Terms in this set (44)
arterial blood gases; taken from radial artery
What does it do?
What is the purpose?
determine the lungs effectiveness in moving CO2 into and out of the lungs
Why? Who would need this?
to rule out pulmonary embolism in pts. someone in respiratory arrest, infants
Normal blood pH
7.35 - 7.45
35 - 45 mmHg; partial pressure of CO2 in lungs. Depth of pulmonary respiration.
80 - 100 mmHg; < 60 anaerobic state = lactic acid buildup
22 - 26 mEq/L; kidneys excrete bicarbonate
> 95 %; watch for hypoxia
Bicarb in relation to CO2
20:1; think about bicarb being strong
PaCO2 < 35 mmHg
PaCO2 > 45 mmHg
measure of H+ ions present.
More H+ = more acidic
Less H+ = more alkaline
Water is neutral = pH of 7
< 7 is acidic and > 7 is alkaline
Acid base imbalance regulation
buffers, respiratory and renal system
Buffers in the body
remove or release H+ ions.
for short term minor distrubances.
seek to buffer carbonic acids (very strong acids)
immediate action but limited in strength. mostly in the ICF
bicarbonate, phosphate, plasma proteins (hemoglobin), cell proteins
expiration gets rid of CO2 (gets rid of acid) - alkalosis
depressed respiration holds CO2 (increases acid) - acidosis
ultimate long term regulator.
slower to respond but more permanent and selective (days)
Excrete or conserve bicarbonate and H+ ions.
anything which prevents body from getting rid of excess CO2, increases acid which decreases pH
anything which makes body lose CO2, decreases acid, which increases pH
anything which decrease HCO3, decreases base, which decreases pH
anything which increases HCO3, increases base, which increases pH
lose above waist; low pH caused by high CO2, high HCO3 will develop later to help balance pH
caused by processes which decrease exchange of CO2 for O2 in lungs
Ex: COPD, CHF, lung cancer, asthma, pneumonia
lose above waist; high pH cause by low CO2, low HCO3 develops later to balance pH
caused by anything which increases respirations
associated imbalances: low K+ and Ca
Ex: fever, pain, anxiety, overventilated, neuro lesions, trauma
lose below waist; low pH caused by low HCO3, CO2 will rapidly decrease to help balance pH
caused by anthing which increases accumulation of acids or decreases the amount of bicarb in the body
associated with increased K+
Ex: renal failure, diuresis, diarrhea, pancreatic fistulas
lose below waist; high pH causes by high HCO3, high CO2 develops quickly to help balance pH
caused by anything which decreases H+ ions in body or increases bicarb
associated imbalances: decreased K+ and Ca
Ex: excessive intake of bicarb (antacids), prolonged vomiting
Respiratory, Opposite, Metabolic, Equal; relative to pH
Steps in interpreting ABG's step 1
Loook at the pH and see if high or low (acidosis or alkalosis)
Steps in interpreting ABG's step 2
If pH is low, then look at CO2, then HCO3
if CO2 is high then respiratory acidosis
if HCO3 low metabolic acidosis
Steps in interpreting ABG's step 3
if pH is high, then look at CO2, then HCO3
if CO2 low is respiratory alkalosis
if HCO3 high is metabolic alkalosis
anytime CO2 and HCO3 are going in the same direction
Bicarbonate containing antacid ingestion
Excessive ventilation by a mechanical ventilator
Hypokalemia from diuretics
Gastric suction aka NG tube
Rapid high protein diet