Finals_Fluid, Electrolyte, and Acid Base Balance Flashcards
delicate balance of fluids,
electrolytes, and acids and bases maintained in the
body
HOMEOSTASIS
primary body fluid
Water
Percentage of water in an average healthy adult’s, infant, and people older than 50 weight respectively
- 60% of average healthy adult’s
weight - 70% to 80% in infants weight
- 50% to people
older than 50
TWO COMPARTMENTS OF BODY’S FLUID
INTRACELLULAR FLUID (ICF)
EXTRACELLULAR FLUID (ECF)
found within the cells of the body; 2/3 of the total body fluid in adults
INTRACELLULAR FLUID (ICF)
found outside the cells; 1/3 of the total body fluid
EXTRACELLULAR FLUID (ECF)
Two sub types of EXTRACELLULAR FLUID (ECF)
INTRAVASCULAR FLUID (PLASMA)
INTERSTITIAL FLUID
COMPOSITION OF BODY FLUIDS
- Ions
- Cations
- Anions
- Electrolytes
COMPOSITION OF BODY FLUIDS
- charged particles
Ions
COMPOSITION OF BODY FLUIDS
- ions that carry a positive
charge
Cations
COMPOSITION OF BODY FLUIDS
- ions that carry a negative
charge
Anions
COMPOSITION OF BODY FLUIDS
- minerals in the body
that have electrical charge;
chemicals from which ions are
made
Electrolytes
How are Electrolytes measured?
in milliequivalents per Liter of water
(mEq/L) or milligrams per 100 milliliters (mg/100mL)
MOVEMENT OF BODY FLUIDS AND ELECTROLYTES
◎ Osmosis
◎ Diffusion
◎ Filtration
◎ Active Transport
Movement of water across cell membranes, from the less concentrated solution to the more concentrated solution
OSMOSIS
substances dissolved in a liquid
Solute
component that can dissolve a solute
Solvent
the concentration of solutes in body fluids; solute per kilogram of water
OSMOLALITY
power of a solution to draw water
across a semipermeable membrane
OSMOTIC PRESSURE
pulls water from the interstitial space into the vascular compartment
COLLOID OSMOTIC PRESSURE (ONCOTIC PRESSURE)
Types of Solutions
- Isotonic solution
- Hypertonic solution
- Hypotonic solution
Identify the Types of Solutions
- solute and solvent are equal
- given to patients with no problem in their body fluids to administer medications
Isotonic solution
Identify the Types of Solutions
- higher osmolality than body
fluids; cells shrink
- given to patients with water retention
Hypertonic solution
Identify the Types of Solutions
- lower osmolality than body
fluids
- cells swell
- given to patients who experience dehydration
Hypotonic solution
Movement of molecules through a semipermeable membrane from an area of higher concentration to an area of lower concentration
DIFFUSION
Fluid and solutes move together across a membranes from an area of higher pressure to one of lower pressure.
FILTRATION
2 types of pressure associated in Filtration
Filtration and Hydrostatic Pressure
pressure in the compartment that results in the movement.
Filtration pressure
Arterial end of net filtration pressure is?
BP is +10mm Hg
Venous end net filtration pressure
- 7 mm Hg
pressure exerted by a fluid within a
closed system on the walls of the container in which it is contained.
Hydrostatic pressure
Normal Pressure of Blood
25 mm Hg
Substances can move across cell membranes from a less concentrated solution to a more concentrated one by expending energy
ACTIVE TRANSPORT
REGULATING BODY FLUIDS
◎ Fluid Intake
◎ Fluid Output
◎ Maintaining Homeostasis
average adult needs how many mL of fluid per day
2,500 mL per day.
Oral fluids = 1,200 to 1,500 mL
Water in foods = 1,000 mL
Water as by-product of food
metabolism = 200 mL
TOTAL = 2,400 to 2,700 mL
Familiarize
- primary regulator of fluid intake
- located in the hypothalamus of
the brain.
Thirst mechanism
How long does it take for fluid to be absorbed and distributed throughout the body
30 minutes to 1 hour
Fluid losses that counterbalance the adult’s 2,500-mL average fluid intake.
