abgs Flashcards
abg use
gives best representation of pH and PaCO2
used to assess acid=base status and determine adequacy of oxygenation and ventillation
vbg
PaCO2 higher
so pH change and PO2 not accurate
PaCO2 normal
35 - 45
resp parameter
HCO3- normal
24 - 29
metabolic parameter, reported as CO2 on chm panel, calculated in ABG
primary event
problem that initiates acid-base imbalance -> hyper/hypovent, v/d, etc
primary disorder
results from primary event -> resp acidosis, met alkalosis, etc
compensation mechanisms
phys process that adjusts pH back to normal, lungs v kidneys
lungs = H2CO3, respiratory, not prolonged compensation
kidneys = HCO3, metabolic
metabolic alkalosis
too much bicarb or not enough carbonic acid
primary = high HCO3, compensation = high CO2 to decrease pH
give H2 blockers, PPI to retain H
metabolic aklalosis: causes
causes: too much baking soda, prolonged v (stomach acid loss), NG suction, diuretics (esp loop), aklaseltzer -> hypoK bc K goes into cell and H comes out
metabolic aklalosis: cm
CNS over excitability, confusion, tremor, muscle cramp, paresthesias (tingling of fingers and toes), coma, n/v/d, resp dep -> hold in to CO2, cardiac cm
restlessness followed by lethargy, dysR (tachy), compensatory hypovent, confusion (decreased LOC, dizzy, irritable), hypoK
respiratory alkalosis
H2CO3 (carbonic acid) deficit in ecf
hypervent = primary event, blow off CO2, can also happen with ventilation
give rebreather
respiratory alkalosis: causes
hypervent, ventilation, increased metabolic demands (fever, sepsis), meds, acute anx, hypoxia, PE or lung disease, CNS lesions, vent settings
respiratory alkalosis: cm
CNS overexcitability
tachypnea (deep and rapid, hypervent), light headed, confusion, blurred vision, paresthesia, hyperactive reflexes, seizure, coma
tachy, decreased or normal BP, hypoK, lethargy and confusion, light headed, n/v
resp acidosis
acute or chronic
hypovent = primary event -> CO2 retained (H+)
acute = resp arrest, chronic = COPD or oversedation
H2CO3 excess in ecf (too much acid/H+)
ABG low pH, CO2 high, HCO3- normal in acute (no time for kidneys to compensate)
HCO3- high and pH normal in chronic bc kidneys have time to compensate
put on vent, dont really give sodium bicarb
resp acidosis: causes
cardiopulm arrest, head injury, narcotics/sedatives, anesthesia, pain and abd distention (cant take deep breath)
pulm distress = acute asthma, CPOD exacerbation, pna, resp failure, drug OD, atelectasis
airway obstruction, chest wall deformities, NM problems bc muscles not strong enough (ALS, guillain-barre)
