Ch 8: Altered Fluid and Electrolyte Flashcards
Body fluids are solutions composed of:
▫️water
▫️electrolytes
▫️non electrolytes
Electrolytes:
▫️cations: Na+; K+; anions: Cl-
Nonelectrolytes - glucose, urea
Plasma proteins:
▫️Albumin
▫️globulins
▫️prothrombin
▫️fibrinogen
Intracellular proteins: large quantity
▫️Myoglobin
▫️Hormones
▫️NT
▫️Enzymes
Electrolytes Imbalances
🔘Major ions:
▫️sodium ▫️potassium ▫️chloride ▫️calcium ▫️magnesium ▫️phosphate
Variations in distribution of body fluids ▫️infants ▫️childhood ▫️adolescents ▫️adults ▫️elderly
▫️infants: 75-85% TBW
▫️childhood: 60-65%
▫️adolescence: similar to adults
▫️adults: lean and muscular frame 70%
Female 50%
Male 60%
Obese 40-45%
▫️elderly: 45%Function of water:
▫️solvent/transporter of nutrients, gases and wastes
▫️cushioning
▫️major components of mucus
▫️body temperature regulation (evaporative heat loss)
▫️medium for chemical reactions
Function of electrolytes: concentration must be tightly regulated
▫️Na+ and K+ for action potentials along neurons and muscle cells (♥️ and brain)
▫️Zn, Cu and Mg2+ are co-factors for enzymes
▫️Ca2+ for blood clotting, muscle contraction, bone and teeth mineralization, and neurotransmission.
Water movement occurs by osmosis- passive transport
▫️Na+
▫️Albumin
Hormonal Regulation of fluid and electrolytes:
▫️ADH (act on kidneys ⬆️H20 absorption)
▫️Aldosterone (stimulates reabsorption of Na+ as well as secretion of K+ and H+)
▫️ANP-Atrial natriuretic peptide (Adrenal medulla inhibits aldosterone release)
Body fluids are divided between two main compartments:
▫️ICF - fluid inside cells, about 1/2 to 2/3 of total body fluids
Helps maintain cell shape. Assists with transport of nutrients across cell membrane, in and out of the cell.
Major ions are: K+, Mg and phosphate (and proteins)
▫️ECF -fluid outside cell, 1/3 of body fluid. Mostly as interstitial fluid and intravascular (plasma).
Major ions are: Na+, Cl- and carbonate
The watery fluid in blood known as plasma
Intravascular fluid
The volume of ECF is the most important regulated aspect of body fluid balance. Without adequate ECF, the body cannot maintain _______
Normal blood pressure
Too much ECF can place a person in a fluid overload state, leading to a ______
HBP and risk for CHF
_____is the fluid that is that is most important in fluid balance
ECF
Factors which move fluid from plasma to interstitial space:
▫️blood hydrostatic pressure
▫️increased capillary permeability (inflammation)
Factors which move fluid from interstitial space to plasma:
▫️Blood osmotic pressure
- plasma proteins, mainly albumin
Excess fluid in interstitial space
▫️Edema
Mechanism involved in the development of edema can also lead to:
▫️third-space shifts
Fluid in the peritoneal cavity
Ascites
Fluid in interstitial space of respiratory or in alveoli
Pulmonary edema
Fluid in pleural space
Pleural effusion
Fluid in the pericardial space
Pericardial effusion
Four major processes in the development of edema
- Increase in capillary hydrostatic pressure
- Increase in capillary permeability
- decrease in colloid onconic pressure (loss of albumin)
- Obstruction in lymphatic drainage
Consequences of edema:
▫️increased distance for diffusion of nutrients, oxygen, and wastes between tissue cells and circulatory system
▫️compression of nerves, blood vessels, other hollow tubes
▫️can be disfiguring
Alteration in fluid and electrolyte balance
▫️sodium imbalance - hyponatremia and hypernatremia
▫️negative fluid balance - hypovolemia
Causes of Dehydration:
▫️⬇️fluid intake