Fluid Output
Urine = 1,400 to 1,500 mL
Insensible Losses
- Lungs (water vapor in the expired air)
and Skin = 350 mL to 400 mL
Sweat = 100 mL
Feces = 100 mL to 200 mL
TOTAL = 2,300-2,600 mL
Familiarize
Homeostatic regulators/mechanisms
- Kidneys
- Antidiuretic Hormone
- Renin-Angiotensin-Aldosterone System
- Atrial Natriuretic Factor
Homeostatic regulators/mechanisms
- Primary regulator of body fluids and electrolyte balance.
- Regulates water and electrolyte secretion
- Plays a significant role in acid-base regulation, excreting hydrogen ion (H+) and retaining bicarbonate
Kidneys
Homeostatic regulators/mechanisms
- Regulates water excretion from the kidney
- Synthesized in the anterior portion of the
hypothalamus
- Produced when serum osmolality rises
- suppressed when serum osmolality decreases
Antidiuretic Hormone (ADH)
Homeostatic regulators/mechanisms
- Restore blood volume (and renal perfusion) through sodium and
water retention
Renin-Angiotensin-Aldosterone System
Renin-Angiotensin-Aldosterone System: in order
- When blood flow or pressure to kidneys decreases, renin is released.
- Renin causes the conversion of angiotensin to angiotensin I, which is
converted to angiotensin II by angiotensin-converting enzyme. - Angiotensin II acts directly on the nephrons to promote Sodium and
water retention. - Stimulates the release of Aldosterone from the adrenal cortex. It
promotes sodium retention.
Homeostatic regulators/mechanisms
- Released from cells in the atrium of the heart in response to excess blood volume and stretching the atrial walls.
- Promotes sodium wasting and acts as a potent diuretic, thus reducing vascular volume
- Reduces thirst, reducing fluid intake
Atrial Natriuretic Factor (ANF)
REGULATING ELECTROLYTES IMPORTANCE
- Maintaining fluid balance
- Contributing to acid-base regulation
- Facilitating enzyme reactions
- Transmitting neuromuscular reactions
Electrolytes Examples
◎ Sodium (Na+)
◎ Potassium (K+)
◎ Calcium (Ca++)
◎ Magnesium (Mg++)
◎ Chloride (Cl-)
◎ Phosphate (PO4-)
◎ Bicarbonate (HCO3-)
Identify the Electrolytes being described
- Most abundant cation in the ECF and a major contribution to serum osmolality
- Normal value: 135-145 mEq/L
- Aids in transmitting nerve impulses and contracting muscles
Sodium (Na+)
Identify the Electrolytes being described
- Major cation in ICF, with only small amount found in ECF.
- Normal serum levels: 3.5 to 5.0 mEq/L
- Vital electrolyte for skeletal, cardiac, and smooth muscle activity.
- Must be consumed everyday because the body cannot conserve it.
- Sources: avocado, raw carrot, spinach, dried fruits, banana, apricot, orange, beef, pork, milk
Potassium (K+)
Identify the Electrolytes being described
- 99% of Calcium is found in the skeletal system, with a relatively small amount in the ECF.
- Vital in regulating muscle contraction and relaxation, neuromuscular function, and cardiac function
- Normal total serum levels: 8.5-10.5 mg/dL
- Normal ionized serum levels: 4-5 mg/dL
- Parathyroid hormone and calcitriol increase serum Ca++ levels; calcitonin decreases serum levels
- Daily intake should be 1,000-1,500 mg of Calcium
Calcium (Ca++)
Identify the Electrolytes being described
- Primarily found in the skeleton and in ICF
- Second most abundant ICF cation
- Normal serum levels: 1.5 to 2.5 mEq/L
- Aids in relaxing muscle contractions, transmitting nerve impulses, regulating cardiac function, and intracellular metabolism.
- Sources: cereal grains, nuts, dried fruits, legumes, green, leafy vegetables, dairy products, meat, fish
Magnesium (Mg++)
Identify the Electrolytes being described
- Major anion of the ECF
- Normal serum levels: 95 to 108 mg/dL
- When sodium is reabsorbed in the kidney, chloride usually follows.
