Biochemistry Flashcards
What test do you use to find the acid-base balance?
arterial blood gases
how can [H+] be buffered?
by:
- Hb
- Bicarbonate
- phosphate ions
- ammonia
What is the [H+] directly proportional to?
the pCO2
what is the [H+] inversely proportional to?
the [HCO3-]
pCO2 is the _____ component.
respiratory
HCO3- is the _____ component
metabolic
Respiratory acidosis/alkalosis is a primary change in…
pCO2
Metabolic acidosis/alkalosis is a primary change in…
HCO3-
what is acidosis?
an increase in the concentration of hydrogen ions.
what is alkalosis?
a decrease in the concentration of hydrogen ions
What is respiratory acidosis?
an increase in [H+] due to an increase in pCO2 due to the lungs not functioning properly so CO2 is accumulating
what is respiratory alkalosis?
a decrease in [H+] due to a loss of CO2 due to hyperventilation
What is metabolic acidosis?
an excess in [H+] due disease such as lactic acidosis
What is metabolic alkalosis?
a net loss of [H+]/acid due to vomiting resulting in alkali surplus
What does too much H+ do to the bicarbonate reaction?
drives the forwards reaction, favouring the production of CO2 and H20
What is the bicarbonate reaction?
H+ + HCO3- -> H2CO3 -> CO2 + H2O
what does too much CO2 do to the reaction?
drives the backwards reaction, favouring the dissociation of carbonic acid
what does too little H+ do o the reaction?
drives the backwards reaction to try to produce more hydrogen from CO2 and H20
What does too little CO2 do to the reaction?
drives the forwards reaction to produce more CO2
how does the body counteract metabolic acidosis?
tachypnoea, by blowing off CO2 as the H+ mops up all the HCO3- so need to loose CO2 to restore the ratio to normality
what is the primary problem and the respiratory compensation for metabolic acidosis?
Primary problem = too much H+
Compensation = blowing off CO2
what is the primary problem and metabolic compensatory response fr respiratory acidosis?
Primary problem = too much CO2
compensation = excreting more H+ and in the process reclaiming HCO3-
what is metabolic alkalosis due to and how does the body compensate?
is due to a net loss of acid (vomiting) resulting in surplus alkali.
Compensation = hypoventilating in order to retain CO2
what is respiratory alkalosis due to and how is it compensated?
lack of acid due to loss of CO2 (hyperventilation).
Compensation = lose alkali, but is slow process
what is metabolic acidosis caused by and how is it compensated?
high H+ due to disease (lactic acidosis)
Counteract: blowing off CO2 by tachypnoea
what is respiratory acidosis and how is it compensated?
high CO2 due to accumulation of it in the lungs due to disease.
Counteract = hold onto alkali, would only really see in chronic acidosis as long process.
On an ABG what would you see if there was a metabolic acidosis that was compensated?
Reduced pH
-ve BE
Compensation = Reduced CO2
what would you see on an ABG of respiratory acidosis if it was compensated?
reduced pH
increased CO2
+ve BE if compensated (as shows metabolic alkalosis but pH says acidosis)
what would you see on an ABG of metabolic alkalosis if it was compensated?
increased pH
+ve BE
Compensated = small increase in CO2 (wants to retain through hypoventilation)
what would you see on an ABG of respiratory alkalosis if it was compensated?
increased pH
decreased CO2
compensated = attempt to lose HC03 but slow process