▫️⬆️fluid output (heat exposure/ heavy exercise)
▫️extreme Na+ loss or lack of Na+ intake (hyponatremia)
▫️excessive Na+ intake (hypernatremia)
▫️fluid shift between compartments
▫️SIADH-syndrome of inappropriate antidiuretic hormone secretion
Manifestation of Dehydration:
▫️thirst
▫️dry mucous membranes
▫️decreased or absent tears
▫️change in vital signs
⬆️ respiration rate
⬇️ blood pressure
Weak pulse
▫️prolonged capillary refill time
▫️depressed fontanels
▫️⬇️ or absent urine output
▫️⬇️level of consciousnessAttempts to compensate for fluid loss:
▫️⬆️ing thirst ▫️⬆️ing ♥️ rate ▫️constriction of cutaneous blood vessels ▫️producing less urine ▫️concentrating urine
Dehydration treatment:
▫️rehydration
Oral
Intravenous
▫️correction of electrolyte imbalances
Causes of hyponatremia:
▫️losses from excessive sweating, vomiting, diarrhea
▫️use of certain diuretic drugs combined with low-salt diets
▫️hormonal imbalances
🔸insufficient aldosterone
🔸adrenal insufficiency
🔸excess ADH secretion
▫️Diuresis
▫️Excessive water intakeEffects of hyponatremia:
▫️low Na+ levels
▫️decreased osmotic pressure in ECF compartment
▫️cause is balance in Na+ and water
🔸insufficient ADH (diabetes insipidus)
-results in large volume of dilute urine
🔸loss of the thirst mechanism
🔸watery diarrhea
🔸prolonged periods of rapid respiration
🔸ingestion of large amounts of sodium without enough water.
Hypernatremia
Effects of hypernatremia..
▫️weakness, agitation ▫️dry, rough mucous membranes ▫️edema ▫️⬆️thirst ▫️⬆️ BP
K+ has two main roles:
- Nerve impulse conduction and muscle contraction
2. Maintain acid-base balance
Acidemia leads to ______
Alkalemia leads to ______
Hyperkalemia
Hypokalemia
Common causes of hyperkalemia:
▫️released from ICF to ECF
🔺injury to cells: burns, trauma
🔺acidosis
▫️inadequate elimination
🔺kidney failure: no longer able to excrete K+ ions
▫️excessive intake
🔺K+ supplements or too much dietary K+
🔺use of salts substitutes (contain K+)
▫️K+ sparring diuretics
▫️deficit of aldosterone
Common causes of Hypokalemia:
▫️excessive losses
🔺vomiting, diarrhea
🔺abnormal loss through kidneys: diuretics or tubular disease.
▫️Excessive aldosterone or glucocorticoids (I.e. Cushing syndrome)
▫️Decreased dietary intake
🔺alcoholism, eating disorders, starvation
▫️treatment of diabetic ketoacidosis with insulin (insulin causes increased K+ uptake by the Na+ pump)
Effects of hypercalcemia
▫️depressed neuromuscular activity
▫️interference with ADH function
▫️Increased strength in cardiac contractions
Four main functions of Magnesium
- enzyme activity [co-factor]
- energy production and ATP - cofactor
- DNA and RNA protection and repair
- Mineral balance - regulates other ions
▫️results from malabsorption or malnutrition often associated with alcoholism
▫️use of diuretics, diabetic ketoacidosis, hyperthyroidism, hyperaldosteronism
Hypomagnesimia
▫️Occurs with renal failure
▫️depresses neuromuscular function
▫️decreased reflexes
Hypermagnesemia
Numerous phosphate functions
▫️ bone and tooth mineralization
▫️important in metabolism of ATP
▫️phosphate buffer System - acid base balance
▫️integral part of the cell membrane
▫️reciprocal relationship with serum calcium
Malabsorption syndromes, diarrhea, excessive antacids
Hypophosphatemia
This phosphate imbalance is caused by renal failure… others: hypocalcemia,
Hyperphosphatemia
Chloride imbalance usually associated with alkalosis. 🔺early stages of vomiting - loss of hydrochloric acid
Hypochloremia
Is an excessive sodium chloride intake
Hyperchloremia