- Major component of gastric juice (HCl), and is involved in regulating acid-base balance.
- Found in the same foods as Sodium.
Chloride (Cl-)
Identify the Electrolytes being described
- Major anion of ICF
- Also found in the ECF, bone, skeletal muscle, and nerve tissue
- Normal serum levels: 2.5 to 4.5 mg/dL
- Aids in metabolizing Carbohydrate, Protein, and Fat; it is absorbed in the intestines
- Sources: meat, fish, poultry, milk products, legumes
Phosphate (PO4-)
Identify the Electrolytes being described
- Present in both ICF and ECF
- Primary function is to regulate acid-base balance (major body buffer)
- Regenerated by the kidneys
- ECF bicarbonate levels are regulated by the kidney
- Produced through metabolic processes
Bicarbonate (HCO3-)
substance that releases hydrogen ions (H+)
Acid
have a low hydrogen ion concentration and can accept hydrogen ions in solution.
Bases (Alkalis)
- the relative acidity or alkalinity of a solution
- reflects the hydrogen ion concentration of the solution (inversely proportional)
pH
normal pH
7.35-7.45
How does our body Regulate acid base balance
- Buffers
- Respiratory Regulation
- Renal Regulation
Identify the type of regulation method of the body
- prevent excessive changes in pH by removing or releasing
hydrogen ions
BUFFERS
Major buffer systems in the ECF
- Bicarbonate (HCO3-)
- Carbonic acid (H2CO3)
Major buffer systems in the ECF
- acid buffer; opponent of acids
Bicarbonate (HCO3-)
Major buffer systems in the ECF
- weak acid
Carbonic acid (H2CO3)
Ratio of carbonic acid and bicarbonic acid to achieve Normal pH
1 part Carbonic Acid (1.2 mEq/L) : 20 parts bicarbonate (24 mEq/L)
adding a strong acid in the ECF, depleting the
bicarbonate and lowering the pH levels
ACIDOSIS
adding a strong base to the ECF, depleting carbonic acid as it combines with the base, increasing the
pH levels.
ALKALOSIS
Identify the type of regulation method of the body
- lungs help regulate acid-base balance by
eliminating or retaining Carbon Dioxide (CO2), a
potential acid.
RESPIRATORY REGULATION
Components of Carbonic acid
Carbon Dioxide (CO2) + Water (H2O)
High Carbonic acid and CO2 or High Bicarbonate levels?
- respiration rate and depth increases, exhaling CO2 and decreasing carbonic acid levels
High Carbonic acid (H2CO3) and CO2 levels
High Carbonic acid and CO2 or High Bicarbonate levels?
- the respiration rate
and dept are reduced, retaining CO2 and increasing carbonic acid levels
High Bicarbonate (HCO3-) levels
Identify the type of regulation method of the body
- Kidneys are the ultimate long-term regulator of acidbase
balance, although slower to respond to changes.
- reabsorbing and regenerating
bicarbonate and hydrogen ions
RENAL REGULATION
Components of Carbonic Acid
Hydrogen ion (H+) +
Bicarbonate (HCO3-)
what does kidney do when there is High H+ ions (acidic) in body?
