ABG interpretation Flashcards
what is acidosis casused by?
caused by retention of too much acid or loss of too much base
what is alkalosis caused by?
caused by loss of too much acid or retention of too much base
how does the body regulate acid-base production?
metabolic processes produce acid that must be neutralized and excreted either through respiratory or renal systems
What are the 2 ways the respiratory system aid in acid-base regulation?
increase respiratory rate = increased co2 elimination
decreased respiratory rate = leads to co2 retention
what are the 2 ways the renal system aid in acid-base regulation?
conserves bicarbonate (HCo3)
excretes acid ( hydrogen ions )
What are the normal values
PH
PACO2
HCO3
PAO2
7.35-7.45
35-45
22-26
80-100
What does the PACO2 tell us?
the amount of carbon dioxide dissolved in arterial blood
what does the HCO3 tell us?
amount of bicarbonate in the bloodstream
what does the paO2 tell us?
oxygen that is dissolved in arterial blood
what are some reasons why we have alterations in the acid-base balance for individuals?
imbalances occurs when compensatory mechanisms fails
respiratory acidosis
what is the cause?
provide examples ^ (2)
CO2 excess
hypoventilation & respiratory failure
how does a person in respiratory acidosis compensate?
the kidneys conserve HCO3 and excrete hydrogen into the urine
what are the clinical manifestations of respiratory acidosis?
confusion, easy fatigue, lethargy, shortness of breath, sleepiness, tachycardia, tachypnea
metabolic acidosis
provide examples to some causes ^ (4)
ketoacidosis, lactic acid accumulation, severe diarrhea, kidney disease
- ketoacidosis
- severe diarrhea
how does a person in metabolic acidosis compensate?
increase CO2 excretion - Kussmaul respirations ( deep and rapid breathing ) & kidneys secrete hydrogen
what are the clinical manifestations of metabolic acidosis?
lethargy, confusion, dizziness, headache, coma, dysrhythmias, cool skin, N/V/D, muscle weakness, deep and rapid respirations
- dysrhytmias
- NVD
- muscle weakness
- kussmal respirations
respiratory alkalosis
what is the cause?
provide examples ^
CO2 deficit
hypoxemia from acute pulmonary disorders, hyperventilation
how does a person in respiratory alkalosis compensate?
rare if acute, if chronic increased HCO3 excretion
what are the clinical manifestation of respiratory alkalosis?
tachypnea, anxiety, tetany, numbness, tingling, convulsions, palpitations, chest pain, dysrhythmias
- convulsions
- chest pain
- palpitations
metabolic alkalosis
what are some examples for the cause?
prolonged GI suctioning, vomiting, diuretic use, hypokalemia
how does a person in metabolic alkalosis compensate ?
reneal excretion of HCO3, decreased respiratory rate to increase CO2
what are the clincal manifestation of metabolic alkalosis?
numbness, tingling, tetany, weakness, hyperreflexia, confusion, hypoventilation
- hyperreflxia
- hypoventilation
what is the anagram to help us remember how to do an ABG interpretation ?
ROME
what does Rome stand for?
respiratory opposite
metabolic equal
what does metabolic equal indicate?
acidosis LOW ph, LOW HCO3
Alkalosis HIGH ph, HIGH HCO3
what does the respiratory opposite indicate?
acidosis LOW ph, HIGH CO2
alkalosis HIGH ph, LOW CO2
a patient can be uncompensated meaning?
a patient can be partially compensated meaning?
a patient can be fully compensated meaning?
so the ph can remain outside the normal range
ph also remains outside the normal range, however we may see opposite system attempting to compensate by raising or lowering PCO2 or HCO3 depending on which system started the problem
the PH has returned to within normal range, although the other values may still be abnormal
some practice
ph 7.33
paco2 67
hco3 37
pao2 47
respiratory acidosis
pH 7.18
PaCO2 38 mm Hg
PaO2 70 mm Hg
HCO3– 15 mEq/L
metabolic acidosis
pH 7.60
PaCO2 30 mm Hg
PaO2 60 mm Hg
HCO3– 22 mEq/L
respiratory alkalosis
pH 7.58
PaCO2 35 mm Hg
PaO2 75 mm Hg
HCO3– 50 mEq/L
metabolic alkalosis
