Exam 1: Fluids & Electrolytes Flashcards
Cell Properties
Molecule: When two of more atoms combine to form substance (pos or neg charge, then is ATOM)
Ion: An atom carries electrical charge bc it has gained or lost electrons
Cation vs Anion
Cation: Positive charge bc its LOST electrons
Anion: Negative charge bc it GAINS electrons
Electrolytes
Occur when substance dissolved in solution (molecules split into electrically charged atoms or ions)
Think of miliequivalents to balance out
Body Fluid Compartments
Fluid in each of the body compartments contain electrolytes
Have to be in the right place and in the right amount with balance of electrolytes
Movement of electrolytes is better when PT is healthy
Body Fluid Compartments Pt. 2
Whenever an electrolyte moves out of a cell, another takes its place. Homeostasis has equal number of cations and anions.
Compartments separated by semi-permeable membranes
Intracellular compartment vs Extracellular compartment
Intracellular - IN the cell
Extracellular - OUTSIDE of the cell —Subcategories:
Intravascular compartment
Interstitial Fluids
Body Fluid
Transportation of nutrients to the cells and carries waste from the cells
body fluid is about 60% of body weights
10% loss is serious
20% is fatal
Constituents of Body Fluid
Mainly water and dissolved substances
Glucose, urea and creatinine do NOT dissociate into ions, stay in same form
Other substances DO dissociate (NaCl) more likely to move around.
Diffusion
Movement of particles in ALL DIRECTIONS though a solution
High to Low concentration
diffusion allows shifting to occur as long as permeable membrane allows for it
Osmosis
Movement of WATER (pulling movement)
Draws water from low concentration to High concentration though selective permeable membrane
Goal is to equal concentration
Filtration
movement of solutes and solvents with Hydrostatic pressure.
Pushing pressure, High pressure, to LOW pressure movement
Osmolality - # of active particles per liter/kg
normal osmolality just under 300 mOsm/kg
Hydrostatic Pressure
Force of fluid pressing OUTWARD against some surface (water in a balloon)
Different in hydrostatic pressure, filtration moves solutes from High to Low pressure (Capillary Dynamics)
Isotonic Solution
Equilibrium on both side of a selectively permeable membrane
0.9%NaCl is isotonic, bc it is isotonic to human cells (very little osmosis)
other isotonic solutions (5% dextrose in 0.225% saline and lactated ringers solution)
Hypotonic solution
solution contains lower concentration of salt than other solutions
If the cell is dehydrated, we give a hypotonic solution to re-hydrate the cell, the cell then fills up
HYPO - think HIPPO fat swollen cell filling with water
Hypertonic solution
solution has a higher concentration of solutes than another solution
Think cell shrinkage, movement out of the cell, if blood needs to be diluted
ex: 10% dextrose in water, %5 dextrose in 0/9% saline
Osmotic Pressure
Force that draws solvent from solution though a selectively permeable membrane to a solution with less solvent activity.
determined by relative # of particles of solute on side of greater concentration
Active Transport
Moving “against the current” and needs to use energy, or moving from area of low concentration to and area of high concentration
the energy for active transport supplied by metabolic processes in the cell
Body Fluid Excretion
Fluids leave by skin, lungs, GI tract and kidneys
KIDNEYS excrete largest amount of fluid
Skin fluid excretion
water lost though skin by DIFFUSION up to 300-400 ml per day (perspiration) avg/ per day is 100ml
Lungs fluid excretion
water is lost from lungs thru expired air which is saturated water vapor
300-400ml/day
GI tract fluid excretion
large quantities of water secreted into GI tract, but ALMOST ALL REABSORBED
200ml/day lost in feces. severe diarrhea will result in lost of fluids and electrolytes
Kidney Fluid Excretion
MAJOR role in regulating fluid and electrolyte balance
normal kidneys can adjust water and electrolytes leaving body
urine output about 1500ml/day, but depends on other factors
Body Fluid Replacement
2400 ml per day is amount fo fluid excreted
water enters thought drink, food and oxidation of foods
oxidation water gained in foods = amount lost in feces
Electrolytes in food and liquids, EXTRA ones will leave in urine (not needed)
Electrolyte Blance / Homeostasis
Balance of internal environment
What is lost, needs to be replaced
when there is an excess of electrolytes, we help them, but watch carefully
Electrolyte Blance / Homeostasis Pt II.
