3. Acid-Base Disorders Flashcards
What can be used to buffer dietary H+?
Bicarb
Bone
Hb
Plasma proteins
What severe effects can a low pH have?
Grand mal seizure
Ischaemic bowel
How is metabolic/respiratory acidosis differentiated from pCO2 and HCO3-?
In metabolic, pH, pCO2 and HCO3- all go in the same direction
What is Winter’s formula used to determine?
If compensation is appropriate
Give Winter’s formula
(HCO3/5) + 1
What is the formula for the anion gap?
Na+ - (Cl- + HCO3-)
What are the causes of normal anion gap acidosis?
Chlorine intoxication eg. dilution w normal saline
GI loss of HCO3- eg. diarrhoea
Renal tubular acidosis (loss of HCO3-)
What are the causes of raised anion gap acidosis?
Lactic acidosis
Renal failure
Ketoacidosis
Poisonings
What is the difference between type 1 and 2 lactic acidosis?
Type 1 is due to tissue hypoxia
Type 2 is due to mitochondrial failure
Give 4 causes of type 1 lactic acidosis
Shock
Respiratory failure
Anaemia
CO poisoning
Give 3 causes of type 2 lactic acidosis
Cyanide
Aspirin
Thiamine deficiency
How does renal failure cause lactic acidosis?
Inability to excrete daily acid intake so multiple anions are retained
How does alcohol cause ketoacidosis?
Increases lipolysis and reduces gluconeogenesis so the patient has reduced glucose
What is the treatment for alcoholic ketoacidosis?
Glucose and B vitamins, NOT INSULIN
How does ethylene glycol cause poisoning?
Broken down by alcohol dehydrogenase into toxic intermediates, glycolic acid and oxalic acid
Oxalic acid can cause kidney failure
