Acid Base Disorders Flashcards
pH = pKa + ?
pH = pKa + log([A-]/[HA])
CO2 + H20 <—> H2CO3 <—–> ?
H+ + HCO3-
What is the name for this equation:
pH = pKa + log([A-]/[HA])
Henderson-Hasselbalch Equation
What does HCO3- and therefore pH depend on?
pCO2
Concentration of weak acids
Strong ion difference
Base Excess
The quantity of acid required to return pH to normal under standard conditions
(particularly used for acidosis, so the base excess will be negative)
Metabolic acidosis symptoms
Body is trying to breathe out the CO2 so will see deep sighing.
Long term effects include growth retardation in children and muscle wasting in adults
Anion gap
Entirely theoretical concept. Difference between cations and anions.
Anion gap = [Na+] + [K+] - [Cl-] - [HCO3-]
Normal is 10-16
High anion gap causes
Renal failure
Lactic acidosis
Ketoacidosis
Acid ingestion
Normal anion gap causes
GI HCO3- loss (diarrhoea, small bowel fistula, urinary diversion)
Renal tubular acidosis
Normal anion gap causes
GI HCO3- loss (diarrhoea, small bowel fistula, urinary diversion)
Renal tubular acidosis
Normal anion gap causes
GI HCO3- loss (diarrhoea, small bowel fistula, urinary diversion)
Renal tubular acidosis
Causes of metabolic alkalosis
Alkali ingestion
Gatrointestinal acid loss (vomiting)
Renal acid loss (hyperaldosteronism, hypokalaemia)
Compensatory mechanism for metabolic alkalosis
hypoventilation (limited by hypoxic drive)
Renal bicarbonate excretion
Respiratory Acidosis
CO2 retention leading to increased carbonic acid dissociation
Compensatory mechanism to respiratory acidosis
Increased renal H+ excretion and bicarbonate retention (if chronic)