- kidneys reabsorb and
regenerate bicarbonate and excrete hydrogen ions - H2CO3»_space; H+ (excreted) and HCO3- (retained)
what does the kidney do when there is Low H+ ions (alkalosis) in the body
- excess bicarbonate is
excreted and H+ ion is retained - H2CO3»_space; H+ (retained) and HCO3- (excreted)
FACTORS AFFECTING BODY FLUID, ELECTROLYTES, AND
ACID-BASE BALANCE:
◎ Age
◎ Gender and Body Size
◎ Environmental Temperature
◎ Lifestyle
Two basic types of Fluid Imbalances
Isotonic and Osmolar
Identify which of the Two basic types of Fluid Imbalances
- water and electrolytes are lost or gained in equal proportions
Isotonic
Identify which of the Two basic types of Fluid Imbalances
- loss or gain of only water, so that the osmolality of the serum is altered (electrolytes are concentrated)
Osmolar
Four Categories of Fluid Imbalances
◎ Fluid Volume Deficit
◎ Fluid Volume Excess
◎ Dehydration (hyperosmolar imbalance)
◎ Overhydration (hypo-osmolar imbalance) 47
Identify the fluid imbalance being described
- body loses both water and electrolytes from the ECF (intravascular compartment) in similar
proportions
Fluid Volume Deficit (FVD) or Hypovolemia
Identify the fluid imbalance being described
Causes:
○ Abnormal losses through the skin, GI tract, kidney
○ Movement of fluid in a third space (area that
deems the fluid unavailable for us)
48
Fluid Volume Deficit (FVD) or Hypovolemia
Identify the fluid imbalance being described
- body retains both water and sodium in similar
proportions to normal ECF
Fluid Volume Excess (FVE) or hypervolemia
Identify the fluid imbalance being described
Causes:
- Increased intake of NaCl (sodium level is still normal, since both water and sodium are equally
retained)
- Infusion of sodium-containing fluids rapidly
- Disease processes (heart failure, kidney failure,
liver cirrhosis)
Fluid Volume Excess (FVE) or hypervolemia
excess interstitial fluid
EDEMA
leaves a small depression or pit after finger
pressure is applied
Pitting Edema
Identify the fluid imbalance being described
- Water is lost from the body, leaving the client with excess sodium
- Cells are dehydrated/shrunk
Dehydration (Hyperosmolar imbalance)
Identify the fluid imbalance being described
- Water is gained in excess of electrolytes, resulting in
low serum osmolality and low serum Na+ levels
- Cells are swollen
Overhydration (hypo-osmolar imbalance)
Identify the fluid imbalance being described
- Can lead to cerebral edema and impaired neurologic function
- causes Syndrome of Inappropriate Anti Diuretic Hormone
(SIADH) and Head Injury
Overhydration (hypo-osmolar imbalance)
ELECTROLYTE
IMBALANCES: Sodium
Hyponatremia and Hypernatremia
ELECTROLYTE
IMBALANCES: Sodium
- Less than 135 mEq/L
- Severe cases:
<110 mEq L
- Can lead to neurological
damage (cerebral edema)
due to low serum osmolality
- Causes: burns, GI losses,
diuretics, head injury
Hyponatremia
ELECTROLYTE
IMBALANCES: Sodium
- Higher than 145 mEq/L
- Cells are dehydrated
- Primary manifestations are neurological in nature
- Causes:
water deprivation,
diabetes insipidus,
excessive use of NaCl
Hypernatremia
ELECTROLYTE
IMBALANCES: Potassium
- Less than 3.5 mEq/L
- Causes:
GI losses (vomiting, diarrhea)
Potassium-wasting diuretics
Poor intake of Potassium
- S/Sx: muscle weakness,
lethargy, cardiac dysrhythmias
Hypokalemia
ELECTROLYTE
IMBALANCES: Potassium
- More than 4.5 mEq/L
- More dangerous than hypokalemia since it can lead to cardiac arrest
- Causes:
1. Renal Failure
2. High Potassium Intake
3. Burns
- S/Sx: confusion, muscle weakness, bradycardia, irregular pulse, numbness
in extremities
Hyperkalemia
ELECTROLYTE
