What is the standard value for Total Body Water in adult male?
60% of a 70kg male, equivalent to 42 L of fluid
.How much less water do females have than males and why?
50% less d/t more adipose tissue
3 factors that affect total body water?
Water is brought into body by? (3)
1. drinking or via IV fluids
2. ingestion of water in food
3. water from oxidative metabolism
3 ways water is excreted from body?
1. Renal excretion
2. Elimination in stool
3. Insensible loss thru skin & respirations
What is ICF?
How much does it account for?
water within the cells
2/3 of total volume
What is ECF?
all fluid outside the cells
1/3 total volume
What are the 2 types of ECFs?
1. Intravascular fluid
2. Interstitial fluid
What is Intravascular fluid?
fluid inside blood vessels
What is interstitial fluid?
fluid between the cells, fluid in the bloodstream (serum), CSF, GI secretions, sweat, urine
TEST MATERIAL STARTS NOW!
Movement of water between compartments is accomplished by the interaction of what 2 processes?
2. Hydrostatic Pressure
How does Osmosis move water between compartments?
-causes water to flow from the capillaries to the interstitial fluids & back into the capillaries
-water moves thru semi-permeable membrane from area of higher particle concentration to an area of lower concentration.
How does Hydrostatic Pressure move fluid etween compartments?
pressure of the heartbeat pushing blood thru the capillary walls into the interstitial space/fluids
What are the 3 concentrations of body fluids?
1. Normal or Isotonic (Osmolality from 275-295)
2. Hypotonic (Osmolality below 275)
3. Hypertonic (Osmolality above 295)
Considered normal for body fluids or neutral in concentration. Same osmolility as blood.
Example of Isotonic Solution?
-0.9% Normal Saline
*Replaces ECF deficits
Examples of Hypotonic Solutions?
-0.45% Normal Saline
*Used to replace body water
Examples of Hypertonic Solutions?
-D5W w/0.45% NS
*Used ECF deficits w/some Sodium & Calories
What 3 ways are body fluids regulated in the body?
How does diffusion occur?
By movement of molecules from an area of higher concentration to an area of lower concentration.
What is active transport?
Movement of ion against electrochemical gradient, b/c energy must be used to transfer the molecule. The energy is ATP, which is stored in cell wall.
(it's like swimming against a current)
What is filtration?
Takes place when molecules from an area of higher concentration move thru permeable membranes to an are of lower concentration as a result of hydrostatic pressure.
ECF primarily have what _____electrolyte to create osmolar pressure?
ICF mainly have _____ to create osmotic pressure?
Intravascular Fluids usually have big _________ molecules which exert a stronger osmotic pressure than the electrolytes.
Protein (albumin, glucose, urea)
What would happen to the tissues of the Resp Tract if you sxn the trachea with sterile distilled water (hypotonic)?
Overhydrate the cells
What would happen to body cells if D5NS was accidentally hung instead of D5W?
If blood has abnormally high levels of sodium in it, what type of solution would it be similar to?
If blood had high levels of sodium in it, water would move ____ intravascular fluid?
What type of fluid is hung with blood?
Normal Salinen (Isotonic), so will not destroy RBCs
On the arterial end of the capillary, hydrostatic pressure if _____, and osmotic pressure is _____.
On the venous end of the capillary, hydrostatic pressure is significantly ____, and the osmotic pressure is ______, thereby pulling fluid back into venous capillary.
now the higher one
What are 2 ways water moves from the IVF into the ISF at the capillary level?
2. Hydrostatic Pressure
What would occur if hydrostatic pressure was higher than osmotic pressure at venous end of capillary?
Cells would bust open & lose fluid
What are the 2 methods in which solutes move?
2. Active Transport
_____occurs in the cell when it is in a hypotonic solution?
sweeling to point of bursting (lyses)
When 2 isotonic fluids are separated by a semi-permeable membrane, what fluid movement occurs?
______ occurs in the cell when it is placed in a hypertonic solution?
What is avg fluid intake for adults?
The loss of 2.2 lbs=loss of _____ of body fluid?
For every ____L of fluid loss, the cardiac output decreases by _____L/min, the heart rate increases by ____ bpm and the core temp rises _____.
0.6 degrees F
What is dehydration?
Depletion of fluid from IVF that can't be replaced by the extra body fluid stores
3 most common causes of Dehydration?
1. Unmonitored loss of urine from diuretics
2. Severe vomiting
3. Severe diarrhea
List some other causes of dehydration?
fever, diaphoresis, hyperglycemia, GI sxn, wound drainage, fistulae, burns, hemorrhage, hyperventilation, hyperthyroidism, decreased ADH, diabetes insipidus, Addison's, diuretic phase of ARF, ileostomy, colostomy
4 reasons the elderly are high risk for dehydration?
1. Decreased renal concentration of urine
2. Altered ADH & thirst response
3. Increase in body fat
4. Decrease in body water in proportion to body fat
What is an example of active transport in the body?
Sodium Potassium Pump
Decreased urine output
Indicates a marked compromise in renal fxn
What is normal urine specific gravity?
With dehydration, what indicates ECF involvement?
Changes in mental status
With severe dehydration, urine SG _____?
