoms is broken, the reaction is called decomposition
o Ion is an atom bearing an electrical charge
o Cation is a positive Ion
o Anion is a negative ion
o Components that dissociate into Ions in water is called electrolytes
Water
o Water is about 60% of total body weight
o 92% of body’s organic and inorganic components dissolve in blood and is transported
o Water absorbs heat resulting from muscle contractions and distribute this over the body
o Water in form of perspiration released from sweat cool the body
o Breaking large molecules into smaller molecules with water is called hydration
Gases
o Oxygen and Carbon Dioxide are important gases for body
o Oxygen is used to release energy from glucose and other molecules
o As a result, Carbon Dioxide is produced and transported to the lung
Acids, Bases, Salts, and pH
o Acid is any substance that in solution yields hydrogen ions bearing positive charge, and
lowers the pH
o Base is a substance that when dissociated produce ions that will combine with
hydrogen ions, and raise the pH
o Salt is formed when acid and base react with each other, and is resulted from
neutralization of an acid by a base, an example will be sodium chloride
o pH
 Acid and Base are classified as strong or weak, strong release many, weak
release few
 pH, or Potential Hydrogen, indicates the hydrogen ion concentration in a solution,
express from 0 to 14 with 7 being neutral
 greater than 7 is alkaline
 lesser than 7 is acidic






HUMAN BLOOD pH RANGE FROM 7.35 TO 7.45
Greatest source of acids is cellular metabolism, and when blood pH fall below
7.35, acidosis occurs
As acidosis occur the central nervous system becomes involved, patient
becomes unconscious, heartbeat become weak and irregular, blood pressure
decrease
When alkalosis occur, pH is raised above 7.45, and symptoms include
heightened state of nervous system, muscle spasmodic contractions,
convulsions, and even death
Buffers
o Substances that attempts to maintain pH range, in body fluids buffers keep pH in normal
range
o Bicarbonate Buffer System
 Found in both extracellular and intracellular fluids
 Has two components, carbonic acid H2CO3 and Sodium Bicarbonate NaHCO3
 Sodium Bicarbonate act as a weak base, and is used to neutralize strong acid
 Carbonic acid act as a weak acid, and is used to neutralize strong base
 Enzyme Carbonic anhydrase accelerate conversion of carbon dioxide to carbonic
acid
o Phosphate Buffer System
 Involved in regulating pH of intracellular fluid and fluid of the kidney tubules
 Has two phosphate components, sodium monohydrogen phosphate NaHPO4
and Sodium dihydrogen phosphate NaH2PO4
 Sodium monohydrogen phosphate act as weak base to neutralize strong acid
 Sodium dihydrogen phosphate act as weak acid to neutralize strong base
o Protein Buffers
 Protein is formed from amino acids
 Carboxyl group from amino acid can act as weak acid
 Amino group from amino acid can act as weak base
 This is found inside cells, especially in hemoglobin of red blood cells, can also be
found in plasma
Substance Movement
o Ability of a membrane to permit substance to pass is called permeability
o Cell membrane allows passage of only certain substances, and this is called
selectively permeable membrane
o Artificial membrane like cellophane is called semi permeable membrane
o Passive Transport
 Passive transport is substance pass through cell membrane without energy
expenditure
 Diffusion
 The tendency of molecules of either gas, liquid, or solid to move from
region of higher molecular concentration to region of lower molecular
concentration


Dialysis is when diffusion is employed to separate molecules out of a
solution by passing them through a semipermeable membrane, such as
when artificial kidney filter harmful molecules
 Osmosis
 Diffusion of water through a semipermeable membrane from a region of
higher water concentration to a region of lower water concentration
 Water is a solvent
 Pressure exerted against cell membrane by water inside the cell is called
osmotic pressure, aka minimum pressure needed to counter osmosis
 Solution with same molecular concentration as cell is called isotonic
solution
 Solution with lower molecular concentration than the cell is called
hypotonic solution
 Death of red blood cell by being in hypotonic solution is called hemolysis
 Solution with higher molecular concentration than the cell is called
hypertonic solution
 Death of red blood cell by being in hypertonic solution is called crenation
 For a person who lost large volume of blood, normal saline is used, which
is 0.9% sodium chloride solution, which is isotonic solution
 Filtration
 Fluid and substances dissolved in there are forced through cell membrane
by hydrostatic pressure
 Hydrostatic pressure is the pressure fluid exerts against the membrane
 Hydrostatic pressure exerted by pumping action of the heart causes some
liquid fraction of the blood to pass out of capillaries, resulting in tissue fluid
 Hydrostatic pressure cause many material to leave blood through tubules
in kidney, waste products removed to form urine
o Active Transport
 Cells must use energy to move the molecules
Fluid and Electrolyte Balance
o Human saline solution is 0.9%
o Body Fluid
 Intracellular fluid contains all water and ions inside the cells. Around 65% is
found here
 Extracellular fluid contains fluid outside the cells
 Interstitial fluid is fluid in the tissue space around each cell
 Intravascular fluid is plasma in the blood vessels and lymph in lymphatic
system
 Major Ion in intracellular fluids are potassium, phosphate, and magnesium
 Major Ion in extracellular fluids are sodium, chloride, bicarbonate
o Exchange between the extracellular and intracellular fluid
 Movement is primarily govern by osmosis, but diffusion and active transport also
play a role


