Acid base balance 2 Flashcards
What happens when metabolic H+ increases in the body
- IMMEDIATE buffering in ECF and then ICF.
- Respiratory compensation within MINUTES.
- Renal correction of the disturbance takes longer to develop the full response and generate new HCO3-
Why is renal response not immediate
Because renal glutaminase takes 4-5 days to reach maximum
What is the effect of respiratory compensation on renal correction of pH
It delays it
?But it’s OK as pH is maintained?
Causes of metabolic alkalosis
Increased H+ ion loss - vomiting loss of gastric secretions
Increased renal H+ loss - aldosterone excess, excess liquorice ingestion
Blood transfusions, because the blood contains CITRATE to PREVENT COAGULATION, which is converted to HCO3-, but need at least 8 units to have this effect.
What 2 things can cause acidosis
Decreased HCO3+ or Increased Pco2
What 2 things can cause alkalosis
Increased HCO3+ or Decreased Pco2
What kind of acidosis in;
- A badly controlled diabetic in ketoacidosis
- A lifelong smoker with lung disease
- A patient that’s had a haemorrhage
- Metabolic
- Respiratory
- Lactic (ie both)
How to reverse hyperkalaemia
Insulin-dextrose
What’s more important restoration of volume or pH
Volume
What is the Anion Gap
Difference between the sum of the principal cations and the principal anions in the plasma
What’s the normal range of the Anion Gap
14-18mmoles/L
What are the principal cations and anions of the plasma
Cations = Na+ and K+ Anions = Cl- and HCO3-
When is the Anion Gap increased and why
Diabetic Ketoacidosis
Due to a loss of bicarbonate which is not compensated by Cl-but other anions
What kind of acidosis causes no change in anion gap and why
Acidosis due to loss of bicarbonate from gut Loss is compensated by increase Cl-
Two other kinds of anions
Lactate
Acetoacetate
