Fluid and Electrolytes

Fluid inside the cell

Fluid outside the cell

Fluid inside the vasculature

Fluid outside of the cell membrane but not within the circulatory system

Abnormal decrease in total body water

Retention of abnormally high amount of body fluid

• Substances that seperate into electrically charged particles
• Cations have a positive charge (+)
• Anions have a negative charge (-)

• Sodium (Na+)
• Potassium (K+)
• Calcium (Ca++)
• Magnesium (Mg++)

• Most prevalent cation in extracellular fluid
• "Water follows sodium"
• Important in transmission of nervous impulses
• Hypernatremia is an abnormal increase in sodium
• Hyponatremia is an abnormal decrease in sodium

• Most prevalent cation in the intracellular fluid
• Important in transmission of electrical impulses
• Hyperkalemia is an abnormally high potassium level
• Hypokalemia is an abnormally low potassium level

• Plays a major role in muscle contraction as well as nervous impulse transmission
• Hypercalcemia is an abnormally increased calcium level
• Hypocalcemia is an abnormally decreased calcium level

• Necessary for several biochemical processes
• Closely associated with phosphate
• Hypermagnesemia is an abnormally increased level of magnesium
• Hypomagnesemia is an abnormally decreases level of magnesium

• Chloride (Cl-)
• Bicarbonate (HCO3-)
• Phosphate (HPO4-)

• Negative charge balances the positive charge of cations
• Major role in fluid balance and renal function
• Associated with sodium

• Principle buffer of the body
• Neutralizes the hydrogen ion and other organic acids

• Important in body energy stores
• Closely associated with magnesium in renal function
• Acts as a buffer, primarily in the intracellular space

The movement of a substance from an area of greater concentration to an area of lower concentration

• Isotonic
• Hypertonic
• Hypotonic

Solutions on opposite sides of a membrane are equal concentration

The concentration of a given solute is greater on one side of a membrane than the other

The concentration of a given solute is less on one side of a membrane than the other

• Osmosis is the movement of water from an area of higher WATER concentration to an area of lesser WATER concentration
• Because water is a solvent, it moves from an area of lower SOLUTE concentration to an area of higher SOLUTE concentration

• The movement of a substance across the cell membrane against the osmosis gradient (towards the side that already has more substance)
• Faster than diffusion
• Requires energy

• Certian molecules can move across the cell membrane with the assistance of "helper proteins"
• Glucose is one example
• Depending on the substance, this movement may or may not require energy

Pressure exerted my the concentration of solutes on one side of a semipermeable membrane

Osmotic pressure exerted by large protein particles

Net filtration=Forces favoring filtration-Forces opposing filtration

Accumulation of water in the interstitial space due to disruption in the forces and mechanisms that normaly keep net filtration at zero

The body maintains a constant balance between intake and excretion of waterAmount gained every day approximately equals the amount lost

• Isotonic
• Hypernatremic
• Hyponatremic

Loss of sodium and water in equal amounts

Loss of water in excess of sodium

Loss of water in excess of water

• Causes
• Severe or long term diarrhea or vomiting
• Systemic infection
• Intestinal obstruction
• Signs and Symptoms
• Dry skin or mucous membranes
• Poor turgor
• Oliguria (less urinary output)
• Anuria (no urinary output)
• Acute weight loss
• Depressed or sunken fontanelles in infants
• Management
• IV infusion of isotonic fluid

• Causes
• Excessive or misuse of diuretics
• Continued administration of sodium in absence of water intake
• Excessive loss of water without loss of sodium
• Profuse, watery diarrhea
• Inhalation or ingestion of salt water
• Signs and Symptoms
• Dry, sticky mucous membranes
• Flushed skin
• Intense thirst
• Oliguria or Anuria
• Increased body temperature
• AMS
• Management
• Volume replacement with isotonic solution or hypotonic based on serum sodium levels

