Fluid, electrolyte, and acid-base balance Flashcards
The movement of water across cell membranes.
Osmosis
The force created when 2 solutions of different concentrations are separated by selectively permeable membrane.
Osmotic pressure
Refers to the number of osmols (unit of osmotic pressure) per kilogram of solvent, which in this case is water.
Osmolality
The number of osmols per Liter of solvent.
Osmolarity
Refers to the level of osmotic pressure of a solution.
Tonicity
An administered solution that has the same osmolarity as blood plasma.
Isotonic solutuin
This solution pulls water from the cell to the extracellular fluid compartment causing cellular shrinkage.
Hypertonic solution
Solutions with a lower osmolarity than body fluids. Excess water moves into the cells, producing cellular swelling.
Hypotonic solution
When plasma proteins are too large to pass through the capillary membrane and hold the fluid in the intravascular space.
Oncotic pressure
The process by which fluid and solutes move together from an area of high pressure to an area of low pressure.
Filtration
The maintenance of fluid balance is controlled by several physiologic mechanisms what are they? RAT
Renin-angiotensin, mechanism\
Antidiuretic hormone (ADH)
Thirst Mechanism
A decrease in bodily fluid volume.
Hypovolemia
Electrolytes move in and out of the intracellular and extracellular spaces through what 3 things? DFA
- Diffusion
- Filtration
- Active transport
The movements of solutes across a selectively permeable membrane from areas of higher concentration to areas of lower concentration until equilibrium is reached.
Diffusion
What 4 factors influence the rate of diffusion? TMSM
Temperature, molecular weight, steepness of the concentration gradient, membrane permeability.
This type of diffusion occurs when a solute is unable to pass through a membrane and requires assistance with a carrier.
Facilitated diffusion
The transport of a solute from areas of lower to higher concentration. Give an example.
Active transport; exchange of sodium and potassium across the cell membrane facilitated by sodium-potassium pump.
What are the 5 major cations?
Sodium (Na), magnesium (Mg), potassium (K), calcium (Ca), and hydrogen (H). All positive.
What are the 3 major anions?
Chloride (Cl), bicarbonate (HCO), and phosphate (PO); all negative.
Which two electrolytes are found primarily inside the cell?
Potassium and Phosphate
Which electrolytes are found in higher concentration in intravascular fluid like blood plasma?
Sodium and Chloride
Excessive fluid loss can lead to decreased circulation volume which directly affects what?
Cardiac output
Fluid volume excess leads to an increase in circulating fluid causing an increase to __________.
The workload of the heart
This occurs when their is an excessive loss or inadequate intake of fluid. What are the 2 types?
Fluid volume deficit; Isotonic and hypertonic
Occurs when water and sodium are lost at the same rate. Circulating volume decreases but serum osmolarity remains the same.
Isotonic fluid deficit (hypovolemia)
As fluid loss continues, the circulating fluid volume decreases and serum osmolarity increases.
Hypertonic fluid loss deficit (dehydration)
A 2% loss of percentage of total body weight is considered what ?
Mild dehydration
A 5% loss of percentage of total body weight is considered what?
Moderate dehydration
An 8% loss of percentage of total body weight is considered what?
Severe dehydration
A 15% loss of percentage of fluids to total body weight is considered what?
Life-threatening dehydration, usually fatal
This occurs when fluid intake exceeds output. What are the two types?
Fluid volume excess; isotonic and hypotonic
Mild fluid volume excess is classified as a _______ % increase in total body weight.
2%
Moderate volume excess is classified as a _______ % increase in total body weight.
5%
Severe volume excess is classified as a _________ % increase in total body weight.
8%
The abnormal accumulation of fluid in the interstitial spaces , typically extremities such as fingers and ankles and feet?
Edema
What is a case in which fluid volume excess and fluid volume deficit can occur simultaneously?
Cirrhosis
The nursing assessment includes what three things for recognizing imbalances? HFR
Health history, focused assessment, and review of diagnostic testing.
This part of nursing assessment includes questions designed to highlight recent changes in fluid intake, diet, and other lifestyle habits.
Health history
In regards to vital signs, a prolonged fever can lead to what?