Kidneys - control balance in fluid and electrolytes
Adrenal glands - secrete aldosterone, controlling extracellular fluid volume by regulating sodium reabsorbed in kidneys
ADH - from pituitary gland, regulates osmotic pressure of extracellular fluid by regulating h2o reabsorbed by kidneys (increased fluid volume)
RAAS System
Decreased Kidney perfusion pressure –> Renin release -> Angiotensin I –>converting enzyme in lungs –> Angiotensin II –> increased BP, increased circulating volume, renal auto-regulation
Water will follow sodium bc of aldosterone release
ADH
Directs kidneys to hold water, increase circulating volume, decrease osmolarity of plasma, helps balance thru negative feedback
Best way to determine fluid volume
body weight
Fluid Volume Deficit
Dehydration where H2O and electrolytes are lost in same proportion
Treat: Fluid Volume restoration, eliminate cause
Hypovolemia
FVD (Fluid volume deficit)
fluid loss> fluid intake
Isotonic: H2O and E.Lytes lost in equal proportions (give isotonic solutions to replace)
Hypotonic: decrease in solutes, but not water, fewer electrolytes, total body fluid less than normal. moving from EXTRACELLULAR to INTRACELLULAR
Hypertonic: decrease in water, but not solutes, shift INTRA to EXTRA cellular to make blood more dilute.
Hypovolemia Etiologies
GI fluid loss: vomiting (GIVE Iso THEN Hypo)
Kidneys: Polyuria d/t DKA (GIVE Iso THEN Hypo)
Fever (GIVE Hyper) bc cells are getting more fluid than blood, restore circulating volume
Third Spacing: fluid stuck in interspicial spaces (ISO to correct circ volume)
decreased fluid intake (GIVE Iso THEN Hyper)
First fluid is to balance volume, 2nd fluid is to replenish cells or blood
Hypovolemia Manifestations
rapid weight loss
decreased skin turgor
dry mucous membranes
decrease urinary output
BUN is increased (kidney fail or dehydration) too much nitrogen in blood
increased RR and decreased temp
orthostatic hypotension (low bp, not enough vol)
increased in thirst
cold extremities
Hypovolemia Treatments
mild: drink water
severe: IV Fluids (ISO to expand plasma volume, increase BP ext..)
When BP returns to normal, then HYPO to refill cells
Fluid Challenge
give fluids, if NO urinary output increase, kidney problems
Fluid Volume Excess (HYPERVOLEMIA)
Restore balance is key
Peripheral edema: excess fluid btwn cells, normal in cells
Cellular edema: excess fluid IN cells, normal btwn cells
Hypervolemia
Fluid Volume Excess (FVE)
Fluid intake > fluid Loss
Isotonic: water and elecyro gained in equal proportion. too much of both in blood and cells
Hypotonic: water intoxication (athletes) not enough solutes, Fluid shift from blood to cells, can burst cells.
Hypertonic: increase in solutes but not water. Cells shrink. fluid shift TCF to ECF
Hypervolemia Etiologies
Excessive intake of sodium and water either PO or IV (not common)
happens with renal failure
SIADH (inappropriate ADH, too much fluid)
Stroke, lesions in brain, chronic liver failure
CHF
Steroid use (puffyness)
Hypervolemia Manifestations
Rapid weight gain
Circulatory overload (Heart failure)
Interstitial edema
(peripheral edema (feet), pulmonary edema - life threatening)
Bounding pulses
JVD - distended neck veins
Hypervolemia treatment
restrict sodium
diuretics (lasix - strong)
fluid restrictions
Hyponatremia
LOW SODIUM
Serum sodium level <135 meq/L (normal 135-145)
Cause:
EXCESSIVE sodium loss (without water)
EXCESSIVE water gain (without sodium)
Decreased serum osmolality
(cell swells from ECF to ICF)
Sodium shift ICF to ECF (very common)
Hyponatremia Etiologies
Excessive sodium loss
-diuretics, GI loss
Insufficient sodium intake or absorption
Excessive water gain
Adrenal insufficiency
Adrenal Insufficiency
