Ex 2: Water, Electrolytes, and Acid-Base Balance Flashcards
Total body water depends on what three characteristics?
Age, Gender, and Fat composition
Water loss and hazardous effects
20% loss can result in death; 10% loss kidney function impacted, BV and nutrient reabsorption decreased
Water composition: a) birth b) obese adult c) normal male and female
a) 75-80% at birth b) 45-55% c) 55% female 60% males
Four stages of heat illness
a) Heat Fatigue b) cramp c) exhaustion d) stroke
Heat fatigue
Thirst, feeling of weakness or fatigue
Heat cramp
Loss of sodium and potassium which causes cramps
Heat exhaustion
headache, dizziness, cramps, nausea/vomiting, weakness, fast HR, profuse sweating
Heat stroke
red, hot, dry skin, high BT x greater than 104, confusion and convulsions
Identify the two basic fluid compartments and the electrolyte most prevalent in each compartment.
The intracellular and extracellular compartments
Intracellular fluid
2/3 of body’s water, fluid w/in cells, higher concentration of potassium
extracellular fluid
1/3 of body’s water, intravascular and interstitial
Identify and explain the two mechanisms for movement of fluids between intracellular (ICF) and extracellular (ECF) areas.
Explained by osmotic pressure and hydrostatic pressure
Hydrostatic pressure
pressure exerted by fluid on the membrane
Differentiate between osmosis and diffusion. Identify the osmolality of blood considered to be normal.
280-300 mOsm/kg
Identify the minimum urine excretion per day to carry away waste products. How does this relate to the undertaking of a high protein diet? High sodium diet?
500-750 ml/day
RAAS Activation
Decreased BV; Decreasing hydrostatic pressure
Angiotensin II
constricts arteries raising BP; triggers release of aldosterone
Aldosterone
kidneys retain sodium; sodium causes water to be retained
Arginine Vasopressin release
(ADH) ; increased osmolality; decreased hydrostatic pressure
Arginine Vasopressin
ADH; increases BV; lowers osmolality
How many liters of digestive fluid is reabsorbed by the illeum and colon?
7-9 liters
How many ml of water is secreted into the feces?
200ml
How does fluid requirements change for patients with fever?
150 ml increase/day for each degree of body temperature above normal
Fluid needs Calculation based on caloric intake
1 ml/kcal
Fluid needs calculation based on body weight
30-35 ml/kg of body weight
Infant Fluid needs calculation based on caloric intake
1.5 ml/kcal; kids have higher percentage of body water, larger surface area per unit of body weight, can’t handle higher protein loads, poor recognizers of dehydration
Infant fluid needs calculation based on body weight
150ml/kg
Maintenance therapy vs Replacement therapy
M - refers to routine fluid and electrolyte needs; Replacement - restore acute volume losses
Why are the elderly at increased dehydration risk?
Lose ability to recognize thirst as we age; have impaired renal concentrating ability
Isotonic IV
D5W - 5% dextrose in water or Normal saline-.9%NaCl
Symptoms of overhydration
Low urine Specific gravity; pitting edema/periorbital edema; excessive frothy sputum; rapid labored and moist respirations
What organ is most susceptible to water intoxication?
The brain; water intoxication causes hyponatremia, which leads to movement of water into the brain cells.
