PT2: Blood Gases Maclaren E3
Terms in this set (64)
what is the primary purpose of looking at blood gases?
first piece of info on the blood gas readings
second piece of info on the blood gas readings
3rd piece of info on the blood gas readings
bicarb or base excess (+/-)
4th piece of info on the blood gas readings
what is the normal pH range?
what is the normal pCO2 range?
what is the normal pO2 range?
what is the normal bicarb/HCO3- range?
what is the normal base excess range?
pH <7.38 and defines a state of below normal blood pH
pH >7.42 and defines a state of above normal blood pH
process leading to a state of acidemia
process leading to a state of alkalemia
primary decrease in HCO3-
primary increase in HCO3-
primary increase in H+ or hypoventilation
primary decrease in H+ or hyperventilation
what do you get rid of when you exhale?
ability of solution (body fluids) containing weak acid or poorly dissociated acid and its anion (base or salt) to resist changes in pH upon addition of strong acid or base
intracellular and bone buffers approximately what amount of acid load?
part of metabolic compensatory mechanisms; controlled by carbonic anhydrase in the brush border of proximal tubules of the kidney
H+ & K+
the intravascular metabolic compensatory mechanism works by an intracellular exchange of what molecules?
controls the respiratory compensatory mechanism; controlled by lung function and respiratory rate
an indirect measurement of indeterminate anions (lactate, keto acids, ethylene, methanol, salicylate, urea) and is equated by Na+ (+) K+ - (Cl- + HCO3-)... defined as >/= 20 mEq/L
anion gap metabolic acidosis
to maintain electrochemical neutrality, the concentration of HCO3- will decrease in response to elevated concentrations of interterminate anions... this is referred to as what?
nonanion gap (normal anion gap)
when a decrease in HCO3- concentration is not accompanied by an anion gap, then Cl- concentration is elevated and is referred to as what?
what is the acronym used for causes of anion gap (>/= 20 mEq/L) metabolic acidosis?
what is the M in MUDPILES?
what is the U in MUDPILES?
what is the D in MUDPILES?
paraldehyde or protease inhibitors (hiv)
what is the P in MUDPILES?
INH (TB test) or Iron (vitamins, etc)
what is the I in MUDPILES?
lactate (from muscles/hypoxia/shock syndromes/just ran a marathon)
what is the L in MUDPILES?
ethanol or ethylene glycol (antifreeze)
what is the E in MUDPILES?
salicylates or starvation (anorexia, cancer, HIV, 3rd world, etc)
what is the S in MUDPILES?
what is the acronym used for nonanion gap metabolic acidosis?
hyperalimenation (TPN, caused by us - not enough acetate in the TPN)
what is the H in HARDUP?
acid ingestion or addison's disease
what is the A in HARDUP?
is disorder resulting from distruction or disfunction of the adrenal cortex resulting in a defeciency in cortisol, aldosterone, adrenal androgens and skin pigmentation
what is the R in HARDUP?
diarrhea or diuretics (aldactone or acetazolamide) (or other drugs; beta2 agonists, insulin, cholestyramine)
what is the D in HARDUP?
uretosigmoidostomy (or ileostomy)
what is the U in HARDUP?
what is the P in HARDUP?
what is the respiratory compensation method our body uses during metabolic acidosis?
intracellular shifting of H+/K+ (metabolic)
what is the fastest compensatory method our body uses for metabolic acidosis?
how long does increasing renal production of HCO3- as a metabolic compensatory method for metabolic acidosis take to reach maximal resonse?
how long does hyperventilation to decrease pCO2 as a respiratory compensatory method for metabolic acidosis take to reach maximal response?
sodium bicarbonate (or shohl's solution )
what is used for chronic treatment of metabolic acidosis (renal acidosis)?
you should replace HCO3- during acute metabolic acidosis if HCO3- falls below what level? (meq/L)
1 L D5W or QNS
what do you always have to add NaHCO3 to so that it is not hypertonic aka veins don't explode?
HCO3- & hypokalemia
what 2 things do you have to monitor when giving a NaCO3- infusion for acute metabolic acidosis tx?
Tromethamine buffer (THAM)
also used as a tx for acute metabolic acidosis; an IV proton binder that does NOT supply Na+
in metabolic alkalosis when bicarb is increased to maintain electrochemical neutrality in response to losing chloride
in metabolic alkalsosis when bicarb is increased irrespective of chloride concentration
what is the respiratory compensation method our body uses during metabolic alkalosis?
carbonic anhydrase inhibitor used to tx metabolic alkalosis, works for both Cl responsive and unresponsive; promotes renal excretion of HCO3-
H2RA or PPI
drugs used to help tx metabolic alkalosis; prevent gastric acid secretion and consequently reduce HCl loss assoc with vomiting or suctioning
what is a tx for metabolic alkalosis that is RARELY used but can be used in severe or emergency cases?
caused by increased pCO2 due to decreased ventilation or ventilation-perfusion abnormalities (ex. COPD, PE, over sedation, obesity hypoventilation syndrome, hypothyroidism)
how long does it take for the metabolic compensatory method of increasing H+ renal secretion in respiratory acidosis to reach maximal effect?
what would worsen hypoventilation (respiratory acidosis) by promoting retention of pCO2?
caused by decreased pCO2 due to increased ventilation (ex. hypoxia, nervousness, anxiety or pain, PE, hyperthyroidism, fever, asthma, CHF)
how long does it take for the metabolic compensatory method of decreasing renal production of HCO3- in respiratory alkalosis to reach maximal effect?