Fluid balance between interstitial fluid and plasma is regulated by hydrostatic
pressure and osmotic pressure
 When fluid accumulates in tissue space, swelling occurs and is known as edema
 Edema is caused by kidney or liver disease, heart disorders
 When more water is lost than replaced, dehydration occurs
 Cause of dehydration include water deprivation, excessive urination, sweating,
diarrhea, vomiting
o Regulators of fluid and electrolyte balance
 Typical per day fluid loss is 2500ml
 Skin
 Water lost through skin is perspiration and diffusion, this is known as
insensible loss because person is not aware
 Average loss of 300-500ml
 Lungs
 Insensible loss of 400-500ml through breating
 Gastrointestinal tract
 About 200ml of water are lost per day as feces, other are reabsorbed,
according to book this is sensible loss
 Kidneys
 Excretes 1000 to 1500ml per day, as sensible loss
 ADH released by posterior pituitary glands act on kidney to reabsorb water
 Aldosterone cause reabsorption of sodium, leading to water retention
 Renin cause release of aldosterone
 Sodium is main electrolyte that promotes retention of water
 Fluid and food intake
 60% fluid is from water consumption
 30% fluid is from food
 8-10% is from metabolism
 Thirst
 Water consumption occurs in response to sensation of thirst
Disturbances in Electrolyte balance
o Sodium
 Major electrolyte in extracellular fluid, regulates fluid balance through osmotic
pressure results from water following sodium in the body
 Normal serum sodium for adult is 135 to 145 mEq/L
 Food rich in sodium include
 processed/prepared foods, like canned vegetables, soups, luncheon
meats, frozen foods, potato chips, snack foods, olives, pickles
 Sodium containing condiments, like soy sauce, salad dressings,
sauces, dips, ketchup, mustard, relishes
 Natural foods, like meat, poultry, dairy, vegetables
 Hyponatremia, which is sodium deficit, can cause edema. Caused by prolonged
vomiting, diarrhea, or gastri/intestinal suctioning, diuretics, or SIADH

Signs include hypotension, tachycardia (fast heart rate), edema,
headache, lethargy (fatigue), confusion, muscle weakness, twitching,
abdominal cramps, dry mucous, and dry skin
 Hypernatremia
 An elevated serum sodium level, caused by excess sodium, loss of water,
or decreased renal function
 Signs are muscle twitching, tremor, hyperreflexia (over responsive reflex)
agitation, restlessness, stupor (lack of critical cognitive function), increase
body temperature, and tachycardia (increase heart rate)
o Potassium
 Major electrolyte in intracellular fluid. Intracellular concentration is 150 mEq/L
 Extracellular potassium is between 3.5 to 5.3 mEq/L
 Maintain normal nerve and muscle activities especially the heart
 Food rich in potassium include Banana, Orange, Apricot, Cantaloupe, Dried
fruit, avocado, raw carrots, baked potato, spinach, milk, yogurt, meat, and
fish
 Hypokalemia, or lack of potassium, is caused by excessive loss of gastric fluid
and use of diuretics
 Associated with Metabolic Alkalosis
 Signs include muscle weakness, paralytic ileus (blockage of bowl),
polyuria (large urination), EKG changes (electrocardiogram changes),
elevated blood glucose level
 Use IV route only when hypokalemia is life threatening, hyperkalemia
can cause heart failure
 Hypokalemia can cause cardiac arrest when potassium level is lower than
2.5 mEq/L, or when client is taking digitalis
 Hyperkalemia, or excessive potassium, caused by renal disease, extensive
trauma, or insulin deficiency.
 Signs include anxiety, irritability, diarrhea, abdominal cramping,
electrocardiogram changes, and cardiac arrest
 Hyperkalemia is much more critical than hypokalemia
o Calcium
 Plays an essential role in bone and teeth integrity, blood clotting, muscle
functioning, and nerve impulse transmission. Vitamin D is required for calcium
absorption. 50% of calcium is ionized, and 50% is bounded to protein, and only
1% is found in blood.
 Normal calcium level is 8.5 to 10.5 mg/dL, values for older adults are lower
 50% of calcium is bound to albumin, correlate serum calcium level with serum
albumin level, because change in albumin will affect calcium
 Food rich in calcium include milk, yogurt, cheese, tofu, almonds, broccoli,
spinach
 Hypocalcemia is low serum calcium level. Caused by hypoalbuminemia (low
blood albumin), renal failure, chronic diarrhea, and hormonal and electrolyte
influence

