LFTs, ABGs & Electrolytes Flashcards
1
Q
Which graph can be memorised to determine whether there is an acidosis or an alkalosis?
A
- metabolic acidosis = low pCO2 and high [H+]
- respiratory acidosis = high pCO2 and high [H+]
- respiratory alkalosis= low pCO2 and low [H+]
- metabolic alkalosis = high pCO2 and low [H+]
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2
Q
What is the “all roads lead to rome” analogy for interpreting ABGs?
A
“all ABGs can be solved with ROME”
- in respiratory pathology, pH and CO2 move in OPPOSITE directions
- when pH goes up, CO2 goes down and vice versa
- in metabolic pathology, pH and CO2 move in the SAME direction
- when pH goes up, so does CO2 and vice versa
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3
Q
What is the first question to ask yourself when interpreting an ABG?
A
does the CO2 explain the pH?
- if it does, then this is respiratory pathology
- if it doesn’t, then this is metabolic pathology
4
Q
What is the respiratory acid equation?
How can this help when working out ABGs?
A
H+ + HCO3- = CO2 + H2O
- the respiratory acid is carbonic acid
- in this equation, both sides must balance
- if there is increased CO2, there must also be increased H+
5
Q
What type of ABG is shown here and how can you tell?
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A
- in this example CO2