• Causes
• Use of diuretics
• Excessive perspiration
• Salt loosing renal disorders
• Increased water intake
• Inhalation or ingestion of fresh water
• Signs and Symptoms
• Abdonimal or muscle cramps
• Seizures
• Rapid thready pulse
• Diaphoresis
• Cyanosis
• Management
• IV replacement with normal saline or lactated ringers
• Occasionally, hypertonic saline

• An increase in body water with a decrease in solute concentration
• May result from..... Parenteral administration of too much water,Impaired cardiac function, Impaired renal function, Some endocrine dysfunctions
• Signs and Symptoms
• SOB
• Puffy eyes
• Edema
• Polyuria
• Moist crackles in the lungs
• Acute weight gain
• Management
• Cause dependent

• A very narrow range of serum level must be maintained for normal function 3.5 to 5.0 mEq
• Loses areusually minimal and are replenished through dietary intake
• Excessive potassium is usually excreted through the kidneys
• Imbalances interfer with neuromuscular functions
• May cause sudden death

• Possible Causes
• Reduced dietary intake
• Poor potassium absorption by the body
• Medications
• Diuretics
• Steroids
• Theophyline
• Signs and Symptoms
• Malaise
• Skeletal muscle weakness
• Decreased reflexes
• Weak pulses
• Faint or distant heart sound
• Shallow respirations
• Low blood pressure
• GI problems
• Anorexia
• Vomiting
• Gaseous distention
• Excessive thirst
• Management
• Based on exact serum level

• Causes
• Acute or chronic renal failure
• Burns
• Crush injuries
• Severe infections in which large amonts of potassium is released
• Excessive use of potassium salts
• Signs and Symptoms
• Irriability
• Abdominal distension
• Nausea
• Diarrhea
• Oliguria
• Weakness to Paralysis

• Essential for body function
• Neuromuscular transmission
• Cell membrane permeability
• Hormone secretion
• Growth and ossification of body
• Muscle contraction
• Calcium intake in a normal balanced diet is sufficient for needs
• Calcium is excreted through :Urine, Feces, Perspiration

• A decrease in serum calcium
• Possible causes
• Endocrine dysfunction
• Renal insufficiency
• Decrease in intake or malabsorption
• Deficiency, malabsoption or inability to activate Vitamin D
• Signs and Symptoms
• Paresthesia
• Tetany
• Abdominal cramps
• Neural excitability
• Personality changes
• Abnormal behavior
• Convulsions

• Possible causes
• Various neoplasms (tumors)
• Parathyroid dysfunction
• Diuretic therapy
• Excessive administration of Vitamin D
• Calcium can be deposited into various body tissue, including organ systems: GI System, CNS, Neuromuscular System, Cardiovascular System
• Signs and Symptoms
• Decreased muscle tone or tension
• Renal stones
• AMS
• Deep bone pain

• Activates many enzymes
• Approximately 50% of the body's magnesium is in insoluble state in the bones
• 45% as an intracellular cation
• 5% as an extracellular solution
• Excreted by the kidneys
• Has physiological effects on the nervous system silimalr to those seen with calcium

• Possible Causes
• Alcoholism
• Malabsorption
• Starvation
• Diarrhea
• Diuresis
• Certain disease states
• Characterized by irritability of the nervous system
• Signs and Symptoms
• Tremors
• Nausea and Vomiting
• Diarrhea
• Hyperactive reflexes
• Confusion
• Muscle spasms or seizures
• Cardiac dysrhythmias
• Management
• IV magnesium sulfate

• Possible Causes
• Chronic renal insufficienct
• Ingestionof large amounts of magnesium compunds such as anacids
• Magnesium Citrate
• Magnesium Sulfate
• Magnesium Hydroxide
• May cause
• CNS depression
• Profund muscle weakness
• Areflecia (absence of reflexes)
• Cardiac rhythm disturbances
• Signs and Symptoms
• Sedation
• Confusion
• Muscle weakness
• Respiratory paralysis
• Management
• Hemodialysis
• Calcium salts
• IV glucose and insulin