SIADH
Hyponatremia Manifestations
> 125 - asymptomatic (incase sodium in diet and you good)
120-125 - nausea
115-120 - headache, lethargy
<110-115 - seizures, coma, personality changes
Lab values:
low urine specific gravity
low Cl
weight gain, but not edema
**FINGERPRINTING OVER STERNUM ** Hallmark of Hyponatremia
Hyponatremia Treatment
Sodium replacement PO or IV
regular: normal saline
for Severe: Na <120 = 3% saline
For excessive water gain: restrict fluid intake
Hypernatremia
TOO MUCH SODIUM
Serum sodium level >145 meq/L
Excession sodium gain (without water)
Excessive water loss (without sodium)
Fluid shift from ICF to ECF (cell shrink)
Most often a water problem
Hypernatremia Etiologies
Water deprivation
Hypertonic tube feeding
Inadequately diluted baby formula
High Protein Diet
Insensible water losses
Watery diarrhea
Excessive admin of 3% saline
Diabetes Insipidus
Near Drowning in sea water
Hypernatremia Manifestiations
Dry sticky mucous membranes*** HALLMARK
CNS abnormalities (neurologic)
Neuromuscular (muscle twitching)
Extreme Thirst *** HALLMARK
Hypernatremia Treatment
SLOW correction with 1/2 NS or 1/4 NS
NOT D5W (risk of fluid overload)
Drug intervention:
Vasporessin (ADH) intranasally SQ or IM
Hypokalemia
LOW POSTASSIUM
Serum potassium level <3.5 meq/L
GENERAL K INFO:
major cation in ICF (greater in cell than outside)
WE don’t store extra K, kidneys excrete
Hypokalemia Etiologies
Critical for Heart and GI system function in particular
GI loss: vomit and diarrhea
Intracellular shifts: DKA
Anorexia Nervosa
Dialysis (excessive removal)
Excessive insulin
Rental losses
Hypokalemia Manifestations
decreased K levels on labs
<2.5 is BAD
Cardiac: dysrhythmias
Labs: increased pH and bicarbonate. urine specific gravity <1.010
increase serum glucose
muscle weakness
GI: Anorexia
Rental: inability to concentrate urine, DILUTE urine
Polyuria - nocturia
polydipsia
Hypokalemia Treatment
IV replacement: urine output MUST BE adequate ** (Kidney NEEDS TO BE WORKING WELL)
Careful NOT > 10mEq/hr - give SLOWLY
NEVER IV PUSH = CARDIAC ARREST
Mix thoroughly
Dietary: foods/supplements
Oral supplements (administer with meals or food to lower Gi irritation
Hyperkalemia
EXCESSIVE POTASSIUM
serum K level > 5.0 mEq/L
seldom in pts with normal kidney function
MORE dangerous than Hypokalemia - leads to cardiac arrest
Iatrogenic causes - OUR faults, this happens
more common with older ppl
Hyperkalemia Etiologies
Decreased renal excretion
Hypoaldosteronism
K-sparing diuretics
Metabolic acidosis, low pH
Tissue injury and lysis of cells
Excessive oral or IV intake
bowel obstruction
Hyperkalemia Manifestations
Cardiac changes***:
EKG signs depressed S-T segment peaked T waves wide QRS complex loss of p-waves prolonged PR interval
CARDIAC ARRHYTHMIAS ** leading to cardiac arrest, this is major issue
Bradycardia
CNS - confusion
muscle weakness
GI - Nausea, diarrhea
Hyperkalemia treatement
Kayexalate PO or PR (cation exchange resin) this is a diarrhetic
ENEMA usually
IV diuretics
Emergency - calcium gluconate - slow IV infusion (protects heart, increase threshold, so heart wont fire quickly)
Sodium bicarbonate
GIK: 500cc 10% glucose, 10u Reg insulin IV
Dialysis
Hypocalcemia
LOW CALCIUM
Serum calcium level < 8.5 mg/dl
if calcium levels drop, calcium pulled from bones, phosphorus follows
parathyroid pulls: calcium pulled from bones (NOT same process as osteoporosis)
Need Vitamin D to absorb calcium
Need good kidney function to assist
Total Calcium
Total calcium = Unbound + Bound calcium
unbound = metabolically active (ionized) BODY REGULATES WITH THIS ONE
need to look at MORE than this value to understand calcium loss
can be due to low plasma proteins
