Chapter 2- Fluid and Electrolytes Flashcards
Water
Major component of the body both within and outside of. cells. Essential for homeostasis. It is the medium where metabolic reactions and other processes take place. Serves as transportation system for the body and facilitates movements of body parts
Intracellular fluid compartment
Fluid inside the cells
Extracellular fluid compartments
Fluid outside the cells
Components of extracellular fluid
Intravascular fluid (blood), interstitial fluid, cerebrospinal fluid, and transcellular fluid
Balance intake and output
Amount of water entering the body should equal the amount leaving the body
Thirst mechanism
In the hypothalamus. Regulates balance of water and electrolytes
Antidiuretic hormone (ADH)
Kidneys; regulates balance of water and electrolytes
Aldosterone hormone
Kidneys; regulates balance of water and electrolytes
Natriuretic peptide hormones
Cardiac muscles. Atrial natriuretic peptide and B-type natriuretic peptide. Regulates balance of water and electrolytes
Hydrostatic pressure
The push
Osmotic pressure
The pull
Osmolarity
Concentration of solute in the fluid. Affects fluid shifts between compartments, including cells
Factors affecting fluid balance
Intake and output, hormonal influence, health of heart, kidneys, and lymphatic system, ability of capillaries, veins, and arteries to respond to interstitial fluid, and hydrostatic and osmotic pressure
Edema
Excessive amount of fluid in the interstitial compartment which causes swelling or enlargement of the tissues. May be localized in one area or generalized throughout the body. Depends on the tissue, it may be highly visible, relatively invisible, or not accurately reflect amount of fluid hidden in the area
Causes of edema
Increased capillary hydrostatic pressure, loss of plasma proteins resulting in a decrease in plasma osmotic pressure, obstruction of lymphatic circulation and increased capillary permeability
Effects of edema
Local area of swelling, pitting edema, significant increase in body weight, and functional impairment. Also pain, arterial circulation impaired, dental issues, and susceptibility to breakdown
Dehydration
Insufficient body fluids due to inadequate intake or excessive loss of fluids or both. Measured by change in body weight
Mild loss
Decrease in 2%
Moderate loss
Decrease in 5%
Severe loss
Decrease in 8%
Causes of dehydration
Vomiting and diarrhea, excessive sweating, DKA, insufficient water intake in elderly or unconscious, use of concentrated formula in attempt to provide more nutrition to infant
Effects of dehydration
Dry mucus membranes in mouth, decreased skin turgor, lower BP, pulse, fatigue, increased hematocrit, and decrease in mental function and confusion
Compensation for dehydration
Increasing thirst, increasing heart rate, pale, cool skin, produce less urine and concentrating urine increasing the specific gravity
Third spacing
Fluid shifts out of the blood into the body cavity or tissue where it is no longer available as circulating fluid. Need lab tests for identification. Found as edema in the area of burn wounds
Sodium imbalance
Hyponatremia/Hypernatremia
Potassium imbalance
Hypokalemia/Hyperkalemia
Calcium imbalance
Hypocalcemia/Hypercalcemia
Magnesium imbalance
Hypomagnesemia/Hypermagnesemia
Sodium
Cation (positively charged). Exists in the extracellular fluid. Controlled by the sodium-potassium pump. Concentration is higher in extracellular than intracellular. Important in extracellular fluid maintenance. Controlled primarily by kidneys (aldosterone hormone). Important in nerve impulses and muscle contraction
Potassium
Major intracellular cation. Under the influence of aldosterone hormone. Imbalances with destabilize cardiac conduction- can lead to lethal cardiac arrhythmias
Calcium
Extracellular cation. Stored in bone. Deficiency can cause nerve imbalances, muscular contraction. Excess can cause decrease in neuromuscular function, mental changes, and changes in personality. Excess may be caused by parathyroid hormone imbalances. When severe, can lead to lethal cardiac arrhythmias
Magnesium
Intracellular cation. Works with calcium and potassium. Majority stored in bone. Deficiencies are rare.
Normal serum pH
7.35 - 7.45
Acidosis
lower than 7.4 pH
Alkalosis
higher than 7.4 pH
Death
pH lower than 6.8 and higher than 7.8
Respiratory acidosis
Increase in CO2 levels (acid) respiratory problems. Caused by acute problems such as pneumonia, airway obstruction, chest injuries, opiate depressing the respiratory center, or chronic problems such as COPD or emphysema
Metabolic acidosis
Decrease in bicarbonate ions
(base) because of metabolic or renal problems. Caused bt excessive loss of bicarbonate ions and renal disease/failure
Respiratory alkalosis
Increased respirations cause a decrease in CO2 (less acid). Caused by hyperventilation (usually caused by anxiety, high fever, or overdose of aspirin)
Metabolic alkalosis
Increase in serum bicarbonate ion; less of hydrogen ions through the kidneys or GI tract. Caused by loss of hydrochloric acid from the stomach either in early stages of vomiting or with drainage from the stomach, or from consuming too many antacids
Mechanisms that control or compensate for pH levels
Buffer pairs respond to immediate changes, respiratory system through carbonic acid (CO2) increasing or decreasing respiratory rate, and kidneys can modify the excretion of acids and the production and absorption of bicarbonate
Hyponatremia
Low serum sodium levels
Hypernatremia
High serum sodium levels
Hypokalemia
Low serum potassium levels
Hyperkalemia
High serum potassium levels
Hypocalcemia
Low serum calcium levels
Hypercalcemia
High serum calcium levels
Hypomagnesemia
Low serum magnesium levels
Hypermagnesemia
High serum magnesium levels