Hypocalcemia cause anxiety, irritability, tetany (involuntary contraction of
muscle), abdominal and muscle cramps, positive chvostek’s sign (facial
twitch), positive trousseau’s sign (flexion of wrist), weak heart
contractions, fractures
 Hypercalcemia is high serum calcium level. Caused by increased use of calcium
supplements, renal dysfunction, diuretics, use of steroids, and
hyperparathyrodiusm. Hypercalcemia can be an indication of more severe
disease
 Associated with Metabolic Alkaloses
 Hypercalcemia can cause depression, signs of heart block, pathological
fractures, kidney stones
o Magnesium
 Most are found in intracellular fluid and in combination with calcium and
phosphorus in bone, muscle, and soft tissue
 Blood serum only contain 1% of magnesium
 When magnesium deficiency develop, body conserves magnesium at expense of
excreting potassium
 Low level of magnesium indicates low level of calcium and potassium, and vise
versa
 Normal level is 1.5 to 2.5 mEq/L
 Hypomagnesemia is low magnesium level, commonly from chronic alcoholism
(main) and steatorrhea (excessive fat in fece), diarrhea, diabetes malnutrition,
use of laxatives, and acute myocardial infarction.
 Hypomagnesemia can cause hyperirritability, tetany like symptoms,
increase tendon reflexes, hypertension (high blood pressure), cardiac
dysrhythmias (irregular heartbeat)
 Hyperlimentation, or excessive eating, can cause hypomagnesemia if
supplements are not taken
 Hypermagnesemia is high magnesium level, associated with uncontrolled
diabetes, renal failure, and ingestion of magnesium or laxative, and magnesium
citrate
 Hypermagnesemia can cause Bradycardia (too slow heartbeat) cardiac
arrest, hypotension (low blood pressure), electrocardiogram changes,
muscle weakness, paralysis, CNS depression, confusion, flushing
o Phosphate
 Main intracellular anion, in serum appear as phosphorus.
 Phosphorus range is 2.5 to 4.5 mg/dL
 Most phosphorus is found in teeth and bone bounded with calcium, and exist with
calcium inversely
 Hypophosphatemia
 Not usually caused by decreased dietary intake, but more from respiratory
alkalosis, intense, prolonged hyperventilation
 Can cause muscle weakness, fatique, tremors, bone pain, seizures, coma,
weak pulse, anorexia, and bone changes
 Hyperphosphatemia




Result from renal failure, excessive use of phosphate laxative, respiratory
acidosis
Can cause Tetany, hyperreflexia, flaccid paralysis (weakness with reduce
muscle tone), tachycardia (fast heart beat), and abdominal cramps
o Chloride
 Major anion in extracellular fluid, maintain osmotic pressure and acid base
balance. Kidney selectively excrete chloride or bicarbonate ions depend on acid
base balance.
 Normal level is 95 to 108 mEq/L
 Hypochloremia results from prolonged diarrhea or diaphoresis, and is related to
vomiting, gastricsuctioning, or gastric surgery
 Signs include tremors, twitching, low blood pressure, slow breating
 Hyperchloremia results from dehydration, hypernatremia, or metabolic acidosis
 Signs include weakness, deep and rapid breathing, and lethargy (fatigue)
Acid Base Balance
o Blood below 7.35 is acidosis, blood above 7.45 is alkalosis
o Regulators of acid-base balances
 Buffer systems, include bicarbonate, phosphate, and protein
 Respiratory Regulation of acid-base balance
 Respiratory system help maintain acid base balance by controlling the
content of carbon dioxide in extracellular fluid
 Rate of metabolism determines formation of carbon dioxide
 When carbon in food joins with oxygen, it is oxidized
 When carbon dioxide level is high, respiratory increase, when carbon
dioxide is low, respiratory decrease
 Renal control of hydrogen ion concentration
 Kidney control extracellular fluid by eliminating either hydrogen ions or
bicarbonate
o Diagnostic and Laboratory data
 Arterial blood gases test measures level of oxygen and carbon dioxide in blood
 pH is tested, but has been discussed
 PO2 is partial pressure of oxygen, normal range is 80-100 mm Hg, this
decrease as pH decrease
 PCO2 is partial pressure of carbon dioxide, normal range is 35 to 45 mm Hg.
When PCO2 is too high, acidosis occurs, vise versa
 SaO2 is percentage of oxygen combines with hemoglobin in blood
 Normal range of HCO3 is 24 to 28 mEq/L
Disturbance in Acid Base Balance
o Acid base imbalances are respiratory acidosis and alkalosis and metabolic acidosis and
alkalosis
o Respiratory Acidosis
 Carbon dioxide not eliminated fast enough, creating carbonic acid
 Hypoventilation cause hypoxemia, or decreased oxygen in blood
 Hyperkalemia can accompany acidosis