IMBALANCES: Calcium
- Total calcium:
<8.5 mg/dL
- Ionized calcium:
<4 mg/dL
- Causes:
total thyroidectomy,
hypomagnesemia, chronic alcoholism
Hypocalcemia
SEVERE HYPOCALCEMIA CAN CAUSE ____________ WITH MUSCLE SPASMS AND PARESTHESIAS
AND CAN LEAD TO CONVULSIONS
Severe Hypocalcemia
Two signs of Hypocalcemia
- Chvostek’s sign
- Trousseau’s sign
ELECTROLYTE
IMBALANCES: Calcium
- Total calcium:
>10.5 mg/dL
- Ionized calcium:
>5 mg/dL
- Calcium is mobilized from the skeleton due to malignancy or prolonged immobilization
- S/Sx:
depressed DTR, cardiac
dysrhythmias, hypercalciuria, flank
pain secondary to urinary calculi
Hypercalcemia
ELECTROLYTE
IMBALANCES: Magnesium
- Less than 1.5 mEq/L
- Common cause: chronic
alcoholism
- Other causes: GI losses, burns, pancreatitis
- S/Sx: Chvostek’s and
Trousseau, increased reflexes, respiratory difficulties, cardiac dysrhythmias
Hypomagnesemia
ELECTROLYTE
IMBALANCES: Magnesium
- More than 2.5 mEq/L
- Often iatrogenic (result of overzealous magnesium therapy)
- S/Sx: depressed DTR,
bradycardia, lethargy,
respiratory depression,
cardiac arrest
Hypermagnesemia
ELECTROLYTE
IMBALANCES: Chloride
- Below 95 mEq/L
- Causes: GI/kidney losses,
sweating
- S/Sx: muscle twitching,
tremors, tetany
Hypochloremia
ELECTROLYTE
IMBALANCES: Chloride
- Above 108 mEq/L
- Causes: excess replacement of NaCl or KCl
- S/Sx: acidosis, weakness,
lethargy, dysrhythmias,
coma
Hyperchloremia
ELECTROLYTE
IMBALANCES: Phosphate
- Below 2.5 mg/dL
- Causes: GI losses, use of
phosphate-binding antacids, alcohol withdrawal
- S/Sx:
paresthesias, muscle
weakness and pain, metal
changes, and possible
seizures
Hypophosphatemia
ELECTROLYTE
IMBALANCES: Phosphate
- Above 4.5 mg/dL
- Causes: tissue trauma,
chemotherapy, renal failure, increased
ingestion/administration of phosphate
- S/Sx: numbness, tingling
around the mouth and
fingertips, muscle spasms,
tetany
Hyperphosphatemia
Classification of Acid Base Imbalances
respiratory or metabolic
How does lungs normally regulate Carbonic acid levels?
retention/excretion of CO2
(respiratory acidosis or alkalosis)
How are Bicarbonate and Hydrogen ion levels regulated?
kidneys through (metabolic acidosis or alkalosis)
- Hypoventilation and CO2
retention cause carbonic acid to increase and the pH to fall below 7.35 - Causes: Asthma, COPD, CNS depression due to anesthesia/narcotic
- causes the kidneys to retain bicarbonate to restore the normal
carbonic acid to bicarbonate ratio - May require hours to days to restore the normal pH
RESPIRATORY ACIDOSIS
- When a person hyperventilates, exhaling
more CO2 and decreasing carbonic acid levels = pH greater than 7.45 - Causes: psychogenic or anxiety-related hyperventilation
- Kidneys will excrete bicarbonate
RESPIRATORY ALKALOSIS
- bicarbonate levels are low in relation to the amount of carbonic acid = decreased pH
- Causes: renal failure, inability of the kidneys to excrete H+, diabetic ketoacidosis
- Stimulates the respiratory center = increase depth and rate of
respirations; CO2 is eliminated and carbonic acid falls
METABOLIC ACIDOSIS
- amount of bicarbonate in the body exceeds to the normal ratio
- Causes: ingestion of NaHCO3 as an antacid, vomiting (loss of HCl)
- Depresses the respiratory rate (slow and shallow) = CO2 is retained and carbonic levels increases
METABOLIC ALKALOSIS
CLINICAL MEASUREMENTS
◎ Daily Weights
◎ Vital Signs
◎ Fluid Intake and Output
LABORATORY TESTS
◎ Serum electrolytes
◎ Urine pH
◎ Urine specific gravity
◎ Urine Sodium and Chloride excretion
◎ Arterial Blood Gases (ABGs) - measures the acidity, or pH, and the levels of oxygen (O2) and carbon dioxide (CO2) from an artery.
