Arterial blood gases

what do ABGs show

oxygenation and acid-base balance

nursing key things to know when drawing an ABG

no changing to O2 15 min before sample, use heparinized syringe, apply pressure (bc artery)

what types of health problems can lead to an acid-base imbalance

DM/DKA, COPD, kidney disease

normal acid to base ratio

1 carbonic acid : 20 base bicarb

what is our acid

CO2

what is our base

HCO3 (bicarb)

what are our regulatory mechanisms with the acid-base system

buffers, resp system, renal system

what speeds do the regulatory mechanisms act at

1. buffer- book it (first)

2. resp- runs (minutes)

3. kidneys- keep it going/chronic probs (2-3 days)

if we are using regulatory mechanisms to compensate,

we are NOT fixing the underlying problem

how does the respiratory system help regulate

body acidotic- increase RR and get rid of CO2

body alkalotic- decrease RR and hold onto CO2

how does the renal system help regulate

it conserves bicarb and excretes acid

s/s acidosis

CNS depression- h/a, lethargy, weakness, confusion, coma, death

huge sign and compensatory mechanism of acidoses

kussmaul's respirations (often when kidneys the problem and lungs are compensating)

s/s alkalosis

CNS irritability- tingling/numbness in fingers, restless, tetany, convulsions, coma

huge compensatory mechanism of alkalosis

hypocalcemia (increase calcium binding to decrease ionized calcium)

ABGs can give us info about

acid-base status, underlying cause of problem, body's ability to regulate pH, oxygen status

acid-base mnemonic to know!!!

ROME- respiratory opposite metabolic equal

respiratory opposite means

-alkalosis: increase pH, decrease CO2

-acidosis: decrease pH, increase CO2

metabolic equal means

-alkalosis: increase pH, increase HCO3

-acidosis: decrease pH, decrease HCO3