 Older adults are more at risk
o Respiratory Alkalosis
 Decrease concentration of hydrogen ions, and below normal PCO 2 level, caused
by hyperventilation, or excessive exhalation of carbon dioxide, and result in
hypocapnia, or decreased arterial carbon dioxide concentration
o Metabolic Acidosis
 Increased concentration of hydrogen ions, or decrease of bicarbonate
concentration.
 Low blood pH, low Bicarbonate level
 Common with kidney disease or diabetes
 Electrolyte shift occurs during metabolic acidosis, which is when hydrogen and
sodium move into cell and potassium exists
o Metabolic Alkalosis
 Loss of acid or gain of base
 Hypokalemia can be caused
 Vomiting, nasogastric suctioning, diarrhea and diuretic therapy put client at risk
for metabolic alkalosis
Nursing Process
o Assessment, collect data to identify patients who have fluid or electrolyte problems
 Health History
 Physical Examination
 Daily Weight, change in body’s total fluid volume is reflected in weight
 Vital Signs
o Fluid volume deficit has increase pulse rate and weak strength, low
blood pressure
o Fluid volume excess has decrease pulse rate and strong strength,
high blood pressure
 Intake and Output
o I&O should be measured on 24 hours basis
o Minimum intake of 1500ml is essential, all liquid taken by mouth,
tube feeling, and parenterallyare included
o Output include urine, vomitus, diarrhea, and drainage from tubes
o Thirst is indicator of fluid deficit
o Food intake help maintain extracellular fluid volume
 Skin
o Edema is symptom of excess fluid, it can be localized or
generalized
o Firmly press thumb against edematous area for 5 seconds and
release to observe severity
 +0 no pitting
 +1: 0 to ¼ inch pitting, mild
 +2 ¼ to ½ inch pitting, moderate
 +3 ½ to 1 inch pitting, severe
 +4 1 inch and up pitting, severe
o Turgor is resiliency of skin, when skin is pinched and released it
test turgor
o Decrease skin turgor indicates dehydration
 Buccal Cavity
o Fluid volume deficit cause decrease saliva, sticky dry mucous
membrane and dry cracked lips, tongue will have longitudinal
furrows
 Eyes
o Sunkenness, dry conjunctiva, and decreased or absent tearing are
signs of fluid volume deficit
o Puffy eyelids are signs of fluid volume excess
 Jugular and Hand veins
o Fluid volume excess causes distention in jugular vein
o Fluid volume deficit cause decreased hand venous filling
 Neuromuscular system
o Calcium and magnesium imbalances cause increase in
neuromuscular irritability
 Diagnostic and Laboratory Data
 Hemoglobin and Hematocrit Indices
o Hemoglobin level decrease with bleeding
o Hematocrit is a measure of level of red blood cell
o Dehydration increase hematocrit
o Overhydration decrease hematocrit
 Osmolality
o A measurement of total concentration of dissolved particles
o Serum Osmolality measure total concentration of dissolved
particles per kilogram of water in serum, separate ions from inactive
substances.
o Osmolarity is concentration of solutes per liter of cellular fluid,
interchangeable with osmolality. However Osmolality refer to body
fluid, and IV fluid refer to osmolarity
o Urine Osmolality measures urine, normal range is 500-800
mOsm/kg
 Urine pH
o Urine normal pH is 4.5 to 8.0
o Acidosis and alkalosis affect urine pH
o Nursing Diagnosis
 Deficit Fluid Volume
 Excess Fluid Volume
 Risks for
 Others
o Planning and Outcome Identification
o Implementation
 Monitor Daily Weight
 Measure Vital Signs
 Vital signs should be taken every 15 minutes
 Measure Intake and Output
 Intake should exceed output by 500ml
 Provide Oral Hygiene
 Good oral hygiene promotes fluid balance
 Mouthwash with alcohol can dry mouth
 Initiate Oral Fluid Therapy
 Nothing by mouth, total restricting of oral fluid
o Oral hygiene important
 Restricted fluid
o Treating excess fluid volume
 Forced fluid
o Encourage intake of oral fluids
o Treating fluid volume deficiency
o Drink room temperature fluid
 Maintain tube feeding
 Monitor IV therapy
 Fluid replacement is based on weight, 2.2 pound is equivalent to 1 liter
 Infiltration is seepage of fluid into interstitial tissue
o Evaluation