LABORATORY TESTS
- pH
Normal: 7.35 - 7.45
If above: Alkalosis
If below: Acidosis
LABORATORY TESTS
- pCO2
Normal: 35-45
If below: Alkalosis
If above: Acidosis
LABORATORY TESTS
- HCO3
Normal 22-26
If below: Acidosis
If above: Alkalosis
LABORATORY TESTS
- pO2
Normal: 80-100
If below: Hypoxemia
If above: O2 Therapy
LABORATORY TESTS
- SaO2
Normal: 95-100%
If below: Hypoexemia
If above: No info
GOALS of Fluid Therapy
◎ Maintain/restore normal fluid balance
◎ Maintain/restore normal balance of electrolytes in the IC and EC compartments
◎ Maintain/restore pulmonary ventilation and
oxygenation
◎ Prevent associated risks
Types of Intravenous Fluids
- Hypertonic solution
- Hypotonic solution
- Isotonic solution
Identify the Types of Intravenous Fluids
- concentrated with solute,
expanding vascular volume
Hypertonic solution
Examples of Hypertonic Fluids
5% DEXTROSE IN NORMAL
SALINE (D5NSS)
- 5% DEXTROSE IN 0.45%
NACL
- 5% DEXTROSE IN
LACTATED RINGERS (D5LR)
- 5% DEXTROSE IN
NORMOSOL-M (D5NM)
Identify the Types of Intravenous Fluids
- less solutes, for treatment of cellular dehydration
Hypotonic solution
Examples of Hypotonic Fluids
- 0.45% NACL (HALF NORMAL SALINE)
- 0.33% NACL (1/3 NORMAL
SALINE)
Identify the Types of Intravenous Fluids
- Isotonic solution
Isotonic solution
Examples of Isotonic Fluids
- 0.9% NACL (NORMAL
SALINE, PLAIN NSS) - LACTATED RINGER’S (PLAIN LR)
- 5% DEXTROSE IN WATER
(D5W)
How to promote wellness in terms of fluid and electrolyte balance
adequate fluids and consumption of a balanced diet
3 ways to implement Enteral Fluid and Electrolyte Replacement
- Fluid intake modifications
- Dietary changes
- Oral electrolyte supplements
Components of Normal Saline
Sodium Chloride
Components of Ringer’s solution
Sodium, chloride, potassium, calcium
Components of Lactated Ringer’s solution
Sodium, chloride, potassium, calcium, and lactate (metabolized in the liver to form bicarbonate)
Components of Volume expanders
dextran, plasma, albumin
Note: used for severe blood/plasma loss
Formula for hourly rate of the fluid (cc/hr)
total infusion volume/total infusion time
Formula for Drops per minute
(total infusion volume x drop factor) divided by total time of infusion in minutes
Drop factors: Macroset
15 or 20 gtts/mL
Drop factors: Microset
60 gtts/mL
Common Venipuncture sites for for intermittent or continuous infusions
Metacarpal, basilic and
cephalic veins
This Venipuncture site is inserted in the subclavian or jugular vein, with the distal tip resting in the SVC
Central Venous Catheters
This Venipuncture site is inserted in basilic or
cephalic vein, for long-term intravenous access when the client will be maintaining IV therapy at home
Peripherally Inserted
Central Venous Catheter
(PICC)
This intervention Can be effective in restoring intravascular (blood)
volume
BLOOD TRANSFUSIONS
Four main groups/types of human blood
A, AB, B, O
the only IV solution that is
compatible with blood products
0.9% NaCl (Plain NSS)
Enumerate Blood Products
- Whole Blood
- Packed Red Blood Cells (RBCs)
- Platelets
- Fresh Frozen Plasma (FFP)
- Albumin and Plasma Protein Fraction
Identify Blood Products
- not commonly used except for extreme cases of acute hemorrhage; RBCs, plasma, plasma proteins, fresh platelets, and other clotting factors
Whole Blood
Identify Blood Products
- to increase the oxygen carrying capacity of blood in anemia, surgery and
blood disorders
Packed Red Blood Cells (RBCs)
Identify Blood Products
- given for patients with bleeding disorders or platelet deficiency
Platelets
Identify Blood Products
- expands blood volume and provides clotting factors. No need to be typed and crossmatched
Fresh Frozen Plasma (FFP)
Identify Blood Products
- blood volume expander
Albumin and Plasma Protein Fraction