N300 Midterm Fluid and Electrolytes Flashcards
Intra or extracellular fluid?
- 40% of TBW
- Mostly found in skeletal muscle cells
- Functions
Intracellular
Osmolality or Osmolarity:
A measure of the total solute concentration per kilogram of solvent; used to describe fluids inside the body; test usually used to evaluate the concentration of plamsa and urine.
Osmolality
Osmolality or Osmolarity
A measure of the total solute concentration per liter of solution; used to describe fluids outside of the body.
Osmolarity
Osmosis?
Movement of water from an area of low solute concentration to higher solute concentration.
what are the major determinants of plasma osmolality?
Sodium and Glucose
___: is the force within a fluid compartment; the major force that pushes water out of the vascular system at the capillary level.
Hydrostatic pressure
___: is osmotic pressure exerted by colloids in solution. The major colloid in the vascular system contributing to the total osmotic pressure is protein. Protein molecules attract water, pulling fluid from the tissue space to the vascular space.
Oncoctic pressure
The amount and direction of fluid movement between the capillary and the interstitium is determined by what 4 types of pressure?
(1) capillary hydrostatic pressure
(2) plasma oncotic pressure
(3) interstitial hydrostatic pressure
(4) interstitial oncotic pressure
Capillary hydrostatic pressure and interstitial oncotic pressure move water \_\_\_\_ of the capillaries. Plasma oncotic (colloidal osmotic) pressure and interstitial hydrostatic pressure move fluid \_\_\_ the capillaries.
OUT
INTO
- Accumulation of fluid in the interstitium (edema) occurs if venous hydrostatic pressure ____ ,
- plasma oncotic pressure ____,
- or interstitial oncotic (colloidal osmotic) pressure ____.
- Edema may also develop if there is an obstruction of lymphatic outflow that causes ____ removal of interstitial fluid.
Rises
Decreases
Rises
decreased
Increasing the pressure at the venous end of the capillary ____ fluid movement back into the capillary, which results in ___ . Causes of increased venous pressure include fluid overload, ____ and ____ failure, obstruction of venous return to the heart (e.g., tourniquets, restrictive clothing, venous thrombosis), and ____ insufficiency (e.g., varicose veins)
inhibits
edema
Heart and liver
venous
_____: is a term used to describe the distribution of body water.
Fluid spacing
- ____ spacing describes the normal distribution of fluid in the ICF and ECF compartments.
- Second spacing refers to an abnormal accumulation of ____ fluid (i.e., edema).
- With Third spacing, fluid accumulates in a portion of the body from which it is not easily exchanged with the rest of the ECF Ie the _____ fluid. Third-spaced fluid is trapped and unavailable for functional use.
First
interstitial
(transcellular fluid) Ex. peritonitis or appendicitis
Examples of what type of spacing:
- ascites
- sequestration of fluid in the abdominal cavity with peritonitis
- edema associated with burns, trauma, or sepsis
Third Spacing
What is the best indicator of hydration?
Weight
Water balance is maintained via the finely tuned balance of water intake and excretion. A body fluid deficit or ____ in plasma osmolality is sensed by ____ in the hypothalamus, which in turn stimulate thirst and release of what hormone? Thirst causes the patient to drink water.
increase
osmoreceptors
antidiuretic hormone (ADH)
ADH (also called vasopressin), which is synthesized in the ______ and stored in the ____ pituitary, acts in the ____ distal and collecting tubules causing water ____.
hypothalamus
posterior
renal
reabsorption
____ hormones suppress secretion of aldosterone, renin, and ADH, and the action of angiotensin II. They act on the renal tubules to promote excretion of sodium and water, resulting in a decrease in blood volume and blood pressure.
Atrial natriuretic peptide (ANP) and b-type natriuretic peptide (BNP)
(hormones produced by cardiomyocytes).
- ____ water loss, which is invisible vaporization from the lungs and skin, assists in regulating body temperature. Only water is lost through this mechanism.
- The excessive sweating caused by fever or high environmental temperatures that may lead to large losses of water and electrolytes is considered ____ perspiration.
Insensible
sensible perspiration
What are the normal levels for the following anions:
Bicarbonate (HCO3–)
Chloride (Cl–)
Phosphate (PO43–)*
Bicarb: 22-26 mEq/L
Chloride: 96-106 mEq/L
Phosphate: 2.4-4.4 mg/dL
What are the normal levels for the following cations: Potassium (K+) Magnesium (Mg2+) Sodium (Na+) Calcium (Ca2+)
Potassium: 3.5-5.0 mEq/L
Magnesium: 1.5-2.5 mEq/L
Sodium 135-145 mEq/L
Calcium total: 8.6-10.2 mg/dL
____: generalized in entire body, independent of positioning
Anasarca
What are 3 sites to evaluate skin turgor?
over the sternum
abdomen
anterior forearm
The areas to be evaluated for edema are those where soft tissues overlie a bone including what preferred sites?
tibia, fibula, and sacrum