An increased loss of body fluids
With fluid volume deficit blood pressure does what?
Decreases
With fluid volume excess, blood pressure does what?
Increases
A condition in which there is a decrease of more than 20 mmHg in systolic pressure or 10 mmHg in diastolic pressure when moving from lying or seated to standing.
Orthostatic hypotension
Measurement of __________ is routinely ordered for patients who are at risk for or have fluid and electrolyte imbalance. Consists of foods, liquids, body fluids, and drainage that can be measured.
Intake and Output
This is a more precise method of monitoring changes in fluids. A change of 1 kg (2.2) lb is equivalent to 1 L of fluid.
Weight
This is a significant and visible indication of fluid volume excess and graded on a 4 + scale and based on depth of indentation.
Edema
Edema- slight indentation of 2 mm
1 +
Edema- deeper indentation of 4 mm
2+
Edema- Deep indentation of 6 mm
3 +
Edema- very deep indentation 8 mm
4+
This edema occurs when there is obvious swelling but the tissue is too firm and hard to be indented.
Brawny edema
In _______ deficit skin remains pinched, or tented, after release
Fluid volume
What is the average daily intake for fluids?
1600 mL
What is the average daily fluid intake of food?
700 mL
What is the average daily fluid intake of metabolism?
200 mL
What is the average daily fluid output of urine, feces, skin including perspiration, and lungs.
1500 mL, 200 mL, 500 mL
What factors can affect fluid, electrolyte, and acid-base balance?
Age- infants have higher metabolism which creates more toxins which require more water to excrete, causes imbalance. Older people are less likely to drink necessary fluid
Stress- aldosterone production is associated with extracellular fluid retention
Surgery-
Medical conditions-
What medical conditions can influence fluid, electrolyte, and acid-base balances?
cardiac
hepatic
renal
respiratory disorders
Restriction of salt that includes 3000-4000 mg/day and indicated as “no added salt”
Mild restriction
Restriction of salt that includes 2000 mg/day and is indicated as the need to consume foods with low-sodium content.
Moderate restriction
Restriction of salt that includes 500 mg/day
Severe restriction
When replacing fluids due to offset losses, about what percentage is taken during the day?
About 50 %
When replacing electrolytes, the body is able to extract needed electrolytes through __________ and _____________.
Food; prescribed supplements
What is recommended intake of calcium for adults between 19 -50?
1000 mg/day
What is recommended intake of calcium for females over 50 and males over 70?
1200 mg/day
When taking calcium supplements what should be increased and why?
Fluid intake should be increased to 2500mL/day to prevent constipation and risk for kidney stones.
This therapy provides access for supplemental or total nutrition replacement and allows transfusion of blood and blood products to increase oxygen-carrying capacity and reestablish normal oncotic pressure.
Intravenous therapy
This type of IV fluid is used primarily for fluid and electrolyte maintenance and replacement. They are categorized based on their tonicity: hypotonic, isotonic, and hypertonic.
Crystalloids
These crystalloid solutions lower the osmolarity of blood plasma and cause fluid to shift into the cell. Used to treat hypernatremia or severe dehydration.
Hypotonic fluid solutions
These crystalloid solutions have tonicity essentially the same as blood plasma. They increase intravascular volume but do not cause fluid shifts in or out of cell. If not monitored correctly can lead to circulatory overload.
Isotonic fluid solutions
These crystalloid solutions have a tonicity that is markedly higher than 290 mOsm/L, increase osmotic pressure of plasma and force fluids to move out of cell and into the blood stream.
Hypertonic fluid solutions
Saline solutions contain what 2 electrolytes in various amounts?
Sodium and chloride
Normal saline consists of how much NaCl?
0.9% NaCl and considered isotonic
Saline solutions that have more than 0.9% NaCl are called _________.
hypertonic
Saline solutions that have less than 0.9% NaCl are called ________.
hypotonic
This solution contains sodium, potassium, calcium, chloride, and lactate and most closely resembles blood plasma.
Lactated Ringer Solution
These IV solutions aka plasma expanders, contain starch and protein. They are used to reestablish circulating volume and oncotic pressure.
Colloids