*would be dark amber
What are normal lab values of Na, BUN, Serum Creatinine, Glucose, Hct, SG of Urine, & Albumin
Creatinine: 0.5-2.3 mg/dl
What is Hypernatremia?
-fluid loss excess
-Na levels >145 mEq/l
-high osmolar pressure meaning the blood exerts higher osmotic pressure than usual, causing water to move into blood vessels
*BP will still rise even though they are dehydrated
What is Hyponatremia?
-Na levels <145 mEg/l
-low osmolar pressure in blood vessels allowing more plasma to seep out into interstitial space.
*BP goes down & urine output decreases
For renal fxn, which 2 labs can be used as double checks?
For hemoconcentration, what labs can be used as double checks?
SG of Urine
possible Glucose or Na
How does hypernatremia effect blood osmolarity, water movement into capillaries, and BP?
Blood osmalarity increases,
Water movement into capillaries Increases,
BP goes Up
What are hyponatremic effects on blood osmolarity, water movement into capillaries, and BP?
Blood osmalarity decreases,
Water movement into capillaries decreases,
BP goes down
What is fluid volume overload?
-Excess ECF volume caused by too much fluid or too much Na
-Failure to excrete fluids such as in kidney failure, CHF, or liver cirrhosis
Patho of Fluid Overload?
hydrostatic pressure of blood is higher than normal @ arterial end pushing extra fluid out, but it isn't reabsorbed @ venous end of capillary, because osmotic pressure too low.
WHat are some causes of hypernatemia?
loss of fluid
excess sodium intake
hypertonic IV solutions
Clinical manifestations of hypernatremia?
neurologic symptoms (seizures)
Clinical manifestations of hyponatremia?
poor skin turgor
What should fluid intake be for hyponatremic pt?
Limited to 30-60mL/hr
*this assists sodium increase & prevents sodium level from dropping further due to dilution
What Iv fluids should be used in the hypernatremic pt?
-Replace water with hypotonic solution
-0.2% or 0.45% NaCl or D5W
What is Hypokalemia?
-may occur w/normal K levels in alkalosis d/t shift of K into cells
What does hypokalemia do to ECG?
creates a prominent "U" Wave--causes deadly arrhythmias
S/S of Hypokalemia?
What is always done to the IV bag of K before administering?
agitate the bag to prevent giving a loading dose of K settled at bottom
What are major safety issues a/w administering K?
-NEVER give IVP
-NEVER give when UO is decreased or renal failure occurs
Common causes of Hyperkalemia?
Excess IV solution
Impaired renal fxn
Meds (Nsaids, ACE, K-sparing diuretics, chemo)
Manifestations of Hyperkalemia?
**Cardiac changes & dysrhythmias
-Muscle weakness w/potential resp impairment
Hyperkalemia medical management?
Limit PO intake
monitor ECG-use Ca Gluconate for arrythmias
IV Sodium Bicarb
Hypertonic dextrose if Meta Acid
Cation exchange resin (Kayexelate) oral or rectal
What affect does Hyperkalemia have on ECG?
Peaked "T" Wave
Crush Injuries, burns, renal dz, insulin deficiency, and Addison's dz can likely cause what imbalance?
What causes Pulmonary Edema?
Capillary pressures increase. Initially, lymph system absorbs the exzcess fluids. The fluid eventually builds in the ECF=pulmonary edema
What conditions can cause low albumin?
Liver or renal dz
Patho of Low Albumin?
Decreased reabsorption of water n venous capillaries, causes peripheral edema or ascites if the plasma retention occurs in the abdomen, such as in liver diseases
How does ascites of liver failure develop?
-Liver becomes congested w/venous blood which is obstrcuted from flowing throughout venous sinuses
-Liver can only absorb 500mL , then plasma seeps out into tissues & into peritoneal cavity
Lab Values in Fluid Overload
SG: Down (dilute)
Creatinine: normal if adequate renal fxn
What lab is the best indicator of glomerular filtration because it is not changed by hydration levels?
How much fluid must accumulate before it is considered edema?
3 or more liters in the ECF
Pulmonary Edema causes what 4 things?
With Pulmonary Edema, changes in LOC may indicate what?
serious complication of ICF shifting
*can cause cerebreal edema
What is BNP?
hormone produced by atria when increased blood volume causes stretching.
-tells whether condition is improving or worsening in Cardiovascular conditions causing pulmonary edema
Generalized edema is common in _____?
Pumonary edema also develops in _____, as kidneys fail.
What is third-spacing?
abn fluid accumulation around cells & vessels resulting in pathologic conditions when lymph tissue can no longer absorb excess fluids
3 common sites of third-spacing?
1. pleaural cavity
2. peritoneal cavity
3. pericardial sac
Causes for third-spacing to develop?
1. Massive tissue injury (burns or crush injuries)
2. Decreased protein intake, production, or storage
Patho of Third-Spacing?
Tissue injury causes the release of histamine & bradykinin. Causes fluids, proteins, & other solutes to move into interstitial spaces surrounding injury. This causes HYPOVOLEMIA!
With third-spacing, when does hypervolemia develop?
As capillary membranes heal & fluid shifts back into intravascular space
Clinical manifestations of third-spacing?
Weak or rapid pulse
Weight is stable
Possible gangrene d/t organ, nerve, or vessel obstruction.