Acid-Base Imbalances Flashcards
extracellular fluid (ECF)
fluid outside cell
20% of body wt.
TBW
sum of fluids w/in body
60% of body wt.
interstitial fluid
fluid around cells
outside bld vessels
intravascular fluid
blood plasma
w/in bld vessels
intracellular fluid (ICF)
fluid inside cell
40% of body wt.
diffusion
mvmt of charged/noncharged particles along conc. gradient
high to low conc.
osmosis
passive mvmt of water across semi-permeable membrane
low to high conc.
osmotic pressure
pressure required to stop osmotic flow of water
determined by solutes, osmolality, and osmolarity
osmolality
conc of mlcls per wt.
osmolarity
conc of mlcls per L
hydrostatic pressure
force of water pushing against cellular membranes
force that moves water out
oncotic pressure
pressure exerted by colloids- plasma proteins
draws water
inc oncotic pressure
draws water out to vasc. space
mvmt of water b/w ICF and ECF
occurs by osmotic forces
Na- ECF osmotic balance
K- ICF osmotic balance
mvmt of water b/w plasma and interstitial fluid
occurs due to changes in hydrostatic pressure (pushes water out of caps) and osmotic forces (pulls water in caps)
edema
accumulation of fluid in interstitial spaces.
etiology of edema
inc hydrostatic press
dec plasma oncotic press- give albumin
inc cap permeability
obstructed lymph flow
regulation of body water
thirst
renal- ADH
what is thirst stimulated by
hyperosmolality, low k, dec BV
how does renal- ADH regulate body water
ADH causes kidneys to retain water.
what is renal- ADH controlled by
osmolality and volume
when is ADH secreted
when osmolality inc, BV dec
normal osmolality
280-294
for excess water
274
for concentrated fluids, deficit of fluids
299
ECF deficit shows what
inc osmolality
what does inc osmolality mean
lots of particles in bld, not a lot of fluid
etiology of ECF deficit
dec intake
inc loss
CM for ECF deficit
thirst weight loss dec UO inc HR weakness shock dec plasma vol dec vasc vol tired weak pulse
treatment for ECF deficit
give fluid- water or IV
ECF excess shows what
dec osmolality (<280)
etiology of ECF excess
inc intake, dec loss
CM for ECF excess
weight gain peripheral edema SOB abd distention seizures, coma, swollen brain cells
treatment for ECF excess
diuretics, water restrictions, depends on underlying problem
function of elytes
regulate water balance, needed for enzymatic rxns, acid-base balance
function of Na
maintain osmolality of ECF, neuromuscular function, acid-base.
Na regulated by
aldosterone
dec Na= inc aldosterone= Na retention.
how do we lose Na
sweat, urine, bowel
how do we get Na
diet
hyponatremia
deficient Na
etiology of hyponatremia
excess water intake/gain
dec water loss
inc Na loss
CM for hyponatremia
weight gain neuro changes (confusion, lethargy, coma) HA GI disturbances inc intracellular fluid
treatment for hyponatremia
fluid restrictions (H20) inc Na intake (food, IV)
hypernatremia
excess Na
etiology of hypernatremia
inc water loss
dec intake of water
excess Na
CM of hypernatremia
thirst dry mucus membranes inc HR restlessness dehydration agitation
treatment for hypernatremia
Na restrictions
IV fluid low in Na followed by diuretics
function of K
osmolarity of ICF neuromuscular control and regulation acid-base balance enzyme rxn HR
how do we get K
diet
how do we lose K
from kidneys- urine
hypokalemia
deficient K
etiology of hypokalemia
dec intake
excess GI loss
excess renal loss
intracellular shift- alkalosis
CM for hypokalemia
cardiac dysrhythmias weakness dec GI motility PVC fatigue sm. muscle weakness/skel. muscle weakness confusion
treatment for hypokalemia
give K
IV fluids that contains K supplements
hyperkalemia
excess K
etiology of hyperkalemia
excess intake/gain
dec renal loss
extracellular shift- acidosis
most common cause of hyperkalemia
dec renal loss
CM for hyperkalemia
EKG changes cardiac arrest muscle weakness arrythmias PVC inc sm. muscle activity diarrhea cramping
treatment for hyperkalemia
dec K in fluid/foods
diuretics (NOT IF HAVE RENAL FAILURE)
insulin
oral solution- resin
what happens when K is too high
fatal
acidosis
process causing acidemia
acid condition of blood pH < 7.35
alkalosis
process causing alkalemia
alkaline condition of blood pH > 7.45
regulation of pH
carbonic acid- bicarbonate buffering
respiratory or metabolic
respiratory mech. of regulating pH
regulates level of C02= acid
resp. acidosis
inc C02 due to hypoventilation
resp. alkalosis
dec C02 due to hyperventilation
metabolic mech. of regulating pH
regulate bicarb (HC03)= base
metab. alkalosis
inc bicarb
metab. acidosis
dec bicarb
normal pH level
7.35 - 7.45
normal paC02
35 - 45
normal bicarb
22 - 26
patho of respiratory acidosis
retain C02 so pH < 7.35
etiology of respiratory acidosis
hypoventilation
CM for respiratory acidosis
depressed CNS confusion HA weakness twitching shallow respiration
compensation for respiratory acidosis
acid urine
treatment for respiratory acidosis
hyperventilate
inc breathing
bronchodilators
get out C02
respiratory alkalosis
blow off C02 so pH > 7.45
etiology of respiratory alkalosis
hyperventilation
CM for respiratory alkalosis
excited CNS- dizzy, confused
numb/tingly toes/fingers
palpitations
sweating
compensation for respiratory alkalosis
alkaline urine- lose bicarb
treatment for respiratory alkalosis
inc C02
paper bag
metabolic acidosis
retain acid so HC03 dec, pH < 7.35
etiology of metabolic acidosis
renal failure diarrhea shock (lactic acid) severe hypoxia ketoacidosis (excess glucose)
CM for metabolic acidosis
SAME AS RESP. ACIDOSIS depressed CNS weak fatigue confusion
compensation for metabolic acidosis
inc RR
Kussmaul respirations
acid urine
treatment for metabolic acidosis
treat underlying problem
give Na bicarb to keep acid-base balanced (IV or tablet)
metabolic alkalosis
loss of acid so HC03 inc, pH > 7.45
etiology of metabolic alkalosis
ingestion of base excessive use of antacids vomitting excess aldosterone diuretic therapy
CM for metabolic alkalosis
RELATED TO RESP ALKALOSIS excited CNS (tingling, cramping) hyperreflexes convulsions weakness confusion
which acid-base imbalance is least common
metabolic alkalosis
compensation for metabolic alkalosis
dec RR
alkaline urine
treatment for metabolic alkalosis
self-correcting
ID cause
restore fluid balance
normal Pa02 level
80-100
ABG
arterial blood gases
tells us C02, 02, pH, bicarb
steps to analyzing ABG
- look at pH- acidemia or alkalemia
- find primary cause- look at PaC02 and HC03
- look at other values to see if compensation
if C02 off and matches pH change
respiratory
if HC03 off and matches pH change
metabolic