Hypocalcemia Etiologies
Post-Op:
Parathyroidectomy
thyroidectomy
radical neck dissection
Renal failure
Alkalosis
Acute Pancreatitis
Drugs
Inadequate intake or absorption
Excessive elimination
Hypoalbuminemia - not enough plasma proteins
Hypocalcemia Manifestations
Neuromuscular: muscular irritability tingling paresthesias hands and feet muscle spasms
CNS: confusion anxiety depression psychosis
Cardio:
myocardial contractility
hypotension
dysrhythmias
EKG: prolonged QT and DT
Hematologic:
clotting factors not working, bleeding
Trousseau’s and Chvostek’s Sign
Trousseau’s:
BP cuff pump up, watch for muscle spasm after 1 min
Chvostek’s:
Twitching face when touched
Hypocalcemia Treatment
Acute: Calcium gluconate - SLOW IV INFUSION - too much can cause tissue necrosis
Chronic:
Oral calcium supplements with vit D and Mg
Calcitonin (prevents osteoporosis)
Fosamax (inhibits bone resorption) in AM only - empty stomach
Hypercalcemia
EXCESSIVE CALCIUM
Serum calcium level > 10.5 mg/dl
When the rate of calcium entry in the blood is greater than rate of renal calcium excretion
Hypercalcemia Etiologies
Excessive supplements
Excessive vitamin D intake
use of thizaide diuretics
HYPERPARATHYROIDISM
prolonged immobility
Drugs
Thyrotoxicosis
Hypophosphatemia - decreased phosphorus
Milk-alkali syndrome
Hypercalcemia Manifestations
Neuromuscular:
excessive sedative effect
weakness - flaccidity
GI: decreased motility
constipation
anorexia
CNS: confusion memory impairment weird behavior LOC to COMA
Renal: polyuria polydipsia renal colic renal failure d/t urinary calculi
Cardiac:
Dysrhythmias
EKG: shortened QT
increased BP
Bone:
Soft tissue calcification
pathologic fractures
Hypercalcemia Treatments
increase fluid intake
Eliminate contributing drugs
increase mobility
Normal Saline IV
hourly In and out and breath sounds
Etidronate (Didronel) - for malignancies NOT hyperparathyroidism
Plicamycin
for breast cancer
Calcitonin (IM)
Magnesium Imbalances
Normal: 1.5-2.3 mEq/L
Sources: cereal grains nuts chocolate legumes veggies dairy fruit meat fish water
Hypomagnesemia
LOW MAGNESIUM
decreased serum magnesium level of less thatn 1.5 meq/L
Hypomagnesemia Causes
decreased intake vomiting diarrhea NG suction GI losses Malabsorption intestinal fistulas excessive loss of calcium and potassium DKA Burns pancreatitis renal disease
Hypomagnesemia Assesment
Neurologic irritability tremors tetany positive chovesteks and trousseas seizures confusion weakness ataxia dysrhythmias ECG abnormalities
Hypomagnesemia Imprelmentation
Monitor VS and dysrhythmias
same for hypocalcemia
Hypermagnesemia
INCREASED magnesium
serum level of 2.3 meq/L
causes:
advanced renal failure***
excessive laxatives
antacids
Hypermagnesemia Assesment
Neurologic depression drowsiness lethargy bradycardia dysrhythmias hypotension weakness too many laxatives areflexia - no reflexes
Hypermagnesemia implementation
increased renal excretion, but only for healthy kidney
mechanical ventilation
pacemaker
dialysis
Phosphorus imbalances
Normal value 3.4-4.5 mg/dl
Major Anion (neg charge)
85% in bones in teeth
rest in soft tissue
<1% in blood
Hypophosphatemia
LOW phosphorus
serum level below 3.0
in Jejunum
Hypophosphatemia Causes
decreased intake poor absorption antacids increased renal excretion DKA Steatorrhea fever hepatic disease
Ph and CA have INVERSE relationship - with kidney, its one of the other
Hyperphosphatemia
TOO MUCH Phosphorus
greater than 4.5 mg/dl
Causes:
excessive intake
adrenal insufficiency
Hyperphosphatemia Assessment
Neurological excitability
seizures
conjunctivitis
Hyperphosphatemia Implementation
increased fecal excretion of phosphorus by binding phosphorus from food in the GI tract
Dialysis
